component
L5991AD
Public Made by Adomby adom
STMicroelectronics AC-DC Controllers And Regulators, SOIC-16. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownL5991AD
STMicroelectronics · AC-DC Controllers And Regulators · SOIC-16
L5991AD from STMicroelectronics, in a SOIC-16. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | SYNC | bidirectional | Synchronization pin operating as clock output in master mode (7mA typical source capability, 4V amplitude) or edge-triggered slave input for external frequency synchronization. |
| 2 | RCT | bidirectional | Oscillator timing node connected to external RC network for frequency control; internal circuit charges and discharges timing capacitor between 1V valley and 3V peak. |
| 3 | DC | input | Duty cycle control input; voltage 1-3V sets maximum duty cycle between 0% and upper limit Dx, <1V inhibits output, floating or >3V selects maximum. |
| 4 | VREF | power_out | 5.0V±1.5% reference voltage output (0.4mV/°C temperature coefficient, 2mV line regulation, 2mV load regulation at 1-10mA output current). |
| 5 | VFB | input | Error amplifier inverting input for feedback signal; compared to internal 2.5V reference with 60-90dB open-loop gain and 1.7-4MHz unity-gain bandwidth. |
| 6 | COMP | output | Error amplifier output for frequency compensation network connection; voltage monitored for standby frequency reduction at light load. |
| 7 | SS | output | Soft-start control pin; external capacitor charged by 14-26µA current source (at 25°C) ramping to 7V clamp voltage for smooth power-up. |
| 8 | VCC | power_in | Signal circuit supply; 7.8-9V startup threshold (L5991A) with 7-8.2V minimum operating voltage (L5991A) and internal 25V zener clamp. |
| 9 | VC | power_in | Power stage driver supply that absorbs pulsed current when driving external switch gate; buffer capacitor recommended near IC. |
| 10 | OUT | output | Totem-pole driver output to external power switch; 1.6A peak source (NPN Darlington), 2A peak sink (VDMOS), 13V internal gate clamp, 20-100ns rise/fall time. |
| 11 | PGND | power_in | Power ground; return path for pulsed gate drive current loop to external switch. |
| 12 | SGND | power_in | Signal ground; reference point for all control circuitry and external control signal returns. |
| 13 | ISEN | input | Current sense input from external resistor hot lead; 100ns internal leading-edge blanking, 1.1-1.3V fault threshold, 2.85-3.15V/V transfer gain. |
| 14 | DIS | input | Device disable control input; threshold >2.5V triggers shutdown with restart requiring VCC below UVLO, must be tied to SGND if unused. |
| 15 | DC-LIM | input | Duty cycle limit control; connection to VREF sets maximum duty cycle to approximately 50%, floating or grounded allows full maximum duty cycle. |
| 16 | ST-BY | input | Standby mode control input; resistor RB to RCT pin sets normal frequency (fosc), connect to VREF or leave floating to enable light-load mode (<13% rated power). |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | STMicroelectronics |
| Package | SOIC-16 |
| Category | Power Management (PMIC) |
| Pins | 16 |
CAD (KiCad official)
- Symbol:
L5991AD - Footprint:
Package_SO:SOIC-16_3.9x9.9mm_P1.27mm - 3D model: SOIC-16 (KiCad packages3D, STEP)
- 3D model files:
l5991ad-etched.step/l5991ad-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);l5991ad.step/l5991ad.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: STMicroelectronics datasheet (19 pp, sha256
a0e39653f17acfa3, retrieved 2026-10-05, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-haiku-4-5-20251001(text), consensusclaude-sonnet-5-5(agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish. - CAD: KiCad official libraries (CC-BY-SA 4.0).