KA3030 View Datasheet(PDF) - Fairchild Semiconductor

Part Name

Description

View to exact match

KA3030

6-Channel Motor Drive IC

Fairchild Semiconductor 

KA3030D

4. FOCUS, TRACKING, SPINDLE, SLED DRIVE CIRCUITS

M

V1’

V2’

−+

V1

Rref

IC

GV2

VREF

+−

V2

−

+

LEVEL SHIFTER

GV1

+−

VREF

(pin 23)

VIN

GV = 20log (VO/VIN) = GV1 + GV2 = 3.5dB + 6dB = 9.5dB

Vref is fixed to 2.5V as the external bias voltage and the input signal through the VIN is amplified to about 9.5dB through two

state AMP.

In the level shift circuitry, the input signal is transformed into the current so that the voltage V1 and V2 are shifted to V1’ and

V2’ respectively.

V1’ = V1 + (IC × VREF) = V1 + ∆V

V2’ = V2 − (IC × VREF) = V2 − ∆V

Because V1 and V2 voltages, in their initial state, are equal, the voltage, VM, on the sides of the motor is following VM = V1’

− V2’ = ∆V − (−)∆V = 2∆V

Rotation occurs due to 2∆V voltage difference at both sides of the motor.

10

Share Link: