MIC2044_05 Datasheet, PDF (1/15 Pages) Micrel Semiconductor – Single Channel, High Current, Low Voltage, Protected Power Distribution Switch

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
Applications
• Docking stations
• LAN servers
• WAN switches
• Hot swap board insertions
• Notebook PCs
• PDAs
• Base stations
• RAID controllers
• USB hosts
Typical Application
+3.3V
Power
Supply
OUT1 OUT2
4.7CmF3
IN
Logic^ON/OFF
Controller
OVERCURRENT
0.1CmF1
20RkW¹
0.022Cm^4F*
0.1CmF2
MIC2044-1BTS
8 _VBIAS
7, 11,
13, 16 _VIN
VOUT ^9,12,14
PGREF ¹⁵
2 _EN
3 _/FAULT
R4
20kW
4 _{SLEW PWRGD} 1
R2924k_W
1%
R243.3k_W
1%
m ^CLOAD
33 F
V_OUT
3.3V@ 3.5A
MIC39100-2.5BS
IN
2.5V
EN
OUT
6 _{ILIM UVLOIN} 5 _(OPEN)
GND
R10_S0ETW
GND
10
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 [phone] • fax + 1 [phone] • http://www.micrel.com
January 2005
1
MIC2044/2045