---
name: lp5912q1-1drvrq1-usage
description: >
  Use when adding a quiet 1.1 V (or other fixed-voltage LP5912-Q1) rail to a board, or
  when placing, wiring, thermally sizing or ordering the TI LP5912Q1.1DRVRQ1. Covers pin
  mapping, the input/output capacitors that keep it stable, EN and power-good wiring,
  exposed-pad and thermal layout for the WSON-6 (DRV) package, dropout and power-budget
  math, picking a different voltage option, and how to pull the symbol, footprint and 3D
  into KiCad or Fusion 360. Trigger words: LP5912, LP5912-Q1, LP5912Q1.1DRVRQ1, automotive
  LDO, AEC-Q100 regulator, 500 mA LDO, low noise LDO, low IQ LDO, 1.1 V rail, clean analog
  supply, PLL or SerDes core supply, power good pin, LDO thermal pad, C5220610, WSON-6 LDO.
user-invocable: true
---

**Parent skill:** [adom/lp5912q1-1drvrq1](https://wiki.adom.inc/adom/lp5912q1-1drvrq1), the
component page carrying the symbol, footprint, 3D, Fusion library and datasheet.

# Using the LP5912Q1.1DRVRQ1

A 500 mA fixed-1.1 V LDO with 12 µV<sub>RMS</sub> noise and 30 µA quiescent current,
AEC-Q100 grade 1. Use it where a switcher's ripple is unacceptable: PLL and VCO supplies,
SerDes and PHY core rails, ADC/DAC analog supplies, image-sensor rails.

## Pin mapping

| Pin | Name | Connect to |
|---|---|---|
| 6 | IN | the upstream rail, 1.6–6.5 V, with 1 µF ceramic to GND at the pin |
| 1 | OUT | the load, with 1 µF ceramic to GND at the pin |
| 4 | EN | a rail or a GPIO. Tie to IN for always-on; the internal 3 MΩ pulldown keeps it off if left floating |
| 3 | PG | a pullup (10–100 kΩ) to whatever rail reads it, then a GPIO. Leave open if unused |
| 5 | GND | ground plane |
| 2 | NC | leave open, or tie to GND |
| 7 | EP | ground copper under the package. Never to any other potential |

## The capacitors are not optional

Stability is specified with **1 µF ceramic on IN and 1 µF on OUT**. What matters is the
effective capacitance in-circuit: ≥ 0.5 µF must survive DC bias and temperature, so at
1.1 V a 1 µF X7R 0402/0603 is the safe pick. C<sub>OUT</sub> may range 0.7–10 µF with
5–500 mΩ ESR. No noise-bypass capacitor is needed; that is the point of this part.

## Dropout, thermals, and the power budget

Dropout at 500 mA is 170 mV typ / 250 mV max for output options below 3.3 V, so the input
must stay above ~1.35 V for a full-current 1.1 V rail. In practice the input is a 3.3 V or
5 V rail, and then **dissipation, not dropout, is the limit**:

    P = (VIN − 1.1 V) × IOUT

At 3.3 V in, 300 mA out that is 0.66 W. With R<sub>θJA</sub> = 71.2 °C/W (JEDEC high-K,
two vias under the pad) the junction runs ~47 °C above ambient: fine at 85 °C ambient,
marginal at 105 °C. Feed it from the lowest rail available, and if the drop is large,
pre-regulate with a switcher and let the LP5912 clean up the result.

Thermal layout, in order of effect: solder the exposed pad to a ground pour, put at least
two 0.2 mm vias in the pad into an inner ground layer, and give the pour room to spread on
both sides of the board.

## Enable and power good

- **EN** thresholds are 1.3 V (on) and 0.3 V (off), so a 1.8 V or 3.3 V GPIO drives it
  directly. Turn-on is ~200 µs to 95% of V<sub>OUT</sub>, with internal soft-start and ≤5%
  overshoot. When EN goes low, a 100 Ω internal pulldown discharges OUT.
- **PG** is open-drain: it releases high once V<sub>OUT</sub> passes 94% of nominal (with a
  140 µs delay) and pulls low below 90%. It cannot source current, so without a pullup it
  reads as a floating input, not a logic high. Sequence downstream rails off this pin
  instead of guessing a delay.

## Layout rules that matter

1. **Both capacitors at the pins.** Loop area from IN/OUT through the cap to GND is what
   sets the real PSRR. Route GND from each cap to the pad's ground via, not across the pour.
2. **Exposed pad = thermal path, not a supply pin.** It is internally tied to the die
   substrate; connect it to ground or leave it floating, never to VIN or VOUT.
3. **Small package.** 2.00 × 2.00 mm body, 0.65 mm pitch, 0.35 × 0.60 mm pads on a 2.10 mm
   span, courtyard 3.20 × 2.60 mm. TI's example stencil is ~88% paste coverage on the
   exposed pad. If your assembler prints 100%, expect float on reflow.
4. **Keep OUT quiet.** Do not run the 1.1 V rail under a switcher inductor; the low noise
   figure is a property of the part, not of the copper around it.

## Picking another voltage

The DRV package is stocked at 0.9, 1.1, 1.2, 1.5, 1.8, 2.8, 3.0 and 3.3 V; the family
covers 0.8–5.5 V in 25 mV steps to order. **Same symbol, same footprint, same 3D**, so swap
the MPN in the BOM only. Options ≥ 3.3 V tighten to ±2% and 95 mV typ dropout; this 1.1 V
option is ±3%.

## Getting the CAD in

```bash
adom-wiki pkg install adom/lp5912q1-1drvrq1   # symbol + footprint + STEP + GLB + .lbr
```

- **KiCad**: add `LP5912Q1_1DRVRQ1.kicad_sym` to sym-lib-table and the directory holding
  `SON65P200X200X80-7N.kicad_mod` to fp-lib-table, both as the nickname
  `LP5912Q1_1DRVRQ1`. The symbol's Footprint field already reads
  `LP5912Q1_1DRVRQ1:SON65P200X200X80-7N`, and the footprint points at
  `lp5912q1-1drvrq1.step` for the 3D viewer.
- **Fusion 360 Electronics**: open `LP5912Q1_1DRVRQ1.lbr` directly. It carries the symbol,
  the package, and a complete deviceset.
- **Altium**: `adom-lbr export-altium lp5912q1-1drvrq1.adom-lbr.json` for .SchLib + .PcbLib,
  or `export-intlib` for one .IntLib.

## Ordering

Mouser `595-LP5912Q1.1DRVRQ1`, DigiKey `296-46972-2-ND`, LCSC `C5220610`. The `DRVR`
suffix is the 3000-piece reel; the `DRVT` (250-piece) variants of this family are obsolete,
so specify DRVR. Part marking on the package is `12QH`.
