MIC2544 Datasheet, PDF (1/12 Pages) Micrel Semiconductor – Programmable Current Limit High-Side Switch Preliminary Information

MIC2544/2548
Micrel
MIC2544/2548
Programmable Current Limit High-Side Switch
Preliminary Information
General Description
The MIC2544 and MIC2548 are integrated high-side power
switches optimized for low loss dc power switching and other
power management applications, including Advanced Con-
figuration and Power Interface (ACPI). The MIC2544/48 is a
cost-effective, highly integrated solution that requires few
external components to satisfy USB and ACPI requirements.
Load current management features include a precision resis-
tor-programmable output current-limit and a soft-start circuit
which minimizes inrush current when the switch is enabled.
Thermal shutdown, along with current-limit, protects the
switch and the attached device.
The MIC2544/48’s open-drain flag output is used to indicate
current-limiting or thermal shutdown to a local controller. The
MIC2548 has an additional internal latch which turns the
output off upon thermal shutdown providing robust fault
control. The enable signal is compatible with both 3V and 5V
logic, and is also used as the thermal shutdown latch reset for
the MIC2548.
The MIC2544 and MIC2548 are available in active-high and
active-low enable versions in the 8-pin SOP (small-outline
package) and 8-pin MSOP (micro-small-outline package).
Features
• 2.7V to 5.5V input
• Adjustable current-limit up to 1.5A
• Reverse current flow blocking (no “body diode”)
• 75µA typical on-state supply current
• 1µA typical off-state supply current
• 120mΩ maximum on-resistance
• Open-drain fault flag
• Thermal shutdown
• Thermal shutdown output latch (MIC2548)
• 2ms (slow) turn-on and fast turnoff
• Available with active-high or active-low enable
Applications
• USB power distribution
• PCI Bus Power Switching
• Notebook PC
• ACPI power distribution
• PC card hot swap applications
• Inrush current-limiting
Typical Application
+5V
R_FLG
On/Off
MIC2544-xBM
EN
FLG
GND
ILIM
OUT
IN
OUT
NC
R_SET
0.1µF
Peripheral
33µF
SOP pinout shown
Typical Advanced Configuration and Power Interface (ACPI) Application
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com
June 2000
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MIC2544/2548