Analog Integrated Circuit Device Data

Freescale Semiconductor

9

17517

FUNCTIONAL DESCRIPTION

INTRODUCTION

FUNCTIONAL DESCRIPTION

INTRODUCTION

The 17517 is a triple totem-pole output H-Bridge power IC

designed to drive small dc motors used in portable

electronics. The 17517 can operate efficiently with supply

voltages as low as 2.0 V to as high as 6.8 V, and provide

continuos motor drive currents of 1.0 A while handling peak

currents up to 3.0 A. It is easily interfaced to low cost MCUs

via parallel 3.0 V- or 5.0 V-compatible logic. The device can

be pulse width modulated (PWM-ed) at up to 200 kHz. The

17517 can drive two motors in two directions one at a time; or

it can drive one motor in two directions and one solenoid with

synchronous rectification of freewheeling currents one at a

time. Two-motor operation is accomplished by hooking one

motor between OUTA and OUTB, and the other motor

between OUTB and OUTC. Motor + solenoid operation is

accomplished by hooking a motor between OUTA and OUTB

and placing a solenoid between OUTC and GND. Table 5,

Truth Table, page 8, describes the operating states versus

the input conditions.

As shown in Figure 2, 17517 Simplified Internal Block

Diagram, page 2, the 17517 is a monolithic triple totem-pole

output bridge with built-in charge pump circuitry. Each of the

six MOSFETs forming the triple totem-pole output has an

integrated charge pump and level shifter (for gate drive

voltages). Additionally, the IC has a built-in shoot-through

current protection circuit and undervoltage lockout function.

This IC has four operating modes: Forward, Reverse, Brake,

and Tri-Stated (High Impedance).

FUNCTIONAL PIN DESCRIPTION

DRIVER OUTPUT (OUTA, OUTB, OUTC)

These pins provide the connection to the internal power

MOSFET triple-totem-pole H-bridge of the IC.

GROUND (GND)

Power and signal ground pin.

CHARGE PUMP OUTPUT CAPACITOR (CRES)

This 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 three

supply gate drive for the internal power MOSFETs.

MOTOR DRIVE POWER SUPPLY (VM)

The two 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 OUTA and OUTB.

The 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.

CONTROL SIGNAL INPUT AND ENABLE CONTROL

SIGNAL INPUT (IN1, IN1, EN1, EN2)

These pins are input control pins used to control the

outputs. These pins are 3.0 V/5.0 V CMOS-compatible

inputs with hysteresis. These pins work together to control

OUTA, OUTB, and OUTC (refer to Table 5, Truth Table).

CHARGE PUMP BUCKET CAPACITOR (C1L, C1H,

C2L, C2H)

These two pairs of pins, the C1L and C1H and the C2L and

C2H, connect to the external bucket capacitors required by

the internal charge pump. The typical value for the bucket

capacitors is 0.1

µF.

CONTROL CIRCUIT POWER SUPPLY (VDD)

This pin carries the logic supply voltage and current into

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.