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UC1904 UC2904 UC3904
Precision Quad Supply and Line Monitor
FEATURES
* * Inputs for Monitoring Up to Four Supply Voltages Two Inputs Preset for -5V and -12V Monitoring, or Programmable Positive Levels Precision 2.5V Reference Separate Inputs for Over-Current and Line Fault Sensing Adjustable Under- to Over-Voltage Fault Windows Latched Over-Voltage and Over-Current Output Power Good and Power Warning Outputs Auto Restart Function with ON/OFF Control, and Programmable Delay Programmable Pwr On Reset Delay
DESCRIPTION
The UC1904 Quad Supply Monitor will respond to under- and over-voltage conditions on up to four continuously monitored voltage levels. Four independent positive voltages can be monitored or, alternatively, two of the sense inputs are preset to monitor -5V and -12V supplies. The device also monitors Over-Current and Line Sense inputs, both with precision input thresholds. Four open collector outputs on the UC1904 give the following responses: 1. The OV/OC output is a latched over-voltage, or over-current response. 2. A Power Good signal responds low with any fault detection - on power-up a programmable delay is used to hold this output low for a system Power On Reset signal. 3. The PWRW output responds only to a Line Sense input, for early warning of power failures. 4. The last open collector, the ON/OFF output, generates a delayed supply OFF control signal in response to an OFF input command, under-voltage condition, or line fault detection. The OV-UV fault window is adjustable with a programming input. The thresholds are centered around the precision 2.5V reference, with a scaled hysteresis for precise, glitch free operation. In the positive mode of operation, the fault windows at each of the sense inputs can be independently scaled using external resistors and the 2.5V reference output. An Auto Restart function couples with the under-voltage and line sensing circuits to allow controlled power supply start-up and shutdown. This device will operate over a supply range of 4.75V to 18V. The device is available in a DIP, SOIC, or PLCC outline. This device is ESD protected on all pins.
* * * * * * *
BLOCK DIAGRAM
Note: Pin Numbers refer to J, N, and DW Packages.
4/97
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ABSOLUTE MAXIMUM RATINGS (Note 1)
Input Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20V Sense Inputs, S1 And S2, Other Analog And Logic Inputs Maximum Forced Voltage . . . . . . . . . . . . . . . . . . -0.3V to 10V Maximum Forced Current . . . . . . . . . . . . . . . . . . . . . . 10mA Sense Input S3, (-12V Sense Input) Maximum Forced Voltage . . . . . . . . . . . . . . . . . . -18V to 10V Maximum Forced Current . . . . . . . . . . . . . . . . . . . . . . 10mA Sense Input S4, (-5V Sense Input) Maximum Forced Voltage . . . . . . . . . . . . . . . . . . -10V to 10V Maximum Forced Current . . . . . . . . . . . . . . . . . . . . . . 10mA Open Collector Outputs Maximum Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20V Maximum Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA Reference Output Current . . . . . . . . . . . . . . . Internally Limited Operating Junction Temperature . . . . . . . . . . . -55C to +150C Storage Temperature . . . . . . . . . . . . . . . . . . . . -65C to +150C
UC1904 UC2904 UC3904
Note 1: Unless otherwise indicated, voltages are reference to ground and currents are positive into, negative out of, the specified terminals.
CONNECTION DIAGRAMS
PLCC-20 (TOP VIEW) Q PACKAGE
PACKAGE PIN FUNCTION FUNCTION PIN
DIL-18, SOIC-18 (TOP VIEW) J or N PACKAGE, DW PACKAGE
2.5V POR DLY N.C. S1 S2 S3 S4 N.C. LS Input OC Input PWRW Out PG Out OV/OC Out VIN ON/OFF Out OFF DLY ON/OFF Input ARST Input WADJ Gnd
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
ELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications hold for TA = 0 to 70C for the
UC3904, -40 to +85C for the UC2904, and -55 to +125C for the UC1904, +VIN = 15V, WADJ = 0.5V, Sense Inputs 1-4, OC and LS Inputs = 2.5V. The ON/OFF Input and the ARST Input = 0V. PARAMETER Input Supply VIN Supply Current VIN UVLO Threshold UVLO Threshold Hysteresis Minimum VIN to Enable PG Out Reference Output Voltage(VREF) TJ = 25C Over Temperature, UC3904 Over Temperature, UC2904 & UC1904 Load Regulation Line Regulation Short Circuit Current Over-Voltage Thresholds S1, S2 Over-Voltage Thresholds S3, S4 Positive Mode IOUT = 0 to 4mA VIN = 4.75 to 18V VREF = 0V WADJ = 0.25V, Offset from VREF, Input L to H WADJ = 0.5V, Offset from VREF, Input L to H WADJ = 1V, Offset from VREF, Input L to H WADJ = 0.25V, Offset from VREF, Input L to H WADJ = 0.5V, Offset from VREF, Input L to H WADJ = 1V, Offset from VREF, Input L to H
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TEST CONDITIONS VIN = 15V Low to High
MIN
TYP 3.2 4.5 50 0.8
MAX 4.5 4.75 1.5 2.525 2.53 2.535 6 5
UNITS mA V mV V V V V mV mV mA
2.475 2.47 2.465
2.5
17 110 230 460 110 230 460 125 250 500 125 250 500 140 270 540 145 280 550
OV UV Window, LS Input, OC Input, ARST Input, and ON/OFF Input Thresholds mV mV mV mV mV mV
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UC1904 UC2904 UC3904
Unless otherwise stated, these specifications hold for TA = 0 to 70C for the UC3904, -40 to ELECTRICAL CHARACTERISTICS (cont): +85C for the UC2904, and -55 to +125C for the UC1904, +VIN = 15V, WADJ = 0.5V, Sense Inputs 1-4, OC and LS Inputs = 2.5V. The ON/OFF Input and the ARST Input = 0V. PARAMETER Under-Voltage Thresholds S1, S2 Under-Voltage Thresholds S3, S4 Positive Mode TEST CONDITIONS WADJ = 0.25V, Offset from VREF, Input H to L WADJ = 0.5V, Offset from VREF, Input H to L WADJ = 1V, Offset from VREF, Input H to L WADJ = 0.25V, Offset from VREF, Input H to L WADJ = 0.5V, Offset from VREF, Input H to L WADJ = 1V, Offset from VREF, Input H to L OV and UV Threshold Hysteresis As a Function of WADJ S3 Negative Mode Thresholds Over-Voltage, WADJ = 0.5V, Input H to L Under-Voltage, WADJ = 0.5V, Input L to H Hysteresis, WADJ = 0.5V S4 Negative Mode Thresholds Over-Voltage, WADJ = 0.5V, Input H to L Under-Voltage, WADJ = 0.5V, Input L to H Hysteresis, WADJ = 0.5V WADJ Input Bias Current LS Threshold OC Threshold ARST Input Threshold ON/OFF Input Threshold 0.25V < WADJ <1.0V Input = H to L Threshold hysteresis Input = H to L Threshold hysteresis Input = L to H Input = H to L Input high level Input low level Sense and Logic Input Bias Currents Sense 1-4, Positive Mode Sense 3 Negative Mode Sense 4 Negative Mode Line, and OC Inputs ON/OFF Input ARST Input Saturation Voltage Leakage current POR Delay Delay Internal Pullup Current Threshold Low to High OFF Delay Delay Internal Pullup current Threshold Low to High OV Fault Delay Delay 10 20 50 s 120 185 12 2.25 250 ms/F A V 160 250 9 2.25 350 ms/F A V Input = 2.8V Input = 2.2V Input = -12V Input = -5V Input = 2.2V Input = 2.5V Input = 0.5 IOUT = 10mA VOUT = 20V -2000 -1000 -700 -700 250 -250 -500 -500 300 150 -700 0.2 0.4 5 -300 -300 1000 600 800 nA nA A A nA nA nA V A 0.6 MIN -140 -270 -540 -150 -285 -555 30 -13.52 -11.06 80 -5.63 -4.61 30 -5 1.96 65 1.9 50 2.25 0.56 2 100 2 100 2.5 0.625 1.74 1.35 TYP -125 -250 -500 -125 -250 -500 50 -13.2 -10.8 120 -5.5 -4.5 50 MAX -110 -230 -460 -110 -230 -460 70 -12.88 -10.54 160 -5.37 -4.39 70 5 2.04 125 2.1 150 2.75 0.69 2.4 UNITS mV mV mV mV mV mV mV/V V V mV V V mV A/V V mV V mV V V V V OV UV Window, LS Input, OC Input, ARST Input, and ON/OFF Input Thresholds (cont.)
Open Collector Outputs (OV/OC Out, PG Out, PWRW Out, ON/OFF Out)
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UC1904 UC2904 UC3904 PIN FUNCTIONAL DESCRIPTION
2.5V: This is the output of the precision 2.5V reference. ARST Input: This input, with a 4:1 hysteretic threshold, is used to sequence a power system through the Auto ReStarT cycle. A delayed representation of a supply output voltage is used at this pin to provide adequate startup time for the power system, and a minimum power-off period. Gnd: Reference point for the internal reference and all thresholds, as well as the return for the remainder of the device. LS Input: The Line Sense input is used to monitor a voltage that varies with the input line voltage to a system. The input is compared to a precision 2.0V level and is used to activate the PWRW and PG outputs, as well as triggering the Auto Restart sequence. OC Input: The Over-Current input can be used to respond to an inverted over-current signal. A low level signal at this input latches in a fault indication at the OV/OC output. OFF DLY: This pin functions similarly to the POR DLY pin to delay the turn-on of the ON/OFF output transistor. The charging current and upper threshold are 12A and 2.1V. ON/OFF Input: With a high level at this input the ON/OFF Out pin is activated after a user-programmable delay. A high level also activates the PG Out pin, and resets the OV/OC fault latch. On/Off Out: This output is an open collector output that is activated by the ON/OFF Input, or the Auto Restart circuitry. Saturation voltage on this and all the open collector outputs is rated at 10mA of current. OV/OC Out: In response to either an Over-Voltage or Over-Current situation this output is latched active low. There is nominal 20s delay in the OV path to the fault latch, providing rejection to transient overshooting on the monitored voltages. The low condition is cleared when the fault latch is reset by the ON/OFF Input, or a UVLO condition on the device. POR DLY: This pin is used, with an external capacitor, to program a Power-On-Reset delay. This delay is reset whenever there is a UV condition at one of the S1-S4 inputs, and then triggered upon the clearing of the UV condition. When reset, the voltage across the capacitor is quickly discharged to near zero volts, and the PG Out pin goes active low. Once triggered the capacitor is charged by a 9A current source. The PG Out pin remains active low until the delay capacitor voltage reaches a 2.1V threshold. PG Out: During any fault, under-voltage, or UVLO condition this output is low. A Power Good indication (output off) is given when all supply conditions are within defined operating limits. During power-up the PG signal is delayed by a programmable Power On Reset delay. During UVLO the output is active low as long as the input supply, VIN, is above approximately 1.0V. PWRW Out: When a low line condition is sensed by the LS Input this output goes low. This output is disabled (off) during a UVLO condition. S1-S4: These are the sense inputs for OV and UV monitoring of external voltages. All four inputs can be used to sense positive voltages with a simple divider to scale the voltage level to the 2.5V centered window. The S3 and S4 inputs can also be used to sense -12V and -5V supplies respectively with no external components. This is done with internal precision resistor dividers and two source only op-amps that are disabled when the pins are used in the positive mode. VIN: Input supply for the UC1904. The device is operational with 4.75V to 18V on this pin. WADJ: The WADJ input is used to program the OV and UV window thresholds. The OV-UV window is centered around the 2.5V reference and is nominally 20% per volt on the WADJ input pin.
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UC1904 UC2904 UC3904
Note: Pin Numbers refer to J, N, and DW Packages.
UNITRODE CORPORATION 7 CONTINENTAL BLVD. * MERRIMACK, NH 03054 TEL. (603) 424-2410 * FAX (603) 424-3460
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IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI's standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE ("CRITICAL APPLICATIONS"). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER'S RISK. In order to minimize risks associated with the customer's applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. TI's publication of information regarding any third party's products or services does not constitute TI's approval, warranty or endorsement thereof.
Copyright (c) 1999, Texas Instruments Incorporated
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