1 Features

1• Sample Rate: 1 MHz

• No Latency Output

• Unipolar, True-Differential Input Range:

–VREF to +VREF

• Wide Common-Mode Voltage Range:

0 V to VREF with 90-dB CMRR (min)

• SPI™-Compatible Serial Interface with

Daisy-Chain Option

• Excellent AC and DC Performance:

– ADS8881C:

INL: ±1 LSB (typ), ±2.0 LSB (max)

DNL: ±1.0 LSB (max), 18-Bit NMC

SNR: 100 dB, THD: –115 dB

– ADS8881I:

INL: ±1.5 LSB (typ), ±3.0 LSB (max)

DNL: +1.5 and –1 LSB (max), 18-Bit NMC

SNR: 100 dB, THD: –115 dB

• Wide Operating Range:

– AVDD: 2.7 V to 3.6 V

– DVDD: 2.7 V to 3.6 V

(Independent of AVDD)

– REF: 2.5 V to 5 V (Independent of AVDD)

– Operating Temperature:

ADS8881C : 0°C to +70°C

ADS8881I : –40°C to +85°C

• Low-Power Dissipation:

– 5.5 mW at 1 MSPS

– 0.55 mW at 100 kSPS

– 55 μW at 10 kSPS

• Power-Down Current (AVDD): 50 nA

• Full-Scale Step Settling to 18 Bits: 290 ns

• Packages: MSOP-10 and VSON-10

2 Applications

• Automatic Test Equipment (ATE)

• Instrumentation and Process Controls

• Precision Medical Equipment

• Low-Power, Battery-Operated Instruments

3 Description

The ADS8881 is an 18-bit, 1-MSPS, true-differential

input, analog-to-digital converter (ADC). The device

operates with a 2.5-V to 5-V external reference,

offering a wide selection of signal ranges without

additional input signal scaling. The reference voltage

setting is independent of, and can exceed, the analog

supply voltage (AVDD).

The device offers an SPI-compatible serial interface

that also supports daisy-chain operation for

cascading multiple devices. An optional busyindicator

bit makes synchronizing with the digital host

easy.

The device supports unipolar, true-differential analog

input signals with a differential input swing of –VREF to

VREF. This true-differential analog input structure

allows for a common-mode voltage of any value in

the range of 0 V to VREF (when both inputs are within

the operating input range of –0.1 V to VREF

+ 0.1 V).

Device operation is optimized for very low-power

operation. Power consumption directly scales with

speed. This feature makes the ADS8881 excellent for

lower-speed applications.