# L5991D013TR

**STMicroelectronics** · AC-DC Controllers And Regulators · SO-16

L5991D013TR from STMicroelectronics, in a SO-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: as master it delivers positive pulses during the oscillator fall, and as slave it is edge-triggered by an external sync pulse (low level 1V max, high level 3.5V min). |
| 2 | RCT | passive | Oscillator pin for the external CT, RA and RB components that set the normal-mode frequency fosc and standby frequency fSB. |
| 3 | DC | input | Duty cycle control: a voltage between 1V and 3V sets the maximum duty cycle between 0 and Dx, a voltage below 1V inhibits the driver output, and leaving it floating gives no duty-cycle limit (internal pull-up holds it above 3V). |
| 4 | VREF | power_out | Reference voltage of 5.0V ±1.5% at 25°C able to deliver some mA to an external circuit, with a small film capacitor (0.1µF typ.) recommended to SGND. |
| 5 | VFB | input | Error amplifier inverting input, compared against the internal 2.5V reference to set the control voltage. |
| 6 | COMP | output | Error amplifier output, used for loop compensation connected to VFB; its voltage is also monitored to enter standby, with thresholds VT1 2.5V and VT2 4V. |
| 7 | SS | passive | Soft-start pin: external capacitor Css to SGND is charged by an internal current (ISSC, 14 to 26µA) up to about 7V. |
| 8 | VCC | power_in | Supply for the internal signal circuitry; the device starts above the startup voltage (15V typ. for L5991, 8.4V typ. for L5991A) and shuts down below the UVLO threshold, with an internal zener limiting VCC to 25V. |
| 9 | VC | power_in | Supply for the power section feeding the external switch driver, which absorbs pulsed current and needs a buffer capacitor to PGND (pin 11). |
| 10 | OUT | output | High-current totem-pole driver output (1.6A source, 2A sink peak) for a power MOSFET or BJT, with an internal clamp limiting the gate voltage to 13V. |
| 11 | PGND | power_in | Power ground: the return path for the external MOSFET gate discharge current, which should be kept short and separate from signal currents. |
| 12 | SGND | power_in | Signal ground referencing the control circuitry; all ground connections of the control-function external parts must lead to this pin. |
| 13 | ISEN | input | Current sense input connected to the hot end of Rsense, where the switch is turned off at the peak-current threshold and a voltage above 1.2V triggers hiccup overcurrent protection, with about 100ns leading-edge blanking. |
| 14 | DIS | input | Device disable: when the voltage rises above 2.5V the IC shuts down (latched) until VCC is pulled below the UVLO threshold; it must never be left floating and should be tied to SGND if unused. |
| 15 | DC-LIM | input | Maximum duty-cycle limit: connecting it to VREF limits the duty cycle to 50% and halves the output frequency, while floating or grounding it imposes no limit. |
| 16 | ST-BY | passive | Standby function pin: connect a resistor to RCT (with RA) to set the standby frequency; connect it to VREF or leave it floating if the standby function is not used. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | STMicroelectronics |
| Package | SO-16 |
| Category | Power Management (PMIC) |
| Pins | 16 |

## CAD (KiCad official)

- Symbol: `L5991D013TR`
- Footprint: `Package_SO:SOIC-16_3.9x9.9mm_P1.27mm`
- 3D model: SO-16 (KiCad packages3D, STEP)
- 3D model files: `l5991d013tr-etched.step` / `l5991d013tr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `l5991d013tr.step` / `l5991d013tr.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [STMicroelectronics datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603324805299261440) (23 pp, sha256 `cbc01f22c7c35f41`, retrieved 2026-10-07, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-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).

[Datasheet PDF](docs/l5991d013tr-datasheet.pdf)