# ADR421ARMZ

**Analog Devices** · Voltage References · MSOP-8

ADR421ARMZ from Analog Devices, in a MSOP-8. 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 | TP | passive | Test pin reserved for factory testing; it has actual internal connections, and users should not connect anything to it or the device may not function properly. |
| 2 | VIN | power_in | Input voltage pin; the ADR421 is specified for a 4.5 V to 18 V input range, with an 18 V absolute maximum supply rating. |
| 3 | NIC | unconnected | No internal connection; the pin has no internal connections. |
| 4 | GND | power_in | Ground pin, defined as 0 V. |
| 5 | TRIM | passive | Trim terminal that adjusts the output voltage over a ±0.5% range without affecting the temperature coefficient; trim network resistors and potentiometer should be low temperature coefficient types, preferably <100 ppm/°C. |
| 6 | VOUT | power_out | Voltage reference output, specified at 2.50 V for the ADR421 with up to 10 mA output current. |
| 7 | NIC | unconnected | No internal connection; the pin has no internal connections. |
| 8 | TP | passive | Test pin reserved for factory testing; it has actual internal connections, and users should not connect anything to it or the device may not function properly. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Analog Devices |
| Package | MSOP-8 |
| Category | Power Management ICs |
| 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 |
|---|---|---|---|---|---|---|---|
| Output voltage, A Grade | VOUT | 2.497 | 2.5 | 2.503 | V |  | 5 |
| Initial accuracy, A Grade (mV) | VOUTERR | -3 |  | 3 | mV |  | 5 |
| Initial accuracy, A Grade (%) | VOUTERR | -0.12 |  | 0.12 | % |  | 5 |
| Temperature coefficient, A Grade | TCVOUT |  |  | 10 | ppm/°C | −40°C < TA < +125°C | 5 |
| Supply voltage headroom | VIN − VOUT | 2 |  |  | V |  | 5 |
| Quiescent current | IIN |  | 390 | 500 | µA | No load | 5 |
| Quiescent current over temperature | IIN |  |  | 600 | µA | −40°C < TA < +125°C | 5 |
| Line regulation | ∆VOUT/∆VIN |  | 10 | 35 | ppm/V | VIN = 5 V to 18 V, −40°C < TA < +125°C | 5 |
| Output trim adjustment range |  | -0.5 |  | 0.5 | % | Adjusted via TRIM terminal | 18 |
| Supply voltage |  |  |  | 18 | V |  | 8 |
| Operating temperature range |  | -40 |  | 125 | °C |  | 8 |
| Storage temperature range |  | -65 |  | 150 | °C |  | 8 |
| Junction temperature range |  | -65 |  | 150 | °C |  | 8 |
| Lead temperature (soldering) |  |  |  | 300 | °C | Soldering, 60 sec | 8 |
| Load regulation | ∆VOUT/∆IL |  | 70 |  | ppm/mA | IL = 0 mA to 10 mA, −40°C < TA < +125°C | 5 |
| Voltage noise, 0.1 Hz to 10 Hz | eN p-p |  | 1.75 |  | µV p-p | 0.1 Hz to 10 Hz | 5 |
| Voltage noise density | eN |  | 80 |  | nV/√Hz | 1 kHz | 5 |
| Turn-on settling time | tR |  | 10 |  | µs |  | 5 |
| Long-term stability | ∆VOUT |  | 50 |  | ppm | 1000 hours | 5 |
| Output voltage hysteresis | VOUT_HYS |  | 40 |  | ppm |  | 5 |
| Ripple rejection ratio | RRR |  | -75 |  | dB | fIN = 1 kHz | 5 |
| Short circuit to GND | ISC |  | 27 |  | mA |  | 5 |
| Thermal resistance junction-to-ambient, 8-Lead MSOP | θJA |  | 190 |  | °C/W | 8-Lead MSOP (RM) | 8 |
| Thermal resistance junction-to-case, 8-Lead MSOP | θJC |  | 44 |  | °C/W | 8-Lead MSOP (RM) | 8 |

## CAD (KiCad official)

- Symbol: `ADR421ARMZ`
- Footprint: `Package_SO:MSOP-8_3x3mm_P0.65mm`
- 3D model: MSOP-8 (KiCad packages3D, STEP)
- 3D model files: `adr421armz-etched.step` / `adr421armz-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `adr421armz.step` / `adr421armz.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Analog Devices datasheet](https://www.analog.com/media/en/technical-documentation/data-sheets/ADR420_421_423_425.pdf) (24 pp, sha256 `a3f954c509a578f6`, retrieved 2026-10-30, 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/adr421armz-datasheet.pdf)