UC3845DR2G ON Semiconductor, UC3845DR2G Datasheet - Page 12
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UC3845DR2G
Manufacturer Part Number
UC3845DR2G
Description
IC CTRLR CURRENT MODE HP 14SOIC
Manufacturer
ON Semiconductor
Type
High Performance Current Mode Controllersr
Datasheet
1.UC3845DR2.pdf
(16 pages)
Specifications of UC3845DR2G
Pwm Type
Current Mode
Number Of Outputs
1
Frequency - Max
60kHz
Duty Cycle
50%
Voltage - Supply
8.2 V ~ 25 V
Buck
No
Boost
Yes
Flyback
Yes
Inverting
Yes
Doubler
No
Divider
No
Cuk
No
Isolated
Yes
Operating Temperature
0°C ~ 70°C
Package / Case
14-SOIC (3.9mm Width), 14-SOL
Frequency-max
60kHz
Output Voltage Range
4.9 V to 5.1 V
Input Voltage Range
30 V
Operating Temperature Range
0 C to + 70 C
Mounting Style
SMD/SMT
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
UC3845DR2GOS
L2, L3 − 25 mH at 1.0 A, Coilcraft Z7157.
T1 − Primary: 45 Turns # 26 AWG
T1 −
T1 −
T1 −
T1 −
T1 −
T1 −
4.7k
18k
L1 − 15 mH at 5.0 A, Coilcraft Z7156.
T1 −
T1 −
T1 −
Secondary ± 12 V: 9 Turns # 30 AWG
Secondary 5.0 V: 4 Turns (six strands)
Secondary Feedback: 10 Turns #30 AWG
Core: Ferroxcube EC35−3C8
Bobbin: Ferroxcube EC35PCB1
Gap ≈ 0.01" for a primary inductance of 1.0 mH
0.01
(2 strands) Bifiliar Wound
#26 Hexfiliar Wound
(2 strands) Bifiliar Wound
1.0nF
33k
8(14)
4(7)
2(3)
1(1)
115VA
C
4.7W
+
−
EA
+
OSC
Bias
MDA
202
5(9)
Figure 30. 27 Watt Off−Line Flyback Regulator
All outputs are at nominal load currents, unless otherwise noted.
Line Regulation:
Load Regulation:
Output Ripple:
Efficiency
+
5.0V
−
+
+
−
ref
+
Comp/Latch
250
Test
S
R
T
Q
http://onsemi.com
+
−
± 12 V
± 12 V
± 12 V
5.0 V
5.0 V
5.0 V
+
56k
7(12)
12
V
V
V
mA
V
V
in
in
in
in
in
7(11)
6(10)
5(8)
3(5)
= 95 VAC to 130 VAC
= 115 VAC, I
= 115 VAC, I
= 115 VAC
= 115 VAC
100
+
1N4935
1N4937
4.7k
1N5819
22W
470pF
68
1.0k
Conditions
out
out
1N4935
+
3300pF
= 1.0 A to 4.0 A
= 100 mA to 300
4N50
MTP
0.5W
47
T1
680pF
2.7k
MBR1635
MUR110
MUR110
1000
2200
1000
1N4937
+
+
+
1000
L1
L2
L3
10
10
D = 50 mV or ± 0.5%
D = 24 mV or ± 0.1%
D = 300 mV or ± 3.0%
D = 60 mV or ± 0.25%
40 mV
80 mV
70%
+
+
+
pp
pp
5.0V/4.0A
5.0V RTN
12V/0.3A
±12V RTN
−12V/0.3A
Results