Texas Instruments ADS61B49IRGZR

Overview

ADS61B49IRGZR from Texas Instruments is a 14-bit, 250MSPS analog-to-digital converter with integrated high-impedance analog input buffer, DDR LVDS/parallel CMOS outputs, and programmable fine gain up to 6dB. It operates from 3.3V analog and 1.8V digital supplies, dissipates 790mW at full rate, and targets wideband communications infrastructure requiring stable DC offset correction and 1Vpp full-scale operation.

For engineers reviewing the ADS61B49IRGZR datasheet, ADS61B49IRGZR pinout, ADS61B49IRGZR application, or ADS61B49IRGZR equivalent, this page delivers verified technical context, real-world interface timing, validated pin functions for both LVDS and CMOS modes, and precise SNR/SFDR performance across 20–300MHz input frequencies - critical for SDR, PA linearization, and radar signal chain design.

Technical Context

The ADS61B49IRGZR implements a pipelined ADC architecture with on-chip analog buffer enabling constant 10kΩ differential input impedance and 750MHz analog bandwidth up to 800MHz with 1Vpp input. Its dual-output interface supports DDR LVDS (14-bit, multiplexed D0–D13 pairs) or parallel CMOS (14 single-ended D0–D13), selectable via DFS pin.

DC offset correction is implemented as a closed-loop digital calibration circuit; fine gain adjustment (0–6dB) trades SNR for SFDR without altering full-scale range. Internal references eliminate external VREF pins and decoupling capacitors, simplifying layout while maintaining –40°C to 85°C industrial temperature operation.

Key Specifications

Pinout & Package

ADS61B49IRGZR uses a 48-pin QFN package (RGZ) with 7mm × 7mm footprint and exposed thermal pad connected to DRGND. Pin functions differ between LVDS and CMOS output modes; dual-mode support requires correct DFS pin configuration and corresponding PCB routing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS6149IRGZR, ADS61B49IRGZR delivers superior signal integrity through its integrated buffer and lower power at equal speed; versus AD9246BCPZ-125, it offers double the sample rate and analog input simplification but lacks high-speed serial interface - selection hinges on whether buffer integration or interface protocol dominates system architecture.

Availability

ADS61B49IRGZR is available at Aetrix Electronics and suitable for wireless infrastructure, radar signal processing, and test equipment requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for ADS61B49IRGZR 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 ADS61Bx9 family was designed specifically for wideband communications infrastructure - emphasizing integrated analog buffering, flexible output interfaces, and robust AC performance across extended input frequency ranges.

FAQ

What is the maximum analog input frequency supported by the ADS61B49IRGZR?

The ADS61B49IRGZR supports analog input frequencies up to 800MHz when using a 1Vpp differential input amplitude, and up to 500MHz at 2Vpp full-scale. This is enabled by its 750MHz analog input bandwidth and buffered front-end, making it suitable for undersampling applications in radar and broadband communications where IF frequencies exceed Nyquist limits.

Does the ADS61B49IRGZR require external reference components?

No, the ADS61B49IRGZR does not require external reference components. It features an internal reference system that eliminates traditional VREF pins and associated decoupling capacitors. The VCM pin serves as either a 2.3V common-mode output (internal reference mode) or an external reference input - simplifying layout and reducing BOM count compared to reference-dependent ADCs.

How does the integrated analog buffer improve system performance in the ADS61B49IRGZR?

The integrated analog buffer in the ADS61B49IRGZR maintains a constant 10kΩ differential input impedance and flat frequency response from DC to 750MHz. This eliminates sensitivity to source impedance variations and removes the need for external driver amplifiers, preserving signal integrity in wideband receivers and reducing design complexity, power, and PCB area in SDR and PA linearization applications.

What are the key timing differences between LVDS and CMOS output modes on the ADS61B49IRGZR?

In LVDS mode, ADS61B49IRGZR uses DDR multiplexing with 0.8–1.2ns setup time (tsu) and 0.25–0.6ns hold time (th) relative to CLKOUTP zero-crossing. In CMOS mode, it provides 14 single-ended outputs with 3.2ns input-clock-to-data delay (tSTART) and 0.7–1.5ns data valid window (tDV). CMOS mode requires stricter load capacitance control (≤5pF) but offers simpler FPGA interfacing at lower speeds.

Can the ADS61B49IRGZR operate with a 1.8V-only supply?

No, the ADS61B49IRGZR requires two independent supplies: 3.3V (AVDD, ±0.3V tolerance) for the analog section and 1.8V (DRVDD, ±0.1V tolerance) for digital and output buffers. Using only 1.8V would violate absolute maximum ratings and prevent proper analog conversion - AVDD must be within 3.0–3.6V to meet specified SNR, SFDR, and input linearity performance.