Analog Integrated Circuit Device Data

Freescale Semiconductor

7

33288

FUNCTIONAL DESCRIPTION

INTRODUCTION

FUNCTIONAL DESCRIPTION

INTRODUCTION

The MC33288DH is a dual high side switch with

appropriate control, protection, and diagnostic features

dedicated to automotive flasher applications. The device

consists of two independent 25mW power switches and an

additionnal 3.2

Ω high-side switch capable of controlling a 1.2

W warning lamp. It interfaces directly with a microcontroller

and the package used is a 20-HSOP power small outline, 20

terminals. The MC33288 incorporates a status terminal and

a load current sense capability.

FUNCTIONAL TERMINAL DESCRIPTIONS

SUPPLY VOLTAGE (VBAT)

The backside TAB is connected to the power supply of the

MC33288DH. In addition to its supply function, this terminal

contributes to the thermal behaviour of the device by

conducting the heat from the switching MOSFET to the

printed circuit board.

LOAD CURRENT SENSE (CUR R)

The Current Sense terminal delivers a ratioed amount (1/

1000) of the sum of the currents that can be used to generate

signal ground referenced output voltages for use by the

microcontroller.

INPUT CHANNEL 1/2 (IN1, IN2)

These are the device input terminals which directly control

their associated outputs. The levels are CMOS compatible.

When the input is a logic low, the associated output MOSFET

is in the OFF state. When input is high, the MOSFET is turned

ON and the load is activated. When both inputs are low, the

device is in standby mode and its supply current is reduced.

Each input terminal has an internal active pull-down, so that

it will not float if disconnected.

OUTPUT CHANNEL (OUT1, OUT2)

Pins 6, 7, and 8 are the source of the output 1 25 m

Ω

MOSFET1. Pins 13, 14, and 15 are the source of the output

2 25 m

Ω MOSFET2. They deliver current to the connected

loads and are controlled via the IN1 and IN2 terminals,

respectively . These outputs are current limited and

thermally protected.

GROUND (GND)

This is the ground terminal of the device.

STATUS FOR BOTH CHANNELS (STATUS)

The Fault output is an open drain indication that goes active

low when a fault mode (Openload, Overtemperature) is

detected by the device on either one channel or both

channels simultaneously. Its internal structure is an open

drain architecture with an internal clamp at 6.0 V. An

WARNING LAMP OUTPUT (WLP)

This terminal is the source of a 3.2

Ω MOSFET. This output

is current limited and thermally protected. It delivers current

through the connected load when both IN1 and IN2 inputs

are logic high. It is usually used as a warning lamp driver for

Flasher application.