KA3017 Fairchild Semiconductor, KA3017 Datasheet - Page 15

• Manufacturer Part Number: KA3017
• Description: MOSFET & Power Driver ICs QFPH-48
• Manufacturer: Fairchild Semiconductor

Specifications of KA3017

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

4. Power Save Function
5. Short Brake Function
When the pick-up mechanism moves from the inner to the outer spindle of the MD(Mini Disk), the brake function of the
reverse voltage is commonly employed to rate the rotational velocity of the spindle motor.However, if the spindle motor
rotates rapidly, the brake function of the reverse voltage may produce too much heat at the drive IC.
To remove these shortcomings and to enhance efficiency, the short brake function is added to KA3017. When the short brake
function is active, all upper Power transistors are turned off and the lower Power transistors turned on, so as to reduce the rota-
tional velocity of the motor. The short brake operation controlled by SB (pin 12), and the input conditions are as follows.
6.
When the junction temperature rises up to 175 C, the output drive circuit shuts down, when the junction temperature falls off
to 160 C, the output drive circuit operates normally. It has the temperature hysteresis of about 15 C.
- The power save circuit is activated by operating TR Q1.
- When the SS (Start/Stop) pin 10 is high (V
- The power save operation controlled by SS (pin 10) input conditions is as follows;
Thermal Shutdown (Tsd) Function
Pin#12
HIGH
LOW
when the SS (Start/Stop) pin 10 is Open or Low (GND), the TR Q1 is turned off and the bias circuit is disabled.
Open/Low
OFF
ON
Pin#10
High
V
CC
SHORT BRAKE
12
OFF
ON
1K
80K
KA3017
Start
Stop
Drive logic
Q1
Start
Stop
CC
V
CC
), the TR Q1 is turned on and the bias circuit is enabled. On the other hand,
10
ON
OFF
30K
12K
14
Bias block
V
M
Q1
100k
15
16
MOTOR
KA3017
15