Texas Instruments ADS8484IBRGZT

Overview

ADS8484IBRGZT from Texas Instruments is an 18-bit, 1.25-MSPS pseudo-bipolar fully differential SAR analog-to-digital converter with integrated 4.096-V reference, ±2.5 LSB max INL, ±1 LSB max DNL, and 98.5 dB SNR. It operates over –40°C to +85°C in a 48-pin 7×7 QFN package and targets high-accuracy data acquisition in medical instruments and magnetometers.

For engineers reviewing the ADS8484IBRGZT datasheet, ADS8484IBRGZT pinout, ADS8484IBRGZT application, or ADS8484IBRGZT equivalent, key selection criteria include its zero-latency conversion, 18-/16-/8-bit parallel bus flexibility, ±0.5-mV offset error, onboard reference buffer, and industrial temperature-rated performance with no missing codes guaranteed.

Technical Context

The ADS8484IBRGZT implements a capacitor-based SAR architecture with inherent sample-and-hold, delivering true 18-bit resolution without interpolation. Its pseudo-bipolar input range spans –V_REF to +V_REF (±4.096 V), supported by fully differential inputs (+IN/–IN) and common-mode rejection of 60 dB at DC.

Conversion is initiated by CONVST falling edge, with BUSY signaling active conversion state; timing-critical read cycles use CS/RD/BYTE/BUS18/16 controls to support 18-bit, dual-cycle 16-bit, or triple-cycle 8-bit transfers - all with zero latency and 610 ns conversion time.

Key Specifications

Pinout & Package

ADS8484IBRGZT is housed in a thermally enhanced 48-pin 7×7 mm QFN package (RGZ) with exposed thermal pad requiring PCB soldering for mechanical integrity and thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed SAR ADC applications.

Compared with ADS8484IBRGZT, ADS8482IBRGZT trades 2 bits of resolution for lower power and cost, while ADS8382IPWR reduces speed and package size at the expense of added reference circuitry - making ADS8484IBRGZT optimal for 18-bit, 1.25-MSPS, self-contained applications.

Availability

ADS8484IBRGZT is available at Aetrix Electronics and suitable for medical instrumentation, optical networking, transducer interface, and magnetometer systems requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.

Supply support for ADS8484IBRGZT 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, embedded processing, and high-performance data converters for industrial, automotive, and communications markets.

The ADS8484IBRGZT belongs to TI's high-speed SAR ADC family designed for precision data acquisition where zero latency, guaranteed 18-bit NMC, and integrated reference simplify system architecture in demanding measurement applications.

FAQ

What is the maximum sample rate of the ADS8484IBRGZT?

The ADS8484IBRGZT achieves a maximum throughput rate of 1.25 MSPS with 610 ns conversion time and zero latency. This rate is fully characterized over the –40°C to +85°C industrial temperature range and supports sustained operation without missing codes or performance degradation. The ADS8484IBRGZT maintains this rate using its internal conversion clock, eliminating need for external timing components.

Does the ADS8484IBRGZT require an external reference voltage?

No, the ADS8484IBRGZT includes an internal 4.096-V reference with ±6 ppm/°C drift and 120-ms startup time, fully usable via REFIN/REFOUT/REFM pins. An external reference may be applied to REFIN (3.0 V to 4.2 V range), but it is not required. The ADS8484IBRGZT reference buffer drives the internal CDAC directly, ensuring stability without external op-amps or filtering.

How does the ADS8484IBRGZT support different data bus widths?

The ADS8484IBRGZT supports 18-bit, 16-bit, and 8-bit parallel transfers using hardware-configurable pins: BUS18/16 selects between full 18-bit bus (DB[17:0]) or folded 16-bit mode, while BYTE determines byte ordering in 8-bit reads. No firmware or external logic is needed - configuration is static at power-up or dynamically changed during operation, enabling flexible microcontroller interfacing.

What is the meaning of "pseudo-bipolar" input in the ADS8484IBRGZT?

"Pseudo-bipolar" in the ADS8484IBRGZT means the differential input range is –V_REF to +V_REF (±4.096 V), but the common-mode voltage is fixed at V_REF/2 (2.048 V). Unlike true bipolar ADCs, it does not support arbitrary common-mode levels - instead, it provides high CMRR around this fixed point, simplifying front-end design while retaining bidirectional measurement capability for transducers and sensors.

Is the ADS8484IBRGZT pin-compatible with other devices in the ADS84xx family?

The ADS8484IBRGZT shares the same 48-pin RGZ QFN package and core pinout (e.g., +IN/–IN, CONVST, BUSY, DB[17:0], REF pins) with ADS8481/ADS8482, but differs in INL/DNL specs and internal reference configuration. While mechanical mounting is identical, functional compatibility requires verification of BUS18/16/BYTE timing and reference handling - ADS8484IBRGZT is not a drop-in replacement for ADS8481IRGZT due to tighter linearity specs and distinct ordering suffix (IB vs I).