UC3845BVD1R2G ON Semiconductor, UC3845BVD1R2G Datasheet - Page 12
UC3845BVD1R2G
Manufacturer Part Number
UC3845BVD1R2G
Description
IC CTRLR CURRENT MODE HP 8SOIC
Manufacturer
ON Semiconductor
Datasheet
1.UC3844BDR2G.pdf
(19 pages)
Specifications of UC3845BVD1R2G
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
8-SOIC (3.9mm Width)
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
UC3845BVD1R2GOS
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
UC3845BVD1R2G
Manufacturer:
OMRON
Quantity:
2 000
Error Amp compensation circuit for stabilizing any current mode topology except
for boost and flyback converters operating with continuous inductor current.
From V
R
R
d
i
R
f
O
C
≥ 8.8k
f
R
1(1)
2(3)
f
2.5V
+
-
EA
5.0V Ref
+
The MCR101 SCR must be selected for a holding of < 0.5 mA @ T
simple two transistor circuit can be used in place of the SCR as shown. All
resistors are 10 k.
MCR
Comp/Latch
1.0mA
101
S
R
T
Q
Figure 29. Error Amplifier Compensation
2R
R
Figure 27. Isolated MOSFET Drive
+
-
Figure 28. Latched Shutdown
3905
5(9)
2N
7(12)
V
CC
http://onsemi.com
7(11)
6(10)
5(8)
3(5)
3903
8(14)
2N
4(7)
2(3)
1(1)
C
Boundary
Isolation
R
R
12
S
EA
R
R
N
S
Q1
+
Osc
1.0 mA
Bias
V
N
in
+
0
-
P
Error Amp compensation circuit for stabilizing current mode boost
and flyback topologies operating with continuous inductor current.
C
From V
R
p
2R
I
pk
p
R
50% DC
=
V
O
GS
R
5(9)
i
V
Waveforms
R
(Pin 1)
d
A(min)
3 R
+
0
-
C
f
- 1.4
S
. The
25% DC
R
1(1)
2(3)
f
N S
N p
2.5V
EA
+
1.0mA
2R
R
5(9)