KA3843 ESTEK [Estek Electronics Co. Ltd], KA3843 Datasheet - Page 3

• Manufacturer Part Number: KA3843
• Description: fixed frequency current mode PWM controller
• Manufacturer: ESTEK [Estek Electronics Co. Ltd]

Pin functions
N
1
2
3
4
5
6
7
8
Function
COMP
V
I
R
GROUND
OUTPUT
V
V
SENSE
FB
T
CC
ref
/C
T
V
CC
7
This pin is the Error Amplifier output and is made for loop compensation.
This is the inverting input of the Error Amplifier. It is normall y connected to the switching power supply
A voltage proportional to inductor current is connected to this input. The PWM uses this information to
The oscillator frequency and maximum Output duty cycle are programmed by connecting resistor R
This pin is the combined control circuitry and power ground.
This output directly drives the gate of a power MOSFET. Peak currents up to 1A are sourced and sink by
This pin is the positive supply of the integrated circuit.
This is the reference output. It provides charging current for capacitor C
output through a resistor divider.
terminate the output switch conduction.
and capacitor C
this pin.
R
S
ON/OFF COMMAND TO S/R OF IC
I
S
R
C
V
V
T
ON
OFF
to ground.
Application information
CURRENT
SENSE
COMP
COMP
V
V
Figure 1. Error Amp Configuration
GND
FB
FB
Figure 2. Undervoltage Lockout
Figure 3. Current Sense Circuit
MIK3842 MIK3843
MIK3844 MIK3845
16V
10V
Peak current is determined by
5
2
_
1
3
+
1
2
2.5V
ERROR
AMP
8.4V
7.6V
3
Description
2R
0.2mA
13mA
R
1mA
I
CC
I
S max
1V
During UVLO, the Output is low
1.0V
R
CURRENT
S
SENSE
COMPARATOR
V
OFF
BEIJING ESTEK ELECTRONICS CO.,LTD
T
through resistor R
V
ON
V
CC
T
.
T
to V
ref