Texas Instruments ADS5421Y/RG4

Overview

ADS5421Y/RG4 from Texas Instruments is a 14-bit, 40 MSPS pipelined analog-to-digital converter (ADC) with on-board differential track-and-hold, 4 VPP full-scale input range, 85 dBFS spurious-free dynamic range at 10 MHz fIN, and 75 dBFS signal-to-noise ratio-designed for high-fidelity IF sampling in communications receivers and test instrumentation.

For engineers reviewing the ADS5421Y/RG4 datasheet, ADS5421Y/RG4 pinout, ADS5421Y/RG4 application, or ADS5421Y/RG4 equivalent, this page delivers verified electrical specifications, LQFP-64 package mapping, real-world interface configurations (transformer-coupled and op-amp-driven), and two validated alternative ADCs for similar high-dynamic-range sampling roles.

Technical Context

The ADS5421Y/RG4 implements a fully differential pipeline architecture with digital error correction logic per stage, enabling ±0.5 LSB differential linearity error up to 10 MHz input frequency and 10-clock-cycle data latency. Its track-and-hold amplifier supports >500 MHz analog input bandwidth and operates with selectable 3 VPP or 4 VPP differential input ranges via SEL1/SEL2 pins.

It accepts low-amplitude differential clock inputs down to 0.5 VPP (sine or square wave), features straight offset binary or binary two's complement output coding, and uses separate analog (+VSA) and digital (+VSD) 5 V supplies with independent output driver supply (VDRV = 3 V or 5 V) for noise isolation.

Key Specifications

Pinout & Package

LQFP-64 package (package code RG4), thermally enhanced with exposed pad; 10 mm × 10 mm footprint, 0.5 mm pitch, JEDEC standard outline.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-dynamic-range, 14-bit, 40 MSPS ADC applications.

Compared with ADS5421Y/RG4, ADS5422YB offers modern 3.3 V I/O and clock synthesis but sacrifices 5 V output drive flexibility, while AD9240ASTZ reduces package size and BOM count at the expense of SFDR and input range configurability-making ADS5421Y/RG4 optimal for demanding IF digitization where dynamic range and interface versatility are critical.

Availability

ADS5421Y/RG4 is available at Aetrix Electronics and suitable for communications receivers, test instrumentation digitizers, professional CCD imaging systems, and high-fidelity data acquisition requiring stable component supply across extended temperature and long production lifecycles.

Supply support for ADS5421Y/RG4 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 ADS5421Y/RG4 belongs to TI's high-speed precision ADC product line, engineered specifically for IF sampling, software-defined radio, and test equipment where spurious-free dynamic range and low aperture jitter are non-negotiable design requirements.

FAQ

What is the absolute maximum clock input voltage for ADS5421Y/RG4?

The absolute maximum differential clock input voltage for ADS5421Y/RG4 is +VSD (5.25 V), but the functional specification guarantees operation down to 0.5 VPP. Exceeding +VSD on either CLK or CLK pin risks permanent damage per the Absolute Maximum Ratings table; sustained operation above 3.3 VPP is not characterized and may degrade jitter performance.

Does ADS5421Y/RG4 support external reference operation?

Yes, ADS5421Y/RG4 supports external reference operation: tie VREF to +VSA and apply a stable 1.4–2.025 V differential reference across REFT and REFB. The full-scale input range becomes twice the external reference voltage-for example, a 2 V reference yields 4 VPP full-scale-enabling custom scaling for specialized sensor interfaces.

What is the purpose of the CM pin on ADS5421Y/RG4?

The CM pin on ADS5421Y/RG4 provides the common-mode bias voltage (typically +2.5 V) for the differential analog inputs IN and IN. It connects directly to the internal reference ladder and must be driven with low impedance and <100 µA load to prevent gain and linearity errors; it is not buffered and its voltage varies slightly with temperature and sampling rate.

Can ADS5421Y/RG4 operate with only a single 5 V supply?

ADS5421Y/RG4 requires three distinct supply connections: +VSA (analog), +VSD (digital), and VDRV (output driver), all rated for +4.75 V to +5.25 V. While all can be sourced from the same 5 V rail, they must be individually bypassed with 0.1 µF + 2.2 µF capacitors near each pin group to prevent digital noise from coupling into analog sections and degrading SFDR.

What does the "RG4" suffix indicate in ADS5421Y/RG4?

The "RG4" suffix in ADS5421Y/RG4 denotes the LQFP-64 package variant with exposed thermal pad and standard lead finish (SnPb or Pb-free per ordering option); it corresponds to TI's package code RG4 per the SBAS237E datasheet's PACKAGE/ORDERING INFORMATION table and is functionally identical to ADS5421Y but with guaranteed mechanical and thermal compliance for surface-mount reflow assembly.