# ADS8028IRTJR

**Texas Instruments** · Analog To Digital Converters (ADC) · QFN-20-EP(4x4)

ADS8028IRTJR from Texas Instruments, in a QFN-20-EP(4x4). 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 | AIN3 | input | Analog input channel 3, with an input range of 0 V to VREF. |
| 2 | AIN4 | input | Analog input channel 4, with an input range of 0 V to VREF. |
| 3 | AIN5 | input | Analog input channel 5, with an input range of 0 V to VREF. |
| 4 | AIN6 | input | Analog input channel 6, with an input range of 0 V to VREF. |
| 5 | AIN7 | input | Analog input channel 7, with an input range of 0 V to VREF. |
| 6 | AGND | power_in | Analog ground; DGND to AGND must remain within -0.3 V to +0.3 V. |
| 7 | REF | bidirectional | ADC internal reference output or external reference input; REF to AGND is limited to AVDD + 0.3 V. |
| 8 | NC | unconnected | No internal connection; a passive component on this pin does not affect device functionality. |
| 9 | DGND | power_in | Digital ground for the digital interface; DGND to AGND must remain within -0.3 V to +0.3 V. |
| 10 | AVDD | power_in | ADC operation supply, 2.7 V to 5.25 V; DVDD must not exceed AVDD + 0.3 V. |
| 11 | CS | input | Active-low chip select; the ADS8028 samples the analog input on the CS falling edge and digital inputs are limited to DVDD + 0.3 V. |
| 12 | TM_BUSY | output | Busy output that stays high during conversion, including the up-to-100 µs temperature sensor conversion; digital outputs are limited to DVDD + 0.3 V. |
| 13 | DIN | input | SPI data input, latched on the first 16 SCLK falling edges after CS falls; setup time 5 ns and hold time 4 ns. |
| 14 | DOUT | output | SPI data output that leaves 3-state after CS falls and returns to 3-state on the 16th SCLK falling edge or CS rising edge. |
| 15 | SCLK | input | SPI serial clock input, up to 20 MHz, used for both conversion and data transfer. |
| 16 | DVDD | power_in | ADC interface supply, 1.65 V to 5.25 V; must satisfy DVDD ≤ AVDD + 0.3 V. |
| 17 | PD/RST | input | Active-low dual-function pin: a low pulse under 60 ns resets the device, while a low pulse over 90 ns powers it down. |
| 18 | AIN0 | input | Analog input channel 0, with an input range of 0 V to VREF. |
| 19 | AIN1 | input | Analog input channel 1, with an input range of 0 V to VREF. |
| 20 | AIN2 | input | Analog input channel 2, with an input range of 0 V to VREF. |
| 21 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | QFN-20-EP(4x4) |
| Category | Data Acquisition |
| Pins | 21 |

## CAD (KiCad official)

- Symbol: `ADS8028IRTJR`
- Footprint: `Package_DFN_QFN:QFN-20-1EP_4x4mm_P0.5mm_EP2.5x2.5mm`
- 3D model: QFN-20-EP(4x4) (KiCad packages3D, STEP)
- 3D model files: `ads8028irtjr-etched.step` / `ads8028irtjr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ads8028irtjr.step` / `ads8028irtjr.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/ads8028) (36 pp, sha256 `2f47b48c9576bc45`, retrieved 2026-10-08, 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/ads8028irtjr-datasheet.pdf)