CP494
SWITCHMODE Pulse Width Modulation Control Circuit
V
ref
V
O
To Output
Voltage of
System
1
2
+
-
R2
R1
Error
Amp
1
2
+
Error
Amp
3
R1
Negative Output Voltage
V
ref
-
R
R
1
V
O
= V
ref
V
O
Positive Output Voltage
2
R2
To Output
Voltage of
System
R
R
1
V = V ą1 +
O ref
2
Figure 14. Error–Amplifier Sensing Techniques
Output
Control
R
1
R
2
V
ref
Output
4
Q
D
T
R
T
C
T
C
5
S
6
V
ref
Output
4
Q
D
T
0.001
30k
R
S
80
Max. % on Time, each output ≈ 45 -
R1
R2
1 +
Figure 15. Deadtime Control Circuit
Figure 16. Soft–Start Circuit
1
1
C
C
Q
C
2.4 V ≤ V ≤ V
OC
ref
1.0 mA to
250 mA
Q
1
Q
Q
1
1
1
E
E
Output
Control
Output
Control
1.0 mA to
500 mA
Push-Pull
Single-Ended
2
2
C
C
1.0 mA to
250 mA
Q
2
0 ≤ V ≤ 0.4 V
OC
2
2
2
E
E
Q
E
Figure 17. Output Connections for Single–Ended and Push–Pull Configurations
* All specs and applications shown above subject to change without prior notice.
1F-5 NO.66 SEC.2 NAN-KAN RD ., LUCHU , TAOYUAN, TAIWAN
Tel:886-3-3214525
Email: server@ceramate.com.tw
Http: www.ceramate.com.tw
Rev 1.0 Apr.19,2004
Page 8 of 11
Fax:886-3-3521052
CERAMATE [ CERAMATE TECHNICAL ]
