Cirrus Logic CRD1631-10W - Manual (Page 15)

CRD1631-10W
DS1005RD2 15
8.1 Flyback Transformer
The flyback transformer stage is a quasi-resonant peak current-regulated DC-DC converter capable of delivering
the highest possible efficiency with constant current output while minimizing line frequency ripple. The auxiliary wind-
ing is used for zero-current detection and overvoltage protection.
Figure 12. Flyback Transformer Schematic
8.1.1 Electrical Specifications
Characteristics conditions:
• Operating temperature range: -25 °C to +120 °C (including coil heat)
Notes: 9. Time = 2sec.
10. Measured across pins 5 and 4.
11. Measured across pins 10 and 9.
12. Measured across pins 3 and 2.
Parameter Condition Symbol Min Typ Max Unit
Flyback Transformer
Electrical Strength (Note 9) f
operate
=50/60Hz - 4K - V
RMS
Primary Inductance (Note 10) f
resonant
=10kHz, 0.3V at 20°C L
P
- 9.7 - mH
Primary Leakage Inductance (Note 10) f
resonant
=10kHz, 0.3V at 20°C L
K
- 138 - H
Primary DC Resistance (Note 10) t
DCR
=20°C - 22.7 - 
Secondary DC Resistance (Note 11) t
DCR
=20°C - 0.3 - 
Auxiliary DC Resistance (Note 12) t
DCR
=20°C - 1 - 
144T
#38 AWG
144T
#38 AWG
36T TWR
#29 AWG
Primary Secondary
5
1
4
10
9
8T
#40 AWG
2
Auxiliary
3