ta84002fg TOSHIBA Semiconductor CORPORATION, ta84002fg Datasheet - Page 5

• Manufacturer Part Number: ta84002fg
• Description: Pwm Chopper-type 2 Phase Bipolar Stepping Motor Driver
• Manufacturer: TOSHIBA Semiconductor CORPORATION

PWM CURRENT CONTROL
The output current is sensed and controlled independently in each bridge by an external sense resistor (RFN),
internal comparator, and mono-stable multi-vibrator.
resistor until the sense voltage (VNF) reaches the level set at the comparator input: V
triggers the mono-stable multivibrator, which turns OFF the lower transistor of the bridge.
When the bridge is turned ON, the current increases in the motor winding and flows through the external sense
The OFF time is determined by the external RC timing components of the monostable multivibrator:
The approximate value of the current limiting (I
t
I
OFF
O
= (V
≈ 1.1 CR.
ref
/ 5) / RNF−0.05.
O
) is given by the following:
5
ref
/ 5. The comparator then
TA84002F/FG
2006-3-6