TA8429H/HQ
TOSHIBA Bipolar Linear Integrated Circuit
Silicon Monolithic
TA8429H/HQ
Full-bridge Driver (H-Switch) for DC Motor
(Driver for Switching between Forward and Reverse Rotation)
The TA8429H/HQ is full-bridge driver IC for brush motor
rotation control that has a current capability of up to 3.0 A (AVE).
Thermal shutdown and short current protection circuits are
provided, and a stand-by function is also available.
Features
Output current of up to 3.0 A (AVE.) and 4.5 A (PEAK)
Four different modes (forward rotation, reverse rotation, stop,
and brake) are supported.
A counter-electromotive force absorber diode is also
incorporated.
Stand-by mode available: I
ST
≤
100 µA
Built-in thermal shutdown and short circuit protection circuits
HZIP power package sealed
Wide range of operating voltage: V
CC
= 7 to 27 V
V
S
= 0 to 27 V
Weight : 4.04 g (typ.)
The TA8429HQ:
The TA8429HQ is Sn plated product including Pb.
The following conditions apply to solderability:
*Solderability
1. Use of Sn-63Pb solder bath
*solder bath temperature = 230°C
*dipping time = 5 seconds
*number of times = once
*use of R-type flux
2. Use of Sn-3.0Ag-0.5Cu solder bath
*solder bath temperature = 245°C
*dipping time = 5 seconds
*the number of times = once
*use of R-type flux
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TA8429H/HQ
Block Diagram
Pin Function
Pin No.
1
2
3
Symbol
IN 1
IN 2
N.C
Functional Description
These pins receive inputs for controlling the state of the outputs.
The input sections incorporate a PNP-type voltage comparator.
Non-connection
This pin connects to a DC motor. It has a current carrying capacity of 3 A in both sink and
source modes.
A diode for absorbing counter-electromotive force in the motor is incorporated on both V
CC
and
ground sides.
Non-connection
GND terminal
Non-connection
This pin, along with pin 4, connects to a motor. It has the same function as pin 4. Its state is
controlled with inputs to pins 1 and 2.
Non-connection
Supply voltage terminal for motor drive
This is a supply voltage pin for the control section. It is completely separated from V
S
.
When this pin is open or connected to a ground, the current flowing through the motor is
minimized (100
µA).
4
OUT1
5
6
7
8
9
10
11
12
N.C
GND
N.C
OUT2
N.C
V
S
V
CC
ST
How Multi-Protection Works
The TA8429H/HQ incorporates two protection functions: over-current (ISD) and overheat (TSD).
Control logic
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Note 1: These protection functions are only a means of temporarily avoiding some output short circuits or other
abnormal conditions and are not guaranteed to prevent damage to the IC.
Note 2: If used under conditions where the maximum ratings are exceeded, the IC may break down before the
protection circuits start operating.
Overheat Protection
(TSD)
●
Basic operation
The input signal of the IC controls the output while the junction temperature (chip temperature) of the IC
is equal to or lower than the TSD detection temperature. If the junction temperature becomes higher than
the TSD detection temperature, the output enters a high-impedance state regardless of the level of the input
signal.
●
Explanation of the operation
The junction temperature is detected by monitoring the VF of a diode on the chip. When the VF becomes
lower than the internal reference voltage, the control logic is directed to turn off the output transistor. While
the VF is higher than the reference voltage, the input signal at pins 1 and 2 controls the logic section.
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Over-current Protection
(ISD)
●
Basic operation
When the output current (pin 4 or 8, that is, I
sink
or I
source
) is equal to or lower than the ISD detection
current, the input signal controls the output. If the output current exceeds the detection current, it changes
to a switching waveform shown in Figure 1.
Detection current of 5 A
(typically)
Figure 1
●
Explanation of the operation
Basic operation
The output current is detected by monitoring the VBE of each output transistor. A detector element is
connected to each output transistor and to a short-circuit prevention circuit. If a current higher than the ISD
detection current flows through one of the four output transistors, the short-circuit prevention circuit starts
operating. This circuit incorporates a timer. If the over-current mode lasts for 20
µs
(typically), the output is
switched to the high-impedance state. It returns to the ON mode in 80
µs
(typically). If the IC is still in the
over current mode, the switching mode stated above is repeated until the IC is released from the
over-current mode.
This circuit cannot limit all types of over current. If the outputs are short-circuited to each other or to a
ground, the IC may break down before the protection circuit starts operating. Therefore use a resistor or fuse
in the supply voltage (V
S
) line.
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Internal Circuit
Function
Input
IN1
H
L
H
L
H/L
IN2
H
H
L
L
H/L
ST
H
H
H
H
L
OUT1
L
L
H
Output
OUT2
L
H
L
Mode
Motor
Short brake
CW/CCW
CCW/CW
Stop
Stand-by
OFF (high impedance)
OFF (high impedance)
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Embedded System
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