CP494 Datasheet, PDF (8/11 Pages) Ceramate Technical – SWITCHMODE Pulse Width Modulation Control Circuit

CP494
SWITCHMODE Pulse Width Modulation Control Circuit
R1
V_ref
R2
V_{O To Output}
Voltage of
System
1
+
Error
Amp
3
-
2
Positive Output Voltage
1
+
Error
Amp
-
2
Negative Output Voltage
V_O = V_ref
R₁
R₂
V_O = V_ref ą1 +
R₁
R₂
Figure 14. Error–Amplifier Sensing Techniques
V_ref
R2
R1
V_O
To Output
Voltage of
System
Output
Control
Output
Q
R_T
6
30k
V_ref
R₁
4
D_T
C_T
R₂
5
0.001
Output
Q
V_ref
C_S
4
D_T
R_S
Max. % on Time, each output ≈ 45 -
80
1
+
R1
R2
Figure 15. Deadtime Control Circuit
Figure 16. Soft–Start Circuit
Output
Control
0 ≤ V_OC ≤ 0.4 V
C¹
Q_{1 E1}
Single-Ended
C²
Q₂
E²
Q_C
1.0 mA to
500 mA
Q_E
2.4 V ≤ V_OC ≤ V_ref
Output
Control
C¹
Q_{1 E1}
Push-Pull
C²
Q_{2 E2}
1.0 mA to
250 mA
1.0 mA to
250 mA
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:[phone]
Fax:[phone]
Page 8 of 11
Email: [e-mail]
Http: www.ceramate.com.tw
Rev 1.0 Apr.19,2004