NEC DTE-29U1TH - Page 42

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Service Manual CP-785F
* STR-F665X oscillating operation
TO PIN4 SM PS
2
3
1
5
GND
R804
C850
OCP/FB
From PIN 6
SM PS
(FEEDBACK)
SOURCE
R808
DRAIN
DRIVE
OSC
Rg2
Rg1
Comp.2
Comp.1
C1
R1
STR-F665X
1.35mA
V th(1)
V th(2)
Oscillating operation
ON
ON ON
OFF
OFFOFF
M OSFET sw itching O N /OFF
V
DS
(M O SFET drain - source voltage)
I
D
(M O SFET drain current)
Pin 1
(OCP / FB)
0V
0.73V
(STR -F6653
internal capacitor)
C1
3.7V
6.5V
1
3
2
4
Waveforms during oscillating operation