UC3845BVDG ON Semiconductor, UC3845BVDG Datasheet - Page 13

• Manufacturer Part Number: UC3845BVDG
• Description: IC CTRLR CURRENT MODE HP 14SOIC
• Manufacturer: ON Semiconductor

Specifications of UC3845BVDG

• Pwm Type: Current Mode
• Number Of Outputs: 1
• Frequency - Max: 275kHz
• 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: -40°C ~ 105°C
• Package / Case: 14-SOIC (3.9mm Width), 14-SOL
• Frequency-max: 275kHz
• Duty Cycle (max): 48 %
• Output Voltage: 4.9 V to 5.1 V
• Output Current: 1000 mA
• Mounting Style: SMD/SMT
• Switching Frequency: 500 KHz
• Operating Supply Voltage: 30 V
• Maximum Operating Temperature: + 70 C
• Fall Time: 50 ns
• Minimum Operating Temperature: 0 C
• Rise Time: 50 ns
• Synchronous Pin: No
• Topology: Boost, Flyback
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: UC3845BVDGOS

18k
4.7k
100
pF
0.01
T1 -
1.0nF
Primary: 45 Turns #26 AWG
Secondary ±12 V: 9 Turns #30 AWG (2 Strands) Bifiliar Wound
Secondary 5.0 V: 4 Turns (six strands) #26 Hexfiliar Wound
Secondary Feedback: 10 Turns #30 AWG (2 strands) Bifiliar Wound
Core: Ferroxcube EC35-3C8
Bobbin: Ferroxcube EC35PCB1
Gap: ≈ 0.10" for a primary inductance of 1.0 mH
150k
33k
8(14)
4(7)
2(3)
1(1)
All outputs are at nominal load currents unless otherwise noted.
115 Vac
Line Regulation: 5.0 V
Load Regulation: 5.0 V
Output Ripple:
Efficiency
4.7W
EA
Test
R
R
+
Osc
Bias
MDA
202
±12 V
±12 V
5.0 V
±12 V
Figure 30. 7 W Off−Line Flyback Regulator
-
+
5(9)
V
V
V
V
V
in
in
in
in
in
= 115 Vac, I
= 115 Vac, I
= 115 Vac
= 115 Vac
= 95 Vac to 130 Vac
5.0V Ref
+
http://onsemi.com
Comp/Latch
250
S
R
T
Conditions
Q
out
out
13
= 1.0 A to 4.0 A
= 100 mA to 300 mA
+
-
7(12)
56k
7(11)
6(10)
5(8)
3(5)
100
L2, L3
4.7k
+
1N4937
1N4935 1N4935
1N5819
L1
68
22
470pF
- 15 mH at 5.0 A, Coilcraft Z7156
- 25 mH at 5.0 A, Coilcraft Z7157
D = 50 mV or ±0.5%
D = 24 mV or ±0.1%
D = 300 mV or ±3.0%
D = 60 mV or ±0.25%
1.0k
+
3300
pF
47
4N50
Results
MTP
40 mV
80 mV
70%
T1
680pF 2.7k
0.5
pp
pp
MUR110
MBR1635
MUR110
2200
1000
1000
+
+
+
1N4937
1000
L2
L1
L3
10
10
+
+
+
5.0V/4.0A
5.0V RTN
12V/0.3A
±
-12V/0.3A
12V RTN