KA9258D 查看數據表（PDF） - Fairchild Semiconductor

零件编号

产品描述 (功能)

比赛名单

KA9258D

4-Channel Motor Driver

Fairchild Semiconductor 

Application Information

1. Mute Function

KA9258D(KA9258CD)

Pin 7

High

Low

Open

Mute circuit

Mute-off

Mute-on

Mute-on

VCC

4-Channels BTL driver

Bias Circuit Block

7

• When the mute (pin 7) is high level, the bias circuit of BTL driver is activated. On the other hand, when the mute (pin7) is

open or low level, the bias circuit of BTL driver is disabled. So that the 4-channels BTL driver output circuit will be muted.

2. TSD (Thermal Shutdown) Function

VREFBG

R11

R12

4-Channels BTL driver

Bias Circuit Block

Q11

• The VREF BG is the output voltage of the band-gap-referenced biasing circuit and acts as the input voltage of the TSD

circuit.

• The base-emitter voltage of the transistor, Q11 is designed to turn-on at below voltage.

•

VBE

=

VREFBG × R12

R11+ R12

=

460[mV ]

• When the chip temperature rises up to 175°C, then the turn-on voltage of the Q11 would drop down to 460mV.

Hence, the Q11 would turn on so the output circuit will be muted. The TSD circuit has the hysteresis temperature of 25°C.

3. OP-AMP

• General OP-amplifier is integrated in the IC for user’s convenience.

16

14

15

9

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