MC79M12BDTRKG from onsemi, in a DPAK-3. 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	GND	power_in	Common ground reference. Must be shared between the input and output voltages of the regulator.
2	VI	power_in	Negative input voltage. Must remain typically at least 1.1 V more negative than VO (dropout), even at the high point of input ripple. Absolute maximum input voltage is −35 Vdc.
3	VO	power_out	Regulated −12 V negative output (nominal −12 V, ±4% tolerance; −11.5 V to −12.5 V at TJ = 25°C). Delivers up to 500 mA with adequate heatsinking; a 1.0 µF output capacitor is recommended for stability and transient response.
4	TAB	power_in	DPAK metal tab; electrically connected to the input pin (pin 2, VI) on this negative regulator family. Provides the primary thermal path to the PCB copper and should be soldered to a heatsinking copper pad.

Key specifications

Parameter	Value
Manufacturer	onsemi
Package	DPAK-3
Category	PMIC
Pins	4

Ordering variants

Same part, different packaging or reel option.

MC79M12BDTRKG
MC79M12BDTRKGBDTG
MC79M12BDTRKGCDT
MC79M12BDTRKGCDTG
MC79M12BDTRKGCDTRK
MC79M12BDTRKGCDTRKG
MC79M12BDTRKGBT
MC79M12BDTRKGBTG
MC79M12BDTRKGCT
MC79M12BDTRKGCTG

CAD (KiCad official)

Symbol: MC79M12BDTRKG
Footprint: Package_TO_SOT_SMD:TO-252-2
3D model: DPAK-3 (KiCad packages3D, STEP)

Provenance

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

Datasheet: onsemi datasheet (9 pp, sha256 cab487486a5292f6, 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