Introduction Of Important Function - Sony S75F Service Manual

BA9741F:
PWM control, voltage range for working: 3.6~35V, Has such functions as short-voltage protection,
Over-voltage protection, over-current protection and etc. The function of each pin and the circuit diagram inside are
as follows:
PIN NAME
1 CT External timing capacitor
2 RT External timing resistor
3 1IN+ Positive input for error amplifier 1
4 1IN- Positive input for error amplifier 2
5 1FBK Error amplifier 1 output
6 1DTC Output 1 dead time/soft start setting
7 1OUT Output 1
8 GND Ground

5.2.3 Introduction of important function

a. Adapter
EMI filter circuit: It is common used to get rid of the disturbance existing in the electric net or coming from
outside. L901 is used to reduce the symmetry disturbance and filter the high frequency noise; C901,
C902 can restrain the symmetry and filter the low frequency noise; R918, R919, R920 is used for
discharging the capacitance when cut off the power. NR901 is used to prevent the impulse of surge
current when start the machine, which possesses minus temperature modulus.
FUNCTION PIN NAME
9 VCC Power supply
10 2OUT Output 2
11 2DTC Output 2 dead time/soft start setting
12 2FBK Error amplifier 2 output
13 2IN+ Positive input for error amplifier
14 2IN- Positive input for error amplifier
15 SCP Timing latch setting
16 REF Reference voltage output (2.5v)
33
S75F Sony
FUNCTION