UC3843BNG from onsemi, in a PDIP-8. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	Compensation	output	Error amplifier output. Available for loop compensation; an external RC network from this pin to Voltage Feedback (pin 2) sets the closed-loop frequency response of the error amplifier.
2	Voltage Feedback	input	Inverting input of the error amplifier. Normally connected to the switching power supply output through a resistor divider; the amplifier's non-inverting input is internally biased to 2.5 V.
3	Current Sense	input	Non-inverting input of the current sense comparator. Monitors switch current via a ground-referenced sense resistor; the internal PWM latch resets when this input reaches ~1.0 V, providing cycle-by-cycle current limiting.
4	RT/CT	passive	Oscillator timing pin. A resistor from Vref to this pin (RT) and a capacitor from this pin to GND (CT) program the oscillator frequency and maximum output duty cycle. Guaranteed operation to 500 kHz.
5	GND	power_in	Signal and power ground return for the IC. In the PDIP-8 / SOIC-8 package, control and power ground share this single pin (the SOIC-14 splits these into separate GND and Power Ground pins).
6	Output	output	High-current totem-pole PWM output, directly drives the gate of a power MOSFET. Sources/sinks up to 1.0 A peak (200 mA typical); output is low when UVLO is active. Rise/fall times ~50 ns into 1.0 nF.
7	VCC	power_in	Positive supply for control logic and the totem-pole output stage. For the UC3843B, UVLO turn-on is 8.4 V typical and turn-off is 7.6 V typical; startup current is 0.3 mA typical, with an internal zener clamp at ~36 V.
8	Vref	power_out	Trimmed 5.0 V reference output (±1% for UC3843B; ±2% for UC2843B/NCV3843BV). Delivers up to 20 mA to external loads and is used to bias the RT/CT timing resistor. Short-circuit protected (~-85 mA typical).

Key specifications

Parameter	Value
Manufacturer	onsemi
Package	PDIP-8
Category	PMIC
Pins	8

Ordering variants

Same part, different packaging or reel option.

UC3843BNGN
UC3843BNG
UC3843BNGD1
UC3843BNGD1G
UC3843BNGD1R2
UC3843BNGD1R2G
UC3843BNGD
UC3843BNGDG
UC3843BNGDR2
UC3843BNGDR2G

CAD (KiCad official)

Symbol: UC3843BNG
Footprint: Package_DIP:DIP-8_W7.62mm
3D model: PDIP-8 (KiCad packages3D, STEP)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: onsemi datasheet (21 pp, sha256 0a568e6a851b8837, retrieved 2026-08-17, tier: manufacturer)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF