# LM3492HCMHX

**Texas Instruments** · LED Drivers · HTSSOP-20-EP

LM3492HCMHX from Texas Instruments, in a HTSSOP-20-EP. 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 | EN | input | Enable input with an internal pullup; connect to a voltage higher than 1.63 V to provide precision enable for the device. |
| 2 | VIN | power_in | Input supply voltage pin; the input voltage range is 4.5 V to 65 V. |
| 3 | SW | output | Switch node, internally connected to the drain of the integrated MOSFET. |
| 4 | SW | output | Switch node, internally connected to the drain of the integrated MOSFET. |
| 5 | VOUT | input | Output voltage sense pin that senses the output voltage for nearly constant switching frequency control. |
| 6 | RT | input | Frequency control pin; an external resistor from the VOUT pin to this pin sets the switching frequency. |
| 7 | FB | input | Output voltage feedback input connected through a feedback resistor divider; the voltage on this pin is from 1.05 V to 2.5 V. |
| 8 | GND | power_in | Analog signal ground; connect directly to the exposed pad beneath the device. |
| 9 | IOUT2 | input | Current regulator input for channel 2; the regulated current is programmable via the IREF pin. |
| 10 | IOUT1 | input | Current regulator input for channel 1; the regulated current is programmable via the IREF pin. |
| 11 | CDHC | input | Dynamic headroom control pin; an external capacitor sets the DHC sensitivity and a 12 µA internal current source charges it at start-up for soft start. |
| 12 | IREF | input | Current setting pin; an external resistor from this pin to ground programs the regulated current of channels 1 and 2. |
| 13 | COMM | bidirectional | Open-drain bidirectional logic pin for power-good, overtemperature, IOUT overvoltage and undervoltage indications, and command sending (switching frequency tuning and channel 1 disabling). |
| 14 | LGND | power_in | Current regulator ground; must be connected to the GND pin and exposed pad for normal operation, and is not internally connected to GND. |
| 15 | DIM1/CLK | bidirectional | Dimming control of channel 1 that turns the channel 1 current regulator on and off; internally pulled low by 5 µA, and also serves as the clock for latching COMM input and output data. |
| 16 | DIM2 | input | Dimming control of channel 2 that turns the channel 2 current regulator on and off; internally pulled low by 5 µA. |
| 17 | PGND | power_in | Integrated MOSFET ground; must be connected to the GND pin and exposed pad for normal operation, and is not internally connected to GND. |
| 18 | PGND | power_in | Integrated MOSFET ground; must be connected to the GND pin and exposed pad for normal operation, and is not internally connected to GND. |
| 19 | VCC | power_out | Internal LED regulator output, nominally regulated to 5.5 V; connect a capacitor of 0.47 µF or larger between the VCC and GND pins. |
| 20 | ILIM | input | Peak current limit adjust; an external resistor from ILIM to VCC reduces the peak current limit, and connecting ILIM to ground gives the maximum current limit. |
| 21 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | HTSSOP-20-EP |
| Category | Nixie Tube Driver/LED Driver |
| Pins | 21 |

## CAD (KiCad official)

- Symbol: `LM3492HCMHX`
- Footprint: `Package_SO:TSSOP-20-1EP_4.4x6.5mm_P0.65mm_EP2.15x3.35mm`
- 3D model: HTSSOP-20-EP, generated from the KiCad footprint (body from the F.Fab outline, terminals on the pads, 1.2 mm nominal TSSOP height). Neither the vendor nor KiCad ships a 3D model for this package, so the dimensions are nominal, not the manufacturer's CAD (STEP)
- 3D model files: `lm3492hcmhx-etched.step` / `lm3492hcmhx-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm3492hcmhx.step` / `lm3492hcmhx.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/cn/lit/gpn/lm3492hc) (32 pp, sha256 `45f254841b8a2c5b`, retrieved 2026-10-11, 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:** 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/lm3492hcmhx-datasheet.pdf)