Inductor construction, 1 flyback transformer, 1 electrical specifications – Cirrus Logic CRD1616-8W User 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
f
operate
=50/60Hz
-
1200
-
V
RMS
Primary Inductance
f
resonant
=10kHz, 0.3V at 20°C
L
P
3.6
4.0
4.4
mH
Primary Leakage Inductance
f
resonant
=10kHz, 0.3V at 20°C
L
K
-
-
80
H
Primary DC Resistance
t
DCR
=20°C
8.8
11
13.2
Secondary DC Resistance
t
DCR
=20°C
-
-
0.372
Auxiliary DC Resistance
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