Analog Integrated Circuit Device Data

8

Freescale Semiconductor

17510

FUNCTIONAL DESCRIPTION

INTRODUCTION

FUNCTIONAL DESCRIPTION

INTRODUCTION

The 17510 is a monolithic H-Bridge power IC applicable to

small DC motors used in portable electronics. The 17510 can

operate efficiently with supply voltages as low as 2.0 V to as

high as 15 V, and it can provide continuos motor drive

currents of 1.2 A while handling peak currents up to 3.8 A. It

is easily interfaced to low-cost MCUs via parallel 5.0 V-

compatible logic. The device can be pulse width modulated

(PWM-ed) at up to 200 kHz. The 17510 has four operating

modes: Forward, Reverse, Brake, and Tri-Stated (High

Impedance).

Basic protection and operational features (direction,

dynamic braking, PWM control of speed and torque, main

power supply undervoltage detection and shutdown, logic

power supply undervoltage detection and shutdown), in

addition to the 1.0 A rms output current capability, make the

17510 a very attractive, cost-effective solution for controlling

a broad range of small DC motors. In addition, a pair of 17510

devices can be used to control bipolar stepper motors. The

17510 can also be used to excite transformer primary

windings with a switched square wave to produce secondary

winding AC currents.

As shown in Figure 2, 17510 Simplified Internal Block

Diagram, page 2, the 17510 is a monolithic H-Bridge with

built-in charge pump circuitry. For a DC motor to run, the

input conditions need to be set as follows: ENable input logic

HIGH, one INput logic LOW, and the other INput logic HIGH

(to define output polarity). The 17510 can execute dynamic

braking by setting both IN1 and IN2 logic HIGH, causing both

low-side MOSFETs in the output H-Bridge to turn ON.

Dynamic braking can also implemented by taking the ENable

logic LOW. The output of the H-Bridge can be set to an open-

circuit high-impedance (Z) condition by taking both IN1 and

IN2 logic LOW. (refer to Table 5, Truth Table, page 7).

The 17510 outputs are capable of providing a continuous

DC load current of up to 1.2 A. An internal charge pump

supports PWM frequencies to 200 kHz. The EN pin also

controls the charge pump, turning it off when EN = LOW, thus

allowing the 17510 to be placed in a power-conserving sleep

mode.

FUNCTIONAL PIN DESCRIPTION

OUTPUT 1 AND OUTPUT2 (OUT1, OUT2)

The OUT1 and OUT2 pins provide the connection to the

internal power MOSFET H-Bridge of the IC. A typical load

connected between these pins would be a small DC motor.

These outputs will connect to either VM or PGND, depending

on the states of the control inputs (refer to Table 5, Truth

Table, page 7).

POWER GROUND AND LOGIC GROUND (PGND,

LGND)

The power and logic ground pins (PGND and LGND)

should be connected together with a very low-impedance

connection.

CHARGE PUMP RESERVOIR CAPACITOR (CRES)

The CRES pin provides the connection for the external

reservoir capacitor (output of the charge pump). Alternatively

this pin can also be used as an input to supply gate-drive

voltage from an external source via a series current-limiting

resistor. The voltage at the CRES pin will be approximately

utilizes a voltage tripler circuit. The

V

CRES

voltage is used by

the IC to supply gate drive for the internal power MOSFET

H-Bridge.

MOTOR SUPPLY VOLTAGE INPUT (VM)

The VM pins carry the main supply voltage and current into

the power sections of the IC. This supply then becomes

controlled and/or modulated by the IC as it delivers the power

to the load attached between OUT1 and OUT2. All VM pins

must be connected together on the printed circuit board with

as short as possible traces offering as low impedance as

possible between pins.

VM has an undervoltage threshold. If the supply voltage

drops below the undervoltage threshold, the output power

stage switches to a tri-state condition. When the supply

voltage returns to a level that is above the threshold, the

power stage automatically resumes normal operation

according to the established condition of the input pins.

CONTROL SIGNAL INPUT AND ENABLE CONTROL

SIGNAL INPUT (IN1, IN2, EN)

The IN1, IN2, and EN pins are input control pins used to

control the outputs. These pins are 5.0 V CMOS-compatible

inputs with hysteresis. The IN1, IN2, and EN work together to

control OUT1 and OUT2 (refer to Table 5, Truth Table).

GATE DRIVER INPUT (GIN)

logic LOW, GOUT supplies a level-shifted high-side gate

HIGH, GOUT is set to GND potential.