AP3842CMTR-E1 from Diodes Incorporated, in a SOIC-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	COMP	output	Error Amplifier output, made available for external loop compensation (typically an R-C network to VFB).
2	VFB	input	Inverting input of the Error Amplifier. Normally connected to the switching power supply output through a resistor divider; internal reference is 2.50 V.
3	ISENSE	input	Current-sense input. A voltage proportional to inductor/switch current is applied here; PWM uses this to terminate output switch conduction on a cycle-by-cycle basis (internal 1 V current-limit threshold).
4	RT/CT	passive	Oscillator timing pin. Frequency and maximum duty cycle are programmed by connecting resistor RT to VREF and capacitor CT to ground. Operation up to 500 kHz.
5	GND	power_in	Combined control circuitry and power ground. All voltages are referenced to this pin.
6	OUTPUT	output	Totem-pole gate-drive output for an external power MOSFET. Peak sink/source currents up to ±1 A.
7	VCC	power_in	Positive supply of the control IC. Absolute maximum 30 V; UVLO on/off thresholds of 16 V/10 V (AP3842C).
8	VREF	power_out	5 V reference output. Provides charging current for the oscillator timing capacitor CT through resistor RT and may be used to bias external circuitry.

Key specifications

Parameter	Value
Manufacturer	Diodes Incorporated
Package	SOIC-8
Category	PMIC
Pins	8

Ordering variants

Same part, different packaging or reel option.

AP3842CMTR-E1
AP3842CMTR-G1
AP3842CMTR-E1CM-E1
AP3842CMTR-E1CM-G1
AP3842CMTR-E1CP-E1
AP3842CMTR-E1CP-G1

CAD (KiCad official)

Symbol: AP3842CMTR-E1
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

Provenance

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

Datasheet: Diodes Incorporated datasheet (14 pp, sha256 becb61c7269e054e, retrieved 2026-08-17, tier: lcsc)
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