VCR PRODUCTS
KA8329B
3. MOTOR SPEED CONTROL (INPUT CURRENT LIMITATION)
The maximum 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
0.67A/V
0 1.25V
VLIM (Pin19)
4. MOTOR SPEED CONTROL (INPUT VOLTAGE CONTROL)
The control of motor speed is possible on the conditions of VCTL (Pin20) ≥ VREF.
The control gain is approx. 1.0A/V as follows.
GML = ∆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.)
1.0A/V
GOUT
0
VREF
VLIM (Pin20)
MIC-99D001
9
January 1999