I2C-Compatible, 12-Bit Analog-to-Digital Converter with Alert Pin


Product details


Resolution (Bits) 12 Number of input channels 1 Sample rate (Max) (kSPS) 189 Interface type I2C Architecture SAR Input type Single-Ended Multi-channel configuration Rating Catalog Reference mode Supply Input range (Max) (V) 5.5 Input range (Min) (V) 0 Features Oscillator, Small Size Operating temperature range (C) -40 to 105 Power consumption (Typ) (mW) 0.26 Analog voltage AVDD (Min) (V) 2.7 SNR (dB) 72.5 Analog voltage AVDD (Max) (V) 5.5 INL (Max) (+/-LSB) 1 Digital supply (Min) (V) 2.7 Digital supply (Max) (V) 5.25 open-in-new Find other Precision ADCs (<=10MSPS)

Package | Pins | Size

SOT-23-THN (DDC) 6 5 mm² 2.9 x 1.6 VSSOP (DGK) 8 15 mm² 3 x 4.9 open-in-new Find other Precision ADCs (<=10MSPS)


  • I2C-Compatible 2-Wire Interface Which Supports Standard (100kHz), Fast (400kHz), and High Speed (3.4MHz) Modes
  • Extended Power Supply Range (+2.7V to +5.5V)
  • Up to Nine Pin-Selectable Chip Addresses (VSSOP Only)
  • Out-of-Range Alert Function
  • Automatic Power-Down Mode while Not Converting
  • Very Small 6-Pin SOT and 8-Pin VSSOP Packages
  • ADC121C021Q is an Automotive Grade Product that is AEC-Q100 Grade 2 Qualified

Key Specifications

  • Resolution: 12 Bits (No Missing Codes)
  • Conversion Time: 1µs (Typ)
  • INL & DNL: ±1 LSB (Max) (Up to 22ksps)
  • Throughput Rate: 188.9 ksps (Max)
  • Power Consumption (at 22 ksps)
    • 3V Supply: 0.26 mW (Typ)
    • 5v Supply: 0.78 mW (Typ)

All trademarks are the property of their respective owners. I2C is a trademark of Texas Instruments.

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These converters are low-power, monolithic, 12-bit, analog-to-digital converters (ADCs) that operates from a +2.7 to 5.5V supply. The converter is based upon a successive approximation register architecture with an internal track-and-hold circuit that can handle input frequencies up to 11MHz. These converters operate from a single supply which also serves as the reference. The device features an I2C-compatible serial interface that operates in all three speed modes, including high speed mode (3.4MHz).

The ADC121C021's Alert feature provides an interrupt that is activated when the analog input violates a programmable upper or lower limit value. The device features an automatic conversion mode, which frees up the controller and I2C interface. In this mode, the ADC continuously monitors the analog input for an "out-of-range" condition and provides an interrupt if the measured voltage goes out-of-range.

The ADC121C021 comes in two packages: a small 6-pin SOT package with an alert output, and an 8-pin VSSOP package with an alert output and two address selection inputs. The   ADC121C021Q is available in a 6-pin SOT package. The ADC121C027 comes in a small 6-pin SOT package with an address selection input. The ADC121C027 provides three pin-selectable addresses while the 8-pin VSSOP version of the ADC121C021 provides nine pin-selectable addresses. Pin-compatible alternatives to the 6-pin SOT options are available with additional address options.

Normal power consumption using a +3V or +5V supply is 0.26mW or 0.78mW, respectively. The automatic power-down feature reduces the power consumption to less than 1µW while not converting. Operation over the industrial temperature range of −40°C to +105°C is ensured. Their low power consumption and small packages make this family of ADCs an excellent choice for use in battery operated equipment.

The ADC121C021 and ADC121C027 are part of a family of pin-compatible ADCs that also provide 8 and 10 bit resolution. For 8-bit ADCs see the ADC081C021 and ADC081C027. For 10-bit ADCs see the ADC101C021 and ADC101C027.

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Technical documentation

= Top documentation for this product selected by TI
No results found. Please clear your search and try again. View all 4
Type Title Date
* Datasheet ADC121C021/C021Q/C027 I2C-Compatible, 12-Bit ADC with Alert Function datasheet (Rev. F) Mar. 19, 2013
E-book Best of Baker's Best: Precision Data Converters -- SAR ADCs May 21, 2015
User guide ADC121C021EVM Booster Pack User’s Guide Sep. 30, 2014
User guide ADC1X1C02X Evaluation Board User Guide Jan. 25, 2012

Design & development

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Hardware development

document-generic User guide

The ADC121C021EVM is a demonstration kit for the ADC121C021, a 12-bit, 1-channel, 188.9ksps, 2-wire interface SAR analog-to-digital converter.  The EVM allows users to evaluate the operation and performance of the ADC121C021 data converter.  The board contains an external analog (...)

  1. On-board analog temperature sensor, LMT84, for quick reading
  2. LaunchPad booster pack
  3. Power by USB

Design tools & simulation

PSpice® for TI design and simulation tool
PSPICE-FOR-TI — PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
  • Leverages Cadence PSpice Technology
  • Preinstalled library with a suite of digital models to enable worst-case timing analysis
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  • Supports simultaneous analysis of multiple products
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SPICE-based analog simulation program
TINA-TI TINA-TI provides all the conventional DC, transient and frequency domain analysis of SPICE and much more. TINA has extensive post-processing capability that allows you to format results the way you want them. Virtual instruments allow you to select input waveforms and probe circuit nodes voltages (...)
document-generic User guide
Analog-to-digital converter (ADC) input driver design tool supporting multiple input types
ADC-INPUT-CALC ADC-INPUT-CALC is an online tool that provides support for designing the input buffer to an analog-to-digital converter (ADC). It offers 24 different op-amp based buffer circuits that can be used to drive an ADC input. The available topologies cover differential, single-ended and transformer-coupled (...)
Analog engineer's calculator
ANALOG-ENGINEER-CALC — The Analog Engineer’s Calculator is designed to speed up many of the repetitive calculations that analog circuit design engineers use on a regular basis. This PC-based tool provides a graphical interface with a list of various common calculations ranging from setting op-amp gain with feedback (...)
  • Expedites circuit design with analog-to-digital converters (ADCs) and digital-to-analog converters (DACs)
    • Noise calculations
    • Common unit translation
  • Solves common amplifier circuit design problems
    • Gain selections using standard resistors
    • Filter configurations
    • Total noise for common amplifier configurations
  • (...)

CAD/CAE symbols

Package Pins Download
SOT-23-THIN (DDC) 6 View options
VSSOP (DGK) 8 View options

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