The NCV3843BV is a high performance fixed frequency current

mode controller. They are specifically designed for Off−Line and

DC−DC converter applications offering the designer a cost−effective

solution with minimal external components. These integrated circuits

feature a trimmed oscillator for precise duty cycle control, a

temperature compensated reference, high gain error amplifier, current

sensing comparator, and a high current totem pole output ideally

suited for driving a power MOSFET.

Also included are protective features consisting of input and

reference undervoltage lockouts each with hysteresis, cycle−by−cycle

current limiting, programmable output deadtime, and a latch for single

pulse metering.

These devices are available in a surface mount (SOIC−8) plastic

package as well as the 14−pin plastic surface mount (SOIC−14). The

SOIC−14 package has separate power and ground pins for the totem

pole output stage.

The NCV3843BV is tailored for lower voltage applications having

UVLO thresholds of 8.5 V (on) and 7.6 V (off).

Features

• Trimmed Oscillator for Precise Frequency Control

• Oscillator Frequency Guaranteed at 250 kHz

• Current Mode Operation to 500 kHz

• Automatic Feed Forward Compensation

• Latching PWM for Cycle−By−Cycle Current Limiting

• Internally Trimmed Reference with Undervoltage Lockout

• High Current Totem Pole Output

• Undervoltage Lockout with Hysteresis

• Low Startup and Operating Current

• These are Pb−Free Devices