MIC2042/2043
Micrel
MIC2042/2043
Single Channel, High Current, Low Voltage,
Protected Power Distribution Switch
General Description
The MIC2042 and MIC2043 are high-side MOSFET switches
optimized for general purpose power distribution applications
which require circuit protection. The devices switch up to 5.5V
and as low as 0.8V while offering both programmable current
limiting and thermal shutdown to protect the device and the
load. A fault status output is provided in order to detect
overcurrent and thermal shutdown fault conditions. Both
devices employ soft-start circuitry to minimize the inrush
current in applications that employ highly capacitive loads.
Additionally, for tighter control over inrush current during
start-up, the output slew-rate may be adjusted by an external
capacitor.
The MIC2043 features a auto-reset circuit breaker mode that
latches the output off upon detecting an overcurrent condition
lasting more than 28ms. The output is reset by removing or
reducing the load.
All support documentation can be found on Micrel’s web
site at www.micrel.com.
Features
•
•
•
•
•
•
•
•
•
•
•
60mΩ max. on-resistance
0.8V to 5.5V operating range
Adjustable current limit
Power-Good detection
Up to 3A continuous output current
Short-circuit protection with thermal shutdown
Adjustable slew-rate control
Circuit breaker mode (MIC2043)
Fault status flag
Undervoltage lockout
Output MOSFET reverse current flow block when
disabled
• Very fast reaction to short-circuits
• Low quiescent current
Applications
•
•
•
•
•
•
•
Docking stations
Notebook PCs
PDAs
Hot swap board insertions
RAID controllers
USB hosts
ACPI power distribution
Typical Application
+3.3V
Power
Supply
OUT1
OUT2
C2
0.1µF
C1
0.1µF
C3
4.7µF
R1
20kΩ
MIC2042-1BTS
7
VBIAS
VIN
EN
/FAULT
VOUT
PGREF
10,11,14
V
OUT
3.3V@ 1.5A
R2
294kΩ
1%
R3
24.3kΩ
1%
C
LOAD
33µF
8, 12
2
13
IN
Logic
Controller
ON/OFF
3
R4
20kΩ
1
OVERCURRENT
9
MIC39100-2.5BS
IN
SLEW PWRGD
ILIM
UVLOIN
GND
5
2.5V
OUT
EN
GND
6
4
C4*
0.022µF
(OPEN)
Note:
All V
IN
pins (8, 12) must be externally tied together.
All V
OUT
pins (10, 11, 14) must be externally tied together.
I
LIMIT
≅
2A.
Output Power-Good = 3.0V.
*C4 is optional. See
"Applications Information."
R
SET
200Ω
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
January 2005
1
M0512-112603
MICREL [ MICREL SEMICONDUCTOR ]
