TA7733 TOSHIBA [Toshiba Semiconductor], TA7733 Datasheet - Page 6

• Manufacturer Part Number: TA7733
• Description: FUNCTIONAL BRIDGE DRIVER
• Manufacturer: TOSHIBA [Toshiba Semiconductor]

Notes on Using the TA7733F/FG
The TA7733F/FG functionable bridge driver is an IC specifically developed to control rotation switching in brush motors.
This IC has been carefully designed and strengthened to withstand counter-electromotive force or startup rush current,
which are problems often associated with driving brush motors.
However, as with other power ICs, application circuits must be designed not to apply surge voltage or excess current that
exceeds the standard values. In addition, when designing PCBs, make sure the wiring pattern does not cause oscillation,
which can result in equipment malfunction or destruction of the IC.
The following are notes on use of the TA7733F/FG. These should be reflected at the design stage.
(1) Power supply voltage
(2) Maximum voltage and current
(3) External diodes
(4) PCB design
(5) Oscillation remedies
Note: Utmost care is necessary in the design of the output, V
To avoid the motor current affecting the TA7733F/FG control-side power supply, we recommend you use two power
supplies: an external transistor power supply, and a TA7733F/FG control-side power supply. However, when using
a single power supply, connect as in the diagram below.
The maximum supply voltage (pin 1) for the TA7733F/FG is 18 V. The operating supply voltage is in the range of
1.8~15 V. No voltage exceeding this range should be applied to pin 1.
The maximum current is 0.5 A (ave.) or 1.5 A (peak). The circuit should be designed so that rush current at startup
does not exceed peak current, and average current during steady operation does not exceed 0.5 A.
As the block diagram shows, the TA7733F/FG has internal diodes.
The lower two diodes, which are the IC’s internal parasitic diodes, have a relatively large capacitance. However,
when a motor with a large reactance such as a core motor is driven, the upper two diodes may be damaged by the
motor’s counter-electromotive force. In such a case, connect external diodes in parallel. The lower diodes should
not be subjected to high current. For brake operation, therefore, external diodes should be connected.
The following points concern the TA7733F/FG pattern design around the power supply line (pin 1) and the pattern
design of the GND (pin 8, pin 12 / 13).
a) Ensure that the bypass capacitor between pin 1, and GND does not share impedance with other lines.
b) The GND line should not be shared by other circuits.
c) The capacitance of the bypass capacitor should be as large as possible.
To prevent noise from sparks when using brush motors, a capacitor may be connected between both pins.
When using the TA7733F/FG, the capacitor is connected between outputs (pins 10 / 11, and pins 14 / 15). This may
cause oscillation. Therefore avoid connecting the capacitor where possible. If connection is necessary to overcome
noise, connect resistors in series as shown in the technical data.
The values for the capacitor and resistors must be determined according to the motor.
short-circuiting between outputs, air contamination faults, or faults due to improper grounding, or by
short-circuiting between contiguous pins.
6
CC
, V
M
, and GND lines since the IC may be destroyed by
TA7733F/FG
2006-3-2