Analog Integrated Circuit Device Data

Freescale Semiconductor

9

17529

SYSTEM/APPLICATION INFORMATION

INTRODUCTION

SYSTEM/APPLICATION INFORMATION

INTRODUCTION

The 17529 is a monolithic dual H-Bridge ideal for portable electronic applications to control bipolar step motors and brush DC motors,

such as those found in camera lens assemblies, camera shutters, optical disk drives, etc. The 17529 operates from 2.0 V to 6.8 V,

providing dual H-bridge motor drivers with parallel 3.0 V or 5.0 V compatible I/O. The device features an on-board charge pump, as well

as built-in shoot-through current protection and undervoltage shutdown.

The 17529 has four operating modes: forward, reverse, brake, and tri-stated (high-impedance). The MOSFETs comprising the output

bridge have a total source + sink RDS(ON) ≤ 1.2 Ω. The 17529 can simultaneously drive two brush DC motors or, as shown in Figure 1,

17529 Simplified Application Diagram on page 1, one bipolar step motor. The drivers are designed to be PWM’ed at frequencies up to

200 kHz.

FUNCTIONAL PIN DESCRIPTION

CONTROL CIRCUIT POWER SUPPLY (VDD)

The VDD pin carries the logic supply voltage and current into the logic sections of the IC. VDD 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.

LOGIC INPUT CONTROL (IN1A, IN1B, IN2A, AND IN2B)

These logic input pins control each H-Bridge output. IN1A logic HIGH = OUT1A HIGH. However, if all inputs are taken HIGH, the

outputs bridges are both tri-stated (refer to Table 6, Truth Table, page 8).

OUTPUT ENABLE (OE)

The OE pin is a LOW = TRUE enable input. When OE = HIGH, all H-Bridge outputs (OUT1A, OUT1B, OUT2A, and OUT2B) are tri-

stated (high-impedance), regardless of logic input (IN1A, IN1B, IN2A, and IN2B) states.

H-BRIDGE OUTPUT (OUT1A, OUT1B, OUT2A, AND OUT2B)

These pins provide connection to the outputs of each of the internal H-Bridges (see Figure 2, 17529 Simplified Internal Block Diagram,

page 3).

MOTOR DRIVE POWER SUPPLY (VM1 AND VM2)

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 loads attached between the output pins. All VM pins must be connected together on

the printed circuit board.

CHARGE PUMP (C1L AND C1H, C2L AND 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.

PRE-DRIVER POWER SUPPLY (CRES)

The CRES pin is the output of the internal charge pump. Its output voltage is approximately three times the VDD voltage. The VCRES

voltage is power supply for internal pre-driver circuit of H-Bridges.

POWER GROUND (PGND)

Power ground pins. They must be tied together on the PCB.

LOGIC GROUND (LGND)

Logic ground pin.