Features and Benefits
- 1Msps Throughput Rate
- ±0.5ppm INL (Typ)
- Guaranteed 20-Bit No Missing Codes
- Low Power: 21mW at 1Msps, 21μW at 1ksps
- 104dB SNR (Typ) at fIN = 2kHz
- –125dB THD (Typ) at fIN = 2kHz
- Digital Gain Compression (DGC)
- Guaranteed Operation to 85°C
- 2.5V Supply
- Fully Differential Input Range ±VREF
- VREF Input Range from 2.5V to 5.1V
- No Pipeline Delay, No Cycle Latency
- 1.8V to 5V I/O Voltages
- SPI-Compatible Serial I/O with Daisy-Chain Mode
- Internal Conversion Clock
- 16-Lead MSOP and 4mm × 3mm DFN Packages
The LTC2378-20 is a low noise, low power, high speed 20-bit successive approximation register (SAR) ADC. Operating from a 2.5V supply, the LTC2378-20 has a ±VREF fully differential input range with VREF ranging from 2.5V to 5.1V. The LTC2378-20 consumes only 21mW and achieves ±2ppm INL maximum, no missing codes at 20 bits with 104dB SNR.
The LTC2378-20 has a high speed SPI-compatible serial interface that supports 1.8V, 2.5V, 3.3V and 5V logic while also featuring a daisy-chain mode. The fast 1Msps throughput with no cycle latency makes the LTC2378-20 ideally suited for a wide variety of high speed applications. An internal oscillator sets the conversion time, easing external timing considerations. The LTC2378-20 automatically powers down between conversions, leading to reduced power dissipation that scales with the sampling rate.
The LTC2378-20 features a unique digital gain compression (DGC) function, which eliminates the driver amplifier’s negative supply while preserving the full resolution of the ADC. When enabled, the ADC performs a digital scaling function that maps zero-scale code from 0V to 0.1 • VREF and full-scale code from VREF to 0.9 • VREF. For a typical reference voltage of 5V, the full-scale input range is now 0.5V to 4.5V, which provides adequate headroom for powering the driving amplifier from a single 5.5V supply.
- Medical Imaging
- High Speed Data Acquisition
- Portable or Compact Instrumentation
- Industrial Process Control
- Low Power Battery-Operated Instrumentation
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (2)
The LTC2378-20, LTC2377-20 and LTC2376-20 are 20‑bit, low power, low noise SAR ADCs with serial outputs that operate from a single 2.5V supply. The demo manual refers to the LTC2378-20 but applies to all parts in the family, the only difference being the maximum sample rate. The LTC2378-20 supports a ±5V fully differential input range with a 104dB SNR, consumes only 21mW and achieves ±2ppm INL max with no missing codes at 20 bits. The DC1925A demonstrates the DC and AC performance of the LTC2378-20 in conjunction with the DC590 QuikEval™ and DC890 PScope™ data collection boards. Use the DC590 to demonstrate DC performance such as peak-to-peak noise and DC linearity.
Demonstration circuit 2135A shows a simple DC accurate ADC driver circuit that converts a ±10V single-ended input signal into a fully differential signal capable of driving the LTC2378-20 with a combined linearity error of only 2ppm. The LTC2378-20 is a low power, low noise 20-bit SAR ADC with a serial output that operates from a single 2.5V supply. The demo manual refers to the LTC2378-20 but applies to all parts in the family, the only difference being the maximum sample rate. The LTC2378-20 supports a ±5V fully differential input range with a 104dB SNR, consumes only 21mW and achieves ±2ppm INL max with no missing codes at 20 bits. The DC2135A is the PCB that goes with DN1032. Refer to this design note for the theory of operation for this demo circuit. An option for a pseudo differential input drive is provided.
Software & Systems Requirements
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
Linduino is Analog Devices’ Arduino compatible system for developing and distributing firmware libraries and example code for our integrated circuits.
Precision ADC Driver Tool - BETA
The Precision ADC Driver Tool is a web application that simulates the performance of precision ADC and driver combinations. Potential issues with driver selection, kickback settling, and distortion are flagged, and design tradeoffs can be quickly evaluated. Simulations and calculations include system noise, distortion, and settling of the ADC input
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Analog Dialogue (1)
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ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.