Datasheet BA6191 Datasheet (ROHM)

Optical disc ICs

2-channel reversible-motor driver

BA6191

The BA6191 is a 2-channel motor driver for CD player changers and electric volume switches, among other applications.
Because it uses a negative power supply, this IC uses the power supply of application products efficiently.

Applications
CD player, etc.

Features

1) Two-channel reversible-motor driver.

2) Four modes - forward, reverse, stop (free rotation)
and brake are output according to control logic input
(two inputs).

3) Output voltage is set with the Vref pin.

Absolute maximum ratings (Ta = 25C)

4) Internal power supply voltage drop mute circuit.

5) Internal thermal shutdown circuit.

6) Negative power supply.

Recommended operating conditions (Ta = 25C)

154

Optical disc ICs BA6191

Block diagram

Pin descriptions

155

Optical disc ICs BA6191

Input/output circuits

156

Optical disc ICs BA6191

Electrical characteristics (unless otherwise noted, Ta=25C, VCC=10V, Vref=2.5V)

Circuit operation

(1) Forward/reverse control block
The IC outputs the forward, reverse, stop (free rotation)
or brake mode in accordance with the two control logic
inputs.

〈Forward and reverse modes〉
An output voltage twice that of the reference voltage is
generated.

〈Stop mode〉
Each pin changes to the high impedance state.

〈Brake mode〉
Each pin outputs 0V.

Logic input and output truth table

1) Normal voltage is not output when the reference volt­age is below 1.0V or about V

CC is the reference voltage for the input voltage of

2) V
logic input pins. In terms of potential relative to V
the HIGH level are (V
(V

CC.)V.

CC/2–1.0V.

EE,

CC+5.0)V and LOW level are

3) Fig. 2 shows each pin’s potential level.

157

Optical disc ICs BA6191

Circuit operation
(2) Thermal shutdown
The BA6191 has an internal shutdown circuit with hyster­esis capabilities. Output current is muted when the chip
temperature exceeds 175C (typically) and restored
when the chip temperature falls to 150C (typically).

Application example

(3) Power supply voltage drop muting
The output current is muted when the power supply volt­age (V

CC) drops below 3.0V. During muting, the output

voltage is V

EE.

Operation notes
(1) Attach a bypass capacitor (roughly 0.1µF) to the
power supply, at the base of the IC.
(2) The radiating fin is internally grounded to the pack­age and so should be connected to an external ground.

158

Optical disc ICs BA6191

Thermal derating curve

Electrical characteristic curves

External dimensions (Units: mm)

159