UC2845BN STMicroelectronics, UC2845BN Datasheet - Page 9

• Manufacturer Part Number: UC2845BN
• Description: IC CTRLR PWM CURR-MODE 8-MINIDIP
• Manufacturer: STMicroelectronics

Specifications of UC2845BN

• Pwm Type: Current Mode
• Number Of Outputs: 1
• Frequency - Max: 500kHz
• Duty Cycle: 50%
• Voltage - Supply: 8.2 V ~ 25 V
• Buck: No
• Boost: Yes
• Flyback: Yes
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: Yes
• Operating Temperature: -25°C ~ 85°C
• Package / Case: 8-DIP (0.300", 7.62mm)
• Frequency-max: 500kHz
• Duty Cycle (max): 50 %
• Output Voltage: 4.95 V to 5.05 V
• Output Current: 1000 mA (Max)
• Mounting Style: Through Hole
• Switching Frequency: 500 KHz
• Operating Supply Voltage: 30 V
• Maximum Operating Temperature: 150 C
• Fall Time: 50 ns
• Minimum Operating Temperature: - 40 C
• Rise Time: 50 ns
• Synchronous Pin: No
• Topology: Boost or Flyback
• Number Of Pwm Outputs: 1
• On/off Pin: No
• Adjustable Output: No
• Switching Freq: 500kHz
• Operating Supply Voltage (max): 30V
• Operating Temperature Classification: Automotive
• Mounting: Through Hole
• Pin Count: 8
• Package Type: PDIP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-3680; 497-3680-5; 497-3680

Figure 19 : Isolated MOSFET Drive and Current Transformer Sensing.
Figure 18 : Slope Compensation Techniques.
R
I
S
S
5.0V ref
+
+
-
R
-
R
SLOPE
1
COMP/LATCH
R
S
Q
+
-
R
C
I
R
SENSE
T
T
V
V
T
REG
/C
CC
T
7
8
4
3
D95IN349
UC3842B
5
GND
6
3
C
BOUNDARY
ISOLATION
R
UC2842B/3B/4B/5B - UC3842B/3B/4B/5B
R
S
R
I
S
S
R
R
SLOPE
1
N
S
Q1
V
in
N
P
R
C
I
R
T
T
SENSE
V
T
REG
/C
+
0
-
I
pk
T
50% DC
=
V
8
4
3
V
(pin 1)
GS
3R
UC3842B
Waveforms
S
-1.4
5
+
0
-
GND
( )
D95IN348
25% DC
N
N
S
P
9/15