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MIC2524/2527
Micrel
MIC2524/2527
Quad USB Power Control Switch Not Recommended for New Designs
Refer to MIC2027
General Description
The MIC2524 and MIC2527 are cost-effective high-side power switches with four independently controlled channels, optimized for self-powered and bus-powered Universal Serial Bus (USB) applications. Few external components are necessary to satisfy USB requirements. The MIC2524/7 satisfies the following USB requirements: each switch channel supplies up to 500mA as required by USB downstream devices; the switch's low on-resistance meets USB voltage drop requirements; fault current is limited to typically 750mA, well below the UL 25VA safety requirements; and a flag output is available to indicate fault conditions to the local USB controller. Soft start eliminates the momentary voltage drop on the upstream port that may occur when the switch is enabled in bus-powered applications. Additional features include thermal shutdown to prevent catastrophic switch failure from high-current loads, undervoltage lockout (UVLO) to ensure that the device remains off unless there is a valid input voltage present, and 3.3V and 5V logic compatible enable inputs. The MIC2524/7 is available in active-high and active-low versions in 16-pin DIP and SOIC packages.
Features
* * * * * * * * * * * * * * * * * * * * Compliant to USB specifications UL Recognized Component 4 independent switches 3V to 5.5V input 500mA minimum continuous load current per port 140m maximum on-resistance (MIC2524) 1.25A maximum short circuit current limit Individual open-drain fault flag pins 220A on-state supply current 1A typical off-state supply current Output can be forced higher than input (off-state) Thermal shutdown 2.4V typical undervoltage lockout (UVLO) 1ms turn-on (soft-start) and fast turnoff Active-high or active-low enable versions 16-pin SOIC and DIP packages USB bus-powered hubs USB self-powered hubs USB monitors USB printers
Applications
Typical Application
MIC2527 5.1V 3% 5V 1% or MIC2524 5V 3% MIC5207-3.3 LDO Regulator IN 4.7 F OUT 1F GND
Ferrite Bead 10k 27k 3.3V USB Controller V+ ON/OFF OVERCURRENT MIC2524 MIC2527 ENA FLGA ENB FLGB D+ D- GND ENC FLGC END FLGD Bold lines indicate 0.1" wide, 1-oz. copper high-current traces. * 33F, 16V tantalum or 100F, 10V electrolytic per port IN IN OUTA OUTB OUTC OUTD GND GND 33F* 0.01F 0.1 F 33F* 0.01F 33F* 0.01F VBUS D+ D- GND Downstream USB Port 1 500mA max.
VBUS D+ D- GND Downstream USB Port 2 500mA max.
VBUS D+ D- GND Downstream USB Port 3 500mA max.
VBUS 33F* 0.01F D+ D- GND Downstream USB Port 4 500mA max.
4-Port Self-Powered Hub
UL Recognized Component Micrel, Inc. * 1849 Fortune Drive * San Jose, CA 95131 * USA * tel + 1 (408) 944-0800 * fax + 1 (408) 944-0970 * http://www.micrel.com
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Micrel
Ordering Information
Part Number MIC2524-1BWM MIC2524-1BN MIC2524-2BWM MIC2524-2BN MIC2527-1BWM MIC2527-1BN MIC2527-2BWM MIC2527-2BN On-Resistance 100m typ. 100m typ. 100m typ. 100m typ. 200m typ. 200m typ. 200m typ. 200m typ. Enable Active High Active High Active Low Active Low Active High Active High Active Low Active Low Temperature Range -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C Package 16-Pin SOIC 16-pin DIP 16-Pin SOIC 16-pin DIP 16-Pin SOIC 16-pin DIP 16-Pin SOIC 16-pin DIP
Pin Configuration
FLGA ENA OUTA GND IN(C/D) OUTC ENC 1 2 3 4 5 6 7 16 FLGB 15 ENB 14 OUTB 13 IN(A/B) 12 GND 11 OUTD 10 END 9 FLGD
4 GND 12 ENC 7 FLGC 8 END 10 FLGD 9
LOGIC, CHARGE PUMP
3 OUTA ENA 2 FLGA 1 ENB 15 FLGB 16
LOGIC, CHARGE PUMP
13 IN(A/B)
LOGIC, CHARGE PUMP
14 OUTB 6 OUTC 5 IN(C/D)
LOGIC, CHARGE PUMP
FLGC 8
11 OUTD
16-Pin SOIC (WM) 16-Pin DIP (N)
Functional Pinout
Pin Description
Pin Number 1 2 3 4, 12 5 6 7 8 9 10 11 13 14 15 16 Pin Name FLGA ENA OUTA GND IN(C/D) OUTC ENC FLGC FLGD END OUTD IN(A/B) OUTB ENB FLGB Pin Function Flag A: (Output): Channel A open-drain fault flag output. Enable A (Input): Channel A control input. Output A: Channel A switch output. Ground: Supply return. Connect both pins to ground. Supply Input: Channel C and D switch, logic, and charge-pump supply input. Output C: Channel C switch output. Enable C (Input): Channel C control input. Flag C (Output): Channel C open-drain fault flag output. Flag D (Output): Channel D open-drain fault flag output. Enable D (Input): Channel D control input. Output D: Channel D switch output. Supply Input: Channel A and B switch, logic, and charge-pump supply input. Output B: Channel B switch output. Enable B (Input): Channel B control input. Flag B (Output): Channel B open-drain fault flag output.
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Absolute Maximum Ratings (Note 1)
Supply Voltage (VIN) ..................................................... +6V Fault Flag Voltage (VFLG) .............................................. +6V Fault Flag Current (IFLG) ............................................ 50mA Output Voltage (VOUT) .................................................. +6V Output Current (IOUT) ............................... Internally Limited Control Input (VEN) ......................................... -0.3V to 12V Storage Temperature (TS) ....................... -65C to +150C Lead Temperature (Soldering 5 sec.) ....................... 260C ESD Rating, Note 3 ...................................................... 2kV
Operating Ratings (Note 2)
Supply Voltage (VIN) ...................................... +3V to +5.5V Ambient Operating Temperature (TA) ........ -40C to +85C Thermal Resistance SOIC (JA) ......................................................... 120C/W DIP(JA) ............................................................. 130C/W
Electrical Characteristics
VIN = +5V; TA = 25C; unless noted. Parameter Supply Current Condition Note 4, switch off, OUT = open Note 4, all switches on, OUT = open Enable Input Threshold low-to-high transition high-to-low transition, Note 4 Enable Input Current Enable Input Capacitance Switch Resistance MIC2524, IOUT = 500mA, each switch MIC2527, IOUT = 500mA, each switch Output Turn-On Delay Output Turn-On Rise Time Output Turnoff Delay Output Turnoff Fall Time Output Leakage Current Continuous Load Current Short-Circuit Current Limit Current-Limit Threshold Overtemperature Shutdown Threshold Error Flag Output Resistance RL = 10 each output RL = 10 each output RL = 10 each output RL = 10 each output each output (output disabled) each output each output (enable into load), VOUT = 4.0V ramped load applied to enabled output, VOUT 4.0V, Note 5 TJ increasing TJ decreasing VIN = 5V, IL = 10mA VIN = 3.3V, IL = 10mA Error Flag Off Current UVLO Threshold VFLAG = 5V VIN = increasing VIN = decreasing
Note 1. Note 2. Note 3. Note 4. Note 5. Exceeding the absolute maximum rating may damage the device. The device is not guaranteed to function outside its operating rating. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF. Off is 0.8V and on is 2.4V for the MIC252x-1. Off is 2.4V and on is 0.8V for the MIC252x-2. The enable input has approximately 200mV of hysteresis. See control threshold charts. See "Functional Characteristics: Current-Limit Response" photo.
Min
Typ 1.5 220 2.1
Max 10 320 2.4
Units A A V V A pF
0.8 -1
1.9 0.01 1 100 200 0.5 1 1 1 20 20 10 140 300 1
VEN = 0V to 5.5V
m m ms ms s s A A
0.5 0.5 0.75 1.6 135 125 10 15 0.01 2.5 2.3 1 1.25 2.2
A A C C A V V
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Typical Characteristics
VIN = 5V; TA = 25C; one switch section; unless noted.
Output On-Resistance vs. Supply Voltage
ON-RESISTANCE (m)
110 OUTPUT RESISTANCE (m)
140
Output On-Resistance vs. Temperature
THRESHOLD VOLTAGE (V)
3.0
UVLO Threshold Voltage vs. Temperature
120
100 Awaiting Full Characterization Data 90 RL = 44 T = 25C 80 3.0 3.5 4.0 4.5 5 SUPPLY VOLTAGE (V) 5.5
2.5
RISING
100
FALLING 2.0
80
RL = 44 VIN = 5V
60 -40 -20 0 20 40 60 80 100 TEMPERATURE (C)
1.5 -40 -20 0 20 40 60 80 100 TEMPERATURE (C)
On-State Supply Current vs. Supply Voltage
500 SUPPLY CURRENT (A) 400 300 200 100 ALL SWITCHES ON 0 0 2 4 6 SUPPLY VOLTAGE (V) 8 0 2 SUPPLY CURRENT (A) 2.0
Off-State Supply Current vs. Supply Voltage
2.5 THRESHOLD VOLTAGE (V)
Control Threshold vs. Supply Voltage
1.5
2.0
VCTL RISING
1.0
1.5
0.5 ALL SWITCHES OFF 3 4 5 6 7 SUPPLY VOLTAGE (V) 8
VCTL FALLING
1.0
2
3 4 SUPPLY VOLTAGE (V)
5
On-State Supply Current vs. Temperature
400 SUPPLY CURRENT (A) SUPPLY CURRENT (A) 350 300 250 200 150 100 50 ALL SWITCHES ON 2.0
Off-State Supply Current vs. Temperature
2.5 ENABLE VOLTAGE (V)
Control Threshold vs. Temperature
1.5
2.0 VEN FALLING 1.5
VEN RISING
1.0
0.5 ALL SWITCHES OFF 0 -40 -20 0 20 40 60 80 100 TEMPERATURE (C)
0 -40 -20 0 20 40 60 80 100 TEMPERATURE (C)
VIN = 5V 1.0 -40 -20 0 20 40 60 80 100 TEMPERATURE (C)
5 4 3 2 1
Output Rise Time vs. Temperature
1.0 0.8
Output Fall Time vs. Temperature
2.0 1.8
Current-Limit Threshold vs. Temperature
Awaiting Full Characterization Data
0.6 0.4 0.2
Awaiting Full Characterization Data
CURRENT (A)
TIME (ms)
TIME (s)
CURRENT LIMIT THRESHOLD 1.6 1.4 SHORT CIRCUIT CURRENT LIMIT 1.2 1.0 -25
0 -40 -20 0 20 40 60 80 100 TEMPERATURE (C)
0 -40 -20 0 20 40 60 80 100 TEMPERATURE (C)
0 25 50 75 TEMPERATURE (C)
100
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Functional Characteristics
Input Voltage Response Turn-On, Turnoff Characteristics
2.6V (UVLO) Threshold
VFLG VOUT IOUT (200mA/div.)(5V/div.) (2V/div.)
VEN VOUT VFLG (2V/div.) (5V/div.) (5V/div.)
VEN (2V/div.)
IOUT (100mA/div.)
VIN = 5.0V RL = 35 CL = 15F
144mA VIN = 5.0V RL = 35 CL = 10F TIME (2.5ms/div.)
TIME (100ns/div.)
Turn-On, Turnoff Characteristics
VEN VFLG (5V/div.) (5V/div.) VFLG (5V/div.)
Short Circuit Response (Short Applied to Output)
VOUT (2V/div.)
IOUT (100mA/div.)
144mA RL = 35 CL = 150F TIME (2.5ms/div.)
VOUT (2V/div.)
IOUT (1A/div.)
1A Short Circuit Current Limit
Thermal Shutdown TIME (500ms/div.)
Short Circuit Response Enable into Short Circuit
VEN (5V/div.) VOUT IOUT (1A/div.) (2V/div.) VFLG (5V/div.)
Thermal Shutdown 1.1A Short Circuit Current-Limiting TIME (250ms/div.)
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Short Circuit Transient Response (Short Applied to Output)
VOUT (5V/div.)
Current-Limit Response (Ramped Load)
VFLG (5V/div.)
2.76A
VOUT (2V/div.)
Current Limit Threshold
VFLG (5V/div.)
IOUT (1A/div.)
1A Current Limit
TIME (500s/div.)
IOUT (1A/div.)
1A Current Limit
TIME (1ms/div.)
Test Circuit
5V 10k 0.1F MIC2524/7 ENA FLGA ENB FLGB ENC FLGC END FLGD IN NC IOUT OUTA CL OUTB OUTC OUTD NC GND (1 output shown) Ferrite Bead
RL
ILOAD (for Current Limit Response)
Functional Characteristics Test Circuit
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Block Diagrams
FLGA
OUTA ENA CHARGE PUMP GATE CONTROL CURRENT LIMIT
OSC.
THERMAL SHUTDOWN
UVLO
1.2V REFERENCE
IN (A/B)
CHARGE PUMP GATE CONTROL ENB
CURRENT LIMIT
OUTB FLGB
FLGC
OUTC ENC CHARGE PUMP GATE CONTROL CURRENT LIMIT
OSC.
THERMAL SHUTDOWN
UVLO
1.2V REFERENCE
IN (C/D)
CHARGE PUMP GATE CONTROL END
CURRENT LIMIT
OUTD FLGD
MIC2527 GND
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Undervoltage Lockout UVLO (undervoltage lockout) prevents the output MOSFET from turning on until VIN exceeds approximately 2.5V. In the undervoltage state, the FLAG will be low. After the switch turns on, if the voltage drops below approximately 2.3V, UVLO shuts off the output MOSFET and signals fault flag. Undervoltage detection functions only when at least one switch is enabled. Current Sensing and Limiting The current-limit threshold is preset internally. The preset level prevents damage to the output MOSFET and external load but allows a minimum current of 0.5A through the output MOSFET of each channel. The current-limit circuit senses a portion of the output FET switch current. The current sense resistor shown in the block diagram is virtual and has no voltage drop. The reaction to an overcurrent condition varies with three scenarios:
Functional Description
The MIC2524/7-1 and MIC2524/7-2 are quad high-side switches with active-high and active-low enable inputs, respectively. Fault conditions turn off or inhibit turn-on of one or more of the output transistors, depending upon the type of fault, and activate the open-drain error flag transistors making them sink current to ground. Input and Output IN (input) is the power supply connection to the logic circuitry and the drain of the output MOSFET. OUTx (output) is the source of its respective MOSFET. In a typical circuit, current flows through the switch from IN to OUT toward the load. If VOUT is greater than VIN, current will flow from OUT to IN since the MOSFET is bidirectional when on. The output MOSFET and driver circuitry are also designed to allow the MOSFET source to be externally forced to a higher voltage than the drain (VOUT > VIN) when the output is off. In this situation, the MIC2524/7 prevents reverse current flow. If VIN < 2.5V, UVLO disables both switches. Thermal Shutdown Thermal shutdown shuts off the affected output MOSFETs and signals all fault flags if the die temperature exceeds 135C. 10C of hysteresis prevents the switch from turning on until the die temperature drops to 125C. Overtemperature detection functions only when at least one switch is enabled. Current Limit Induced Thermal Shutdown Internal circuitry increases the output MOSFET on-resistance until the series combination of the MOSFET on-resistance and the load impedance limit current to typically 850mA. The increase in power dissipation, in most cases, will cause the MIC2524/7 to go into thermal shutdown, disabling affected channels. When this is undesirable, thermal shutdown can be avoided by externally responding to the fault and disabling the current limited channel before the shutdown temperature is reached. The delay between the flag indication of a current limit fault and thermal shutdown will vary with ambient temperature, board layout, and load impedance, but is typically several hundred milliseconds. The USB controller must therefore recognize a fault and disable the appropriate channel within this time. If the fault is not removed or the switch is not disabled within this time, then the device will enter into a thermal oscillation of about 2Hz. This does not cause any damage to the device. Refer to "Functional Characteristics: Thermal Shutdown Response."
Switch Enabled into Short Circuit If a switch is powered on or enabled into a heavy load or shortcircuit, the switch immediately goes into a constant-current mode, reducing the output voltage. The fault flag goes low until the load is reduced. See the "Functional Characteristics: Short Circuit Response, Enabled into Short Circuit" photo. Short Circuit Applied to Output When a heavy load is applied, a large transient current may flow until the current limit circuitry will respond. Once this occurs, the device limits current to less than the short-circuit current limit specification. See the "Short Circuit Transient Response, Short Applied to Output" graph. Current-Limit Response The MIC2524/7 current-limit profile exhibits a small foldback effect of approximately 500mA. Once this current-limit threshold is exceeded the device enters constant-current mode. This constant current is specified as the short circuit current limit in the "Electrical Characteristics" table. It is important to note that the MIC2524/7 will deliver load current up to the current-limit threshold which is typically 1.6A. Refer to "Functional Characteristics: Current-Limit Response" photo for details. Fault Flag FLG is an N-channel, open-drain MOSFET output. The faultflag is active (low) for one or more of the following conditions: undervoltage (while 2V < VIN < 2.7), current limit, or thermal shutdown. The flag output MOSFET is capable of sinking a 10mA load to typically 100mV above ground. Multiple FLG pins may be "wire NORed" to a common pull-up resistor.
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Transient Overcurrent Filter When the MIC2524/7 is enabled, large values of capacitance at the output of the device will cause inrush current to exceed the short circuit current-limit threshold of the device and assert the flag. The duration of this time will depend on the size of the output capacitance. Refer to the "Functional Characteristics" turn-on and turnoff behaviors for details. During the capacitance charging time, the device enters into constant-current mode. As the capacitance is charged, the current decreases below the short circuit current-limit threshold, and the flag will then be deasserted. In USB applications, it is required that output bulk capacitance is utilized to support hot-plug events. When the MIC2524/7 is enabled, the flag may go active for about 1ms due to inrush current exceeding the current-limit setpoint. Additionally, during hot-plug events, inrush currents may also cause the flag to go active for 30s. Since these conditions are not valid overcurrent faults, the USB controller must ignore the flag during these events. To prevent this erroneous overcurrent reporting, a 1ms RC filter as shown in Figure 2 may be used. Alternatively, a 1ms debounce routine may be programmed into the USB logic controller, eliminating the need for the RC filter.
Applications Information
Supply Filtering A 0.1F to 1F bypass capacitor from IN to GND, located at the device, is strongly recommended to control supply transients. Without a bypass capacitor, an output short may cause sufficient ringing on the input (from supply lead inductance) to damage internal control circuitry. Input or output transients must not exceed the absolute maximum supply voltage (VIN max = 7V) even for a short duration.
VIN 2.7V to 5.5V MIC2524/7 FLGA ENA 0.1F to 1F GND IN IN GND FLGB ENB 0.1F to 1F
OUTA OUTB
OUTC OUTD ENC FLGC END FLGD
Figure 1. Supply Bypassing Enable Input EN must be driven logic high or logic low for a clearly defined input. Floating the input may cause unpredictable operation. EN should not be allowed to go negative with respect to GND. Soft Start The MIC2524/7 presents a high impedance when off, and slowly becomes a low impedance as it turns on. This reduces inrush current and related voltage drop that results from charging a capacitive load, satisfying the USB voltage droop requirements.
USB Controller OVERCURRENT 10k FLGA 10k 0.1F FLGB FLGC FLGD
Figure 2. Transient Filter
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Package Information
PIN 1
0.157 (3.99) 0.150 (3.81)
DIMENSIONS: INCHES (MM)
0.020 (0.51) REF 0.050 (1.27) BSC
0.020 (0.51) 0.013 (0.33) 0.0098 (0.249) 0.0040 (0.102)
45 0-8 0.050 (1.27) 0.016 (0.40) 0.244 (6.20) 0.228 (5.79)
0.0648 (1.646) 0.0434 (1.102)
0.394 (10.00) 0.386 (9.80)
SEATING PLANE
16-Pin SOP (M)
0.780 MAX (19.812) PIN 1 0.030-0.110 RAD (0.762-2.794)
.2500.005 (6.3500.127)
0.0250.015 (0.6350.381) 0.1300.005 (3.3020.127) 0.040 TYP (1.016)
0.020 (0.508)
0.290-0.320 (7.336-8.128)
0-10 0.020 MIN (0.508) 0.125 MIN (3.175) 0.009-0.015 (0.229-0.381) 0.0180.003 (0.4570.076) 0.1000.010 (2.5400.254) +0.025 -0.015 +0.635 8.255 -0.381 0.325
(
)
16-Pin Plastic DIP (N)
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Micrel
MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131
TEL
USA
+ 1 (408) 944-0800
FAX
+ 1 (408) 944-0970
WEB
http://www.micrel.com
This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc. (c) 1999 Micrel Incorporated
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