IMP2525A
P
OWER
M
ANAGEMENT
Low-Resistance
USB High-Side Power Switch
Key Features
N
Meets or exceeds USB Rev. 1.1 and 2.0
specification
N
Low MOSFET R
ON
(0.07Ω at 3V)
N
Pin compatible with the Micrel MIC2525
– 50% lower than MIC2525
N
2.7V to 5.5V input operation
N
Current limiting
N
Soft-start turn-on (1ms) prevents turn-on glitches
N
500mA continuous load current
N
MOSFET short-circuit current limit (2.5A max)
N
Low supply current
– 110µA ON state current, 1µA OFF state current
N
Active-LOW or Active-HIGH Enable input
N
3.3V or 5V logic compatibility
N
Open-drain Fault Flag indicates three fault
conditions:
– Undervoltage
– Current limit
– Thermal shutdown
N
2.4V Undervoltage Lockout (UVLO)
- Single switch
- 0.07
Ω
"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 (R
ON
) 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 charg-
ing 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.
Applications
N
USB power management
N
USB hosts and self-powered hubs
N
Battery-charger circuits and power supplies
Block Diagrams
IN
EN
7
1
1.2V
Reference
50% Lower
Resistance
Than MIC2525
8
OUT
OUT
Current
Limit
6
Power
Switch
Gate
Control
2
UVLO
Thermal
Shutdown
Charge
Pump
3
FLG
Oscillator
GND
IMP2525A
2525A_01.eps
© 2000 IMP, Inc.
408-432-9100/www.impweb.com
1
A1PROS [ A1 PROS CO., LTD. ]
