KA8329B
VCR PRODUCTS
3. MOTOR SPEED CONTROL(INPUT CURRENT LIMITATION)
The maxmum output current is limitted by Pin 19 voltage as follows. So a motor speed is controlled by
the output current. In case of no-use, it is to be short-circuit with VCC1.
£ £ GML= Io/ VLIM=(Io2-Io1)/(VLIM2-VLIM1), where VLIM1=1.45V => Output current=Io1
VLIM2=1.55V => Output current=Io2
Output
Current
(Max)
19
0.67 A/V
0 1.25V
VLIM(Pin 19)
4. MOTOR SPEED CONTROL(INPUT VOLTAGE CONTROL )
ÿ The control of motor speed is possible on the conditions of VCTL(Pin 20) VREF.
The control gain is approx. 1.0 A/V as follows.
£ £ GM= Io/ VCTL=(Io2-Io1)/(VCTL2-VCTL1), where VREF=2.5V, VCTL1=2.6V => Output Current=Io1
VREF=2.5V, VCTL2=2.7V => Output Current=Io2
VCC1
20
Output
Current
(Max)
1.0 A/V
GOUT
0
VREF
VCTL(Pin 20)
5. VOLTAGE CONTROL REFERENCE
21
11
Rs
þ þ The input voltage range is 2V VREF (VCC1-2V).
PM-97-D012
April 1997.