Cirrus Logic CRD1616-8W - Manual (Page 14)

CRD1616-8W
14 DS1003RD4
7. INDUCTOR CONSTRUCTION
The CRD1616-8W provides power factor correction and dimmer compatibility with a constant output current, quasi-
resonant flyback stage. The following sections describe the flyback transformer installed on the CRD1616-8W.
7.1 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.
7.1.1 Electrical Specifications
Characteristics conditions:
• Operating temperature range: -25 °C to +120 °C (including coil heat)
Notes: 1. Time = 2sec.
2. Measured across pins 4 and 5.
3. Measured across pins B and A.
4. Measured across pins 6 and 7.
Parameter Condition Sym Min Typ Max Unit
Flyback Transformer
Electrical Strength
(Note 1) f
operate
=50/60Hz - 1200 - V
RMS
Primary Inductance (Note 2) f
resonant
=10kHz, 0.3V at 20°C L
P
3.6 4.0 4.4 mH
Primary Leakage Inductance (Note 2) f
resonant
=10kHz, 0.3V at 20°C L
K
- - 80 H
Primary DC Resistance (Note 2) t
DCR
=20°C 8.8 11 13.2 
Secondary DC Resistance (Note 3) t
DCR
=20°C - - 0.372 
Auxiliary DC Resistance (Note 4) t
DCR
=20°C 0.304 0.38 0.456 
99.5T
# 37AWG
(0.12mm)
140.5 T
#37 AWG
(0.12 mm)
25T
#31AWG
(0.226mm)
Primary
4
8
5
6
Auxiliary
7
Secondary
32T
#30AWG
(0.25mm)
A
B
Figure 10. Flyback Transformer Schematic