LM3402MMX from Texas Instruments, in a VSSOP-8-0.65mm. 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	SW	output	Switch node. Drain of the internal high-side N-channel MOSFET; connect to the output inductor and the cathode of the recirculating Schottky diode. Swings between VIN and about -1 V during switching.
2	BOOT	passive	High-side MOSFET gate-drive bootstrap pin. Connect a 10-nF ceramic capacitor from BOOT to SW to develop the boosted gate-drive rail. BOOT-to-SW rating is 14 V max.
3	DIM	input	PWM dimming / enable input. Logic-level input (VIH >= 2.2 V, VIL <= 0.8 V) that gates the power MOSFET to modulate average LED current or place the part in low-power shutdown. Has an internal ~75 uA pull-up so the pin defaults high.
4	GND	power_in	Device ground. Connect directly to the system ground plane and to the return of CIN, CF, and RSNS.
5	CS	input	LED current-sense feedback input. Regulated to VREF-REG = 200 mV (typical) above GND; sets LED current via RSNS from CS to GND (ILED = 0.2 V / RSNS). CS above ~300 mV triggers the over-voltage / open-LED comparator that turns SW off.
6	RON	input	ON-time programming pin. A resistor from RON to VIN sets the controlled switch ON-time and thus the switching frequency of the hysteretic loop. Pulling RON below the shutdown threshold (~0.7 V) also forces the part into low-power shutdown.
7	VCC	power_out	Output of the internal 7-V linear regulator that supplies the gate-drive and control circuits. Bypass to GND with a >= 0.1 uF X5R/X7R ceramic capacitor. Not intended to source external loads (current limit ~16 mA).
8	VIN	power_in	Input supply pin. 6 V to 42 V operating range on the LM3402 (6 V to 75 V on the LM3402HV). Decouple locally to GND with CIN. Absolute-maximum 45 V (LM3402) / 76 V (HV).

Key specifications

Parameter	Value
Manufacturer	Texas Instruments
Package	VSSOP-8-0.65mm
Category	LED-drv
Pins	8

Ordering variants

Same part, different packaging or reel option.

LM3402MMX
LM3402MMXMR
LM3402MMXMRX

CAD (KiCad official)

Symbol: LM3402MMX
Footprint: Package_SO:VSSOP-8_2.3x2mm_P0.5mm
3D model: VSSOP-8-0.65mm (KiCad packages3D, STEP)

Provenance

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

Datasheet: Texas Instruments datasheet (42 pp, sha256 a2d1eed98007c56f, 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