POWER MANAGEMENT USB Power Switch IMP252 4/27 Quad USB High-Side Power Switch with Fault Detection IMP2525 USB High-Side Power Switch IMP2525A Low-Resistance, USB High-Side Power Switch IMP2526 Dual USB High-Side Power Switch 408-432-9100/www.impweb.com U S B Po w e r S w i t c h P r o d u c t G u i d e Product Selection Guide Part Number Type Package Switch "ON" Resistance Enable Logic Undervoltage Lockout Current Limit Thermal Shutdown Fault Flag IMP2524-1BWM Quad 16-pin, SO 0.14Ω HIGH IMP2524-2BWM Quad 16-pin, SO 0.14Ω LOW IMP2524-1BN Quad 16-pin, DIP 0.14Ω HIGH IMP2524-2BN Quad 16-pin, DIP 0.14Ω LOW IMP2525A-1BM Single 8-pin, SO 0.070Ω HIGH IMP2525A-2BM Single 8-pin, SO 0.070Ω LOW IMP2525A-1BN Single 8-pin, DIP 0.070Ω HIGH IMP2525A-2BN Single 8-pin, DIP 0.070Ω LOW IMP2525-1BM Single 8-pin, SO 0.14Ω HIGH IMP2525-2BM Single 8-pin, SO 0.14Ω LOW IMP2525-1BN Single 8-pin, DIP 0.14Ω HIGH IMP2525-2BN Single 8-pin, DIP 0.14Ω LOW IMP2526-1BM Dual 8-pin, SO 0.14Ω HIGH IMP2526-2BM Dual 8-pin, SO 0.14Ω LOW IMP2526-1BN Dual 8-pin, DIP 0.14Ω HIGH IMP2526-2BN Dual 8-pin, DIP 0.14Ω LOW IMP2527-1BWM Quad 16-pin, SO 0.30Ω HIGH • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • IMP2527-2BWM Quad 16-pin, SO 0.30Ω LOW IMP2527-1BN Quad 16-pin, DIP 0.30Ω HIGH IMP2527-2BN Quad 16-pin, DIP 0.30Ω LOW USBSEL01 All devices are pin-compatible with the MIC2525/2526 devices. Compared to the Micrel MIC2525, the enhanced IMP2525A has a 50% lower "ON" resistance. Product Cross Reference Guide Micrel Part Number MIC2524-1BWM MIC2524-2BWM MIC2524-1BN MIC2524-2BN MIC2525A-1BM MIC2525A-2BM MIC2525A-1BN MIC2525A-2BN MIC2525-1BM MIC2525-2BM MIC2525-1BN MIC2525-2BN MIC2526-1BM MIC2526-2BM MIC2526-1BN MIC2526-2BN MIC2527-1BWM MIC2527-2BWM MIC2527-1BN MIC2527-2BN IMP Part Number IMP2524-1BWM IMP2524-2BWM IMP2524-1BN IMP2524-2BN IMP2525A-1BM IMP2525A-2BM IMP2525A-1BN IMP2525A-2BN IMP2525-1BM IMP2525-2BM IMP2525-1BN IMP2525-2BN IMP2526-1BM IMP2526-2BM IMP2526-1BN IMP2526-2BN IMP2527-1BWM IMP2527-2BWM IMP2527-1BN IMP2527-2BN Type Package Switch "ON" Resistance Quad Quad Quad Quad Single Single Single Single Single Single Single Single Dual Dual Dual Dual Quad Quad Quad Quad 16-pin, SO 16-pin, SO 16-pin, DIP 16-pin, DIP 8-pin, SO 8-pin, SO 8-pin, DIP 8-pin, DIP 8-pin, SO 8-pin, SO 8-pin, DIP 8-pin, DIP 8-pin, SO 8-pin, SO 8-pin, DIP 8-pin, DIP 16-pin, SO 16-pin, SO 16-pin, DIP 16-pin, DIP 0.14Ω 0.14Ω 0.14Ω 0.14Ω 0.070Ω vs. 0.14Ω for Micrel 2525 0.070Ω vs. 0.14Ω for Micrel 2525 0.070Ω vs. 0.14Ω for Micrel 2525 0.070Ω vs. 0.14Ω for Micrel 2525 0.14Ω 0.14Ω 0.14Ω 0.14Ω 0.14Ω 0.14Ω 0.14Ω 0.14Ω 0.30Ω 0.30Ω 0.30Ω 0.30Ω USBXref02 408-432-9100/www.impweb.com © 2000 IMP, Inc. 6 IMP252 4/2 7 POWER MANAGEMENT ADVANCE PRODUCT INFORMATION Quad USB High-Side Power Switch with Fault Detection Key Features The IMP2524 and IMP2527 are complete power management solutions for bus-powered and self-powered USB hubs. Each device contains four independent power switches and fault detection logic. The IMP2524 channel resistance is a low 140mΩ maximum and the IMP2527 channel resistance is 300Ω maximum. Both device operate with voltage inputs from 2.7V to 5.5V The IMP2524/2527 conform to the new USB 1.1 standard. Fault current is limited to 750mA typically, and a flag output for each switch conveys fault information to the local USB controller. The IMP252x “Soft-Start” function ramps the ON-current to eliminate any excessive voltage drop on the input side that could occur when capacitive loads are charged. ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ Self-monitoring features include thermal shutdown to prevent catastrophic switch failure from high-current loads and undervoltage lockout (UVLO) that insures that the device remains OFF unless there is sufficient supply voltage present. ◆ The switch Enable input logic can interface with both 3.3V and 5V logic. Both active-HIGH (-1 devices) and active-LOW (-2 devices) enable logic versions are available. Supply current is a low 0.75µA when disabled and just 110µA when enabled ◆ ◆ ◆ ◆ The quad IMP2524/7 devices are available in 16-pin DIP and 16-pin SO packages and are pin compatible replacements for the Micrel MIC2524-1/-2 and MIC2527-1/2 devices. IMP offers a complete family of USB power management products. For single-switch applications see the IMP2525 and IMP2525A data sheets. The single-switch IMP2525A features a 0.07Ω switch resistance. For dual-switch applications, refer to the IMP2526 data sheet. Typical Application Applications ◆ USB host and self-powered hubs ◆ USB video monitors ◆ USB printers Ferrite Bead IMP2527 5.1V ± 3% 5V ± 1% or IMP2524 5V ± 3% 4.7mF USB Rev. 1.1 and 2.0 Compliant Four independent switches 2.7V to 5.5V input operation Low MOSFET ON resistance – IMP2524: 0.1Ω, 0.14Ω maximum – IMP2527: 0.2Ω, 0.3Ω maximum 500mA continuos load current per switch Low supply current – 110µA ON-state current, 0.75µA OFF-state current 1.25A maximum current limit, 750mA typical Thermal shutdown 2.4V undervoltage lockout (UVLO) Open-drain flag output – Undervoltage – Current limit – Thermal shutdown Output can be force higher than input Active HIGH(-1) and active LOW(-2) enable 16-pin SO and DIP packages, Die available Pin compatible with the Micrel MIC2524 and MIC2527 10k + IN OUT LDO GND V+ ON/OFF OVERCURRENT USB Controller VBUS 27k 2 1 3 4 5 Data D+ D– 6 GND 1mF 7 8 IMP2524 IMP2527 ENA INA/B FLGA INC/D ENB OUTA FLGB OUTB ENC OUTC FLGC OUTD END GND FLGD GND 33mF* + 16 D+ 0.01mF GND 15 14 13 12 11 D– 0.1mF 33mF* Downstream USB Port 1 500mA max. VBUS + D+ 0.01mF 10 D– GND Downstream USB Port 2 500mA max. 9 VBUS 33mF* + Bold/Blue lines indicate 0.1" wide, 1-oz. copper high-current traces. D+ 0.01mF D– GND Downstream USB Port 3 500mA max. *33mF, 16V tantalum or 100mF, 10V electrolytic per port VBUS 33mF* + D+ 0.01mF D– GND Downstream USB Port 4 500mA max. 2524/27_01.eps © 2000 IMP, Inc. 408-432-9100/www.impweb.com 1 IMP2524/27 Pin Configuration SO/DIP FLGA FLGA 1 16 FLGB ENA ENA 2 15 ENB FLGB OUTA 3 GND 4 13 INA/B INC/D 5 12 GND OUTC 6 11 OUTD ENC 7 10 END FLGC FLGC 8 9 FLGD IMP2524/27 14 OUTB ENB 2 16 15 ENC FLGD END 7 1 FLGA 2 ENA 3 4 OUTA GND 5 INC/D 6 OUTC 7 ENC 8 FLGC 9 FLGD 10 END 11 12 OUTD GND 13 INA/B 14 OUTB 15 ENB 16 FLGB 13 Logic, Charge Pump 14 6 Logic, Charge Pump 8 9 10 Pin Descriptions Name Logic, Charge Pump IMP2524/27 2524/27_02.eps Pin Number 3 1 5 Logic, Charge Pump 11 4 12 GND GND OUTA INA/B OUTB OUTC INC/D OUTD 2524/27_03.eps Function Fault Flag A output. This open-drain output goes into an active-LOW state in response to undervoltage, current limit or thermal shutdown conditions. Enable A Input. This pin is the Channel B MOSFET switch driver control logic input. Both active-HIGH (-1 suffix) and active-LOW (-2 suffix) logic devices are available. Channel-A switch output (MOSFET Source). The output pin drives the load into ON and OFF states. Ground. Power supply return for the internal circuitry of the IC. Connect both pins 4 and 6 together. Channel C and D positive power supply input voltage. This is the switching MOSFET drain connection. It is the channel C and channel D supply voltage input for the logic and the charge-pump circuit. Channel-C switch output (MOSFET Source). The output pin drives the load into ON and OFF states. Enable C Input. This pin is the Channel B MOSFET switch driver control logic input. Both active-HIGH (-1 suffix) and active-LOW (-2 suffix) logic devices are available. Fault Flag C output. This open-drain output goes into an active-LOW state in response to undervoltage, current limit or thermal shutdown conditions. Fault Flag D output. This open-drain output goes into an active-LOW state in response to undervoltage, current limit or thermal shutdown conditions. Enable D Input. This pin is the Channel B MOSFET switch driver control logic input. Both active-HIGH (-1 suffix) and active-LOW (-2 suffix) logic devices are available. Channel-D switch output (MOSFET Source). The output pin drives the load into ON and OFF states. Ground. Power supply return for the internal circuitry of the IC. Connect both pins 4 and 6 together. Channel A and B positive power supply input voltage. This is the switching MOSFET drain connection. It is the channel A and channel B supply voltage input for the logic and the charge-pump circuit. Channel-B switch output (MOSFET Source). The output pin drives the load into ON and OFF states. Enable B Input. This pin is the Channel-B MOSFET switch driver control logic input. Both active-HIGH (-1 suffix) and active-LOW (-2 suffix) logic devices are available. Fault Flag B output. This open-drain output goes into an active-LOW state in response to undervoltage, current limit or thermal shutdown conditions. 2524/27t01 Ordering Information Pin Number Enable Logic Typical “ON” Resistance IMP2524-1BWM IMP2524-2BWM IMP2524-1BN IMP2524-2BN IMP2527-1BWM IMP2527-2BWM IMP2527-1BN IMP2527-2BN Active HIGH Active LOW Active HIGH Active LOW Active HIGH Active LOW Active HIGH Active LOW 100mΩ 100mΩ 100mΩ 100mΩ 200mΩ 200mΩ 200mΩ 200mΩ Temperature Range –40° –40° –40° –40° –40° –40° –40° –40° C to +85° C to +85° C to +85° C to +85° C to +85° C to +85° C to +85° C to +85° C C C C C C C C Pins-Package 16-SO 16-SO 16-DIP 16-DIP 16-SO 16-SO 16-DIP 16-DIP 2524/27t02 2 408-432-9100/www.impweb.com © 2000 IMP, Inc. 6 IMP2524/27 Absolute Maximum Ratings Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . +8.0V Fault Flag Voltage . . . . . . . . . . . . . . . . . . . . . . +8.0V Fault Flag Current . . . . . . . . . . . . . . . . . . . . . . 50mA Output Voltage . . . . . . . . . . . . . . . . . . . . . . . . . +8.0V Output Current . . . . . . . . . . . . . . . . . . . . . . . . . Internally Limited Enable Input . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3V to 12V Storage Temperature . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C Lead Temperature (Soldering, 5 sec.) . . . . . . . 260°C Package Thermal Resistance SO (θJA ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160°C/W DIP(θJA ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130°C/W Note: All voltages are referenced to GND. These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. Electrical Characteristics Unless otherwise noted, VIN = 5V and TA = 25°C. Parameter Symbol Conditions Supply Voltage Range VIN Operating Temperature Range TA Min TA = – 40°C to +85°C Typ Max Units 2.7 5.5 V – 40 85 °C Supply Current Switch OFF IIN OFF Switch OFF, No load VENOFF ≤ 0.8V, VENON ≥ 2.4V IMP2524/27-1 VENON ≤ 0.8V, VENOFF ≥ 2.4V IMP2524/27-2 0.75 10 µA Supply Current Switch ON IIN ON Switch ON, No load VENOFF ≤ 0.8V, VENON ≥ 2.4V IMP2524/27-1 VENON ≤ 0.8V, VENOFF ≥ 2.4V IMP2524/27-2 110 320 µA Enable Input Threshold VENH LOW to HIGH (“0” to “1”) Enable Voltage, Note 1 2.1 2.4 V VENL HIGH to LOW (“1” to “0”) Enable Voltage, Note 1 µA Enable Input Current IEN Enable Input Capacitance CEN Switch ON Resistance RON Continuous Load Current IL 0.8 1.9 VEN = 2.4V 0.01 1 VEN = 0.8V 0.01 1 1 pF IMP2524: IOUT = 500mA each switch 0.10 0.14 IMP2527: IOUT = 500mA each switch 0.20 0.30 Each output 0.5 Ω A Output Turn-On Delay TDON RL = 10Ω each output 0.25 ms Output Turn-On Rise Time TRON RL = 10Ω each output 1 ms Output Turn-Off Delay TDOFF RL = 10Ω each output 1 20 µs Output Turn-Off Fall Time TFOFF RL = 10Ω each output 1 20 µs Output Leakage Current IOFF 10 µA Short-circuit Current Limit ISC 0.75 1.25 A 0.50 Overtemperature Shutdown TJ increasing 135 Threshold TJ decreasing 125 Error Flag Output Resistance RFLAG VIN = 5V, IL = 10mA 10 VIN = 3.3V, IL = 10mA 15 Error Flag Output Current IFLAG VFLAG = 5V 0.01 UVLO Threshold VUVLO VIN Increasing 2.5 VIN Decreasing 2.3 °C Ω 1 µA V Notes 1. Switch OFF is VEN ≤ 0.8V and Switch ON is VEN ≥ 2.4V for the IMP2524/27-1. Switch OFF is VEN ≥ 2.4V and Switch ON is VEN ≤ 0.8V for the IMP2524/27-2. The Enable input has approximately 200mV of hysteresis. © 2000 IMP, Inc. USB High-Side Power Switches 3 IMP2524/27 Package Dimensions Plastic DIP (16-Pin) Inches Min D1 Min Max Plastic DIP (16-Pin)* N E1 E D A2 A A1 L e 0°–15° B1 C eA eB B Plastic DIP (16-Pin).eps SO (16-Pin) E H 0°– 8° A C e L B A1 A A1 A2 B B1 C D D1 E E1 e eA eB L ——— 0.015 0.125 0.016 0.045 0.008 0.745 0.005 0.300 0.240 0.100 0.300 ——— 0.115 0.200 ——— 0.175 0.022 0.065 0.012 0.765 0.080 0.325 0.310 ——— ——— 0.400 0.150 ——— 0.38 3.18 0.41 1.14 0.20 18.92 0.13 7.62 6.10 2.54 7.62 ——— 2.92 5.08 ——— 4.45 0.56 1.65 0.30 19.43 2.03 8.26 7.87 ——— ——— 10.16 3.81 SO (16-Pin)** D 4 Millimeters Max 16-Pin (SO).eps A 0.926 0.1043 A1 0.0040 0.0118 B 0.013 0.020 C 0.0091 0.0125 D 0.3977 0.4133 E 0.2914 0.2662 e 0.050 BSC H 0.394 0.419 L 0.016 0.050 * JEDEC Drawing MO-058AB ** JEDEC Drawing MS-013AA 408-432-9100/www.impweb.com 2.35 2.65 0.10 0.30 0.33 0.51 0.23 0.32 10.10 10.50 7.40 7.60 1.27 BSC 10.00 10.65 0.40 1.27 2524/26_t03.at3 © 2000 IMP, Inc. 6 IMP2525 POWER MANAGEMENT USB High-Side Power Switch – Single switch – 0.14Ω "ON" resistance at 3V – MIC2525 pin compatible The IMP2525 high-side power switch IC is designed for self-powered and bus-powered Universal Serial Bus (USB) power supply and power management applications. The IMP2525 conforms to USB standards with a low output switch ON-resistance (RON) and minimal voltage drop across the switch. The fault current is limited to 750mA typically, and a flag output conveys fault conditions to the local USB controller. The IMP2525 provides a “Soft-Start” function that ramps up the ONcurrent to eliminate any excessive voltage drop on the input side that could occur due to charging a capacitive load in bus-powered applications. Self-monitoring features include thermal shutdown to prevent catastrophic switch failure from high-current loads and undervoltage lockout (UVLO) that insures that the device remains off unless there is a valid supply voltage present. The Enable input logic can be interfaced with both 3.3V and 5V logic. Both active-HIGH and active-LOW enable logic versions are available. The IMP2525 devices are available in 8-pin DIP and 8-pin SO packages. IMP offers a complete family of USB power management products. For dual-switch applications see the IMP2526 data sheet and for quad-switch application, see the IMP2524. The single-switch IMP2525A features a 50% lower switch resistance, 0.07Ω. EN ◆ Meets or exceeds USB Rev. 1.1 and 2.0 specification ◆ Low MOSFET RON (0.14Ω at 3V) ◆ 2.7V to 5.5V input operation ◆ Current limiting ◆ Soft-start turn-on (1ms) prevents turn-on glitches ◆ 500mA continuous load current ◆ MOSFET short-circuit current limit (1.25A max) ◆ Low supply current – 110µA ON state current, 1µA OFF state current ◆ Active-LOW or Active-HIGH Enable input ◆ 3.3V or 5V logic compatibility ◆ Fault Flag indicates three fault conditions: – Undervoltage – Current limit – Thermal shutdown ◆ Open-drain Fault Flag output ◆ 2.4V Undervoltage Lockout (UVLO) ◆ Pin compatible with the Micrel MIC2525 Applications ◆ USB power management ◆ USB hosts and self-powered hubs ◆ Battery-charger circuits and power supplies Block Diagrams IN Key Features 7 1 8 1.2V Reference UVLO Power Switch Gate Control Thermal Shutdown Oscillator NC/OUT 6 Current Limit OUT 2 Charge Pump 3 FLG GND IMP2525 2525_01.eps © 2000 IMP, Inc. 408-432-9100/www.impweb.com 1 IMP2525 Pin Configuration SO/DIP 8 EN 1 FLG 2 GND NC 8 IMP2525 OUT 7 IN 3 6 NC/OUT 4 5 NC * EN FLG 1 2 Logic, Charge Pump OUT 6 7 IN 3 *Connect pins 6 and 8 for MIC2525 compatibility GND 2525_02.eps 2525_03.eps Pin Descriptions Pin Number Name 1 EN 2 FLG Fault flag output. This open-drain output goes into an active-LOW state in response to undervoltage, current limit or thermal shutdown conditions. 3 GND Ground. Power supply return for the internal circuitry of the IC. 4, 5 NC 6 NC/OUT 7 IN 8 OUT Function Enable input. This pin is the MOSFET switch driver logic input. Both active-HIGH (-1 suffix) and active-LOW (-2 suffix) logic devices are available. No connection. These pins have no internal connections to the device. No connection. This pin has no internal connection to the device. Connect pins 6 and 8 to maintain pin-compatibility with the MIC2525. Positive power supply voltage input. This is the switching MOSFET drain connection as well as the positive supply for the IC. MOSFET source. The output pin supplies power to the load. Ordering Information 2 Part Number Enable Logic Temperature Range Pins-Package IMP2525-1BM Active HIGH – 40°C to +85°C 8-SO IMP2525-2BM Active LOW – 40°C to +85°C 8-SO IMP2525-1BN Active HIGH – 40°C to +85°C 8-DIP IMP2525-2BN Active LOW – 40°C to +85°C 8-DIP 408-432-9100/www.impweb.com © 2000 IMP, Inc. 6 IMP2525 Absolute Maximum Ratings Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . +6.0V Fault Flag Voltage . . . . . . . . . . . . . . . . . . . . . . +6.0V Fault Flag Current . . . . . . . . . . . . . . . . . . . . . . 50mA Output Voltage . . . . . . . . . . . . . . . . . . . . . . . . . +6.0V Output Current . . . . . . . . . . . . . . . . . . . . . . . . . Internally Limited Enable Input . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3V to 12V Storage Temperature . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C Lead Temperature (Soldering, 5 sec.) . . . . . . . 260°C Package Thermal Resistance SO (θJA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120°C/W DIP(θJA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130°C/W Note: All voltages are referenced to GND. These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. Electrical Characteristics Unless otherwise noted, VIN = 5V and TA = 25°C. Parameter Supply Voltage Range Symbol Conditions VIN Min TA = – 40°C to +85°C Typ 2.7 Max Units 5.5 V 85 °C Supply Current Switch OFF IIN OFF Switch OFF, No load VENOFF ≤ 0.8V, VENON ≥ 2.4V IMP2525-1 VENON ≤ 0.8V, VENOFF ≥ 2.4V IMP2525-2 0.75 5 µA Supply Current Switch ON IIN ON Switch ON, No load VENOFF ≤ 0.8V, VENON ≥ 2.4V IMP2525-1 VENON ≤ 0.8V, VENOFF ≥ 2.4V IMP2525-2 110 160 µA Enable Input Threshold VENH LOW to HIGH (“0” to “1”) Enable Voltage, Note 1, 2 2.1 2.4 V VENL HIGH to LOW (“1” to “0”) Enable Voltage, Note 1, 2 0.8 1.9 VEN = 0V to 5.5V –1 ±0.01 1 µA Operating Temperature Range TA Enable Input Current IEN Enable Input Capacitance CEN Switch ON Resistance RON – 40 1 pF VIN = 5V, IOUT = 500mA 0.1 0.14 VIN = 3.3V, IOUT = 500mA 0.14 0.18 Ω Output Turn-On Delay TDON RL = 10Ω 0.25 ms Output Turn-On Rise Time TRON RL = 10Ω 1 ms Output Turn-Off Delay TDOFF RL = 10Ω, Note 2 1 20 µs Output Turn-Off Fall Time TFOFF RL = 10Ω, Note 2 1 20 µs Output Leakage Current IOFF 10 µA Short-circuit Current Limit ISC 0.75 1.25 A 0.50 Overtemperature Shutdown TJ increasing 135 Threshold TJ decreasing 125 Error Flag Output Resistance RFLAG °C VIN = 5V, IL = 10mA 10 25 VIN = 3.3V, IL = 10mA 15 40 1 Error Flag Output Current IFLAG VFLAG = 5V 0.01 UVLO Threshold VUVLO VIN Increasing 2.5 VIN Decreasing 2.3 Ω µA V Notes 1. Switch OFF is VEN ≤ 0.8V and Switch ON is VEN ≥ 2.4V for the IMP2525-1. Switch OFF is VEN ≥ 2.4V and Switch ON is VEN ≤ 0.8V for the IMP2525-2. The Enable input has approximately 200mV of hysteresis. 2. Over operating temperature range, –40°C ≤ TA ≤ 85°C. © 2000 IMP, Inc. USB High-Side Power Switches 3 IMP2525 Detailed Descriptions The IMP2525 is a high-side N-channel MOSFET switch that interfaces with a USB controller by means of a Switch-Enable input and a Fault-Flag output. The Enable input turns ON the power MOSFET with either a logic “1” for the IMP2525-1 or logic “0” for the IMP2525-2. Any one of three fault conditions will activate the open-drain Fault-Flag Output to alert the controller that the power MOSFET has been turned OFF. Input and Output The IN (input) pin is the power supply connection to the logic circuitry and the “High-Side” of the switch (the Drain of the power MOSFET). The OUT (output) pin is the “Low-Side” of the switch (the Source of the power MOSFET). In a typical circuit, current flows through the switch from IN to OUT toward the load. The switch is referred to as a “High-Side” switch since it drives the positive (or high) side of the load. The output MOSFET source can be forced to a higher voltage than the drain (VOUT > VIN) when the output is OFF with little leakage current. If, however, VIN drops below 2.3V, reverse current may flow out the IN pin regardless of the enable state. When the power switch is ON, current can flow in either direction. Fault Flag - FLG Pin The Fault Flag pin, FLG, connects to an N-channel, open-drain MOSFET and goes LOW (“0”) for an occurrence of one or more of three conditions: undervoltage, current limit, or thermal shutdown. The FLG output MOSFET is capable of sinking a 10mA load to typically 100mV above ground. Table 1 gives the states of the FLG and OUT pins when a fault condition is detected. Thermal Shutdown Thermal shutdown is active when the output switch is enabled (turned ON). Thermal shutdown shuts off the output MOSFET and sets the Fault Flag if the on-chip temperature sensor exceeds 135°C. The switch is held OFF until the die temperature drops to 125°C or below. This 10°C of hysteresis will result in ON-OFF short-circuit cycling if the short-circuit condition is not removed or the bus-controller does turn off the switch with the Enable input. Over temperature detection is active only if the chip is enabled. Undervoltage Lockout The Undervoltage lockout (UVLO) prevents the output MOSFET from being put into the ON state until the positive supply voltage, VIN, exceeds 2.5V. When the output switch is in the ON state and the positive supply voltage drops below 2.3V, the UVLO circuitry will assert the Fault Flag, FLG, and shut OFF the output MOSFET. The FLG output will only assert an active LOW state when the MOSFET switch is in the ON state. Undervoltage detection is active only if the chip is enabled. Current Limiting Current limiting is achieved by sensing the voltage drop from Drain-to-Source of the power MOSFET. When the internal threshold is exceeded the power MOSFET is turned OFF. Table 1. Fault Flag Conditions - Switch Enabled 4 Condition Cause FLG pin “0” Until Thermal Shutdown TJ > 135°C TJ ≤ 125°C Turns OFF Undervoltage Lockout (UVLO) VIN < 2.3V VIN > 2.5V Turns OFF Current Limiting IO > 0.5A (step load) IO > 0.63A (ramped load) Enable off or Thermal Shutdown Stays ON 408-432-9100/www.impweb.com Switch State (FLG = “0”) © 2000 IMP, Inc. 6 IMP2525 Application Information Supply Filtering Enable Input IMP strongly recommends the use of a 0.1µF to 1µF bypass capacitor to control transients on the power supply pin. This capacitor, connected from IN to GND, should be in close proximity to the IMP2525 for maximum transient suppression. The lack of suitable bypassing can result in ringing on the IN input when transients occur. This ringing, due to supply lead inductance, could damage IMP2525 control circuitry if the 8V maximum input rating is exceeded. As with any logic input, the enable pin, EN, must be driven to a definitive logic state at all times. Floating the input can result in spurious operation. Do not drive EN below GND. 4.0V to 5.5V IMP2525 7 IN 3 GND 0.1µF to 1µF Fault Flag Output Soft Start The IMP2525 provides a “Soft-Start” function that ramps up the ON-current to eliminate any excessive voltage drop that could occur due to charging a capacitive load in bus-powered applications. The "Soft-Start" results from a switch ON resistance, RON, that is ramped down from a high impedance to 0.14Ω in milliseconds. This RON ramping reduces the inrush current and related transients occur when charging capacitive loads; a requirement for meeting the USB voltage drop standards for bus-powered applications (see Figure 2). In circuits with large load capacitances, CBULK, exceeding 10µF, the soft-start circuit shown in Figure 3 can be used to limit the inrush start-up current to USB transient specifications. The current limiting feature of the IMP2525 provides this high-load, soft-start operation. 2525_04.eps Figure 1. Supply Bypassing USB Controller IMP2525-xBM 1 VBUS 2 3 USB Host 4.7µF EN OUT FLG IN GND OUT 4 NC 8 7 6 NC 5 Capacitive Load 0.1µF CBULK GND Cable Bus Powered Hub Cable Downstream USB Device 2525_06.eps Figure 2. Soft-Start Application © 2000 IMP, Inc. USB High-Side Power Switches 5 IMP2525 Application Information USB Controller IMP2525-2 1 VBUS 2 FLG 3 USB Hub 8 OUT EN 7 IN GND USB Function 6 OUT NC 5 4 NC 4.7µF CBULK GND Cable USB Peripheral 2525_07.eps Figure 3. Inrush Current-Limit Application Transient Overcurrent Filter V+ If a heavy capacitive load is suddenly connected to the output, the switch current-limiting function may cause the fault-flag to go low for 10µs to 200µs as the switch, in a constant current mode, charges the capacitance. If this transient over-current fault reporting is not wanted, a simple 1ms RC low-pass filter in series with the fault flag circuit will prevent this momentary flag (Figure 4). 10k USB Controller 10k IMP2525 2 OVERCURRENT FLG 0.1µF 2525_05.eps Figure 4. Transient Filter VCC 5.0V 10k Upstream VBUS 100mA max VBUS IN OUT VIN ON/OFF OVERCURRENT D+ LDO 3.3V USB Controller GND GND 100k 1 2 EN Ferrite Beads OUT 8 7 FLG IN IMP2525-2 6 OUT D– GND 1µF VBUS D+ 150µF D– + USB Port GND 3 1µF GND 0.1µF 2525_08.eps Data Data Figure 5. Single-Port Self-Powered Hub Application 6 408-432-9100/www.impweb.com © 2000 IMP, Inc. 6 IMP2525 Package Dimensions Plastic DIP (8-Pin) Inches D1 Millimeters Max Min Max Plastic DIP (8-Pin)* Min E D E1 A A2 L A1 0°–15° e C b2 eA eB b Plastic DIP (8-Pin)a.eps SO (8-Pin) 0°– 8° L A ––––– 0.210 –––– 5.33 A1 0.015 A2 0.115 ––––– 0.38 ––––– 0.195 2.92 4.95 b b2 0.014 0.022 0.36 0.56 0.045 0.070 1.14 1.78 b3 0.030 0.045 0.80 1.14 D 0.355 0.400 9.02 10.16 D1 0.005 ––––– 0.13 ––––– E 0.300 0.325 7.62 8.26 6.10 E1 0.240 0.280 e 0.100 ––––– eA 0.300 ––––– eB ––––– 0.430 eC ––––– 0.060 L 0.115 0.150 A 0.053 0.069 7.11 2.54 7.62 ––––– 10.92 2.92 3.81 SO (8-Pin)** E H C D A e B A1 SO (8-Pin).eps 1.35 1.75 A1 0.004 0.010 0.10 0.25 B 0.013 0.020 0.33 0.51 C 0.007 0.010 0.19 0.25 e 0.050 1.27 E 0.150 0.157 3.80 4.00 H 0.228 0.244 5.80 6.20 L 0.016 0.050 0.40 1.27 D 0.189 0.197 4.80 5.00 * JEDEC Drawing MS-001BA ** JEDEC Drawing MS-012AA © 2000 IMP, Inc. USB High-Side Power Switches 7 Notes Project 8 408-432-9100/www.impweb.com © 2000 IMP, Inc. 6 IMP2525A POWER MANAGEMENT Low-Resistance USB High-Side Power Switch - Single switch - 0.07Ω "ON" resistance at 3V - 50% lower resistance than MIC2525 - MIC2525 pin compatible The IMP2525A high-side power switch IC is designed for self-powered and bus-powered Universal Serial Bus (USB) power supply and power management applications. The IMP2525A conforms to USB standards with a low output switch ON-resistance (RON) and minimal voltage drop across the switch. Switch resistance is 50% lower than the MIC2525. The fault current is limited to 1.5A typically, and a flag output conveys fault conditions to the local USB controller. The IMP2525A provides a “Soft-Start” function that ramps up the ON-current to eliminate any excessive voltage drop on the input side that could occur due to charging a capacitive load in bus-powered applications. Self-monitoring features include thermal shutdown to prevent catastrophic switch failure from high-current loads and undervoltage lockout (UVLO) that insures that the device remains off unless there is a valid supply voltage present. The Enable input logic can be interfaced with both 3.3V and 5V logic. Both active-HIGH and active-LOW enable logic versions are available. The IMP2525A devices are available in 8-pin DIP and 8-pin SO packages. IMP offers a complete family of USB power management products. For dual-switch applications see the IMP2526 data sheet and for quad-switch application, see the IMP2524. The single-switch IMP2525 matches the performance of the Micrel MIC2525. Block Diagrams IN EN Key Features ◆ Meets or exceeds USB Rev. 1.1 and 2.0 specification ◆ Low MOSFET RON (0.07Ω at 3V) ◆ Pin compatible with the Micrel MIC2525 – 50% lower than MIC2525 ◆ 2.7V to 5.5V input operation ◆ Current limiting ◆ Soft-start turn-on (1ms) prevents turn-on glitches ◆ 500mA continuous load current ◆ MOSFET short-circuit current limit (2.5A max) ◆ Low supply current – 110µA ON state current, 1µA OFF state current ◆ Active-LOW or Active-HIGH Enable input ◆ 3.3V or 5V logic compatibility ◆ Open-drain Fault Flag indicates three fault conditions: – Undervoltage – Current limit – Thermal shutdown ◆ 2.4V Undervoltage Lockout (UVLO) Applications ◆ USB power management ◆ USB hosts and self-powered hubs ◆ Battery-charger circuits and power supplies 7 1 8 1.2V Reference Current Limit 50% Lower Resistance Than MIC2525 UVLO OUT 6 Power Switch Gate Control 2 Thermal Shutdown Oscillator OUT Charge Pump 3 FLG GND IMP2525A 2525A_01.eps © 2000 IMP, Inc. 408-432-9100/www.impweb.com 1 IMP2525A Pin Configuration SO/DIP 8 EN 1 FLG 2 IMP2525A 8 OUT 7 IN GND 3 6 OUT NC 4 5 NC EN FLG 1 2 Logic, Charge Pump OUT 6 7 IN 3 2525A_02.eps GND 2525A_03.eps Pin Descriptions Pin Number Name 1 EN 2 FLG Fault flag output. This open-drain output goes into an active-LOW state in response to undervoltage, current limit or thermal shutdown conditions. 3 GND Ground. Power supply return for the internal circuitry of the IC. 4, 5 NC 6 OUT 7 IN 8 OUT Function Enable input. This pin is the MOSFET switch driver logic input. Both active-HIGH (-1 suffix) and active-LOW (-2 suffix) logic devices are available. No connection. These pins have no internal connections to the device. MOSFET source. The output pin supplies power to the load. Positive power supply voltage input. This is the switching MOSFET drain connection as well as the positive supply for the IC. MOSFET source. The output pin supplies power to the load. Ordering Information 2 Part Number Enable Logic Temperature Range Pins-Package IMP2525A-1BM Active HIGH – 40°C to +85°C 8-SO IMP2525A-2BM Active LOW – 40°C to +85°C 8-SO IMP2525A-1BN Active HIGH – 40°C to +85°C 8-DIP IMP2525A-2BN Active LOW – 40°C to +85°C 8-DIP 408-432-9100/www.impweb.com © 2000 IMP, Inc. 6 IMP2525A Absolute Maximum Ratings Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . +6.0V Fault Flag Voltage . . . . . . . . . . . . . . . . . . . . . . +6.0V Fault Flag Current . . . . . . . . . . . . . . . . . . . . . . 50mA Output Voltage . . . . . . . . . . . . . . . . . . . . . . . . . +6.0V Output Current . . . . . . . . . . . . . . . . . . . . . . . . . Internally Limited Enable Input . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3V to 12V Storage Temperature . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C Lead Temperature (Soldering, 5 sec.) . . . . . . . 260°C Package Thermal Resistance SO (θJA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120°C/W DIP(θJA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130°C/W Note: All voltages are referenced to GND. These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. Electrical Characteristics Unless otherwise noted, VIN = 5V and TA = 25°C. Parameter Supply Voltage Range Symbol Conditions VIN Min TA = – 40°C to +85°C Typ 2.7 Max Units 5.5 V 85 °C Supply Current Switch OFF IIN OFF Switch OFF, No load VENOFF ≤ 0.8V, VENON ≥ 2.4V IMP2525A-1 VENON ≤ 0.8V, VENOFF ≥ 2.4V IMP2525A-2 0.75 5 µA Supply Current Switch ON IIN ON Switch ON, No load VENOFF ≤ 0.8V, VENON ≥ 2.4V IMP2525A-1 VENON ≤ 0.8V, VENOFF ≥ 2.4V IMP2525A-2 110 160 µA Enable Input Threshold VENH LOW to HIGH (“0” to “1”) Enable Voltage, Note 1, 2 2.1 2.4 V VENL HIGH to LOW (“1” to “0”) Enable Voltage, Note 1, 2 0.8 1.9 VEN = 0V to 5.5V –1 ±0.01 1 µA Operating Temperature Range TA Enable Input Current IEN Enable Input Capacitance CEN Switch ON Resistance RON – 40 1 pF VIN = 5V, IOUT = 500mA 0.05 0.07 VIN = 3.3V, IOUT = 500mA 0.07 0.09 Ω Output Turn-On Delay TDON RL = 10Ω 0.25 ms Output Turn-On Rise Time TRON RL = 10Ω 1 ms Output Turn-Off Delay TDOFF RL = 10Ω, Note 2 1 20 µs Output Turn-Off Fall Time TFOFF RL = 10Ω, Note 2 1 20 µs Output Leakage Current IOFF 10 µA Short-circuit Current Limit ISC 1.5 2.5 A 1.0 Overtemperature Shutdown TJ increasing 135 Threshold TJ decreasing 125 Error Flag Output Resistance RFLAG °C VIN = 5V, IL = 10mA 10 25 VIN = 3.3V, IL = 10mA 15 40 1 Error Flag Output Current IFLAG VFLAG = 5V 0.01 UVLO Threshold VUVLO VIN Increasing 2.5 VIN Decreasing 2.3 Ω µA V Notes 1. Switch OFF is VEN ≤ 0.8V and Switch ON is VEN ≥ 2.4V for the IMP2525A-1. Switch OFF is VEN ≥ 2.4V and Switch ON is VEN ≤ 0.8V for the IMP2525A-2. The Enable input has approximately 200mV of hysteresis. 2. Over operating temperature range, –40°C ≤ TA ≤ 85°C. © 2000 IMP, Inc. USB High-Side Power Switches 3 IMP2525A Detailed Descriptions The IMP2525A is a high-side N-channel MOSFET switch that interfaces with a USB controller by means of a Switch-Enable input and a Fault-Flag output. The Enable input turns ON the power MOSFET with either a logic “1” for the IMP2525-1 or logic “0” for the IMP2525-2. Any one of three fault conditions will activate the open-drain Fault-Flag Output to alert the controller that the power MOSFET has been turned OFF. Input and Output The IN (input) pin is the power supply connection to the logic circuitry and the “High-Side” of the switch (the Drain of the power MOSFET). The OUT (output) pin is the “Low-Side” of the switch (the Source of the power MOSFET). In a typical circuit, current flows through the switch from IN to OUT toward the load. The switch is referred to as a “High-Side” switch since it drives the positive (or high) side of the load. The output MOSFET source can be forced to a higher voltage than the drain (VOUT > VIN) when the output is OFF with little leakage current. If, however, VIN drops below 2.3V, reverse current may flow out the IN pin regardless of the enable state. When the power switch is ON, current can flow in either direction. Fault Flag - FLG Pin The Fault Flag pin, FLG, connects to an N-channel, open-drain MOSFET and goes LOW (“0”) for an occurrence of one or more of three conditions: undervoltage, current limit, or thermal shutdown. The FLG output MOSFET is capable of sinking a 10mA load to typically 100mV above ground. Table 1 gives the states of the FLG and OUT pins when a fault condition is detected. Thermal Shutdown Thermal shutdown is active when the output switch is enabled (turned ON). Thermal shutdown shuts off the output MOSFET and sets the Fault Flag if the on-chip temperature sensor exceeds 135°C. The switch is held OFF until the die temperature drops to 125°C or below. This 10°C of hysteresis will result in ON-OFF short-circuit cycling if the short-circuit condition is not removed or the bus-controller does turn off the switch with the Enable input. Over temperature detection is active only if the chip is enabled. Undervoltage Lockout The Undervoltage lockout (UVLO) prevents the output MOSFET from being put into the ON state until the positive supply voltage, VIN, exceeds 2.5V. When the output switch is in the ON state and the positive supply voltage drops below 2.3V, the UVLO circuitry will assert the Fault Flag, FLG, and shut OFF the output MOSFET. The FLG output will only assert an active LOW state when the MOSFET switch is in the ON state. Undervoltage detection is active only if the chip is enabled. Current Limiting Current limiting is achieved by sensing the voltage drop from Drain-to-Source of the power MOSFET. When the internal threshold is exceeded the power MOSFET is turned OFF. Table 1. Fault Flag Conditions - Switch Enabled 4 Condition Cause FLG pin “0” Until Thermal Shutdown TJ > 135°C TJ ≤ 125°C Turns OFF Undervoltage Lockout (UVLO) VIN < 2.3V VIN > 2.5V Turns OFF Current Limiting IO > 1.0A (step load) IO > 1.25A (ramped load) Enable off or Thermal Shutdown Stays ON 408-432-9100/www.impweb.com Switch State (FLG = “0”) © 2000 IMP, Inc. 6 IMP2525A Application Information Supply Filtering Enable Input IMP strongly recommends the use of a 0.1µF to 1µF bypass capacitor to control transients on the power supply pin. This capacitor, connected from IN to GND, should be in close proximity to the IMP2525A for maximum transient suppression. The lack of suitable bypassing can result in ringing on the IN input when transients occur. This ringing, due to supply lead inductance, could damage IMP2525A control circuitry if the 8V maximum input rating is exceeded. As with any logic input, the enable pin, EN, must be driven to a definitive logic state at all times. Floating the input can result in spurious operation. Do not drive EN below GND. 4.0V to 5.5V IMP2525A 7 IN 3 GND 0.1µF to 1µF Fault Flag Output Soft Start The IMP2525A provides a “Soft-Start” function that ramps up the ON-current to eliminate any excessive voltage drop that could occur due to charging a capacitive load in bus-powered applications. The "Soft-Start" results from a switch ON resistance, RON, that is ramped down from a high impedance to 0.07Ω in milliseconds. This RON ramping reduces the inrush current and related transients occur when charging capacitive loads; a requirement for meeting the USB voltage drop standards for bus-powered applications (see Figure 2). In circuits with large load capacitances, CBULK, exceeding 10µF, the soft-start circuit shown in Figure 3 can be used to limit the inrush start-up current to USB transient specifications. The current limiting feature of the IMP2525A provides this high-load, soft-start operation. 2525A_04.eps Figure 1. Supply Bypassing USB Controller IMP2525A-xBM 1 VBUS 2 3 USB Host 4.7µF EN OUT FLG IN GND OUT 4 NC 8 7 6 NC 5 Capacitive Load 0.1µF CBULK GND Cable Bus Powered Hub Cable Downstream USB Device 2525A_06.eps Figure 2. Soft-Start Application © 2000 IMP, Inc. USB High-Side Power Switches 5 IMP2525A Application Information USB Controller IMP2525A-2 1 VBUS EN 2 FLG 3 USB Hub GND 4 NC 8 OUT 7 IN USB Function 6 OUT NC 5 4.7µF CBULK GND Cable USB Peripheral 2525A_07.eps Figure 3. Inrush Current-Limit Application Transient Overcurrent Filter V+ If a heavy capacitive load is suddenly connected to the output, the switch current-limiting function may cause the fault-flag to go low for 10µs to 200µs as the switch, in a constant current mode, charges the capacitance. If this transient over-current fault reporting is not wanted, a simple 1ms RC low-pass filter in series with the fault flag circuit will prevent this momentary flag (Figure 4). 10k USB Controller 10k IMP2525A 2 OVERCURRENT FLG 0.1µF 2525A_05.eps Figure 4. Transient Filter VCC 5.0V 10k Upstream VBUS 100mA max VBUS IN OUT VIN ON/OFF OVERCURRENT D+ LDO 3.3V USB Controller 100k 1 2 EN Ferrite Beads OUT 8 7 FLG IN IMP2525A-2 6 OUT D– GND GND GND 1µF VBUS D+ 150µF D– + USB Port GND 3 1µF GND 0.1µF 2525A_08.eps Data Data Figure 5. Single-Port Self-Powered Hub Application 6 408-432-9100/www.impweb.com © 2000 IMP, Inc. 6 IMP2525A Package Dimensions Plastic DIP (8-Pin) Inches D1 Millimeters Max Min Max Plastic DIP (8-Pin)* Min E D E1 A A2 L A1 0°–15° e C b2 eA eB b Plastic DIP (8-Pin)a.eps SO (8-Pin) 0°– 8° L A ––––– 0.210 –––– 5.33 A1 0.015 A2 0.115 ––––– 0.38 ––––– 0.195 2.92 4.95 b b2 0.014 0.022 0.36 0.56 0.045 0.070 1.14 1.78 b3 0.030 0.045 0.80 1.14 D 0.355 0.400 9.02 10.16 D1 0.005 ––––– 0.13 ––––– E 0.300 0.325 7.62 8.26 6.10 E1 0.240 0.280 e 0.100 ––––– eA 0.300 ––––– eB ––––– 0.430 eC ––––– 0.060 L 0.115 0.150 A 0.053 0.069 7.11 2.54 7.62 ––––– 10.92 2.92 3.81 SO (8-Pin)** E H C D A e B A1 SO (8-Pin).eps 1.35 1.75 A1 0.004 0.010 0.10 0.25 B 0.013 0.020 0.33 0.51 C 0.007 0.010 0.19 0.25 e 0.050 1.27 E 0.150 0.157 3.80 4.00 H 0.228 0.244 5.80 6.20 L 0.016 0.050 0.40 1.27 D 0.189 0.197 4.80 5.00 * JEDEC Drawing MS-001BA ** JEDEC Drawing MS-012AA © 2000 IMP, Inc. USB High-Side Power Switches 7 Notes Project 8 408-432-9100/www.impweb.com © 2000 IMP, Inc. 6 IMP2526 POWER MANAGEMENT Dual USB High-Side Power Switch Key Features – Dual switch – 0.14Ω /0.1Ω “ON” resistance at 3/5V – MIC2526 pin compatible The IMP2526 dual high-side power switch IC is designed for selfpowered and bus-powered Universal Serial Bus (USB) power supply and general purpose power management applications. ON resistance is a low 100mΩ at 5V input and 140mΩ at 3V input. The IMP2526 conforms to the new USB Revision 1.1 standard. Fault current is limited to 750mA typically, and a flag output for each switch conveys fault information to the local USB controller. The IMP2526 “SoftStart” function ramps the ON-current to eliminate any excessive voltage drop on the input side that could occur when capacitive loads are charged. Self-monitoring features include thermal shutdown to prevent catastrophic switch failure from high-current loads and undervoltage lockout (UVLO) that insures that the device remains OFF unless there is a sufficient supply voltage present. The switch Enable input logic can interface with both 3.3V and 5V logic. Both active-HIGH (-1 devices) and active-LOW (-2 devices) enable logic versions are available. Supply current is a low 0.75µA when disabled and just 110µA when enabled. The IMP2526 devices are available in 8-pin DIP and 8-pin SO packages and are pin compatible replacements for the Micrel MIC2526-1/-2. IMP Block Diagrams ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ USB Rev. 1.1 and 2.0 compliant 2.7V to 5.5V input operation Low MOSFET ON resistance (0.1Ω at 5V) Low supply current – 110µA ON state current, 1µA OFF state current 500mA continuous load current per switch 1.25A maximum current limit, 750mA typical Thermal shutdown 2.4V undervoltage lockout (UVLO) Open-drain flag output – Undervoltage – Current limit – Thermal shutdown Active HIGH(-1) and active LOW(-2) enable Pin compatible with the Micrel MIC2526 offers a complete family of USB power management products. For single-switch applications see the IMP2525 and IMP2525A data sheets. The single-switch IMP2525A features a 50% lower switch resistance, 0.07Ω. For quadswitch applications, refer to the IMP2524 data sheet. Applications ◆ ◆ ◆ ◆ USB host and self-powered hubs Bus-powered hubs Hot plug-in power supplies Battery chargers 2 IMP2526 ENA 8 1 Charge Pump Oscillator Gate Control Thermal Shutdown Gate Control Charge Pump ENB 7 5 3 © 2000 IMP, Inc. IN Current Limit 4 6 OUTA Current Limit 1.2V Reference UVLO FLGA OUTB FLGB 2526_01.eps GND 408-432-9100/www.impweb.com 1 IMP2526 Pin Configuration SO/DIP IMP2526 ENA ENA 1 FLGA 2 FLGB 3 ENB IMP2526 4 8 OUTA 7 IN 6 GND 5 FLGA FLGB OUTB ENB 2526_02.eps 8 1 2 Logic, Charge Pump 7 3 4 Logic, Charge Pump 5 OUTA IN OUTB 6 GND 2526_03.eps Pin Descriptions Pin Number Name Function 1, 4 ENA, ENB 2, 3 FLGA, FLGB 6 GND 7 IN 8, 5 OUTA, OUTB Enable input. This pin is the MOSFET switch driver logic input. Both active-HIGH (-1 suffix) and active-LOW (-2 suffix) logic devices are available. Fault flag output. This open-drain output goes into an active-LOW state in response to undervoltage, current limit or thermal shutdown conditions. Ground. Power supply return for the internal circuitry of the IC. Positive power supply voltage input. This is the switching MOSFET drain connection as well as the positive supply for the IC. MOSFET source. The output pin supplies power to the load. Ordering Information 2 Part Number Enable Logic Temperature Range Pins-Package IMP2526-1BM Active HIGH – 40°C to +85°C 8-SO IMP2526-2BM Active LOW – 40°C to +85°C 8-SO IMP2526-1BN Active HIGH – 40°C to +85°C 8-DIP IMP2526-2BN Active LOW – 40°C to +85°C 8-DIP 408-432-9100/www.impweb.com © 2000 IMP, Inc. 6 IMP2526 Absolute Maximum Ratings Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . +6.0V Fault Flag Voltage . . . . . . . . . . . . . . . . . . . . . . +6.0V Fault Flag Current . . . . . . . . . . . . . . . . . . . . . . 50mA Output Voltage . . . . . . . . . . . . . . . . . . . . . . . . . +6.0V Output Current . . . . . . . . . . . . . . . . . . . . . . . . . Internally Limited Enable Input . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3V to 12V Storage Temperature . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C Lead Temperature (Soldering, 5 sec.) . . . . . . . 260°C Package Thermal Resistance SO (θJA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120°C/W DIP(θJA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130°C/W Note: All voltages are referenced to GND. These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. Electrical Characteristics Unless otherwise noted, VIN = 5V and TA = 25°C. Parameter Supply Voltage Range Symbol Conditions VIN Min TA = – 40°C to +85°C Typ 2.7 Max Units 5.5 V 85 °C Supply Current Switch OFF IIN OFF Switch OFF, No load VENOFF ≤ 0.8V, VENON ≥ 2.4V IMP2526-1 VENON ≤ 0.8V, VENOFF ≥ 2.4V IMP2526-2 0.75 5 µA Supply Current Switch ON IIN ON Switch ON, No load VENOFF ≤ 0.8V, VENON ≥ 2.4V IMP2526-1 VENON ≤ 0.8V, VENOFF ≥ 2.4V IMP2526-2 110 160 µA Enable Input Threshold VENH LOW to HIGH (“0” to “1”) Enable Voltage, Note 1 2.1 2.4 V VENL HIGH to LOW (“1” to “0”) Enable Voltage, Note 1 0.8 1.9 VEN = 0V to 5.5V –1 ±0.01 1 µA Operating Temperature Range TA Enable Input Current IEN Enable Input Capacitance CEN Switch ON Resistance RON – 40 1 pF VIN = 5V, IOUT = 500mA 0.10 0.14 VIN = 3.3V, IOUT = 500mA 0.14 0.18 Ω Output Turn-On Delay TDON RL = 10Ω each output 0.25 ms Output Turn-On Rise Time TRON RL = 10Ω each output 1 ms Output Turn-Off Delay TDOFF RL = 10Ω each output 1 20 µs Output Turn-Off Fall Time TFOFF RL = 10Ω each output 1 20 µs Output Leakage Current IOFF 10 µA Short-circuit Current Limit ISC Overtemperature Shutdown Threshold 0.50 0.75 1.25 135 TJ decreasing 125 VIN = 5V, IL = 10mA 10 25 15 40 0.01 1 Error Flag Output Resistance RFLAG Error Flag Output Current IFLAG VFLAG = 5V UVLO Threshold VUVLO VIN Increasing 2.5 VIN Decreasing 2.3 VIN = 3.3V, IL = 10mA A °C TJ increasing Ω µA V Notes 1. Switch OFF is VEN ≤ 0.8V and Switch ON is VEN ≥ 2.4V for the IMP2526-1. Switch OFF is VEN ≥ 2.4V and Switch ON is VEN ≤ 0.8V for the IMP2526-2. The Enable input has approximately 200mV of hysteresis. © 2000 IMP, Inc. USB High-Side Power Switches 3 IMP2526 Detailed Descriptions The IMP2526 dual high-side N-channel MOSFET switch interfaces with a USB controller by means of a Switch-Enable input and a Fault-Flag output. The Enable input, with either a logic “1” for the IMP2526-1 or logic “0” for the IMP2526-2, turns the power MOSFET ON. Any one of three fault conditions will activate the open-drain Fault-Flag Output to alert the controller that the power MOSFET has been turned OFF. Input and Output The IN (input) pin is the power supply connection to the logic circuitry and the “High-Side” of the switch (the Drain of the power MOSFET). The OUTA/B (output) pin is the “Low-Side” of the switch (the Source of the power MOSFET). In a typical circuit, current flows through the switch from IN to OUT toward the load. The switch is referred to as a “High-Side” switch since it drives the positive (or high) side of the load. The output MOSFET source can be forced to a higher voltage than the drain (VOUT > VIN) when the output is OFF with little leakage current. If, however, VIN drops below 2.3V, reverse current may flow out the IN pin regardless of the enable state. When the power switch is ON, current can flow in either direction. Thermal Shutdown Thermal shutdown is active when the output switch is enabled (turned ON). Thermal shutdown shuts off the output MOSFET and sets the Fault Flag if the on-chip temperature sensor exceeds 135°C. The switch is held OFF until the die temperature drops to 125°C or below. This 10°C of hysteresis will result in ON-OFF short-circuit cycling if the short-circuit condition is not removed or the bus-controller does turn off the switch with the Enable input. Over temperature detection is active only if the chip is enabled. Undervoltage Lockout The Undervoltage lockout (UVLO) prevents the output MOSFET from being put into the ON state until the positive supply voltage, VIN, exceeds 2.5V. When the output switch is in the ON state and the positive supply voltage drops below 2.3V, the UVLO circuitry will assert the Fault Flag, FLG, and shut OFF the output MOSFET. The FLG output will only assert an active LOW state when the MOSFET switch is in the ON state. Undervoltage detection is active only if the chip is enabled. Current Limiting Fault Flag - FLG Pin The Fault Flag pin, FLGA/B, connects to an N-channel, opendrain MOSFET and goes LOW (“0”) for an occurrence of one or more of three conditions: undervoltage, current limit, or thermal shutdown. The FLG output MOSFET is capable of sinking a 10mA load to typically 100mV above ground. Both flags may be wire-NORed to a common pull-up resistor. Current limiting is achieved by sensing the voltage drop from Drain-to-Source of the power MOSFET. When the internal threshold is exceeded the power MOSFET is turned OFF. Table 1 gives the states of the FLG and OUT pins when a fault condition is detected. Table 1. Fault Flag Conditions - Switch Enabled Condition Cause FLG pin “0” Until Switch State (FLG = “0”) Thermal Shutdown TJ > 135°C TJ ≤ 125°C Turns OFF Undervoltage Lockout (UVLO) VIN < 2.3V VIN > 2.5V Turns OFF Current Limiting IO > 0.5A (step load) IO > 0.63A (ramped load) Enable off or Thermal Shutdown Stays ON* * The switch and Fault Flag behavior during current-limiting is more complex than shown by this table. The detailed discussion on each of these fault conditions gives additional information. 4 408-432-9100/www.impweb.com © 2000 IMP, Inc. 6 IMP2526 Application Information Supply Filtering Enable Input IMP strongly recommends the use of a 0.1µF to 1µF bypass capacitor to control transients on the power supply pin. This capacitor, connected from IN to GND, should be in close proximity to the IMP2526 for maximum transient suppression. The lack of suitable bypassing can result in ringing on the IN input when transients occur. This ringing, due to supply lead inductance, could damage IMP2526 control circuitry if the 8V maximum input rating is exceeded. As with any logic input, the enable pins, ENA/ENB, must be driven to a definitive logic state at all times. Floating the input can result in spurious operation. Do not drive ENA/ENB below GND. 2.7V to 5.5V IMP2526 7 IN 6 GND 0.1µF to 1µF Fault Flag Output Soft Start The IMP2526 provides a “Soft-Start” function that ramps up the ON-current to eliminate any excessive voltage drop that could occur due to charging a capacitive load in bus-powered applications. The "Soft-Start" results from a switch ON resistance, RON, that is ramped down from a high impedance to 0.14Ω in milliseconds. This RON ramping reduces the inrush current and related transients occur when charging capacitive loads; a requirement for meeting the USB voltage drop standards for bus-powered applications (see Figure 2). In circuits with large load capacitances, CBULK, exceeding 10µF, the soft-start circuit shown in Figure 3 can be used to limit the inrush start-up current to USB transient specifications. The current limiting feature of the IMP2526 provides this high-load, soft-start operation. 2526_04.eps Figure 1. Supply Bypassing USB Controller IMP2526-xBM 1 VBUS 2 3 USB Host 4.7µF ENA OUTA FLGA IN FLGB GND 4 ENB 8 7 6 OUTB 5 0.1µF Capacitive Load CBULK GND Cable Bus Powered Hub Cable Downstream USB Device 2526_06.eps Figure 2. Soft-Start Application © 2000 IMP, Inc. USB High-Side Power Switches 5 IMP2526 Application Information USB Controller IMP2526-2 1 VBUS ENA 2 FLGA 3 FLGB USB Hub 4 ENB OUTA IN GND OUTB 8 USB Function 7 CBULK 6 5 USB Function 4.7µF CBULK GND Cable USB Peripheral 2526_07.eps Figure 3. Inrush Current-Limit Application Transient Overcurrent Filter V+ If a heavy capacitive load is suddenly connected to the output, the switch current-limiting function may cause the fault-flag to go low for 10µs to 200µs as the switch, in a constant current mode, charges the capacitance. If this transient over-current fault reporting is not wanted, a simple 1ms RC low-pass filter in series with the fault flag circuit will prevent this momentary flag (Figure 4). 10k USB Controller 10k 2 OVERCURRENT IMP2526 FLG 0.1µF 2526_05.eps Figure 4. Transient Filter Upstream VBUS 100mA max 10k 100k 10k 100k VCC 5.0V Ferrite Beads 3.3V USB Controller VBUS IN OUT D+ VIN ON/OFF OVERCURRENT D– LDO OVERCURRENT GND GND ON/OFF 1µF 8 ENA OUTA IMP2526-2 7 2 FLGA IN 3 FLGB GND 6 4 5 ENB OUTB VBUS 1 + 47µF 0.1µF D+ USB Port 1 D– GND 1µF VBUS Data D+ 47µF + USB Port 2 D– GND Data (Two Pair) 2526_08.eps Figure 5. Single-Port Self-Powered Hub Application 6 408-432-9100/www.impweb.com © 2000 IMP, Inc. 6 IMP2526 Package Dimensions Plastic DIP (8-Pin) Inches D1 Millimeters Max Min Max Plastic DIP (8-Pin)* Min E D E1 A A2 L A1 0°–15° e C b2 eA eB b Plastic DIP (8-Pin)a.eps SO (8-Pin) 0°– 8° L A ––––– 0.210 –––– 5.33 A1 0.015 ––––– 0.38 ––––– A2 0.115 0.195 2.92 4.95 b 0.014 0.022 0.36 0.56 b2 0.045 0.070 1.14 1.78 b3 0.030 0.045 0.80 1.14 D 0.355 0.400 9.02 10.16 D1 0.005 ––––– 0.13 ––––– E 0.300 0.325 7.62 8.26 E1 0.240 0.280 6.10 e 0.100 ––––– eA 0.300 ––––– eB ––––– 0.430 eC ––––– 0.060 L 0.115 0.150 7.11 2.54 7.62 ––––– 10.92 2.92 3.81 SO (8-Pin)** E H C D A e B A1 SO (8-Pin).eps A 0.053 0.069 1.35 A1 0.004 0.010 0.10 0.25 B 0.013 0.020 0.33 0.51 C 0.007 0.010 0.19 e 0.050 1.75 0.25 1.27 E 0.150 0.157 3.80 4.00 H 0.228 0.244 5.80 6.20 L 0.016 0.050 0.40 1.27 D 0.189 0.197 4.80 5.00 * JEDEC Drawing MS-001BA ** JEDEC Drawing MS-012AA © 2000 IMP, Inc. USB High-Side Power Switches 7 Notes Project 8 408-432-9100/www.impweb.com © 2000 IMP, Inc. 6 IMP, Inc. Corporate Headquarters 2830 N. First Street San Jose, CA 95134-2071 Tel: 408-432-9100 Fax: 408-434-0335 e-mail: [email protected] http://www.impweb.com The IMP logo is a registered trademark of IMP, Inc. All other company and product names are trademarks of their respective owners. 2000 © IMP, Inc. Printed in USA Publication #: 5001 Revision: C Issue Date: 07/13/00 Type: Preliminary