 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| TC9400/9401/9402 Voltage-to-Frequency/Frequency-to-Voltage Converters Features: VOLTAGE-TO-FREQUENCY * Choice of Linearity: - TC9401: 0.01% - TC9400: 0.05% - TC9402: 0.25% * DC to 100 kHz (F/V) or 1 Hz to 100 kHz (V/F) * Low Power Dissipation: 27 mW (Typ.) * Single/Dual Supply Operation: - +8V to +15V or 4V to 7.5V * Gain Temperature Stability: 25 ppm/C (Typ.) * Programmable Scale Factor General Description: The TC9400/TC9401/TC9402 are low-cost Voltage-toFrequency (V/F) converters, utilizing low-power CMOS technology. The converters accept a variable analog input signal and generate an output pulse train, whose frequency is linearly proportional to the input voltage. The devices can also be used as highly accurate Frequency-to-Voltage (F/V) converters, accepting virtually any input frequency waveform and providing a linearly proportional voltage output. A complete V/F or F/V system only requires the addition of two capacitors, three resistors, and reference voltage. FREQUENCY-TO-VOLTAGE * Operation: DC to 100 kHz * Choice of Linearity: - TC9401: 0.02% - TC9400: 0.05% - TC9402: 0.25% * Programmable Scale Factor Package Type 14-Pin Plastic DIP/CERDIP IBIAS 1 ZERO ADJ 2 IIN 3 VSS 4 14 VDD 13 NC Applications: * * * * * * * P Data Acquisition 13-bit Analog-to-Digital Converters Analog Data Transmission and Recording Phase Locked Loops Frequency Meters/Tachometer Motor Control FM Demodulation VREF OUT 5 GND 6 VREF 7 TC9400 TC9401 TC9402 12 AMPLIFIER OUT THRESHOLD 11 DETECTOR 10 FREQ/2 OUT 9 OUTPUT COMMON 8 PULSE FREQ OUT 14-Pin SOIC IBIAS 1 2 3 4 5 6 7 14 13 VDD NC AMPLIFIER OUT THRESHOLD DETECTOR FREQ/2 OUT OUTPUT COMMON PULSE FREQ OUT Device Selection Table Part Number TC9400COD TC9400CPD TC9400EJD TC9401CPD TC9401EJD TC9402CPD TC9402EJD Linearity (V/F) 0.05% 0.05% 0.05% 0.01% 0.01% 0.25% 0.25% Package 14-Pin SOIC (Narrow) 14-Pin PDIP 14-Pin CerDIP 14-Pin PDIP 14-Pin CerDIP 14-Pin PDIP 14-Pin CerDIP Temperature Range 0C to +70C 0C to +70C -40C to +85C 0C to +70C -40C to +85C 0C to +70C C to +85C ZERO ADJ IIN VSS VREF OUT GND VREF TC9400 TC9401 11 TC9402 10 9 8 12 NC = No Internal Connection (c) 2006 Microchip Technology Inc. DS21483C-page 1 TC9400/9401/9402 Functional Block Diagram Integrator Capacitor Input Voltage RIN IIN Integrator Op Amp Threshold Detector One Shot Pulse Output Reference Capacitor /2 Pulse/2 Output TC9400 IREF Reference Voltage DS21483C-page 2 (c) 2006 Microchip Technology Inc. TC9400/9401/9402 1.0 ELECTRICAL CHARACTERISTICS *Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions above those indicated in the operation sections of the specifications is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Absolute Maximum Ratings* VDD - VSS ........................................................... +18V IIN ....................................................................... 10 mA VOUTMAX - VOUT Common...................................... 23V VREF - VSS ..........................................................-1.5V Storage Temperature Range.............. -65C to +150C Operating Temperature Range: C Device ........................................... 0C to +70C E Device......................................... -40C to +85C Package Dissipation (TA 70C): 8-Pin CerDIP ............................................. 800 mW 8-Pin Plastic DIP ....................................... 730 mW 8-Pin SOIC ................................................ 470 mW TABLE 1-1: TC940X ELECTRICAL SPECIFICATIONS Electrical Characteristics: VDD = +5V, VSS = -5V, VGND = 0V, VREF = -5V, RBIAS = 100 k, Full Scale = 10 kHz, unless otherwise specified. TA = +25C, unless temperature range is specified (-40C to +85C for E device, 0C to +70C for C device). Parameter Min Typ Max Min Typ Max Min Typ Max Units Test Conditions Voltage-to-Frequency Accuracy Linearity 10 kHz -- TC9400 0.01 0.05 -- TC9401 0.004 0.01 -- TC9402 0.05 0.25 % Output Deviation from Full Scale Straight Line Between Normalized Zero and Full Scale Input % Output Deviation from Full Scale Straight Line Between Normalized Zero Reading and Full Scale Input ppm/C Variation in Gain A due Full Scale to Temperature Change % of Nominal mV Variation from Ideal Accuracy Correction at Zero Adjust for Zero Output when Input is Zero Variation in Zero Offset Due to Temperature Change Linearity 100 kHz -- 0.1 0.25 -- 0.04 0.08 -- 0.25 0.5 Gain Temperature Drift (Note 1) Gain Variance Zero Offset (Note 2) Zero Temperature Drift (Note 1) Note 1: 2: 3: 4: 5: 6: 7: 8: 9: 10: -- -- -- 25 10 10 40 -- 50 -- -- -- 25 10 10 40 -- 50 -- -- -- 50 10 20 100 -- 100 -- 25 50 -- 25 50 -- 50 100 V/C Full temperature range; not tested. IIN = 0. Full temperature range, IOUT = 10 mA. IOUT = 10 A. Threshold Detect = 5V, Amp Out = 0V, full temperature range. 10 Hz to 100 kHz; not tested. 5sec minimum positive pulse width and 0.5sec minimum negative pulse width. tR = tF = 20nsec. RL 2 k, tested @ 10 k. Full temperature range, VIN = -0.1V. (c) 2006 Microchip Technology Inc. DS21483C-page 3 TC9400/9401/9402 TABLE 1-1: TC940X ELECTRICAL SPECIFICATIONS (CONTINUED) Electrical Characteristics: VDD = +5V, VSS = -5V, VGND = 0V, VREF = -5V, RBIAS = 100 k, Full Scale = 10 kHz, unless otherwise specified. TA = +25C, unless temperature range is specified (-40C to +85C for E device, 0C to +70C for C device). Parameter Analog Input IIN Full Scale -- 10 -- -- 10 -- -- 10 -- A Full Scale Analog Input Current to achieve Specified Accuracy Over Range Current Settling Time to 0.1% Full Scale Min Typ Max Min Typ Max Min Typ Max Units Test Conditions IIN Over Range Response Time Digital Section VSAT @ IOL = 10mA VOUTMAX - VOUT Common (Note 4) Pulse Frequency Output Width -- -- -- 2 TC9400 50 -- -- -- -- 2 TC9401 50 -- -- -- -- 2 TC9402 50 -- A Cycle -- -- 0.2 -- 0.4 18 -- -- 0.2 -- 0.4 18 -- -- 0.2 -- 0.4 18 V V Logic "0" Output Voltage (Note 3) Voltage Range Between Output and Common -- 3 -- -- 3 -- -- 3 -- sec Frequency-to-Voltage Supply Current IDD Quiescent (Note 5) ISS Quiescent (Note 5) VDD Supply VSS Supply Reference Voltage VREF - VSS Accuracy Non-Linearity (Note 10) -- 0.02 0.05 -- 0.01 0.02 -- 0.05 0.25 % Deviation from ideal Full Scale Transfer Function as a Percentage Full Scale Voltage Hz Frequency Range for Specified Non-Linearity -2.5 -- -- -2.5 -- -- -2.5 -- -- V Range of Voltage Reference Input -- 1.5 6 -- 1.5 6 -- 3 10 mA Current Required from Positive Supply during Operation Current Required from Negative Supply during Operation Operating Range of Positive Supply Operating Range of Negative Supply -- -1.5 -6 -- -1.5 -6 -- -3 -10 mA 4 -4 -- -- 7.5 -7.5 4 -4 -- -- 7.5 -7.5 4 -4 -- -- 7.5 -7.5 V V Input Frequency Range (Notes 7 and 8) Frequency Input Note 1: 2: 3: 4: 5: 6: 7: 8: 9: 10: 10 -- 100k 10 -- 100k 10 -- 100k Full temperature range; not tested. IIN = 0. Full temperature range, IOUT = 10 mA. IOUT = 10 A. Threshold Detect = 5V, Amp Out = 0V, full temperature range. 10 Hz to 100 kHz; not tested. 5sec minimum positive pulse width and 0.5sec minimum negative pulse width. tR = tF = 20nsec. RL 2 k, tested @ 10 k. Full temperature range, VIN = -0.1V. DS21483C-page 4 (c) 2006 Microchip Technology Inc. TC9400/9401/9402 TABLE 1-1: TC940X ELECTRICAL SPECIFICATIONS (CONTINUED) Electrical Characteristics: VDD = +5V, VSS = -5V, VGND = 0V, VREF = -5V, RBIAS = 100 k, Full Scale = 10 kHz, unless otherwise specified. TA = +25C, unless temperature range is specified (-40C to +85C for E device, 0C to +70C for C device). Parameter Positive Excursion Min 0.4 Typ -- Max VDD Min 0.4 Typ -- Max VDD Min 0.4 Typ -- Max VDD Units V Test Conditions Voltage Required to Turn Threshold Detector On Voltage Required to Turn Threshold Detector Off Time between Threshold Crossings Time Between Threshold Crossings Negative Excursion -0.4 -2 -0.4 -- -2 -0.4 -- -2 V Minimum Positive Pulse Width (Note 8) Minimum Negative Pulse Width (Note 8) Input Impedance Analog Outputs Output Voltage (Note 9) Output Loading Supply Current IDD Quiescent (Note 10) ISS Quiescent (Note 10) VDD Supply VSS Supply Reference Voltage VREF - VSS Note 1: 2: 3: 4: 5: 6: 7: 8: 9: 10: -- 5 -- -- 5 -- -- 5 -- sec -- 0.5 -- -- 0.5 -- -- 0.5 -- sec -- 10 TC9400 -- -- 10 TC9401 -- -- TC9402 10 M -- VDD - 1 -- -- VDD - 1 -- -- VDD - 1 -- V Voltage Range of Op Amp Output for Specified Non-Linearity Resistive Loading at Output of Op Amp 2 -- TC9400 -- 2 -- TC9401 -- 2 -- TC9402 -- k -- 1.5 6 -- 1.5 6 -- 3 10 mA Current Required from Positive Supply During Operation Current Required from Negative Supply During Operation Operating Range of Positive Supply Operating Range of Negative Supply -- -1.5 -6 -1.5 -6 -- -3 -10 mA 4 -4 -- -- 7.5 -7.5 4 -4 -- -- 7.5 -7.5 4 -4 -- -- 7.5 -7.5 V V -2.5 -- -- -2.5 -- -- -2.5 -- -- V Range of Voltage Reference Input Full temperature range; not tested. IIN = 0. Full temperature range, IOUT = 10 mA. IOUT = 10 A. Threshold Detect = 5V, Amp Out = 0V, full temperature range. 10 Hz to 100 kHz; not tested. 5sec minimum positive pulse width and 0.5sec minimum negative pulse width. tR = tF = 20nsec. RL 2 k, tested @ 10 k. Full temperature range, VIN = -0.1V. (c) 2006 Microchip Technology Inc. DS21483C-page 5 TC9400/9401/9402 2.0 PIN DESCRIPTIONS The descriptions of the pins are listed in Table 2-1. TABLE 2-1: PIN FUNCTION TABLE Symbol IBIAS ZERO ADJ IIN VSS VREF OUT GND VREF PULSE FREQ OUT OUTPUT COMMON FREQ/2 OUT THRESHOLD DETECTOR NC VDD Description This pin sets bias current in the TC9400. Connect to VSS through a 100 k resistor. Low frequency adjustment input. Input current connection for the V/F converter. Negative power supply voltage connection, typically -5V. Reference capacitor connection. Analog ground. Voltage reference input, typically -5V. Frequency output. This open drain output will pulse LOW each time the Freq. Threshold Detector limit is reached. The pulse rate is proportional to input voltage. Source connection for the open drain output FETs. This open drain output is a square wave at one-half the frequency of the pulse output (Pin 8). Output transitions of this pin occur on the rising edge of Pin 8. Input to the Threshold Detector. This pin is the frequency input during F/V operation. Pin No. 14-Pin PDIP/CERDIP 14-Pin SOIC (Narrow) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 AMPLIFIER OUT Output of the integrator amplifier. No internal connection. Positive power supply connection, typically +5V. DS21483C-page 6 (c) 2006 Microchip Technology Inc. TC9400/9401/9402 3.0 3.1 DETAILED DESCRIPTION Voltage-to-Frequency (V/F) Circuit Description The TC9400 V/F converter operates on the principal of charge balancing. The operation of the TC9400 is easily understood by referring to Figure 3-1. The input voltage (VIN) is converted to a current (IIN) by the input resistor. This current is then converted to a charge on the integrating capacitor and shows up as a linearly decreasing voltage at the output of the op amp. The lower limit of the output swing is set by the threshold detector, which causes the reference voltage to be applied to the reference capacitor for a time period long enough to charge the capacitor to the reference voltage. This action reduces the charge on the integrating capacitor by a fixed amount (q = CREF x VREF), causing the op amp output to step up a finite amount. At the end of the charging period, CREF is shorted out. This dissipates the charge stored on the reference capacitor, so that when the output again crosses zero, the system is ready to recycle. In this manner, the continued discharging of the integrating capacitor by the input is balanced out by fixed charges from the refer- ence voltage. As the input voltage is increased, the number of reference pulses required to maintain balance increases, which causes the output frequency to also increase. Since each charge increment is fixed, the increase in frequency with voltage is linear. In addition, the accuracy of the output pulse width does not directly affect the linearity of the V/F. The pulse must simply be long enough for full charge transfer to take place. The TC9400 contains a "self-start" circuit to ensure the V/F converter always operates properly when power is first applied. In the event that, during power-on, the op amp output is below the threshold and CREF is already charged, a positive voltage step will not occur. The op amp output will continue to decrease until it crosses the -3.0V threshold of the "self-start" comparator. When this happens, an internal resistor is connected to the op amp input, which forces the output to go positive until the TC9400 is in its normal Operating mode. The TC9400 utilizes low-power CMOS processing for low input bias and offset currents, with very low power dissipation. The open drain N-channel output FETs provide high voltage and high current sink capability. +5V 14 VDD 11 Threshold Detect 3sec Delay Threshold Detector FOUT/2 10 SelfStart -3V 12 AMP OUT 5 CINT 820 pF INPUT VIN 0V -10V 50 k -5V Offset Adjust 10 k RIN 1M +5V CREF 180 pF 3 IIN 510 k Zero Adjust 2 VREF OUT 20 k 12 pF 60 pF - Op Amp + IBIAS 1 RBIAS 100 k VSS 4 VREF 7 Reference Voltage (Typically -5V) -5V GND 6 /2 Output Common 9 FOUT 8 +5V RL 10 k +5V RL 10 k TC9400 TC9401 TC9402 FIGURE 3-1: 10 Hz to 10 kHz V/F Converter (c) 2006 Microchip Technology Inc. DS21483C-page 7 TC9400/9401/9402 3.2 Voltage-to-Time Measurements The TC9400 output can be measured in the time domain as well as the frequency domain. Some microcomputers, for example, have extensive timing capability, but limited counter capability. Also, the response time of a time domain measurement is only the period between two output pulses, while the frequency measurement must accumulate pulses during the entire counter time-base period. Time measurements can be made from either the TC9400's PULSE FREQ OUT output, or from the FREQ/2 OUT output. The FREQ/2 OUT output changes state on the rising edge of PULSE FREQ OUT, so FREQ/2 OUT is a symmetrical square wave at one-half the pulse output frequency. Timing measurements can, therefore, be made between successive PULSE FREQ OUT pulses, or while FREQ/2 OUT is high (or low). DS21483C-page 8 (c) 2006 Microchip Technology Inc. TC9400/9401/9402 4.0 4.1 PIN FUNCTIONS Threshold Detector Input 4.2 Pulse Freq Out In the V/F mode, this input is connected to the AMPLIFIER OUT output (Pin 12) and triggers a 3sec pulse when the input voltage passes through its threshold. In the F/V mode, the input frequency is applied to this input. The nominal threshold of the detector is half way between the power supplies, or (VDD + VSS)/2 400 mV. The TC9400's charge balancing V/F technique is not dependent on a precision comparator threshold, because the threshold only sets the lower limit of the op amp output. The op amp's peak-to-peak output swing, which determines the frequency, is only influenced by external capacitors and by VREF. 3msec Typ. This output is an open drain N-channel FET, which provides a pulse waveform whose frequency is proportional to the input voltage. This output requires a pullup resistor and interfaces directly with MOS, CMOS, and TTL logic (see Figure 4-1). 4.3 Freq/2 Out This output is an open drain N-channel FET, which provides a square wave one-half the frequency of the pulse frequency output. The FREQ/2 OUT output will change state on the rising edge of PULSE FREQ OUT. This output requires a pull-up resistor and interfaces directly with MOS, CMOS, and TTL logic. FOUT FOUT/2 1/f CREF CINT VREF Amp Out 0V Notes: 1. To adjust FMIN, set VIN = 10 mV and adjust the 50 kW offset for 10 Hz output. 2. To adjust FMAX, set VIN = 10V and adjust RIN or VREF for 10 kHz output. 3. To increase FOUTMAX to 100 kHz, change CREF to 2pF and CINT to 75 pF. 4. For high performance applications, use high stability components for RIN, CREF, VREF (metal film resistors and glass capacitors). Also, separate output ground (Pin 9) from input ground (Pin 6). FIGURE 4-1: Output Waveforms 4.4 Output Common 4.6 Amplifier Out The sources of both the FREQ/2 OUT and the PULSE FREQ OUT are connected to this pin. An output level swing from the drain voltage to ground, or to the VSS supply, may be obtained by connecting this pin to the appropriate point. This pin is the output stage of the operational amplifier. During V/F operation, a negative going ramp signal is available at this pin. In the F/V mode, a voltage proportional to the frequency input is generated. 4.7 4.5 RBIAS An external resistor, connected to VSS, sets the bias point for the TC9400. Specifications for the TC9400 are based on RBIAS = 100 k 10%, unless otherwise noted. Increasing the maximum frequency of the TC9400 beyond 100 kHz is limited by the pulse width of the pulse output (typically 3sec). Reducing RBIAS will decrease the pulse width and increase the maximum operating frequency, but linearity errors will also increase. RBIAS can be reduced to 20 k, which will typically produce a maximum full scale frequency of 500 kHz. Zero Adjust This pin is the non-inverting input of the operational amplifier. The low frequency set point is determined by adjusting the voltage at this pin. 4.8 IIN The inverting input of the operational amplifier and the summing junction when connected in the V/F mode. An input current of 10 A is specified, but an over range current up to 50 A can be used without detrimental effect to the circuit operation. IIN connects the summing junction of an operational amplifier. Voltage sources cannot be attached directly, but must be buffered by external resistors. (c) 2006 Microchip Technology Inc. DS21483C-page 9 TC9400/9401/9402 4.9 VREF 5.0 A reference voltage from either a precision source, or the VSS supply is applied to this pin. Accuracy of the TC9400 is dependent on the voltage regulation and temperature characteristics of the reference circuitry. Since the TC9400 is a charge balancing V/F converter, the reference current will be equal to the input current. For this reason, the DC impedance of the reference voltage source must be kept low enough to prevent linearity errors. For linearity of 0.01%, a reference impedance of 200W or less is recommended. A 0.1 F bypass capacitor should be connected from VREF to ground. VOLTAGE-TO-FREQUENCY (V/F) CONVERTER DESIGN INFORMATION Input/Output Relationships 5.1 The output frequency (FOUT) is related to the analog input voltage (VIN) by the transfer equation: EQUATION 5-1: Frequency Out = VIN 1 ,x (VREF)(VREF) RIN 4.10 VREF Out 5.2 5.2.1 External Component Selection RIN The charging current for CREF is supplied through this pin. When the op amp output reaches the threshold level, this pin is internally connected to the reference voltage and a charge, equal to VREF x CREF, is removed from the integrator capacitor. After about 3sec, this pin is internally connected to the summing junction of the op amp to discharge CREF. Break-before-make switching ensures that the reference voltage is not directly applied to the summing junction. The value of this component is chosen to give a full scale input current of approximately 10 A: EQUATION 5-2: RIN VIN FULLSCALE 10 A EQUATION 5-3: RIN 10V = 1 M 10 A Note that the value is an approximation and the exact relationship is defined by the transfer equation. In practice, the value of RIN typically would be trimmed to obtain full scale frequency at VIN full scale (see Section 5.3 "Adjustment Procedure", Adjustment Procedure). Metal film resistors with 1% tolerance or better are recommended for high accuracy applications because of their thermal stability and low noise generation. 5.2.2 CINT The exact value is not critical but is related to CREF by the relationship: 3CREF CINT 10CREF Improved stability and linearity are obtained when CINT 4CREF. Low leakage types are recommended, although mica and ceramic devices can be used in applications where their temperature limits are not exceeded. Locate as close as possible to Pins 12 and 13. DS21483C-page 10 (c) 2006 Microchip Technology Inc. TC9400/9401/9402 5.2.3 CREF 5.3 Adjustment Procedure The exact value is not critical and may be used to trim the full scale frequency (see Section 7.1 "Input/Output Relationships", Input/Output Relationships). Glass film or air trimmer capacitors are recommended because of their stability and low leakage. Locate as close as possible to Pins 5 and 3 (see Figure ). 500 400 VDD = +5V VSS = -5V RIN = 1MW VIN = +10V TA = +25C 10 kHz Figure 3-1 shows a circuit for trimming the zero location. Full scale may be trimmed by adjusting RIN, VREF, or CREF. Recommended procedure for a 10 kHz full scale frequency is as follows: 1. 2. Set VIN to 10 mV and trim the zero adjust circuit to obtain a 10 Hz output frequency. Set VIN to 10V and trim either RIN, VREF, or CREF to obtain a 10 kHz output frequency. CREF (pF) +12pF If adjustments are performed in this order, there should be no interaction and they should not have to be repeated. 300 5.4 200 100 100 kHz 0 -1 -2 -3 -4 VREF (V) -5 -6 -7 Improved Single Supply V/F Converter Operation FIGURE 5-1: VREF 5.2.4 VDD, VSS Recommended CREF vs. A TC9400, which operates from a single 12 to 15V variable power source, is shown in Figure 5-2. This circuit uses two Zener diodes to set stable biasing levels for the TC9400. The Zener diodes also provide the reference voltage, so the output impedance and temperature coefficient of the Zeners will directly affect power supply rejection and temperature performance. Full scale adjustment is accomplished by trimming the input current. Trimming the reference voltage is not recommended for high accuracy applications unless an op amp is used as a buffer, because the TC9400 requires a lowimpedance reference (see Section 4.9 "VREF", VREF pin description, for more information). The circuit of Figure 5-2 will directly interface with CMOS logic operating at 12V to 15V. TTL or 5V CMOS logic can be accommodated by connecting the output pull-up resistors to the +5V supply. An optoisolator can also be used if an isolated output is required; also, see Figure 5-3. Power supplies of 5V are recommended. For high accuracy requirements, 0.05% line and load regulation and 0.1 F disc decoupling capacitors, located near the pins, are recommended. (c) 2006 Microchip Technology Inc. DS21483C-page 11 TC9400/9401/9402 +12 to +15V 1.2k 1 F R1 910k R3 Gain R4 100k 14 VDD 11 Threshold Detect CINT 12 Amp Out CREF 5 C REF D2 5.1 VZ 10k 10k TC9400 3 IIN 2 Zero Adjust FOUT 8 10 Output Frequency 100k R2 910k R5 91k D1 5.1 VZ 6 GND 0.1 7V REF 1I BIAS FOUT/2 Output 9 Common Input Voltage (0 to 10V) Rp Offset 20k Analog Ground Component Selection CREF CINT F/S FREQ. 2200 pF 4700 pF 1 kHz 180 pF 470 pF 10 kHz 27 pF 75 pF 100 kHz 100k VSS 4 Digital Ground FIGURE 5-2: Voltage-to-Frequency DS21483C-page 12 (c) 2006 Microchip Technology Inc. TC9400/9401/9402 V+ = 8V to 15V (Fixed) R2 0.9 R1 Gain Adjust V2 5V 8.2 k 2 k Offset Adjust RIN 1 M VIN 0V-10V IIN 100 k 0.2 R1 820 pF 0.01 F 2 6 14 8 10 k FOUT 10 k 10 FOUT/2 TC9400 7 VREF 11 0.01 F 12 5 180 pF 3 IIN 1 4 9 R2 R1 V+ 10V 1 M 10 k 12V 1.4 M 14 k 15V 2 M 20 k FOUT = IIN 1 (V2 - V7) (CREF) + (V+ - V2) (0.9R1 + 0.2R1) IIN = (VIN - V2) RIN FIGURE 5-3: Fixed Voltage - Single Supply Operation (c) 2006 Microchip Technology Inc. DS21483C-page 13 TC9400/9401/9402 6.0 FREQUENCY-TO-VOLTAGE (F/V) CIRCUIT DESCRIPTION When used as an F/V converter, the TC9400 generates an output voltage linearly proportional to the input frequency waveform. Each zero crossing at the threshold detector's input causes a precise amount of charge (q = CREF VREF) to be dispensed into the op amp's summing junction. This charge, in turn, flows through the feedback resistor, generating voltage pulses at the output of the op amp. A capacitor (CINT) across RINT averages these pulses into a DC voltage, which is linearly proportional to the input frequency. DS21483C-page 14 (c) 2006 Microchip Technology Inc. TC9400/9401/9402 7.0 7.1 F/V CONVERTER DESIGN INFORMATION Input/Output Relationships 7.2 Input Voltage Levels The output voltage is related to the input frequency (FIN) by the transfer equation: EQUATION 7-1: VOUT = [VREF CREF RINT] FIN The response time to a change in FIN is equal to (RINT CINT). The amount of ripple on VOUT is inversely proportional to CINT and the input frequency. CINT can be increased to lower the ripple. Values of 1 F to 100 F are perfectly acceptable for low frequencies. When the TC9400 is used in the Single Supply mode, VREF is defined as the voltage difference between Pin 7 and Pin 2. The input frequency is applied to the Threshold Detector input (Pin 11). As discussed in the V/F circuit section of this data sheet, the threshold of Pin 11 is approximately (VDD + VSS)/2 400 mV. Pin 11's input voltage range extends from VDD to about 2.5V below the threshold. If the voltage on Pin 11 goes more than 2.5 volts below the threshold, the V/F mode start-up comparator will turn on and corrupt the output voltage. The Threshold Detector input has about 200 mV of hysteresis. In 5V applications, the input voltage levels for the TC9400 are 400 mV, minimum. If the frequency source being measured is unipolar, such as TTL or CMOS operating from a +5V source, then an AC coupled level shifter should be used. One such circuit is shown in Figure 7-1(a). The level shifter circuit in Figure 7-1(b) can be used in single supply F/V applications. The resistor divider ensures that the input threshold will track the supply voltages. The diode clamp prevents the input from going far enough in the negative direction to turn on the start-up comparator. The diode's forward voltage decreases by 2.1mV/C, so for high ambient temperature operation, two diodes in series are recommended; also, see Figure . +8V to +5V +5V 14 VDD 10k 14 VDD TC9400 Frequency Input +5V 0V GND 6 VSS 4 -5V 33k 0.01 F 11 IN914 1.0M DET Frequency Input +5V 0V 0.1 F 10k 33k 0.01 F IN914 11 1.0M TC9400 DET VSS 4 (a) 5V Supply (b) Single Supply FIGURE 7-1: Frequency Input Level Shifter (c) 2006 Microchip Technology Inc. DS21483C-page 15 TC9400/9401/9402 V+ = 10V to 15V 14 10k 6 GND 6.2V .01 F 10k VREF OUT 5 2 Zero Adjust V+ Offset Adjust Frequency Input 33k 0.01 F 1.0k 11 IN914 DET GND 1.0M IBIAS VREF VSS 7 0.1 F 1.0k 100k 4 IIN 47 pF 3 1M Amp Out 12 6 VOUT .001 F VDD TC9400 500k 100k Note: The output is referenced to Pin 6, which is at 6.2V (Vz). For frequency meter applications, a 1mA meter with a series scaling resistor can be placed across Pins 6 and 12. FIGURE 7-2: F/V Single Supply F/V Converter 7.3 Input Buffer 0.5msec Min Input 5.0msec Min FOUT and FOUT/2 are not used in the F/V mode. However, these outputs may be useful for some applications, such as a buffer to feed additional circuitry. Then, FOUT will follow the input frequency waveform, except that FOUT will go high 3sec after FIN goes high; FOUT/2 will be square wave with a frequency of one-half FOUT. If these outputs are not used, Pins 8, 9 and 10 should be connected to ground (see Figure 7-3 and Figure 7-4). FOUT Delay = 3msec FOUT/2 FIGURE 7-3: F/V Digital Outputs DS21483C-page 16 (c) 2006 Microchip Technology Inc. TC9400/9401/9402 +5V V+ 14 VDD * 42 FOUT/2 10 V+ Output Common 9 * * 3msec Delay Threshold Detector VREF OUT FOUT 8 *Optional/If Buffer is Needed See Figure 7-1: FIN "Frequency Input Level Shifter" Threshold Detect 11 TC9400A TC9401A TC9402A 5 CREF 56 pF RINT 1 M CINT 1000 pF VOUT 12 pF Offset Adjust +5V 100 k 2 k 2.2 k 2 Zero Adjust IBIAS 1 10 k -5V VREF (Typically -5V) VSS 4 VREF 7 - Op Amp + IIN 3 60 pF Amp Out 12 GND 6 FIGURE 7-4: DC - 10 kHz Converter FIGURE 7-1: VREF OUT 5 47 pF 7.4 Output Filtering RIPPLE FILTER The output of the TC9400 has a sawtooth ripple superimposed on a DC level. The ripple will be rejected if the TC9400 output is converted to a digital value by an integrating Analog-to-Digital Converter, such as the TC7107 or TC7109. The ripple can also be reduced by increasing the value of the integrating capacitor, although this will reduce the response time of the F/V converter. The sawtooth ripple on the output of an F/V can be eliminated without affecting the F/V's response time by using the circuit in Figure 7-1. The circuit is a capacitance multiplier, where the output coupling capacitor is multiplied by the AC gain of the op amp. A moderately fast op amp, such as the TL071, should be used. TC9400 IIN 3 1M .001 F 200 AMP OUT 12 .01 F 1M GND 6 2 3 1M - + 7 6 +5 FIGURE 7-5: Ripple Filter (c) 2006 Microchip Technology Inc. DS21483C-page 17 + 0.1 F VOUT TL071 4 -5 TC9400/9401/9402 8.0 F/V POWER-ON RESET In F/V mode, the TC9400 output voltage will occasionally be at its maximum value when power is first applied. This condition remains until the first pulse is applied to FIN. In most frequency measurement applications, this is not a problem because proper operation begins as soon as the frequency input is applied. In some cases, however, the TC9400 output must be zero at power-on without a frequency input. In such cases, a capacitor connected from Pin 11 to VDD will usually be sufficient to pulse the TC9400 and provide a Power-on Reset (see Figure 8-1 (a) and (b)). Where predictable power-on operation is critical, a more complicated circuit, such as Figure 8-1 (b), may be required. (a) VDD VDD 14 1000 pF FIN 1 k 11 Threshold Detector 3 100 k 4 A 16 VCC CLRA 5 B (b) 2 R 1 C CD4538 Q VSS 8 6 To TC9400 TC9400 1 F FIN FIGURE 8-1: Power-On Operation/Reset DS21483C-page 18 (c) 2006 Microchip Technology Inc. TC9400/9401/9402 9.0 9.1 9.2 PACKAGE INFORMATION Package Marking Information Taping Form Component Taping Orientation for 14-Pin SOIC (Narrow) Devices Package marking data is not available at this time. User Direction of Feed Pin 1 W P Standard Reel Component Orientation for 713 Suffix Device Carrier Tape, Reel Size, and Number of Components Per Reel Package Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size 14-Pin SOIC (N) 12 mm 8 mm 2500 13 in 9.3 Package Dimensions 14-Pin CDIP (Narrow) Pin 1 .300 (7.62) .230 (5.84) .098 (2.49) Max. .030 (0.76) Min. .780 (19.81) .740 (18.80) .040 (1.02) .020 (0.51) .015 (0.38) .008 (0.20) .320 (8.13) .290 (7.37) .200 (5.08) .160 (4.06) .200 (5.08) .125 (3.18) 3 Min. .150 (3.81) Min. .110 (2.79) .090 (2.29) .065 (1.65) .045 (1.14) .020 (0.51) .016 (0.41) .400 (10.16) .320 (8.13) Dimensions: inches (mm) (c) 2006 Microchip Technology Inc. DS21483C-page 19 TC9400/9401/9402 9.3 Package Dimensions (Continued) 14-Pin PDIP (Narrow) Pin 1 .260 (6.60) .240 (6.10) .770 (19.56) .745 (18.92) .200 (5.08) .140 (3.56) .150 (3.81) .115 (2.92) .310 (7.87) .290 (7.37) .040 (1.02) .020 (0.51) .015 (0.38) .008 (0.20) .400 (10.16) .310 (7.87) 3 Min. .110 (2.79) .090 (2.29) .070 (1.78) .045 (1.14) .022 (0.56) .015 (0.38) Dimensions: inches (mm) 14-Pin SOIC (Narrow) Pin 1 .157 (3.99) .244 (6.20) .150 (3.81) .228 (5.79) .050 (1.27) Typ. .344 (8.74) .337 (8.56) .069 (1.75) .053 (1.35) .010 (0.25) .004 (0.10) 8 Max. .050 (1.27) .016 (0.40) .010 (0.25) .007 (0.18) .018 (0.46) .014 (0.36) Dimensions: inches (mm) DS21483C-page 20 (c) 2006 Microchip Technology Inc. TC9400/9401/9402 THE MICROCHIP WEB SITE Microchip provides online support via our WWW site at www.microchip.com. This web site is used as a means to make files and information easily available to customers. Accessible by using your favorite Internet browser, the web site contains the following information: * Product Support - Data sheets and errata, application notes and sample programs, design resources, user's guides and hardware support documents, latest software releases and archived software * General Technical Support - Frequently Asked Questions (FAQ), technical support requests, online discussion groups, Microchip consultant program member listing * Business of Microchip - Product selector and ordering guides, latest Microchip press releases, listing of seminars and events, listings of Microchip sales offices, distributors and factory representatives CUSTOMER SUPPORT Users of Microchip products can receive assistance through several channels: * * * * * Distributor or Representative Local Sales Office Field Application Engineer (FAE) Technical Support Development Systems Information Line Customers should contact their distributor, representative or field application engineer (FAE) for support. Local sales offices are also available to help customers. A listing of sales offices and locations is included in the back of this document. Technical support is available through the web site at: http://support.microchip.com CUSTOMER CHANGE NOTIFICATION SERVICE Microchip's customer notification service helps keep customers current on Microchip products. Subscribers will receive e-mail notification whenever there are changes, updates, revisions or errata related to a specified product family or development tool of interest. To register, access the Microchip web site at www.microchip.com, click on Customer Change Notification and follow the registration instructions. (c) 2006 Microchip Technology Inc. DS21483C-page 21 TC9400/9401/9402 READER RESPONSE It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150. Please list the following information, and use this outline to provide us with your comments about this document. To: RE: Technical Publications Manager Reader Response Total Pages Sent ________ From: Name Company Address City / State / ZIP / Country Telephone: (_______) _________ - _________ Application (optional): Would you like a reply? Y N Literature Number: DS21483C FAX: (______) _________ - _________ Device: TC9400/9401/9402 Questions: 1. What are the best features of this document? 2. How does this document meet your hardware and software development needs? 3. Do you find the organization of this document easy to follow? If not, why? 4. What additions to the document do you think would enhance the structure and subject? 5. What deletions from the document could be made without affecting the overall usefulness? 6. Is there any incorrect or misleading information (what and where)? 7. How would you improve this document? DS21483C-page 22 (c) 2006 Microchip Technology Inc. Note the following details of the code protection feature on Microchip devices: * * Microchip products meet the specification contained in their particular Microchip Data Sheet. Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip's Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property. Microchip is willing to work with the customer who is concerned about the integrity of their code. Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as "unbreakable." * * * Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our products. Attempts to break Microchip's code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act. Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights. Trademarks The Microchip name and logo, the Microchip logo, Accuron, dsPIC, KEELOQ, microID, MPLAB, PIC, PICmicro, PICSTART, PRO MATE, PowerSmart, rfPIC, and SmartShunt are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. AmpLab, FilterLab, Migratable Memory, MXDEV, MXLAB, SEEVAL, SmartSensor and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. Analog-for-the-Digital Age, Application Maestro, dsPICDEM, dsPICDEM.net, dsPICworks, ECAN, ECONOMONITOR, FanSense, FlexROM, fuzzyLAB, In-Circuit Serial Programming, ICSP, ICEPIC, Linear Active Thermistor, Mindi, MiWi, MPASM, MPLIB, MPLINK, PICkit, PICDEM, PICDEM.net, PICLAB, PICtail, PowerCal, PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB, rfPICDEM, Select Mode, Smart Serial, SmartTel, Total Endurance, UNI/O, WiperLock and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. (c) 2006, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. Microchip received ISO/TS-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona, Gresham, Oregon and Mountain View, California. The Company's quality system processes and procedures are for its PICmicro(R) 8-bit MCUs, KEELOQ(R) code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip's quality system for the design and manufacture of development systems is ISO 9001:2000 certified. (c) 2006 Microchip Technology Inc. DS21483C-page 23 WORLDWIDE SALES AND SERVICE AMERICAS Corporate Office 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7200 Fax: 480-792-7277 Technical Support: http://support.microchip.com Web Address: www.microchip.com Atlanta Alpharetta, GA Tel: 770-640-0034 Fax: 770-640-0307 Boston Westborough, MA Tel: 774-760-0087 Fax: 774-760-0088 Chicago Itasca, IL Tel: 630-285-0071 Fax: 630-285-0075 Dallas Addison, TX Tel: 972-818-7423 Fax: 972-818-2924 Detroit Farmington Hills, MI Tel: 248-538-2250 Fax: 248-538-2260 Kokomo Kokomo, IN Tel: 765-864-8360 Fax: 765-864-8387 Los Angeles Mission Viejo, CA Tel: 949-462-9523 Fax: 949-462-9608 San Jose Mountain View, CA Tel: 650-215-1444 Fax: 650-961-0286 Toronto Mississauga, Ontario, Canada Tel: 905-673-0699 Fax: 905-673-6509 ASIA/PACIFIC Australia - Sydney Tel: 61-2-9868-6733 Fax: 61-2-9868-6755 China - Beijing Tel: 86-10-8528-2100 Fax: 86-10-8528-2104 China - Chengdu Tel: 86-28-8676-6200 Fax: 86-28-8676-6599 China - Fuzhou Tel: 86-591-8750-3506 Fax: 86-591-8750-3521 China - Hong Kong SAR Tel: 852-2401-1200 Fax: 852-2401-3431 China - Qingdao Tel: 86-532-8502-7355 Fax: 86-532-8502-7205 China - Shanghai Tel: 86-21-5407-5533 Fax: 86-21-5407-5066 China - Shenyang Tel: 86-24-2334-2829 Fax: 86-24-2334-2393 China - Shenzhen Tel: 86-755-8203-2660 Fax: 86-755-8203-1760 China - Shunde Tel: 86-757-2839-5507 Fax: 86-757-2839-5571 China - Wuhan Tel: 86-27-5980-5300 Fax: 86-27-5980-5118 China - Xian Tel: 86-29-8833-7250 Fax: 86-29-8833-7256 ASIA/PACIFIC India - Bangalore Tel: 91-80-4182-8400 Fax: 91-80-4182-8422 India - New Delhi Tel: 91-11-5160-8631 Fax: 91-11-5160-8632 India - Pune Tel: 91-20-2566-1512 Fax: 91-20-2566-1513 Japan - Yokohama Tel: 81-45-471- 6166 Fax: 81-45-471-6122 Korea - Gumi Tel: 82-54-473-4301 Fax: 82-54-473-4302 Korea - Seoul Tel: 82-2-554-7200 Fax: 82-2-558-5932 or 82-2-558-5934 Malaysia - Penang Tel: 60-4-646-8870 Fax: 60-4-646-5086 Philippines - Manila Tel: 63-2-634-9065 Fax: 63-2-634-9069 Singapore Tel: 65-6334-8870 Fax: 65-6334-8850 Taiwan - Hsin Chu Tel: 886-3-572-9526 Fax: 886-3-572-6459 Taiwan - Kaohsiung Tel: 886-7-536-4818 Fax: 886-7-536-4803 Taiwan - Taipei Tel: 886-2-2500-6610 Fax: 886-2-2508-0102 Thailand - Bangkok Tel: 66-2-694-1351 Fax: 66-2-694-1350 EUROPE Austria - Wels Tel: 43-7242-2244-399 Fax: 43-7242-2244-393 Denmark - Copenhagen Tel: 45-4450-2828 Fax: 45-4485-2829 France - Paris Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79 Germany - Munich Tel: 49-89-627-144-0 Fax: 49-89-627-144-44 Italy - Milan Tel: 39-0331-742611 Fax: 39-0331-466781 Netherlands - Drunen Tel: 31-416-690399 Fax: 31-416-690340 Spain - Madrid Tel: 34-91-708-08-90 Fax: 34-91-708-08-91 UK - Wokingham Tel: 44-118-921-5869 Fax: 44-118-921-5820 02/16/06 DS21483C-page 24 (c) 2006 Microchip Technology Inc. |
Price & Availability of TC940006
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |