Texas Instruments ADS42LB69IRGCT

Overview

ADS42LB69IRGCT from Texas Instruments is a dual-channel, 16-bit, 250-MSPS analog-to-digital converter (ADC) with DDR or QDR LVDS output interface, 2-VPP/2.5-VPP programmable differential input, and 85-fs aperture jitter. It delivers 73.2 dBFS SNR and 87 dBc SFDR (HD2+HD3) at 170 MHz input under –1 dBFS, targeting high-linearity RF receiver chains in microwave and I/Q systems.

For engineers reviewing the ADS42LB69IRGCT datasheet, ADS42LB69IRGCT pinout, ADS42LB69IRGCT application, or ADS42LB69IRGCT equivalent, key selection criteria include its 16-bit resolution at 250 MSPS, dual-channel isolation of 100 dB, flexible clock divider (÷1/2/4), internal dither, and VQFN-64 package compatibility with high-frequency layout requirements.

Technical Context

The ADS42LB69IRGCT integrates two independent 16-bit ADC cores with buffered analog inputs offering 900-MHz bandwidth and 1.2-kΩ differential input impedance at 170 MHz. Its digital block supports SPI-programmable gain, test patterns, and configurable overrange detection via CTRL1/CTRL2 pins.

It operates with dual supply domains: 1.8-V AVDD/DRVDD and 3.3-V AVDD3V for the analog buffer. Clocking supports differential LVPECL/LVDS/LVCMOS inputs up to 250 MSPS, with on-chip divide-by-1/2/4 and optional output clocks (CLKOUTP/M, DACLKP/M, DBCLKP/M) for synchronous data capture.

Key Specifications

Pinout & Package

ADS42LB69IRGCT uses a 64-pin VQFN package (9 mm × 9 mm, RGC suffix) with exposed thermal pad on underside. Pin functions are mode-dependent (DDR vs QDR LVDS); DDR configuration is default after reset.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS42JB69IRGCT and AD9653BCPZ-250, the ADS42LB69IRGCT uniquely balances LVDS interface simplicity, 87-dBc SFDR at RF IFs, and integrated dither-making it optimal for cost-sensitive, high-performance wireless infrastructure where JESD204B is unnecessary and CMOS noise immunity is insufficient.

Availability

ADS42LB69IRGCT is available at Aetrix Electronics and suitable for microwave radio, cellular base station, radar acquisition, and test equipment applications requiring stable component supply and long-term production continuity.

Supply support for ADS42LB69IRGCT 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, communications, and automotive markets.

The ADS42LB69IRGCT belongs to TI's ADS42LBx9 family-designed specifically for high-linearity, dual-channel digitization in broadband wireless infrastructure, radar, and instrumentation where SFDR, channel isolation, and flexible clocking are critical.

FAQ

What is the maximum analog input frequency supported by ADS42LB69IRGCT?

The ADS42LB69IRGCT supports up to 400 MHz with 2-VPP input amplitude and 250 MHz with 2.5-VPP input amplitude, as specified in the Recommended Operating Conditions table. Its analog input bandwidth is 900 MHz (with 50-Ω source/termination), enabling undersampling of RF carriers well into the S-band. Performance metrics like SNR and SFDR are characterized up to 230 MHz, with validated operation at 170 MHz being typical for microwave IF applications.

Does ADS42LB69IRGCT support both DDR and QDR LVDS output modes?

Yes, ADS42LB69IRGCT supports both DDR and QDR LVDS output interfaces. The mode is selected via SPI register configuration; DDR is the default state after hardware reset. QDR mode reduces pin count by using 4-bit buses per channel (DA[3:0], DB[3:0]) with frame and clock signals, while DDR uses full 16-bit buses. Pin assignments differ significantly between modes-refer to the Pin Configuration and Functions section of the SLAS904F datasheet.

What is the purpose of the VCM pin on ADS42LB69IRGCT?

The VCM pin (pin 27) on ADS42LB69IRGCT outputs a regulated 1.9-V common-mode voltage used to bias the differential analog inputs (INAP/INAM, INBP/INBM). It provides ±10 mA drive capability and must be connected directly to the center-tap of the input transformer or resistor network. This eliminates the need for external common-mode generation and ensures consistent input stage biasing across temperature and process variation.

How does the internal dither function improve performance in ADS42LB69IRGCT?

The internal dither in ADS42LB69IRGCT injects a small, uncorrelated noise signal into the ADC core to randomize quantization error, thereby reducing harmonic distortion and improving SFDR-especially at low input amplitudes. This feature is particularly valuable in communication receivers where weak desired signals coexist with strong interferers, as it prevents tonal artifacts from degrading adjacent-channel selectivity. Dither is enabled/disabled via SPI register control.

Can ADS42LB69IRGCT operate with a single-ended clock input?

No, ADS42LB69IRGCT requires a differential clock input (CLKINP/CLKINM). While the datasheet lists LVCMOS as a supported clock type, it specifies "LVCMOS, single-ended, ac-coupled" only as a *voltage-level option*-the actual interface remains differential. A single-ended LVCMOS source must be converted to differential (e.g., using a transformer or dedicated clock buffer like LMH1218) before connecting to CLKINP/CLKINM. Direct single-ended connection violates absolute maximum ratings and will cause malfunction.