IMP2525
P
OWER
M
ANAGEMENT
Key Features
USB High-Side Power Switch
– Single switch
ꢀ
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
– 0.14Ω "ON" resistance at 3V
– MIC2525 pin compatible
ꢀ Current limiting
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 ON-
current to eliminate any excessive voltage drop on the input side that
could occur due to charging a capacitive load in bus-powered applica-
tions. 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.
ꢀ 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
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.
Applications
ꢀ USB power management
ꢀ USB hosts and self-powered hubs
ꢀ Battery-charger circuits and power supplies
Block Diagrams
7
8
IN
OUT
1
1.2V
Reference
NC/OUT
6
EN
Current
Limit
Power
Switch
Gate
UVLO
Control
Thermal
Shutdown
2
FLG
Charge
3
Oscillator
Pump
GND
IMP2525
2525_01.eps
© 2000 IMP, Inc.
408-432-9100/www.impweb.com
1
A1PROS [ A1 PROS CO., LTD. ]
