Epson LX-HOO Technical Manual page 135

REV.-A
A.1.4 494 Regulator IC
The 494 regulator IC is described in Figures A-10 and A-1 1 and Table A-7.
0 V
I
pin No.
2
3
4
5
6
7
8
9
I
10
12
13 OUTPUT CONTROL
14
15
16
, CONTROL ,
6 - - - -
(1 L495 ONLY)
Fig. 'A"-10. 494 IC Pin and Block Diagrams
Table A-7. 494 IC Port Functions
Signal
NON INV
FEEDBACK
CONTROL
CT
RT
c l
El
E2
C2
NON INV
NON
c!
El
INPUT BACK TIME
INPuT
F e e d b a c k f o r p h a s e c o r r e c t i o n .
Controls transistor OFF time.
Capacitor for oscillation frequency adjustment.
Resistor for oscillation frequency adjustment.
Ground
Transistor collector for pulse amplification.
Transistor emitter for pulse amplification.
Transistor collector for pulse amplification.
Power
Selection of parallel or push-pull.
1-5V reference voltage
Non. Inv. Input of error amplifier for output current detection.
A-1 O
I
F E E D O E A O
C
T
CONTROL
-
Description
I I
I I
Cl