MIC94050/94051

Micrel

July 2002

1

MIC94050/94051

MIC94050/94051

4-Terminal TinyFET™ P-Channel MOSFET

Final

General Description

The MIC94050 and MIC94051 are 4-terminal silicon gate

P-channel MOSFETs that provide low on-resistance in a very

small package.

Designed for high-side switch applications where space is

critical, the MIC94050/1 exhibits an on-resistance of typically

0.125

Ω at 4.5V gate-to-source voltage. The MIC94050/1 also

operates with only 1.8V gate-to-source voltage.

The MIC94050 is the basic 4-lead P-channel MOSFET. The

MIC94051 is a variation that includes an internal gate pull-up

resistor that can reduce the system parts count in many

applications.

The 4-terminal SOT-143 package permits a substrate con-

nection separate from the source connection. This 4-terminal

configuration improves the

θ

and makes reverse-blocking switch applications practical.

The small size, low threshold, and low R

MIC94050/1 the ideal choice for PCMCIA, USB, back-up

battery-power, and distributed power management applica-

tions.

Features

• 0.125

Ω typical on-resistance

at 4.5V gate-to-source voltage

• Operates with 1.8V gate-to-source voltage

• Separate substrate connection allows reverse-blocking

Applications

• Distributed power management

• PCMCIA card power management

• USB ports

• Battery-powered computers, peripherals

• Handheld bar-code scanners

• Portable communications equipment

• Reverse blocking battery management

Ordering Information

Part Number

Temperature Range*

Package

MIC94050BM4

–40

°C to +150°C

SOT-143

MIC94051BM4

–40

°C to +150°C

SOT-143

* Operating Junction Temperature

Gate

Source

Drain

Substrate

Schematic Symbol

MIC94050

MIC94051

Schematic Symbol

Pin Configuration

SOT-143 Package (M4)

Typical PCB Layout

S

D

G

SS

PCB heat sink

plane improves

heat dissipation

PCB traces

G

S

D

SS

~350k

Ω

Internal

gate-to-source

pull-up resistor

G

S

D

SS

Functional Diagrams

Substrate

Source

Gate

Drain

P5x

Part

Identification

Part Number

Identification

MIC94050BM4

P50

MIC94051BM4

P51

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com

TinyFET is a trademark of Micrel, Inc.