KA3843A Datasheet, PDF (1/9 Pages) Wing Shing Computer Components – Current���� Mode��PWM��Cont roller

Current Mode PWM Controller
KA3843A(AM)
DESCRIPTION
The KA3843AM are fixed frequency current mode PWM
controller. They are specially designed for OFF−Line and DC to DC converter applications
with a minimal external components. Internally implemented circuits include a trimmed
oscillator for precise duty cycle control, a temperature compensated reference, high gain
error amplifier, current sensing comparator, and a high current totempole output ideally
suited for driving a power MOSFET. Protection circuitry includes built undervoltage lockout
and current limiting.
The corresponding thresholds for the The KA3843AM are 8.4V(on) and 7.6V (off)
The KA3843AM can operate within 100% duty cycle.
The KA3843AM has Start-Up Current 0.17mA (typ).
FEATURES
• Low Start-Up and Operating Current
• High Current Totem Pole Output
• Undervoltage Lockout With Hysteresis
• Operating Frequency Up To 500KHz
PIN
CONNECTION
(TOP VIEW)
BLOCK DIAGRAM
Absolute Maximum Ratings
Characteristic
Supply Voltage (low impedance
source)
Output Current
Input Voltage (Analog Inputs pins 2,3)
Error Amp Output Sink Current
Power Dissipation (T_A=25⁰C)
Storage Temperature Range
Lead Temperature (soldering 5 sec.)
Symbol
V_CC
I_O
V_I
I_{SINK (E.A)}
P_O
Tstg
T_L
Value
30
±1
−0.3 to 5.5
10
1
-65 to150
260
Unit
V
A
V
mA
W
o_C
o_C
1