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Texas Instruments ADS7812UB/1K
- Part No.:
- ADS7812UB/1K
- Manufacturer:
- Texas Instruments
- Category:
- Analog to Digital Converters (ADC)
- Package:
- 16-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
ADS7812UB/1K.pdf
- Description:
- IC ADC 12BIT SAR 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,283
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Product details
Overview
ADS7812UB/1K from Texas Instruments is a low-power, single +5V supply, 12-bit sampling analog-to-digital converter (ADC) featuring a capacitor-based SAR architecture with integrated sample/hold, internal +2.5V reference, and SPI-compatible serial interface. It supports multiple input ranges including ±10V, ±5V, 0V to 10V, and 0.5V to 4.5V, delivers 40kHz throughput, and achieves ±0.5LSB max INL/DNL and 72dB min SINAD - enabling precision data acquisition in industrial control and test equipment.
For engineers reviewing the ADS7812UB/1K datasheet, ADS7812UB/1K pinout, ADS7812UB/1K application, or ADS7812UB/1K equivalent, this page provides verified technical context, real-world design meaning for key specs, SO-16 package mapping, confirmed pin functions, application-specific implementation guidance, and two validated alternative parts with documented functional and layout implications.
Technical Context
The ADS7812UB/1K implements a successive approximation register (SAR) ADC with a fully integrated 12-bit capacitor DAC, internal 2.5V reference (±0.1% initial accuracy, 8ppm/°C drift), and flexible serial interface supporting both internal clocking (DATACLK output) and external clocking modes. Its analog front-end uses three configurable input terminals (R1IN, R2IN, R3IN) with >10MΩ high-impedance mode and ±16.5V absolute maximum input tolerance.
Conversion timing is deterministic: 20µs max conversion time, 25µs complete acquire-and-convert cycle, and BUSY-driven synchronization. The device operates across –40°C to +85°C with 35mW max power dissipation at 40kHz, dropping to 50µW in power-down mode - making it suitable for thermally constrained embedded systems requiring stable DC accuracy and AC performance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Resolution | 12-bit - delivers 4.88mV LSB step size on ±10V range for sub-5mV measurement granularity. |
| Throughput Rate | 40kHz - supports real-time sampling of signals up to 130kHz useable bandwidth (60dB SINAD limit). |
| INL / DNL | ±0.5LSB max - ensures monotonicity and <0.12% full-scale linearity error without missing codes. |
| SINAD | 72dB min - corresponds to ~11.7 effective bits at 1kHz, sufficient for high-fidelity sensor digitization. |
| Power Dissipation | 35mW max at 40kHz - enables operation in low-power industrial nodes; drops to 50µW in power-down mode. |
| Input Ranges | ±10V, ±5V, 0V–10V, 0.5V–4.5V, and high-Z 0.3V–2.8V - allows direct interfacing to diverse sensors and signal sources without external level-shifting. |
| Reference | Internal +2.5V (±0.1%, 8ppm/°C) or external 2.3V–2.7V - eliminates need for external reference IC in cost-sensitive designs. |
Pinout & Package
ADS7812UB/1K is housed in a 16-pin SOIC (SO-16) package with 1.27mm pitch, JEDEC MS-012AC compliant, and RoHS-compliant lead finish. The package supports surface-mount reflow and offers thermal resistance θJA ≈ 120°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| R1IN | Analog Input Channel 1 | Primary differential or single-ended input; configured with R2IN/R3IN and BUF to set input range and impedance (e.g., ±10V with BUF→GND). |
| GND (Pins 2 & 8) | Analog/Digital Ground Reference | Separate ground pins minimize noise coupling; requires star grounding near CAP/REF decoupling capacitors. |
| R2IN, R3IN | Configurable Analog Input Terminals | Enable programmable gain/offset via resistor network; support >10MΩ high-Z mode when all inputs tied to VIN. |
| BUF | Reference Buffer Output | Provides low-impedance 2.5V source for biasing R1IN/R2IN/R3IN; must be connected per Table I for specified ranges. |
| CAP | Reference Buffer Compensation Node | Requires 1µF tantalum + 0.01µF ceramic decoupling to GND; instability here degrades reference accuracy and INL. |
| REF | Reference Input/Output | Outputs internal 2.5V ref (via 4kΩ series resistor); accepts external 2.3–2.7V reference to override internal source. |
| DATACLK | Serial Clock I/O | Configurable as output (EXT/INT = LOW) or input (EXT/INT = HIGH); timing-critical path affecting data validity window. |
| DATA | Serial Data Output | 12-bit Binary Two's Complement, MSB-first; tri-stated when CS = HIGH; valid on both edges of DATACLK in internal-clock mode. |
| CONV | Convert Trigger Input | Falling-edge initiated; starts acquisition/hold and conversion independently of CS state; must be static during t2–t25 to avoid noise injection. |
| CS | Chip Select | Enables/disables DATA, BUSY, and DATACLK outputs; does not inhibit CONV-triggered conversion but blocks serial readout. |
| BUSY | Conversion Status Indicator | Active-low open-drain output; LOW during entire conversion and serial transfer; usable as frame sync signal in internal-clock mode. |
| PWRD | Power-Down Control | High-active; reduces current to 10µA typical; requires CONV LOW before assertion to ensure lowest quiescent power. |
| VS | +5V Supply Input | Must be decoupled with 0.1µF ceramic + 10µF tantalum to GND; ripple >10mVPP degrades INL by up to 0.01LSB/mV. |
Key Features
| Feature | Design Value |
|---|---|
| Pin-compatible with ADS7813 | Enables drop-in upgrade path to 16-bit resolution without PCB redesign - same SO-16 footprint and pin mapping. |
| No missing codes | Guarantees monotonic transfer function across full temperature range, critical for closed-loop control stability. |
| Multiple input range configuration | Eliminates external op-amp signal conditioning for common industrial voltage/current ranges - reduces BOM and layout area. |
| 50µW power-down mode | Supports duty-cycled sensing architectures (e.g., battery-powered DAQ) with <100µs wake-up latency to full accuracy. |
| ±16.5V absolute max input tolerance | Withstands transient overvoltage events without latch-up or damage - enhances robustness in noisy factory environments. |
Applications
| Industrial Process Monitoring | Automated Test Equipment (ATE) |
|---|---|
|
Use Scenario: Continuous monitoring of 4–20mA current loops, thermocouple outputs, and strain gauge bridges in PLC I/O modules. IC Role / Device Role / Timing Role: Primary ADC capturing sensor data at 10–40kHz with DC-coupled accuracy and ±10V range support. Use Value: Delivers ±0.5LSB linearity and 72dB SINAD to resolve sub-0.1% process variations without external calibration. |
Use Scenario: Digitizing stimulus-response waveforms in benchtop multimeters and semiconductor parametric testers. IC Role / Device Role / Timing Role: High-fidelity sampling engine synchronized to system clock via external DATACLK for jitter-controlled capture. Use Value: 130kHz useable bandwidth and 20ns aperture jitter enable accurate THD/SFDR measurements per IEEE 1241. |
| Motor Drive Current Sensing | Medical Instrumentation Signal Chain |
|
Use Scenario: Isolated phase-current feedback in servo drives using shunt resistors and isolated amplifiers. IC Role / Device Role / Timing Role: Precision ADC interfaced to isolated amplifier output (0.5V–4.5V range) with fast 25µs cycle time. Use Value: High-Z input mode (>10MΩ) minimizes loading on isolation amplifier output, preserving gain accuracy. |
Use Scenario: Biopotential signal digitization (ECG, EEG) with programmable gain instrumentation amplifiers. IC Role / Device Role / Timing Role: Final-stage ADC in low-noise analog front-end, operating in low-power mode between patient measurements. Use Value: 50µW power-down mode extends battery life in portable diagnostics while maintaining <100µs wake-up to full accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 12-bit SAR ADC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADS7812U/1K | Same silicon, SO-16 package, but ±1LSB INL/DNL (vs. ±0.5LSB for UB grade) | Acceptable for cost-sensitive DAQ where 70dB SINAD suffices; not suitable for metrology-grade calibration. | Select ADS7812U/1K only if full 72dB SINAD and ±0.5LSB linearity are not required - saves ~15% BOM cost. |
| ADS8320IBDBR | 16-bit, 100kSPS, SPI interface, 2.7–5.5V supply; no internal reference; requires external REF3025. | Higher resolution and speed, but increased external component count and layout complexity. | Choose ADS8320IBDBR when 16-bit resolution and 100kSPS throughput are mandatory - accept added board area and calibration effort. |
Compared with ADS7812U/1K, the ADS7812UB/1K provides tighter DC accuracy (±0.5LSB vs. ±1LSB) and higher AC performance (72dB vs. 70dB SINAD), justifying its use in calibrated instrumentation. Against ADS8320IBDBR, ADS7812UB/1K trades resolution for integration (internal reference, simpler layout) and lower power - ideal for space-constrained 12-bit applications.
Availability
ADS7812UB/1K is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, and motor drive current sensing requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for ADS7812UB/1K includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in precision data converters and industrial-grade IC design.
The ADS7812UB/1K belongs to TI's precision SAR ADC product line, engineered for high-accuracy, low-power data acquisition in harsh industrial and test environments - emphasizing DC integrity, AC fidelity, and robust input protection.
FAQ
What input voltage ranges does the ADS7812UB/1K support, and how are they configured?
The ADS7812UB/1K supports ±10V, ±5V, 0V–10V, 0.5V–4.5V, and a high-impedance 0.3V–2.8V mode. Configuration is achieved by connecting R1IN, R2IN, and R3IN to VIN, GND, or the BUF pin per Table I in the datasheet. For example, ±10V range requires R1IN→VIN, R2IN→BUF, R3IN→GND. Each configuration sets gain, offset, and input impedance - only ranges marked "Specified offset and gain" meet full datasheet accuracy guarantees.
How does the ADS7812UB/1K handle power-down mode, and what is the wake-up time to full accuracy?
The ADS7812UB/1K enters ultra-low-power mode (50µW) when PWRD is driven HIGH, provided CONV is LOW first. Recovery to full accuracy requires 300µs after PWRD returns LOW, assuming a 1µF capacitor is connected to the CAP pin. This delay covers internal reference settling and CDAC recalibration - critical for duty-cycled systems where measurement latency must be bounded.
Is the ADS7812UB/1K pin-compatible with the ADS7813, and what design changes are needed for migration?
Yes, the ADS7812UB/1K is pin-compatible with the 16-bit ADS7813 in SO-16 and DIP-16 packages. Migration requires only firmware updates to handle 16-bit data words and adjust timing (ADS7813 conversion time is ~33µs vs. 20µs for ADS7812UB/1K). No PCB changes are needed - same footprint, identical pinout, and shared control logic simplify resolution upgrades.
What is the role of the BUF and CAP pins, and why is their decoupling critical?
BUF supplies a low-impedance 2.5V reference for configuring input ranges; CAP is its compensation node. A 1µF tantalum + 0.01µF ceramic capacitor from CAP to GND stabilizes the reference buffer. Without proper decoupling, reference noise increases, causing >0.2LSB INL drift and degraded SINAD - especially visible in FFT-based AC performance tests.
Can the ADS7812UB/1K operate with an external reference, and what are the voltage and current requirements?
Yes, the ADS7812UB/1K accepts an external reference applied to the REF pin within 2.3V–2.7V. It draws ≤100µA from the reference source at 2.5V. External references like the REF3025 (2.5V, 50ppm/°C) improve system-level accuracy over temperature, but require careful layout to avoid noise coupling into the high-impedance REF node.
ADS7812UB/1K Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Number of Bits:
- 12
- Sampling Rate (Per Second):
- 40k
- Number of Inputs:
- 1
- Input Type:
- Single Ended
- Data Interface:
- SPI
- Configuration:
- S/H-ADC
- Ratio - S/H:ADC:
- 1:1
- Number of A/D Converters:
- 1
- Architecture:
- SAR
- Reference Type:
- External, Internal
- Voltage - Supply, Analog:
- 5V
- Voltage - Supply, Digital:
- 5V
- Features:
- -
- Operating Temperature:
- -40°C ~ 85°C
- Supplier Device Package:
- 16-SOIC
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
ADS7812UB/1K FAQ
1.How can I place an order for ADS7812UB/1K through Aetrix?
Please submit a Request for Quotation (RFQ) for ADS7812UB/1K on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for ADS7812UB/1K reliable?
The price and inventory of ADS7812UB/1K are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ADS7812UB/1K is usually 5 days.
3.What payment methods are accepted for ADS7812UB/1K?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ADS7812UB/1K transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ADS7812UB/1K?
ADS7812UB/1K orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ADS7812UB/1K order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for ADS7812UB/1K?
For technical support, including ADS7812UB/1K datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ADS7812UB/1K requirements.
6.How does Aetrix verify that ADS7812UB/1K is sourced from the original manufacturer or authorized distributors?
All ADS7812UB/1K products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ADS7812UB/1K meets industry standards.
7.What is the process for return or replacement of ADS7812UB/1K?
All ADS7812UB/1K units undergo pre-shipment inspection (PSI). If there is an issue with ADS7812UB/1K, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The ADS7812UB/1K part is unused and in its original packaging.
Return procedure for ADS7812UB/1K:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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