TL494 Datasheet, PDF (9/12 Pages) Motorola, Inc – SWITCHMODE PULSE WIDTH MODULATION CONTROL CIRCUIT

TL494
Figure 18. Slaving Two or More Control Circuits
Vref
Figure 19. Operation with Vin > 40 V Using
External Zener
6 _RT
RT
5 _CT
CT
Master
Vref
RS
Vin > 40V
VCC
12
1N975A
VZ = 39V
5.0V
Ref
270
Gnd
7
6
RT
5
CT
Slave
(Additional
Circuits)
+Vin = 8.0V to 20V
Figure 20. Pulse Width Modulated Push–Pull Converter
1M
33k
0.01 0.01
12
1+
VCC
2–
C1 ⁸
3 _Comp
15 _–
TL494
16 ₊
OC VREF DT CT RT Gnd E1 E2
13 14 4 5 6 7 9 10
+
4.7k
4.7k
10
15k
10k _0.001
C2 ¹¹
47
T1
Tip
32
+
Tip 50
32 25V
47
1N4934
L1
1N4934
+VO = 28 V
IO = 0.2 A
22
k
+
50
35V
4.7k ₊
50
35V
1.0
240
All capacitors in µF
Test
Line Regulation
Load Regulation
Output Ripple
Short Circuit Current
Efficiency
Conditions
Vin = 10 V to 40 V
Vin = 28 V, IO = 1.0 mA to 1.0 A
Vin = 28 V, IO = 1.0 A
Vin = 28 V, RL = 0.1 Ω
Vin = 28 V, IO = 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
MOTOROLA ANALOG IC DEVICE DATA
9