ADS8681 16-Bit, 1-MSPS, 1-Ch SAR ADC with programmable (±12/±10/±6/±5/±2.5V) input ranges on +5V supply | TI.com

ADS8681 (ACTIVE) 16-Bit, 1-MSPS, 1-Ch SAR ADC with programmable (±12/±10/±6/±5/±2.5V) input ranges on +5V supply

 

Description

The ADS8681, ADS8685, and ADS8689 belong to a family of integrated data acquisition system based on a successive approximation (SAR) analog-to-digital converter (ADC). The devices feature a high-speed, high-precision SAR ADC, integrated analog front-end (AFE) input driver circuit, overvoltage protection circuit up to ±20 V, and an on-chip 4.096-V reference with extremely low temperature drift.

The devices operate on a single 5-V analog supply, but support true bipolar input ranges of ±12.288 V, ±6.144 V, ±10.24 V, ±5.12 V, and ±2.56 V, as well as unipolar input ranges of 0 V to 12.288 V, 0 V to 10.24 V, 0 V to 6.144 V, and 0 V to 5.12 V. The gain and offset errors are accurately trimmed within the specified values for each input range to ensure high dc precision. The input range selection is done by software programming of the device internal registers. The devices offer a high resistive input impedance (≥ 1 MΩ) irrespective of the selected input range.

The multiSPI digital interface is backward-compatible to the traditional SPI protocol. Additionally, configurable features simplify interface to a wide range of host controllers.



Features

  • 16-Bit ADC With Integrated Analog Front-End
  • High Speed:
    • ADS8681: 1 MSPS
    • ADS8685: 500 kSPS
    • ADS8689: 100 kSPS
  • Software Programmable Input Ranges:
    • Bipolar Ranges: ±12.288 V, ±10.24 V, ±6.144 V, ±5.12 V, and ±2.56 V
    • Unipolar Ranges: 0 V–12.288 V, 0 V–10.24 V, 0 V–6.144 V, and 0 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:
    • DNL: ±0.4 LSB; INL: ±0.5 LSB
    • SNR: 92 dB; THD: –107 dB
  • ALARM → High, Low Threshold
  • multiSPI™ Interface With Daisy-Chain
  • Extended Industrial Temperature Range:
    –40°C to +125°C

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Parametrics

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Part number Order 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) SNR (dB) THD (Typ) (dB) Rating
ADS8681 Order now 16     1000     1     Enhanced SPI
SPI    
-40 to 125     TSSOP | 16
WQFN | 16    
4.10 | 1ku     42     16TSSOP: 22 mm2: 4.4 x 5 (TSSOP | 16)
16WQFN: 16 mm2: 4 x 4 (WQFN | 16)    
SAR     Single-Ended         Ext
Int    
Oscillator
Over-Voltage Protection
PGA    
12.288     -12.288     4.75     5.25     1.65     5.25     1.2     90.5     -102     Catalog    
ADS8661 Order now 12     1250     1     Enhanced SPI
SPI    
-40 to 125     TSSOP | 16     2.00 | 1ku     36     16TSSOP: 22 mm2: 4.4 x 5 (TSSOP | 16)     SAR     Single-Ended         Ext
Int    
Oscillator
Over-Voltage Protection
PGA    
12.288     -12.288     4.75     5.25     1.65     5.25     0.35     73.5     -102     Catalog    
ADS8665 Order now 12     500     1     Enhanced SPI
SPI    
-40 to 125     TSSOP | 16     1.50 | 1ku     25     16TSSOP: 22 mm2: 4.4 x 5 (TSSOP | 16)     SAR     Single-Ended         Ext
Int    
Oscillator
Over-Voltage Protection
PGA    
12.288     -12.288     4.75     5.25     1.65     5.25     0.35     73.5     -102