ADS8694 18-Bit 500kSPS 4-Channel SAR ADC With Bipolar Inputs Off 5V Supply | TI.com

ADS8694 (ACTIVE)

18-Bit 500kSPS 4-Channel SAR ADC With Bipolar Inputs Off 5V Supply

 

Description

The ADS8694 and ADS8698 are 4- and 8-channel, integrated data acquisition systems based on a 18-bit successive approximation (SAR) analog-to-digital converter (ADC), operating at a throughput of 500 kSPS. The devices feature integrated analog front-end circuitry for each input channel with overvoltage protection up to ±20 V, a 4- or 8-channel multiplexer with automatic and manual scanning modes, and an on-chip, 4.096-V reference with low temperature drift. Operating on a single 5-V analog supply, each input channel on the devices can support true bipolar input ranges of ±10.24 V, ±5.12 V, and ±2.56 V, as well as unipolar input ranges of 0 V to 10.24 V and 0 V to 5.12 V. The gain of the analog front-end for all input ranges is accurately trimmed to ensure a high dc precision. The input range selection is software-programmable and independent for each channel. The devices offer a 1-MΩ constant resistive input impedance irrespective of the selected input range.

The ADS8694 and ADS8698 offer a simple SPI-compatible serial interface to the digital host and also support daisy-chaining of multiple devices. The digital supply operates from 1.65 V to 5.25 V, enabling direct interface to a wide range of host controllers.

Features

  • 18-Bit ADCs with Integrated Analog Front-End
  • 4-, 8-Channel MUX with Auto and Manual Scan
  • Channel-Independent Programmable Inputs:
    • ±10.24 V, ±5.12 V, ±2.56 V
    • 10.24 V, 5.12 V
  • 5-V Analog Supply: 1.65-V to 5-V I/O Supply
  • Constant Resistive Input Impedance: 1 MΩ
  • Input Overvoltage Protection: Up to ±20 V
  • On-Chip, 4.096-V Reference with Low Drift
  • Excellent Performance:
    • 500-kSPS Aggregate Throughput
    • DNL: ±0.5 LSB; INL: ±1.5 LSB
    • Low Drift for Gain Error and Offset
    • SNR: 93.5 dB; THD: –105 dB
    • Low Power: 65 mW
  • AUX Input → Direct Connection to ADC Inputs
  • ALARM → High and Low Thresholds per Channel
  • SPI™-Compatible Interface with Daisy-Chain
  • Industrial Temperature Range: –40°C to 125°C
  • TSSOP-38 Package (9.7 mm × 4.4 mm)

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Parametrics Compare all products in Precision ADCs (<=10MSPS)

 
Resolution (Bits)
Sample Rate (Max) (kSPS)
Number of input channels
Interface
Operating temperature range (C)
Package Group
Approx. price (US$)
Power consumption (Typ) (mW)
Package size: mm2:W x L (PKG)
Architecture
Input type
Multi-channel configuration
Reference mode
Features
Input range (Max) (V)
Input range (Min) (V)
Analog voltage AVDD (Min) (V)
Analog voltage AVDD (Max) (V)
Digital supply (Min) (V)
Digital supply (Max) (V)
INL (Max) (+/-LSB)
SINAD (dB)
SNR (dB)
THD (Typ) (dB)
Rating
ADS8694 ADS8664 ADS8668 ADS8674 ADS8678 ADS8684 ADS8684A ADS8688 ADS8688A
18     12     12     14     14     16     16     16     16    
500     500     500     500     500     500     500     500     500    
4     4     8     4     8     4     4     8     8    
SPI     SPI     SPI     SPI     SPI     SPI     SPI     SPI     SPI    
-40 to 125     -40 to 125     -40 to 125     -40 to 125     -40 to 125     -40 to 125     -40 to 125     -40 to 125     -40 to 125    
TSSOP | 38     TSSOP | 38     TSSOP | 38     TSSOP | 38     TSSOP | 38     TSSOP | 38     TSSOP | 38     TSSOP | 38     TSSOP | 38    
8.30 | 1ku     2.80 | 1ku     4.00 | 1ku     4.25 | 1ku     6.00 | 1ku     5.90 | 1ku     6.40 | 1ku     8.45 | 1ku     9.00 | 1ku    
65     65     65     65     65     65     65     65     65    
38TSSOP: 62 mm2: 6.4 x 9.7 (TSSOP | 38)     38TSSOP: 62 mm2: 6.4 x 9.7 (TSSOP | 38)     38TSSOP: 62 mm2: 6.4 x 9.7 (TSSOP | 38)     38TSSOP: 62 mm2: 6.4 x 9.7 (TSSOP | 38)     38TSSOP: 62 mm2: 6.4 x 9.7 (TSSOP | 38)     38TSSOP: 62 mm2: 6.4 x 9.7 (TSSOP | 38)     38TSSOP: 62 mm2: 6.4 x 9.7 (TSSOP | 38)     38TSSOP: 62 mm2: 6.4 x 9.7 (TSSOP | 38)     38TSSOP: 62 mm2: 6.4 x 9.7 (TSSOP | 38)    
SAR     SAR     SAR     SAR     SAR     SAR     SAR     SAR     SAR    
Single-Ended     Single-Ended     Single-Ended     Single-Ended     Single-Ended     Single-Ended     Single-Ended     Single-Ended     Single-Ended    
Multiplexed     Multiplexed     Multiplexed     Multiplexed     Multiplexed     Multiplexed     Multiplexed     Multiplexed     Multiplexed    
Int     Int     Int     Int