# OPA1656

**Texas Instruments** · Operational Amplifier · SOIC-8

The OPA1656 is a dual audio operational amplifier that combines the low noise of bipolar-input parts (2.9 nV/sqrt(Hz)) with the high input impedance of CMOS. Its low distortion, wide bandwidth, and ability to drive low-impedance loads suit high-fidelity preamplifiers, active filters, and headphone drivers.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | OUT A | output | Output, channel A. Rail-to-rail output capable of sourcing/sinking 100 mA and swinging to within 250 mV of the rails with a 2-kΩ load. |
| 2 | -IN A | input | Inverting input, channel A. High-impedance FET input (100 MΩ differential || 9.1 pF), input bias current typically ±10 pA. |
| 3 | +IN A | input | Noninverting input, channel A. High-impedance FET input; common-mode range (V-) to (V+) - 2.25 V. |
| 4 | V- | power_in | Negative (lowest) power supply. Dual-supply range ±2.25 V to ±18 V or single-supply 4.5 V to 36 V referenced with V+. |
| 5 | +IN B | input | Noninverting input, channel B. High-impedance FET input; common-mode range (V-) to (V+) - 2.25 V. |
| 6 | -IN B | input | Inverting input, channel B. High-impedance FET input, input bias current typically ±10 pA. |
| 7 | OUT B | output | Output, channel B. Rail-to-rail output capable of 100 mA drive; swings to within 250 mV of the rails into a 2-kΩ load. |
| 8 | V+ | power_in | Positive (highest) power supply. Supply range 4.5 V to 36 V single-supply or ±2.25 V to ±18 V dual-supply. Quiescent current 3.9 mA per channel. |

## Key specifications

| Parameter | Value |
|---|---|
| Type | Dual CMOS audio op-amp |
| Input noise voltage | 2.9 nV/sqrt(Hz) |
| THD+N | 0.00005% typ |
| Gain-bandwidth product | 53 MHz typ |
| Slew rate | 24 V/us typ |
| Supply voltage | +-2.25 V to +-18 V |
| Operating temperature | -40 C to 125 C |

## Ordering variants

Same part, different packaging or reel option.

- `OPA1656D`
- `OPA1656DR`

## CAD (KiCad official)

- Symbol: `opa1656.kicad_sym`
- Footprint: `opa1656.kicad_mod`
- 3D model: SOIC-8 body from KiCad `Package_SO/SOIC-8_3.9x4.9mm_P1.27mm`.
- 3D model files: `opa1656-etched.step` / `opa1656-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `opa1656.step` / `opa1656.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/opa1656.pdf) (42 pp, sha256 `4243b58e553e6f27`, retrieved 2026-08-17, tier: manufacturer)
- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/opa1656-datasheet.pdf)