# LM5009AMMX

**Texas Instruments** · DC-DC Converters · VSSOP-8-0.65mm

LM5009AMMX from Texas Instruments, in a VSSOP-8-0.65mm. 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 | SW | output | Switching node: power switching node connected to the output inductor, recirculating diode, and bootstrap capacitor. |
| 2 | BST | input | Boost pin (bootstrap capacitor input) requiring an external capacitor between BST and SW, with a 0.01-µF ceramic capacitor recommended. |
| 3 | RCL | input | Current limit OFF-time set pin; a resistor between RCL and RTN sets the OFF time when current limit is detected, preset to 35 µs if FB = 0 V. |
| 4 | RTN | power_in | Ground pin providing ground for the entire circuit. |
| 5 | FB | input | Feedback input from the regulated output to the inverting input of the internal regulation comparator, with a regulation threshold of 2.5 V. |
| 6 | RT/SD | input | On-time set pin; a resistor between RT/SD and VIN sets the switch on time, with a minimum recommended on time of 400 ns at maximum input voltage, and the pin is also used for remote shutdown. |
| 7 | VCC | power_out | Output of the internal high-voltage series pass regulator providing gate drive power, current limited to 9 mA, requiring a local 0.47-µF decoupling capacitor. |
| 8 | VIN | power_in | Input voltage pin with an operating input range of 6 V to 95 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | VSSOP-8-0.65mm |
| Category | Power Management (PMIC) |
| Pins | 8 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| VIN to GND | VIN | -0.3 |  | 100 | V |  | 4 |
| BST to GND | BST | -0.3 |  | 114 | V |  | 4 |
| SW to GND (steady state) | SW | -1 |  |  | V | steady state | 4 |
| BST to VCC | BST-VCC |  |  | 100 | V |  | 4 |
| BST to SW | BST-SW |  |  | 14 | V |  | 4 |
| VCC to GND | VCC |  |  | 14 | V |  | 4 |
| All other inputs to GND |  | -0.3 |  | 7 | V |  | 4 |
| Storage temperature | Tstg | -55 |  | 150 | °C |  | 4 |
| Input voltage | VIN | 6 |  | 95 | V |  | 4 |
| Operating junction temperature | TJ | -40 |  | 125 | °C |  | 4 |
| Junction-to-ambient thermal resistance (DGK) | RθJA |  | 157.7 |  | °C/W | DGK (VSSOP) 8 pins | 4 |
| Junction-to-case (top) thermal resistance (DGK) | RθJC(top) |  | 50.2 |  | °C/W | DGK (VSSOP) 8 pins | 4 |
| Junction-to-board thermal resistance (DGK) | RθJB |  | 77.9 |  | °C/W | DGK (VSSOP) 8 pins | 4 |
| VCC regulator output | VCC Reg | 6.6 | 7 | 7.4 | V | VIN = 48 V | 5 |
| Iin operating current | Iin |  | 550 | 750 | µA | FB = 3 V, VIN = 48 V | 5 |
| Iin shutdown current | Iin |  | 110 | 176 | µA | RT/SD = 0 V | 5 |
| Current limit threshold |  | 0.24 | 0.3 | 0.36 | A |  | 5 |
| ON-time generator | TON-1 | 2.15 | 2.77 | 3.5 | µs | VIN = 10 V, RON = 200 K | 5 |
| ON-time generator | TON-2 | 200 | 300 | 420 | ns | VIN = 95 V, RON = 200 K | 5 |
| Remote shutdown threshold | RT/SD | 0.4 | 0.7 | 1.05 | V | Rising | 5 |
| FB reference threshold | FB | 2.445 | 2.5 | 2.55 | V | Internal reference, trip point for switch ON | 5 |
| Buck switch RDS(ON) | RDS(ON) |  | 2.2 | 4.6 | Ω | Itest = 200 mA | 6 |
| Gate drive UVLO | Vbst, Vsw | 2.8 | 3.8 | 4.8 | V | Vbst, Vsw rising | 6 |

## CAD (KiCad official)

- Symbol: `LM5009AMMX`
- Footprint: `Package_SO:VSSOP-8_2.3x2mm_P0.5mm`
- 3D model: VSSOP-8-0.65mm (KiCad packages3D, STEP)
- 3D model files: `lm5009ammx-etched.step` / `lm5009ammx-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm5009ammx.step` / `lm5009ammx.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Texas Instruments datasheet](https://www.ti.com/lit/ds/symlink/lm5009a.pdf) (30 pp, sha256 `9fc4082d8b7a33e9`, retrieved 2026-11-05, tier: manufacturer)
- **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/lm5009ammx-datasheet.pdf)