Loads on click. Unloads only if this page sits in the background.

Symbol & Footprint

Schematic Symbol

Open full view ↗
Loads on click. Unloads only if this page sits in the background.

PCB Footprint

Open full view ↗
Loads on click. Unloads only if this page sits in the background.
Loads on click. Unloads only if this page sits in the background.
Download PDF
Contents

README

markdown

LM5021MMX-1

Texas Instruments · AC-DC Controllers and Regulators · VSSOP-8-0.65mm

LM5021MMX-1 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 COMP input Control input for the PWM and Hiccup comparators. Internally pulled up through a 5 kΩ resistor to allow biasing an opto-coupler transistor for isolated feedback. Open-circuit voltage ~5.1 V, short-circuit current ~1.1 mA.
2 VIN power_in Input to the start-up regulator. Directly connected to the rectified high-voltage bus. Internally clamped to 36 V (typ) by a zener diode; recommended operating range 8-30 V, absolute max 30 V to GND with 5 mA clamp current.
3 VCC power_out Output of the internal linear bias supply regulator, nominally 8.5 V (regulator current limit ~22 mA). Supplies the controller and gate driver sections. Requires an external bypass capacitor to GND. Regulator enables at ~7 V and disables at ~5.8 V.
4 OUT output MOSFET gate driver output. High-current push-pull driver to the external power MOSFET gate, with source/sink capability of 0.3 A / 0.7 A respectively.
5 GND power_in Ground return for the device. All bypass and timing components should reference this pin with a short, low-inductance path.
6 CS input Current sense input for current-mode control and over-current protection. Cycle-by-cycle current limit threshold ~0.5 V. If CS exceeds 0.5 V above the OUT-off level (>~0.5 V during a leading edge), OUT is switched low. CS is held low for 90 ns after OUT switches high to blank the leading-edge current spike (internal sinking impedance ~35 Ω). Absolute max 1.25 V.
7 RT/SYNC bidirectional Oscillator timing resistor pin and synchronization input. An external resistor from RT to GND sets the oscillator frequency (e.g. 44.2 kΩ → 150 kHz, 13.3 kΩ → 500 kHz). Also accepts synchronization pulses from an external clock (sync threshold ~3.2 V).
8 SS output Soft-start and hiccup timing pin. An external capacitor combined with the internal 22 µA current source sets the soft-start ramp. The same capacitor controls the hiccup-mode period during persistent overload. Open-circuit voltage ~5.2 V.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

  • LM5021MMX-1
  • LM5021MMX-1MM-1
  • LM5021MMX-1N-1

CAD (KiCad official)

  • Symbol: LM5021MMX-1
  • 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 (37 pp, sha256 c6cf9f41dac472b2, retrieved 2026-08-17, tier: lcsc)
  • Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
  • 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