# ADS8638SRGER

**Texas Instruments** · Analog To Digital Converters (ADC) · QFN-24-EP(4x4)

ADS8638SRGER from Texas Instruments, in a QFN-24-EP(4x4). Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | AVDD | power_in | Analog power supply; supply voltage range 2.7V to 5.25V. |
| 2 | AGND | power_in | Analog ground connection for analog circuits. |
| 3 | AGND | power_in | Analog ground connection for analog circuits. |
| 4 | NC | unconnected | Not internally connected; must not float and should be connected to AGND. |
| 5 | AINGND | power_in | Analog input ground sense terminal for all input channels; operates within ±0.2V of system ground. |
| 6 | AIN7 | input | Analog input channel 7; voltage range software-selectable from ±10V, ±5V, ±2.5V, 0-5V, or 0-10V. |
| 7 | AIN6 | input | Analog input channel 6; voltage range software-selectable from ±10V, ±5V, ±2.5V, 0-5V, or 0-10V. |
| 8 | AIN5 | input | Analog input channel 5; voltage range software-selectable from ±10V, ±5V, ±2.5V, 0-5V, or 0-10V. |
| 9 | AIN4 | input | Analog input channel 4; voltage range software-selectable from ±10V, ±5V, ±2.5V, 0-5V, or 0-10V. |
| 10 | AIN3 | input | Analog input channel 3; voltage range software-selectable from ±10V, ±5V, ±2.5V, 0-5V, or 0-10V. |
| 11 | AIN2 | input | Analog input channel 2; voltage range software-selectable from ±10V, ±5V, ±2.5V, 0-5V, or 0-10V. |
| 12 | AIN1 | input | Analog input channel 1; voltage range software-selectable from ±10V, ±5V, ±2.5V, 0-5V, or 0-10V. |
| 13 | AIN0 | input | Analog input channel 0; voltage range software-selectable from ±10V, ±5V, ±2.5V, 0-5V, or 0-10V. |
| 14 | HVDD | power_in | High-voltage positive supply for multiplexer channels; range 5V to 15V with (HVDD - HVSS) restricted to 10V to 30V. |
| 15 | HVSS | power_in | High-voltage negative supply for multiplexer channels; range -15V to 0V with (HVDD - HVSS) restricted to 10V to 30V. |
| 16 | CS | input | Chip select digital input; active-low signal that controls frame synchronization and conversion start. |
| 17 | SCLK | input | Serial clock input; maximum frequency 20MHz at DVDD = 3.3V; controls data shift timing and conversion. |
| 18 | DIN | input | Serial data input; 16-bit command words latched on SCLK rising edges for device configuration and control. |
| 19 | DOUT | tri_state | Serial data output; 16-bit conversion results or register data shifted out on SCLK falling edges; transitions to high-Z when CS is high. |
| 20 | DGND | power_in | Digital ground connection for digital circuits. |
| 21 | DVDD | power_in | Digital I/O power supply; supply voltage range 1.65V to 5.25V. |
| 22 | AL_PD | bidirectional | Programmable pin functioning as active-high alarm output or active-low asynchronous power-down input; features internal pull-up to DVDD when configured as input. |
| 23 | REFGND | power_in | Reference ground terminal; provides return path for external reference circuit or decoupling ground for internal reference. |
| 24 | REF | input | Voltage reference input; accepts 2.0V to 3.0V external reference or serves as decoupling terminal for internal 2.5V precision reference. |
| 25 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | QFN-24-EP(4x4) |
| Category | Data Acquisition |
| Pins | 25 |

## CAD (KiCad official)

- Symbol: `ADS8638SRGER`
- Footprint: `Package_DFN_QFN:QFN-24-1EP_4x4mm_P0.5mm_EP2.6x2.6mm`
- 3D model: QFN-24-EP(4x4) (KiCad packages3D, STEP)
- 3D model files: `ads8638srger-etched.step` / `ads8638srger-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ads8638srger.step` / `ads8638srger.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/ads8638) (75 pp, sha256 `88befd8fff5977e4`, retrieved 2026-09-23, 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 0.2`, primary `claude-haiku-4-5-20251001` (text), consensus `claude-sonnet-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/ads8638srger-datasheet.pdf)