CP494 Datasheet, PDF (9/11 Pages) Ceramate Technical – SWITCHMODE Pulse Width Modulation Control Circuit

CP494
SWITCHMODE Pulse Width Modulation Control Circuit
V_ref
6 _RT
R_T
5 _CT
C_T
Master
V_ref
6
R_T
5 _CT
Slave
(Additional
Circuits)
Figure 18. Slaving Two or More Control Circuits
+V_in = 8.0V to 20V
R_S
V_in > 40V
V_CC
12
1N975A
V_Z = 39V
5.0V
Ref
270
Gnd
7
Figure 19. Operation with V_in > 40 V Using
External Zener
1M
33k
0.01 0.01
12
1+
V_CC
2-
3 _Comp
15 _-
CP494
16 ₊
OC V_REF DT C_T R_T Gnd E¹ E²
13 14 4 5 6 7 9 10
+
4.7k
4.7k
10
10k
0.001
15k
C₁ ⁸
C₂ ¹¹
47
T₁
Tip
32
+
Tip 50
32 25V
47
1N4934
+V_O = 28 V
I_O = 0.2 A
L₁
1N4934
22
k
+
50
35V
4.7k ₊
50
35V
1.0
240
All capacitors in mF
Figure 20. Pulse Width Modulated Push–Pull Converter
Test
Line Regulation
Load Regulation
Output Ripple
Short Circuit Current
Efficiency
Conditions
V_in = 10 V to 40 V
V_in = 28 V, I_O = 1.0 mA to 1.0 A
V_in = 28 V, I_O = 1.0 A
V_in = 28 V, R_L = 0.1 W
V_in = 28 V, I_O = 1.0 A
Results
14 mV 0.28%
3.0 mV 0.06%
65 mV pp P.A.R.D.
1.6 A
71%
L1 - 3.5 mH @ 0.3 A
T1 - Primary: 20T C.T. #28 AWG
T1 - Secondary: 12OT C.T. #36 AWG
T1 - Core: Ferroxcube 1408P-L00-3CB
* 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 9 of 11
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Http: www.ceramate.com.tw
Rev 1.0 Apr.19,2004