MIC5018

IttyBitty is a trademark of Micrel, Inc.

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (

April 2006

M9999-042406

(408) 955-1690

General Description

The MIC5018 IttyBitty™ high-side MOSFET driver is

designed to switch an N-channel enhancement-type

MOSFET from a TTL compatible control signal in high- or

low-side switch applications. This driver features the tiny

4-lead SOT-143 package.

The MIC5018 is powered from a +2.7V to +9V supply

and features extremely low off-state supply current.

An internal charge pump drives the gate output higher

than the driver supply voltage and can sustain the gate

voltage indefinitely. An internal zener diode limits the

gate-to-source voltage to a safe level for standard

N-channel MOSFETs.

In high-side configurations, the source voltage of the

MOSFET approaches the supply voltage when switched

on. To keep the MOSFET turned on, the MIC5018’s output

drives the MOSFET gate voltage higher than the supply

voltage. In a typical high-side configuration, the driver is

powered from the load supply voltage. Under some

conditions, the MIC5018 and MOSFET can switch a load

voltage that is slightly higher than the driver supply

voltage.

In a low-side configuration, the driver can control a

MOSFET that switches any voltage up to the rating of the

MOSFET. The gate output voltage is higher than the

typical 3.3V or 5V logic supply and can fully enhance a

standard MOSFET.

The MIC5018 is available in the SOT-143 package and is

rated for –40°C to +85°C ambient temperature range.

Features

• +2.7V to +9V operation

• 150µA typical supply current at 5V supply

• ≤1µA typical standby (off) current

• Charge pump for high-side low-voltage applications

• Internal zener diode gate-to-ground MOSFET protection

• Operates in low- and high-side configurations

• TTL compatible input

• ESD protected

Applications

• Battery conservation

• Power bus switching

• Solenoid and motion control

• Lamp control

Typical Applications

On

Off

VS

CTL

G

GND

MIC5018

4.7µF

IRFZ24*

N-Channel

MOSFET

+5V

1

23

4

* International Rectifier

100m , 17A max.

TO-220 package

On

Off

VS

CTL

G

GND

MIC5018

4.7µF

Si9410DY*

N-channel

MO SF ET

‡

1

23

4

+2.7 to +9V

MOSFET drain-to-source rating

* Siliconix

8-lead SOIC package

Low-Voltage High-Side Power Switch

Low-Side Power Switch