IMP252 4/2 7
P
OWER
M
ANAGEMENT
A
DVANCE
P
RODUCT
I
NFORMATION
Key Features
N
N
N
N
N
N
N
N
N
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
Quad USB High-Side Power
Switch with Fault Detection
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.
N
N
N
N
Applications
N
USB host and self-powered hubs
N
USB video monitors
N
USB printers
V
BUS
Typical Application
IMP2527
5.1V
±
3%
5V
±
1%
or
IMP2524
5V
±
3%
4.7
m
F
Ferrite Bead
10k
27k
2
1
3
4
5
6
IMP2524
IMP2527
ENA
ENB
INA/B
OUTA
16
15
14
13
12
11
10
9
33
m
F*
+
D+
0.01
m
F
D–
GND
+
IN OUT
LDO
GND
V+
ON/OFF
OVERCURRENT
USB Controller
D+
D–
1
m
F
GND
FLGA INC/D
FLGB OUTB
ENC OUTC
FLGC OUTD
END
FLGD
GND
GND
Downstream
USB
Port 1
500mA max.
0.1
m
F
33
m
F*
V
BUS
+
D+
0.01
m
F
D–
GND
V
BUS
Data
7
8
Downstream
USB
Port 2
500mA max.
33
m
F*
Bold/Blue
lines indicate 0.1" wide, 1-oz. copper high-current traces.
*33
m
F, 16V tantalum or 100
m
F, 10V electrolytic per port
+
D+
0.01
m
F
D–
GND
V
BUS
Downstream
USB
Port 3
500mA max.
33
m
F*
+
D+
0.01
m
F
D–
GND
Downstream
USB
Port 4
500mA max.
2524/27_01.eps
©
1999 IMP, Inc.
408-432-9100/www.impweb.com
1
IMP [ IMP, INC ]
