Current Mode PWM Controller

1

PIN

CONNECTION

(TOP VIEW)

DESCRIPTION

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

can operate within 100% duty cycle.

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

BLOCK DIAGRAM

Absolute Maximum Ratings

Characteristic

Symbol

Value

Unit

Supply Voltage (low impedance

source)

30

V

Output Current

±1

A

Input Voltage (Analog Inputs pins 2,3)

−0.3 to 5.5

V

Error Amp Output Sink Current

10

mA

1

W

Storage Temperature Range

Tstg

-65 to150

Lead Temperature (soldering 5 sec.)

260

KA3843A(AM)

The KA3843AM

The KA3843AM are 8.4V(on) and 7.6V (off)

The KA3843AM

The KA3843AM

500KHz