Radiation Tolerant 20-Bit, 1Msps, Low Power Plastic Package SAR ADC

The RT2378-20 is a low noise, low power, high speed 20-bit successive approximation register (SAR) ADC. Operating from a 2.5V supply, the RT2378-20 has a ±VREF fully differential input range with VREF ranging from 2.5V to 5.1V. The RT2378-20 consumes only 21mW and achieves ±2ppm INL maximum, no missing codes at 20 bits with 104dB SNR.

The RT2378-20 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 RT2378-20 ideally suited for a wide variety of high speed applications. An internal oscillator sets the conversion time, easing external timing considerations. The RT2378-20 automatically powers down between conversions, leading to reduced power dissipation that scales with the sampling rate.

The RT2378-20 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

* High-Accuracy Instrumentation

* Imaging Systems

* High-Speed Data Acquisition

* Low-Power Conversion

* Processed and Qualified to Proprietary RT Flow Using PEM-INST-001 as a Guideline

* 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)

* 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 Package