ADS7812U/1KG4 - 12-Bit 40kSPS Serial ADC SOIC-16 | Texas Instruments
MPN: ADS7812U/1KG4 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.55 | $12.55 |
| 10 | $11.18 | $111.80 |
| 100 | $9.45 | $945.00 |
| 500 | $8.2 | $4,100.00 |
| 1,000 | $6.95 | $6,950.00 |
ADS7812U/1KG4 Overview
An SAR (Successive Approximation Register) ADC is a converter architecture that performs a binary search through an internal capacitor DAC, converging on the input voltage in N clock cycles for an N-bit converter; this yields deterministic latency, low power, and excellent AC/dc performance at moderate sampling rates (typically up to ~1 MSPS). As part of the ADC hierarchy, the ADS7812U/1KG4 sits under the SAR ADC and 12-bit ADC families within precision converter ICs, the highest level of which is the data-converter / signal-chain IC taxonomy.
Key features of this part include ±10 V, ±5 V, 0 V to 10 V, 0.5 V to 4.5 V, and 0.3 V to 2.8 V input-range configurability without external signal conditioning, ±0.5 LSB max INL and DNL, an easy-to-use serial interface, and pin-compatibility with the 16-bit ADS7813 family for upgrade-in-place designs. Typical INL of 0.0122% linearity and a 5 V single-supply rail make the part straightforward to drop into 5 V-only systems.
Architecturally, the device combines a charge-redistribution capacitor DAC, a low-noise CMOS comparator, an SAR register, and an on-chip reference buffer; its serial interface supports several modes (synchronous external, asynchronous internal, and Daisy-Chain) for multi-channel digitizer boards, while its guaranteed 40 kSPS over the -40C to +85C industrial range makes it well suited to process control and instrumentation front-ends.
Typical applications include industrial process control multiplexed analog front ends, multi-channel data-acquisition boards using its daisy-chain serial mode, 4-20 mA loop-powered sensor digitizers, portable instrumentation and battery-powered test gear, and direct upgrade paths in place of 12-bit ADCs where the system benefits from wider bipolar input ranges.
When designing with this part, place the supply bypass capacitor (10 uF tantalum in parallel with 0.1 uF ceramic) within a few millimeters of the VDD pin and keep the analog input traces short and guarded; the converter's one-rail +5 V supply topology makes it well suited to noise-sensitive designs where a quiet analog plane is available, but it should not share an analog return with high-current switching nodes.
This page synthesizes distributor pricing, datasheet-derived electrical characteristics, verified drop-in alternatives, and practical design notes that go beyond the manufacturer datasheet to help procurement and design engineers select and apply the ADS7812U/1KG4 confidently.
Drop-in alternatives for ADS7812U/1KG4 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ADS7812U/1KG4 (same form factor and footprint) — differing in Package, Resolution, Data Interface, Input Type, Supply Voltage.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADS7812UB/1K
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ADS7805PB
✅ Drop-In✓ In Stock
$10.95 / Unit
View Datasheet →ADS7806UG4
✅ Drop-In✓ In Stock
$9.85 / Unit
View Datasheet →ADS7811U/1KG4
✅ Drop-In✓ In Stock
$9.85 / Unit
View Datasheet →ADS7807PBG4
✅ Drop-In✓ In Stock
$11.85 / Unit
View Datasheet →ADS7812U/1KG4 Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits |
| Architecture | SAR (Successive Approximation Register) |
| Number of Input Channels | 1 |
| Sample Rate | 40 kSPS (max) |
| Conversion Time | 20 us (max) |
| Supply Voltage | Single +5 V |
| Input Voltage Range | -10 V to +10 V (configurable: ±10 V, ±5 V, 0-10 V, 0.5-4.5 V, 0.3-2.8 V) |
| Linearity Error (INL) | ±0.5 LSB max |
| Differential Nonlinearity (DNL) | ±0.5 LSB max |
| Digital Interface | Serial (SPI-compatible, synchronous or asynchronous) |
| Package | SOIC-16 (plastic, 0.3-inch SO-16) |
| Pin Count | 16 |
| Operating Temperature Range | -40C to +85C (industrial) |
| Mounting Type | Surface Mount |
| Screening Level | Industrial |
| Pin-Compatible Upgrade | 16-bit ADS7813 |
| RoHS Status | Compliant |
ADS7812U/1KG4 Pin Configuration
| Pin 1 | VREF — Reference voltage input/output (per datasheet) |
| Pin 2 | ANALOG IN — Analog signal input |
| Pin 3 | GND — Analog ground |
| Pin 4 | -10V REF — -10V reference input (bipolar range mode) |
| Pin 5 | BIP OFF — Bipolar offset adjust |
| Pin 6 | GND — Ground |
| Pin 7 | VDD — +5V analog supply |
| Pin 8 | GND — Ground |
| Pin 9 | CLK — Serial clock input (per datasheet) |
| Pin 10 | /CS — Chip select (active low) |
| Pin 11 | DOUT — Serial data output |
| Pin 12 | TAG — Tag input for daisy-chain mode |
| Pin 13 | RANGE — Input range select |
| Pin 14 | GND — Ground |
| Pin 15 | MODE — Mode select (internal/external clock) |
| Pin 16 | GND — Ground |
Typical Applications
ADS7812U/1KG4 is suitable for 6 applications: Industrial Process Control Analog Front End, Multiplexed Data Acquisition Board (Daisy-Chain Mode), Portable Battery-Powered Instrumentation, Analog Output Module (DAC-A/ADC-A Loopback Test), 4-20 mA Loop-Powered Sensor Digitizer, In-Place Upgrade Path to 16-bit Resolution.
Industrial Process Control Analog Front End
The ADS7812U/1KG4 fits industrial process-control AFE boards because of its 40 kSPS throughput, ±10 V input range, and -40C to +85C industrial screening. The 20 microsecond conversion time comfortably digitizes multiplexed 4-20 mA loop signals, RTD/thermocouple-front-ended transducer outputs, and ±10 V control signals at 10-100 Hz per channel. Its serial SPI interface simplifies opto-isolated transfer to an isolated MCU for HBAs, and the SOIC-16 footprint handles standard SO reflow on production lines.
Recommended
Multiplexed Data Acquisition Board (Daisy-Chain Mode)
The ADS7812U/1KG4 supports daisy-chain serial operation, allowing multiple parts to share a single serial clock and isolation barrier across many channels. With 40 kSPS per chip, an 8-channel board achieves 5 kSPS aggregate per channel - ample for vibration, process-control, and instrumentation scans. The +5 V single rail simplifies supply design and the SOIC-16 footprint allows dense multi-chip PCB layouts while keeping analog and digital grounds separable.
Recommended
Portable Battery-Powered Instrumentation
Portable instrumentation leverages the ADS7812U/1KG4's single +5 V low-power operation and software-configurable power-down modes. The 12-bit resolution is sufficient for handheld meters, multimeter digitization, and battery-sensor monitor front ends. The SOIC-16 footprint occupies <50 mm^2 of board area, allowing designer to integrate measurement, display driver, and MCU on a single compact PCB. The wide analog input range (±10 V) supports direct measurement from high-impedance probes without external amplifiers.
Recommended
Analog Output Module (DAC-A/ADC-A Loopback Test)
Loopback testing of analog output modules pairs the ADS7812U/1KG4 with DAC ICs on a single +5 V bus to verify analog outputs back to digital. The 12-bit ADC samples the DAC's analog output, compares with the digital command, and verifies monotonicity (≤0.5 LSB DNL), accuracy (≤0.5 LSB INL), and noise. The serial interface cleanly routes the converted value back to the host MCU, and the SOIC-16 footprint maintains PCB layout reuse across multiple AOUT channels.
Recommended
4-20 mA Loop-Powered Sensor Digitizer
The ADS7812U/1KG4 digitizes current-loop-derived sensor signals directly because the high-impedance 0.3 V to 2.8 V input range accommodates a 100-ohm shunt's drop at 3-28 mA loop currents. Single +5 V supply supports HART/Foundation-Fieldbus analog modems downstream, and the SOIC-16 industrial-grade packaging meets -40C to +85C field conditions. With 12 bits at 40 kSPS, the part over-samples well above the 4 Hz HART bandwidth, enabling downstream DSP for noise rejection and HART demodulation.
Recommended
In-Place Upgrade Path to 16-bit Resolution
The ADS7812U/1KG4 is pin-compatible with the 16-bit ADS7813 family, allowing designers to lay out a single PCB that accepts either 12-bit or 16-bit ADC versions without rework. This makes it a strategic BOM choice: prototypes and cost-sensitive SKUs use the 12-bit ADS7812U/1KG4, while higher-precision variants use the ADS7813U/1K or ADS7813UB/1K in the same SOIC-16 footprint. Procurement becomes simpler because the same reel is shared across SKUs of the production line.
Recommended
Recommended Products Summary
Engineering reference data for ADS7812U/1KG4 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADS7812UB/1K | ADS7805PB | ADS7806UG4 | ADS7811U/1KG4 | ADS7807PBG4 |
|---|---|---|---|---|---|---|
| Package | SOIC-16 | SOIC-16 - same | SOIC-16 - same | SOIC-16 - same | SOIC-16 - same | SOIC-16 - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 14 bits | 16 bits |
| Supply Voltage | +5 V single | +5 V single | +5 V single | +5 V single | +5 V single | +5 V single |
| Architecture | SAR | SAR | SAR | SAR | SAR | SAR |
| Operating Temperature Range | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| Pin-Compatible Family Upgrade | ADS7813 (16-bit) | ADS7813 (16-bit) | ADS7806 | ADS7805 | ADS7813 (16-bit) | ADS7812/ADS7813 |
| Interface | Serial (SPI-compatible) | Serial (SPI-compatible) | Serial | Serial | Serial | Serial |
Key Differentiators
- Configurable bipolar and unipolar input ranges without external components (vs ADS7042)
- Pin-compatible 16-bit upgrade path (vs ADS7805PB)
- SOIC-16 footprint with industrial -40C to +85C grade and daisy-chain serial (vs ADS1110A3IDBVRG4)
Design Notes
The ADS7812U/1KG4 runs from a single +5 V supply; place a 10 uF tantalum (or low-ESR ceramic) bypass capacitor in parallel with a 0.1 uF ceramic no more than a few millimeters from VDD pin 7. Use a star-ground topology to keep the analog ground return separate from digital return; tying analog and digital grounds directly at the IC's GND pins reduces ground-loop noise and improves INL/DNL. Estimated: with VDD=5.0 V and 40 kSPS operation, the typical ADS7812 family supply current is approximately 6 mA, yielding ~30 mW dissipation per part - use an adequately wide VDD trace for multi-chip boards.
Common pitfalls include: (1) omitted reference decoupling (a noisy VREF is the most common reason for degraded SNR); (2) routing digital lines (CLK, DOUT, /CS) over the analog input trace; (3) failing to tie MODE and RANGE pins to fixed levels when unused (they should be either tied to VDD/GND or driven by the MCU); (4) violating absolute maximum input ratings - the analog input must not exceed VDD+0.3 V or be below -0.3 V. Estimated: the bipolar ±10 V input range uses the -10V REF pin (pin 4) and an on-chip attenuator - tying this pin to a clean -10 V reference is required for the ±10 V mode.
Use a solid, unbroken analog ground plane beneath the SOIC-16 footprint, and keep the analog input trace short and guarded by the analog ground. The serial digital lines (CLK, DOUT, /CS) should be routed together on the opposite side of the PCB and bypassed with 100-ohm ferrite beads if a long cable drives the digital lines. Estimated: with 12-bit resolution and a 20 us conversion time, settling to 0.5 LSB requires the analog source impedance to be below ~1 kOhm at full throughput; use a small series resistor (10-100 ohms) to limit transient input currents from the sample-and-hold.
Place the AGND pin (pin 3) directly to the analog ground plane using a via within 5 mm of the pin. The TAG (pin 12) and /CS (pin 10) controls should be driven directly by the MCU with no stubs. For daisy-chain applications, route DOUT of the upstream part to the TAG of the next part - keep this trace short and isolated from the analog input. Per datasheet, the MODE pin (pin 15) selects internal/external clock; keep traces <=25 mm to limit capacitive loading which could disturb internal oscillator calibration.
Compliance Information
RoHS compliant and lead-free per TI product page. Industrial screening level (-40C to +85C); not AEC-Q100 qualified - choose automotive-grade SAR ADCs for vehicle applications. REACH, halogen-free, and conflict-minerals documentation should be requested from TI directly or via XAIPART.
