SBAS905C
November 2019 – July 2020
ADS8686S
PRODUCTION DATA
1
Features
2
Applications
3
Description
4
Revision History
5
Pin Configuration and Functions
6
Specifications
6.1
Absolute Maximum Ratings
6.2
ESD Ratings
6.3
Recommended Operating Conditions
6.4
Thermal Information
6.5
Electrical Characteristics
6.6
Timing Requirements
6.7
Switching Characteristics
6.8
Timing Diagrams: Universal
6.9
Timing Diagrams: Parallel Data Read
6.10
Timing Diagrams: Serial Data Read
6.11
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Analog Inputs
7.3.2
Analog Input Impedance
7.3.3
Input Clamp Protection Circuit
7.3.4
Programmable Gain Amplifier (PGA)
7.3.5
Second-Order, Programmable, Low-Pass Filter (LPF)
7.3.6
ADC Driver
7.3.7
Multiplexer
7.3.8
Digital Filter and Noise
7.3.9
Reference
7.3.9.1
Internal Reference
7.3.9.2
External Reference
7.3.9.3
Supplying One VREF to Multiple Devices
7.3.10
ADC Transfer Function
7.4
Device Functional Modes
7.4.1
Device Interface: Pin Description
7.4.1.1
REFSEL (Input)
7.4.1.2
RESET (Input)
7.4.1.3
SEQEN (Input)
7.4.1.4
HW_RANGESEL[1:0] (Input)
7.4.1.5
SER/BYTE/PAR (Input)
7.4.1.6
DB[3:0] (Input/Output)
7.4.1.7
DB4/SER1W (Input/Output)
7.4.1.8
DB5/CRCEN (Input/Output)
7.4.1.9
DB[7:6] (Input/Output)
7.4.1.10
DB8 (Input/Output)
7.4.1.11
DB9/BYTESEL (Input/Output)
7.4.1.12
DB10/SDI (Input/Output)
7.4.1.13
DB11/SDOB (Input/Output)
7.4.1.14
DB12/SDOA (Input/Output)
7.4.1.15
DB13/OS0 (Input/Output)
7.4.1.16
DB14/OS1 (Input/Output)
7.4.1.17
DB15/OS2 (Input/Output)
7.4.1.18
WR/BURST (Input)
7.4.1.19
SCLK/RD (Input)
7.4.1.20
CS (Input)
7.4.1.21
CHSEL[2:0] (Input)
7.4.1.22
BUSY (Output)
7.4.1.23
CONVST (Input)
7.4.2
Device Modes of Operation
7.4.2.1
Shutdown Mode
7.4.2.2
Operation Mode
7.4.2.2.1
Hardware Mode
7.4.2.2.2
Software Mode
7.4.2.3
Reset Functionality
7.4.2.4
Channel Selection
7.4.2.4.1
Hardware Mode Channel Selection
7.4.2.4.2
Software Mode Channel Selection
7.4.2.5
Sequencer
7.4.2.5.1
Hardware Mode Sequencer
7.4.2.5.2
Software Mode Sequencer
7.4.2.6
Burst Sequencer
7.4.2.6.1
Hardware Mode Burst Sequencer
7.4.2.6.2
Software Mode Burst Sequencer
7.4.2.7
Diagnostics
7.4.2.7.1
Analog Diagnosis
7.4.2.7.2
Interface Diagnosis: SELF TEST and CRC
7.5
Programming
7.5.1
Parallel Interface
7.5.1.1
Reading Conversion Results
7.5.1.2
Writing Register Data
7.5.1.3
Reading Register Data
7.5.2
Parallel Byte Interface
7.5.2.1
Reading Conversion Results
7.5.2.2
Writing Register Data
7.5.2.3
Reading Register Data
7.5.3
Serial Interface
7.5.3.1
Reading Conversion Results
7.5.3.2
Writing Register Data
7.5.3.3
Reading Register Data
7.6
Register Maps
7.6.1
Page1 Registers
8
Application and Implementation
8.1
Application Information
8.2
Typical Applications
8.2.1
8x2 Channel Data Acquisition System (DAQ) for Power Automation
8.2.1.1
Design Requirements
8.2.1.2
Detailed Design Procedure
8.2.1.3
Application Curve
8.2.2
Input Protection for Electrical Overstress
9
Power Supply Recommendations
9.1
Power Supplies
10
Layout
10.1
Layout Guidelines
10.2
Layout Examples
11
Device and Documentation Support
11.1
Device Support
11.1.1
Development Support
11.2
Documentation Support
11.2.1
Related Documentation
11.3
Receiving Notification of Documentation Updates
11.4
Support Resources
11.5
Trademarks
11.6
Electrostatic Discharge Caution
11.7
Glossary
1
Features
16-channel, 16-bit ADC with integrated analog front-end
Dual simultaneous sampling: 8x2 channels
Supply:
Analog: 5 V
Digital: 1.8 V to 5 V
Constant 1-MΩ input impedance front-end
Independently programmable input ranges with 20% overrange
Programmable low-pass filter:
15 kHz, 39 kHz, 376 kHz
Excellent DC and AC performance
On-chip reference and reference buffer
Excellent over temperature performance
Overvoltage input clamp with 8-kV ESD
Optional cyclic redundancy check (CRC) error checking
On-chip self diagnostic function
Temperature range: –40°C to +125°C