Analog Devices Inc. EVAL-LTC2420-EBZ

Overview

EVAL-LTC2420-EBZ from Analog Devices (formerly Linear Technology) is an evaluation board for the LTC2420 20-bit micropower delta-sigma ADC in SO-8 package. It enables rapid characterization of 8ppm INL, 1.2ppm RMS noise, and 110dB 50/60Hz notch rejection under single-supply 2.7V–5.5V operation - critical for precision weight scales and industrial process control sensor interfaces.

For engineers reviewing the EVAL-LTC2420-EBZ datasheet, EVAL-LTC2420-EBZ pinout, EVAL-LTC2420-EBZ application, or EVAL-LTC2420-EBZ equivalent, this board provides verified hardware reference design, jumper-configurable FO pin routing for 50Hz/60Hz rejection selection, on-board 2.5V reference, and direct SPI/MICROWIRE™ interface access to validate conversion timing, live-zero input range (–12.5% to +112.5% VREF), and auto-shutdown current (20µA).

Technical Context

The EVAL-LTC2420-EBZ implements the LTC2420's full signal chain: analog input conditioning with extended range support (–0.125×VREF to 1.125×VREF), internal oscillator-based 15.36kHz conversion clock, and 3-wire serial interface with SDO/SCK/CS routed to test points and headers. It supports both internal oscillator modes (FO = GND for 60Hz notch, FO = VCC for 50Hz notch) and external clock injection via dedicated FO test point.

Board-level design includes 10µF tantalum + 0.1µF ceramic VCC bypassing per LTC2420 requirements, isolated analog/digital ground planes, and 1kΩ series resistors on VIN/VREF inputs to limit fault current without degrading INL - enabling robust validation of ±100nA input leakage impact and 0.5ppm offset error performance across temperature.

Key Specifications

Availability

EVAL-LTC2420-EBZ is available at Aetrix Electronics and suitable for precision instrumentation, industrial process control, and high-resolution data acquisition systems requiring stable component supply and validated reference designs for low-drift, low-noise ADC integration.

Supply support for EVAL-LTC2420-EBZ 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

Analog Devices, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The EVAL-LTC2420-EBZ belongs to ADI's precision data acquisition evaluation platform family, designed to accelerate development of ultra-stable, low-power measurement systems using delta-sigma ADCs with integrated oscillators and line-frequency rejection.

FAQ

What is the primary function of the EVAL-LTC2420-EBZ evaluation board?

The EVAL-LTC2420-EBZ evaluation board is a fully assembled and tested hardware platform for evaluating the LTC2420 20-bit micropower delta-sigma ADC. It provides immediate access to all critical signals - including VIN, VREF, SDO, SCK, CS, and FO - with proper bypassing, grounding, and jumper options to validate key specifications such as 8ppm INL, 110dB 50/60Hz rejection, and live-zero input range. The board enables direct measurement of EVAL-LTC2420-EBZ performance without custom PCB design.

How does the EVAL-LTC2420-EBZ support 50Hz vs 60Hz line-frequency rejection testing?

The EVAL-LTC2420-EBZ supports 50Hz/60Hz rejection via a 3-position jumper (JP1) that configures the FO pin: grounded for 60Hz ±2% notch, connected to VCC for 50Hz ±2% notch, or left floating for external clock injection. This matches the LTC2420's internal oscillator behavior and allows engineers to verify >110dB normal-mode rejection in either configuration using standard power-line interference test setups - a capability directly enabled by the EVAL-LTC2420-EBZ layout and component selection.

Can the EVAL-LTC2420-EBZ be used to measure the LTC2420's 20-bit no-missing-codes performance?

Yes. The EVAL-LTC2420-EBZ provides low-noise, well-bypassed analog signal paths and precise reference voltage (2.5V) to enable full-scale linearity testing. When paired with a calibrated low-drift voltage source and host microcontroller or logic analyzer, it allows direct capture and histogram analysis of 24-bit output words (4 status + 20 data bits) across the full –0.125×VREF to 1.125×VREF range - confirming the LTC2420's guaranteed no-missing-codes operation and 8ppm INL specification as documented in the EVAL-LTC2420-EBZ user guide and LTC2420 datasheet.

Does the EVAL-LTC2420-EBZ include provisions for measuring the LTC2420's sleep-mode current?

Yes. The EVAL-LTC2420-EBZ includes a dedicated test point (TP3) in series with the LTC2420's VCC supply path, allowing direct current measurement during sleep mode. With CS held high (VCC), the board validates the LTC2420's specified 20–30µA sleep current over temperature - a critical parameter for battery-powered applications. This measurement capability is built into the EVAL-LTC2420-EBZ design and requires only a picoammeter connected to TP3 and GND.

Is the EVAL-LTC2420-EBZ pin-compatible with other Linear Technology ADC evaluation boards?

No. The EVAL-LTC2420-EBZ is specifically optimized for the LTC2420 in SO-8 package and is not mechanically or electrically pin-compatible with evaluation boards for other ADCs (e.g., LTC2400). However, it shares functional interface conventions - such as 3-wire SPI/MICROWIRE™ compatibility, identical FO pin functionality, and similar jumper-based configuration - enabling consistent lab workflows across ADI's precision ADC evaluation ecosystem. Its design reflects the unique timing, power, and layout requirements of the EVAL-LTC2420-EBZ target device.