MIC2044/2045
Micrel
MIC2044/2045
Single Channel, High Current, Low Voltage,
Protected Power Distribution Switch
General Description
The MIC2044 and MIC2045 are high-side MOSFET switches
optimized for general purpose power distribution applications
that require circuit protection. These 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 to indicate
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 MIC2045 features a auto-reset circuit breaker that latches
the output OFF upon detecting an overcurrent condition
lasting more than 32ms. The output is reset by removing or
reducing the load.
Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
Features
30mΩ maximum on-resistance
0.8V to 5.5V operating range
Adjustable current limit
Up to 6A continuous output current
Short circuit protection
Very fast reaction to short circuits
Thermal shutdown
Adjustable slew-rate control
Circuit breaker mode (MIC2045)
Fault status flag
Power-Good detection
Undervoltage lockout
No reverse current flow through the switching MOSFET
when OFF or disabled
• Low quiescent current
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Applications
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Docking stations
LAN servers
WAN switches
Hot swap board insertions
Notebook PCs
PDAs
Base stations
RAID controllers
USB hosts
Typical Application
OUT1
+3.3V
Power
Supply
IN
OUT2
Logic
Controller
OVERCURRENT
ON/OFF
C3
4.7
m
F
R1
20k
W
C1
0.1
m
F
C2
0.1
m
F
MIC2044-1BTS
8
7, 11,
13, 16
2
3
4
C4*
0.022
m
F
6
R
SET
100
W
VBIAS VOUT
9,12,14
VIN PGREF
15
EN
R4
20k
W
/FAULT
SLEW PWRGD
1
ILIM UVLOIN
5
(OPEN)
GND
10
R2
W
294k
1%
R3
W
24.3k
1%
C
LOAD
33
m
F
V
OUT
3.3V@ 3.5A
EN
IN
MIC39100-2.5BS
GND
OUT
2.5V
Note:
All V
IN
pins (7, 11, 13, 16) must be externally tied together.
All V
OUT
pins (9, 12, 14) must be externally tied together.
I
LIMIT
= 4A.
Output Power-Good = 3.0V.
*C4 is optional. See
"Applications Information."
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
October 2003
1
MIC2044/2045
MICREL [ MICREL SEMICONDUCTOR ]
