ZHCSGA6A February 2017 – June 2017 ADS114S06 , ADS114S08
PRODUCTION DATA.
- 1 特性
- 2 应用
- 3 说明
- 4 修订历史记录
- 5 Device Family Comparison Table
- 6 Pin Configuration and Functions
- 7 Specifications
- 8 Parameter Measurement Information
-
9 Detailed Description
- 9.1 Overview
- 9.2 Functional Block Diagram
- 9.3
Feature Description
- 9.3.1 Multiplexer
- 9.3.2 Low-Noise Programmable Gain Amplifier
- 9.3.3 Voltage Reference
- 9.3.4 Clock Source
- 9.3.5 Delta-Sigma Modulator
- 9.3.6 Digital Filter
- 9.3.7 Excitation Current Sources (IDACs)
- 9.3.8 Bias Voltage Generation
- 9.3.9 System Monitor
- 9.3.10 Status Register
- 9.3.11 General-Purpose Inputs and Outputs (GPIOs)
- 9.3.12 Low-Side Power Switch
- 9.3.13 Cyclic Redundancy Check (CRC)
- 9.3.14 Calibration
- 9.4 Device Functional Modes
- 9.5 Programming
- 9.6
Register Map
- 9.6.1
Configuration Registers
- 9.6.1.1 Device ID Register (address = 00h) [reset = xxh]
- 9.6.1.2 Device Status Register (address = 01h) [reset = 80h]
- 9.6.1.3 Input Multiplexer Register (address = 02h) [reset = 01h]
- 9.6.1.4 Gain Setting Register (address = 03h) [reset = 00h]
- 9.6.1.5 Data Rate Register (address = 04h) [reset = 14h]
- 9.6.1.6 Reference Control Register (address = 05h) [reset = 10h]
- 9.6.1.7 Excitation Current Register 1 (address = 06h) [reset = 00h]
- 9.6.1.8 Excitation Current Register 2 (address = 07h) [reset = FFh]
- 9.6.1.9 Sensor Biasing Register (address = 08h) [reset = 00h]
- 9.6.1.10 System Control Register (address = 09h) [reset = 10h]
- 9.6.1.11 Reserved Register (address = 0Ah) [reset = 00h]
- 9.6.1.12 Offset Calibration Register 1 (address = 0Bh) [reset = 00h]
- 9.6.1.13 Offset Calibration Register 2 (address = 0Ch) [reset = 00h]
- 9.6.1.14 Reserved Register (address = 0Dh) [reset = 00h]
- 9.6.1.15 Gain Calibration Register 1 (address = 0Eh) [reset = 00h]
- 9.6.1.16 Gain Calibration Register 2 (address = 0Fh) [reset = 40h]
- 9.6.1.17 GPIO Data Register (address = 10h) [reset = 00h]
- 9.6.1.18 GPIO Configuration Register (address = 11h) [reset = 00h]
- 9.6.1
Configuration Registers
- 10Application and Implementation
- 11Power Supply Recommendations
- 12Layout
- 13器件和文档支持
- 14机械、封装和可订购信息
9.3.7 Excitation Current Sources (IDACs)
The ADS114S0x incorporates two integrated, matched current sources (IDAC1, IDAC2). The current sources provide excitation current to resistive temperature devices (RTDs), thermistors, diodes, and other resistive sensors that require constant current biasing. The current sources are programmable to output values between 10 μA to 2000 μA using the IMAG[3:0] bits in the excitation current register 1 (06h). Each current source can be connected to any of the analog inputs AINx as well as the REFP1 and REFN1 inputs for the ADS114S06. Both current sources can also be connected to the same pin. The routing of the IDACs is configured by the I1MUX[3:0] and I2MUX[3:0] bits in the excitation current register 2 (07h). In three-wire RTD applications, the matched current sources can be used to cancel errors caused by sensor lead resistance (see the Typical Application section for more details). Figure 75 details the IDAC connection through the input multiplexer.
Figure 75. IDAC Block Diagram
The internal reference must be enabled for IDAC operation. As a current source, the IDAC requires voltage headroom to the positive supply to operate. This voltage headroom is the compliance voltage. When driving resistive sensors and biasing resistors, take care not to exceed the compliance voltage of the IDACs, otherwise the specified accuracy of the IDAC current may not be met. For IDAC compliance voltage specifications, see the Electrical Characteristics table.