SBAS777B
December 2016 – March 2021
ADS8691
,
ADS8695
,
ADS8699
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: Conversion Cycle
6.7
Timing Requirements: Asynchronous Reset
6.8
Timing Requirements: SPI-Compatible Serial Interface
6.9
Timing Requirements: Source-Synchronous Serial Interface (External Clock)
6.10
Timing Requirements: Source-Synchronous Serial Interface (Internal Clock)
6.11
Timing Diagrams
6.12
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Analog Input Structure
7.3.2
Analog Input Impedance
7.3.3
Input Protection Circuit
7.3.4
Programmable Gain Amplifier (PGA)
7.3.5
Second-Order, Low-Pass Filter (LPF)
7.3.6
ADC Driver
7.3.7
Reference
7.3.7.1
Internal Reference
7.3.7.2
External Reference
7.3.8
ADC Transfer Function
7.3.9
Alarm Features
7.3.9.1
Input Alarm
7.3.9.2
AVDD Alarm
7.4
Device Functional Modes
7.4.1
Host-to-Device Connection Topologies
7.4.1.1
Single Device: All multiSPI Options
7.4.1.2
Single Device: Standard SPI Interface
7.4.1.3
Multiple Devices: Daisy-Chain Topology
7.4.2
Device Operational Modes
7.4.2.1
RESET State
7.4.2.2
ACQ State
7.4.2.3
CONV State
7.5
Programming
7.5.1
Data Transfer Frame
7.5.2
Input Command Word and Register Write Operation
7.5.3
Output Data Word
7.5.4
Data Transfer Protocols
7.5.4.1
Protocols for Configuring the Device
7.5.4.2
Protocols for Reading From the Device
7.5.4.2.1
Legacy, SPI-Compatible (SYS-xy-S) Protocols with a Single SDO-x
7.5.4.2.2
Legacy, SPI-Compatible (SYS-xy-S) Protocols With Dual SDO-x
7.5.4.2.3
Source-Synchronous (SRC) Protocols
7.5.4.2.3.1
Output Clock Source Options
7.5.4.2.3.2
Output Bus Width Options
7.6
Register Maps
7.6.1
Device Configuration and Register Maps
7.6.1.1
DEVICE_ID_REG Register (address = 00h)
7.6.1.2
RST_PWRCTL_REG Register (address = 04h)
7.6.1.3
SDI_CTL_REG Register (address = 08h)
7.6.1.4
SDO_CTL_REG Register (address = 0Ch)
7.6.1.5
DATAOUT_CTL_REG Register (address = 10h)
7.6.1.6
RANGE_SEL_REG Register (address = 14h)
7.6.1.7
ALARM_REG Register (address = 20h)
7.6.1.8
ALARM_H_TH_REG Register (address = 24h)
7.6.1.9
ALARM_L_TH_REG Register (address = 28h)
8
Application and Implementation
8.1
Application Information
8.2
Typical Application
8.2.1
Design Requirements
8.2.2
Detailed Design Procedure
8.2.3
Application Curves
9
Power Supply Recommendations
9.1
Power Supply Decoupling
9.2
Power Saving
9.2.1
NAP Mode
9.2.2
Power-Down (PD) Mode
10
Layout
10.1
Layout Guidelines
10.2
Layout Example
11
Device and Documentation Support
11.1
Documentation Support
11.1.1
Related Documentation
11.2
Receiving Notification of Documentation Updates
11.3
Support Resources
11.4
Trademarks
11.5
Electrostatic Discharge Caution
11.6
Glossary
Package Options
Mechanical Data (Package|Pins)
PW|16
MPDS361A
Thermal pad, mechanical data (Package|Pins)
Orderable Information
sbas777b_oa
sbas777b_pm
1
Features
18-bit ADC with integrated analog front-end
High speed:
ADS8691: 1 MSPS
ADS8695: 500 kSPS
ADS8699: 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: ±0.6 LSB; INL: ±1.75 LSB
SNR: 92.5 dB; THD: –110 dB
ALARM → high, low threshold
multiSPI™
interface with daisy-chain
Extended industrial temperature range:
–40°C to +125°C