Texas Instruments ADS7829IBDRBTG4

Overview

ADS7829IBDRBTG4 from Texas Instruments is a 12-bit, 125 kSPS successive approximation register (SAR) analog-to-digital converter with pseudo-differential rail-to-rail input, SPI-compatible serial interface, and micropower operation at 2.7 V supply. It features ±1.25 LSB integral nonlinearity, 72 dB SINAD at 1 kHz, and operates from 2.0 V to 5.25 V. It is used in battery-powered sensor interfaces requiring precision, low power, and compact size.

For engineers reviewing the ADS7829IBDRBTG4 datasheet, ADS7829IBDRBTG4 pinout, ADS7829IBDRBTG4 application, or ADS7829IBDRBTG4 equivalent, key selection criteria include guaranteed 12-bit no-missing-codes performance at 2.7 V, 3 µA max shutdown current, 8-pin SON package footprint, and compatibility with external reference voltages from 50 mV to VCC.

Technical Context

The ADS7829IBDRBTG4 implements a capacitive redistribution SAR architecture fabricated in 0.6 µm CMOS, integrating sample/hold functionality without external components. Its conversion cycle requires exactly 12 DCLOCK cycles for acquisition and conversion, followed by 16-cycle serial output timing synchronized to the falling edge of DCLOCK.

It uses a synchronous 3-wire serial interface (CS/SHDN, DCLOCK, DOUT) with straight-binary output, where the first bit after CS assertion is a null bit, then 12 MSB-first data bits. The -In input is limited to –0.2 V to +1.0 V and functions as remote ground sense-not as a fully differential input-enabling common-mode rejection only for small offsets.

Key Specifications

Pinout & Package

ADS7829IBDRBTG4 is housed in an 8-pin SON (PDSO) package measuring 3 mm × 3 mm with 0.65 mm pitch, exposing a thermal pad on the bottom for enhanced heat dissipation in space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit SAR ADC applications.

Compared with ADS7822U and MAX11100ETE+, the ADS7829IBDRBTG4 uniquely combines guaranteed 12-bit performance at 2.7 V, 3 µA shutdown, and 3 × 3 mm SON packaging-making it optimal for ultra-low-power, space-constrained, single-supply sensor nodes where external reference flexibility is essential.

Availability

ADS7829IBDRBTG4 is available at Aetrix Electronics and suitable for battery-operated systems, remote data acquisition modules, isolated industrial I/O, and simultaneous multichannel sampling applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for ADS7829IBDRBTG4 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 U.S.-based semiconductor company specializing in analog and embedded processing technologies, with leadership in precision data converters, power management, and signal chain solutions.

The ADS7829IBDRBTG4 belongs to TI's micropower SAR ADC product line, designed specifically for ultra-low-energy, high-accuracy sensing in portable, isolated, and multichannel measurement systems where supply voltage headroom and PCB area are constrained.

FAQ

What is the guaranteed integral nonlinearity (INL) specification for ADS7829IBDRBTG4 over temperature?

The ADS7829IBDRBTG4 guarantees ±1.25 LSB integral nonlinearity over the full operating temperature range of –40°C to +85°C, as specified in the SLAS388 datasheet for the 'IB' grade. This corresponds to ≤0.03% of full-scale error with a 2.5 V reference, ensuring monotonic behavior and predictable transfer function in closed-loop sensor systems. The ADS7829IBDRBTG4 achieves this without trimming, relying on matched capacitor array design in its SAR architecture.

Does ADS7829IBDRBTG4 support true differential input operation?

No, the ADS7829IBDRBTG4 does not support true differential input. Its +In and –In pins implement a pseudo-differential configuration: the –In input is restricted to –0.2 V to +1.0 V and is intended for remote ground sensing-not independent signal inversion. Common-mode rejection is limited to small offsets (<1 V), and the full-scale input span remains +In – (–In), not symmetrical around zero. For true differential operation, consider the ADS8320 or similar dedicated differential-input SAR ADCs.

What is the minimum DCLOCK frequency supported by ADS7829IBDRBTG4?

The ADS7829IBDRBTG4 supports a minimum DCLOCK frequency of 10 kHz, as stated in the Theory of Operation section of the SLAS388 datasheet. At lower frequencies, internal capacitor leakage may cause sampling errors. The device maintains guaranteed specifications down to 7.5 kHz sample rate (requiring 120 kHz DCLOCK), but the absolute clock input limit remains 10 kHz. Below this, DOUT timing margins and conversion accuracy are not assured.

Can ADS7829IBDRBTG4 operate from a 2.0 V supply, and what performance trade-offs apply?

Yes, the ADS7829IBDRBTG4 operates from 2.0 V to 5.25 V, but at 2.0 V ≤ VCC < 2.7 V, maximum sample rate drops to 75 kSPS and reference voltage must be reduced to 1.024–1.25 V to maintain linearity. The 125 kSPS rating, ±1.25 LSB INL, and 72 dB SINAD are only guaranteed at VCC ≥ 2.7 V. Using 2.0 V supply trades speed and dynamic performance for ultra-low voltage compatibility in coin-cell applications.

How does the power-down mode of ADS7829IBDRBTG4 reduce system energy consumption?

The ADS7829IBDRBTG4 enters sub-3 µA shutdown mode when CS/SHDN is driven high, disabling both analog circuitry (comparator, CDAC, S/H amp) and digital logic (serial interface, control state machine). This eliminates static current draw while preserving pin states and allowing instant wake-up (<1 µs) upon CS assertion. In a 100 ms burst-sampling system running at 7.5 kHz, this reduces average current from 20 µA to <1 µA-extending CR2032 battery life from months to years.