20-Bit, 500ksps, Low Power SAR ADC with 0.5ppm INL

The LTC2377-20 is a low noise, low power, high speed 20-bit successive approximation register (SAR) ADC. Operating from a 2.5V supply, the LTC2377-20 has a ±VREF fully differential input range with VREF ranging from 2.5V to 5.1V. The LTC2377-20 consumes only 10.5mW and achieves ±2ppm INL maximum, no missing codes at 20 bits with 104dB SNR.

The LTC2377-20 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 500ksps throughput with no cycle latency makes the LTC2377-20 ideally suited for a wide variety of high speed applications. An internal oscillator sets the conversion time, easing external timing considerations. The LTC2377-20 automatically powers down between conversions, leading to reduced power dissipation that scales with the sampling rate.

The LTC2377-20 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.

Applications

* Medical Imaging

* High Speed Data Acquisition

* Portable or Compact Instrumentation

* Industrial Process Control

* Low Power Battery-Operated Instrumentation

* ATE

* 500ksps Throughput Rate* ±0.5ppm INL (Typ)* Guaranteed 20-Bit No Missing Codes* Low Power: 10.5mW at 500ksps, 10.5μW at 500sps* 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