Texas Instruments ADS41B25IRGZT

Overview

ADS41B25IRGZT from Texas Instruments is a 12-bit, 125MSPS ultralow-power analog-to-digital converter with integrated high-impedance analog input buffer (3.5pF dc input capacitance, 10kΩ dc input resistance), DDR LVDS/parallel CMOS output interface, and programmable gain for SNR/SFDR trade-off. It delivers 68.3dBFS SNR at 170MHz input and consumes only 114mW on 1.8V analog supply - optimized for multi-carrier communications and PA linearization.

For engineers reviewing the ADS41B25IRGZT datasheet, ADS41B25IRGZT pinout, ADS41B25IRGZT application, or ADS41B25IRGZT equivalent, key selection considerations include its buffered analog input impedance stability across frequency, dual-output interface flexibility (DDR LVDS up to 500MBPS or 1.8V CMOS), low-swing LVDS mode (200mV), and industrial temperature range (–40°C to +85°C) in QFN-48 package.

Technical Context

The ADS41B25IRGZT employs an integrated analog input buffer to maintain constant 10kΩ/3.5pF input impedance from dc to 800MHz bandwidth, eliminating sensitivity to PCB layout and source impedance variations. Its architecture supports both high-performance modes (MODE 1 register 03h=03h for broad-band optimization; MODE 2 register 4Ah=01h for >230MHz inputs) via serial interface configuration.

It features digital gain and dc offset correction loops, enabling SNR/SFDR tuning at reduced full-scale input ranges and automatic offset cancellation. Power scaling at lower sampling rates (e.g., 20–80 MSPS) maintains dynamic performance without penalty, while DDR LVDS outputs support programmable swing (200mV or 350mV) and termination strength (50Ω or 100Ω).

Key Specifications

Pinout & Package

ADS41B25IRGZT is housed in a 7mm × 7mm QFN-48 package with exposed PowerPAD™ thermally connected to DRGND. Pin functions differ between CMOS and LVDS output modes; dual-mode operation requires correct DFS pin voltage configuration (e.g., AVDD for offset binary/DDR LVDS).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS41B25IRGZT, ADS4149IRGZT offers higher resolution and speed at significantly higher power and no input buffering, while AD9230BCPZ-125 matches sample rate and resolution but lacks the buffered interface and requires external input termination - making ADS41B25IRGZT uniquely suited for impedance-sensitive, low-power wideband receivers.

Availability

ADS41B25IRGZT is available at Aetrix Electronics and suitable for wireless infrastructure, test equipment, and industrial data acquisition requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ADS41B25IRGZT 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 ADS41B25IRGZT belongs to TI's ADS4xxx ultralow-power ADC family, designed specifically for multi-carrier communications systems requiring buffered analog inputs, flexible digital interfaces, and scalable power consumption.

FAQ

What is the minimum analog input frequency supported by the ADS41B25IRGZT?

The ADS41B25IRGZT does not specify a minimum analog input frequency - its buffered analog input operates from dc to 800MHz. Performance metrics such as SNR and SFDR are characterized starting at 20MHz, but the device fully supports dc-coupled and low-frequency (<1MHz) signal acquisition with verified dc accuracy (±15mV offset error, ±3.5LSB INL). The ADS41B25IRGZT maintains stable 10kΩ input resistance and 3.5pF capacitance across this entire range.

Does the ADS41B25IRGZT require external reference voltage or generate its own?

The ADS41B25IRGZT uses an internal reference and does not require an external reference voltage. Its reference is integrated and trimmed, contributing to ±2%FS gain error from reference inaccuracy alone. The device provides a dedicated VCM pin (1.7V ±50mV) to bias the analog input common-mode level, which is derived from the internal reference and intended for external termination - no external reference components are needed for standard operation.

Can the ADS41B25IRGZT operate with only the 1.8V supply rails, or is the 3.3V AVDD_BUF mandatory?

The 3.3V AVDD_BUF supply is mandatory for ADS41B25IRGZT operation. The analog input buffer is powered exclusively by AVDD_BUF (specified 3.0–3.6V), and operation outside this range violates absolute maximum ratings. Omitting or under-volting AVDD_BUF disables the buffer, degrading input impedance stability and dynamic performance. All recommended operating conditions and electrical characteristics assume AVDD_BUF = 3.3V; the ADS41B25IRGZT will not function correctly without it.

How does the low-swing LVDS mode affect timing margins in FPGA interfacing?

In low-swing LVDS mode (200mV differential), the ADS41B25IRGZT reduces output voltage excursion, which decreases slew rate and slightly increases setup/hold time requirements - datasheet specifies tSU = 2.3–3.0ns and tH = 0.35–0.6ns. However, the reduced swing lowers crosstalk and EMI, improving noise immunity in dense PCB layouts. FPGA receivers must be configured for 200mV thresholds, and termination remains 100Ω differential; timing closure is achievable with standard Xilinx/Intel LVDS I/O standards.

Is the serial interface required to configure high-performance modes like MODE 1 and MODE 2 on the ADS41B25IRGZT?

Yes, the serial interface is required to configure MODE 1 (register 03h = 03h) and MODE 2 (register 4Ah = 01h) on the ADS41B25IRGZT. These registers cannot be set when RESET is tied high (i.e., when serial interface is disabled). In that default hardware-reset state, the device operates in standard mode. To enable these optimized performance modes, SEN, SCLK, and SDATA pins must be actively driven, and the corresponding register writes executed - the ADS41B25IRGZT does not support pin-strapped or auto-detect activation of MODE 1/MODE 2.