Teac MV1421, Service Manual

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6-9. STR-S5707 ( Hybrid IC for a Switching Regulator )
1. Feature
S m a ll S IP is ola te d p a c ka g e : R e s in se a le d ty p e (tra n sfe r m o ld )
L o po w e r d is c ip a tio n a t a lig h ter lo a d
M a ny pro te ctio n fun c tio n fu n c tio n : - P ulse -b y-p u ls e o v e r c urre n t p ro te ctio n
- O v e r-v o lta g e p ro te ctio n w ith a la tc h
- T h e rm a l p rote ctio n w ith a la tc h
T h e s e p ro te c tion fu n c tio n s a re in co rp o ra te d a n d c a n b e la tc h e d w ith a n e x te rn a l s ig n a l.
2. Description
T h e S T R -S 5 7 0 7 is a H y b rid IC w ith a b u ilt in p o w e r tra n s is to r a n d a s e pa ra te e xc ita tio n co n tro l IC ,
d e s ig n e d for co n v e rte r ty p e s w itc h in g m o d e p o w e r s up p ly ap p lica tio n s.
T h e IC is a c a p a ble o f q u a si-re so n a n t m o d e a n d re q u ire s s m a ll n u m b e r o f e x te rn a l c o m p o n e n t.
3. Block Diagram
4. Pin Description
S Y M B O L PIN D ES C R IP T IO N
C 1 collector of pow er TR
G N D 2 ground(Em itter of pow er TR )
B 3 Base of pow er TR
SIN K 4 Base current (IS) input
O C P 5 over current sensing signal input
IN H 6 input for synchronizing O FF tim e and latch
circuit operation
SEN S 7 constant voltage control signal input
D R IVE 8 output(-)Base drive current (ID ) output
VIN 9 supply voltage for control circuit