原标题：IDT ZSSC3230容性传感器信号调理解决方案

　　IDT公司的ZSSC3230容性传感器信号调理器是CMOS集成电路,具有精确的电容/数字转换和容性传感器信号的传感器专用的修正.传感器失调,灵敏度和温度飘移是通过内部数字信号处理器进行数字补偿,该处理器运行修正算法,其修正系数存储在非易失多次编程(NVM)存储器.编程ZSSC3230是通过串行接口进行.接口由PC进行控制校正程序,它有一组存储器中的校正系数来编程. ZSSC3230容性传感器的容量高达30pF,其输出分辨率高达18位.它和单端容性传感器兼容. ZSSC3230提供加速的信号处理,增加分辨率和提高的抗噪声性,以支持高速控制,安全性和实时检测应用,并满足能效的最高要求.每秒1次取样时的低电流消耗为1.3μA.I2C接口支持标准模式(100kHz),快速模式(400kHz)和高速模式(3.4MHz),工作电压VDD为1.68V-3.6V,工作温度-40℃ 到125℃.主要用在湿度传感器,压力传感器,水平传感器,能效解决方案的智能数字容性传感器,消费类电子/白色家电如HVAC以及医疗电子设备.本文介绍了ZSSC3230主要特性,框图和基本应用框图,以及评估板ZSSC3230 EVK主要特性,电路图,材料清单和PCB设计图.

　　The ZSSC3230 is a CMOS integrated circuit for accurate capacitance-to-digital conversion and sensor-specific correction ofcapacitive sensor signals. Digital compensation of sensor offset,sensitivity, and temperature drift is accomplished via an internaldigital signal processor running a correction algorithm withcalibration coefficients stored in a nonvolatile, multiple-timEPROgrammable (NVM) memory. Programming the ZSSC3230 issimple via the serial interface. The interface is used for the PCcontrolled　calibration procedure, which programs the set ofcalibration coefficients in memory. The ZSSC3230 is configurablefor capacitive sensors with capacitances up to 30pF and will　provide an output resolution that is scalable up to 18-bit. It iscompatible with single-ended capacitive sensors. Measured andcorrected sensor values can be output as I2C (≤ 3.4MHz).

　　The ZSSC3230 provides accelerated signal processing, increasedresolution, and improved noise immunity in order to support highspeedcontrol, safety, and real-time sensing applications with thehighest requirements for energy efficiency.

　　The ZSSC3230 can be set up for one of three main operating modes:Sleep Mode – Sleep Mode based operation is recommended for smart sensors for the lowest average power consumption. TheZSSC3230 automatically enters an idle state after command execution for minimum current consumption; however, the interface is still　listening and accepts commands. After receiving of a valid command, the ZSSC3230 wakes up, executes the command, and provides theresults at the digital interface and then returns to Sleep State.

　　Command Mode – Command Mode is most appropriate for evaluation, test, and calibration purposes. In this mode, all commands areavailable, both digital and analog outputs are supported, and no restrictions for any functionality need to be considered. Command Modecan be used for applications requiring re-occurring (or even continuous) digital interaction and minimum latency. Applications inCommand Mode are only active on command request. See Table 15 for definitions of the commands.

　　Cyclic Measurement Mode – Cyclic operation means autonomous, cyclically repeated sensor measurements and related digital andoutput updates.

　　After power-on, the voltage regulators are switched on, and the ZSSC3230’s low-voltage section (LV) is active while the related interfaceconfiguration information is read from memory. Then the LV section is switched off, the ZSSC3230 goes into Sleep Mode, and the interface isready to receive commands. The interface is always powered by VDD, so it is referred to as the high voltage section (HV).

　　ZSSC3230主要特性:

　　 Low current consumption: 1.3μA at 1 sample per second

　　 Maximum target input capacitance: 30pF

　　 Programmable capacitance span and offset

　　 High sampling rate with 2ms at 14-bit resolution

　　 ADC resolution: Adjustable in speed and resolution, 18-bitmaximum

　　 Internal auto-compensated temperature sensor; not stresssensitive

　　 Programmable measurement sequence, single-shot andautomatic cycling of measurements with end-of-sequenceinterrupt output

　　 Oversampling modes using internal averaging

　　 Interrupt features

　　 Integrated NVM for configuration and free space forcustomer use

　　 Small die size

　　 External reset pin (low active)

　　 No external trimming components required

　　 Highly integrated CMOS designPhysical Characteristics

　　 Supply voltage VDD: 1.68V to 3.6V

　　 Operating temperature: -40℃ to 125℃ depending on the partcode

　　 I2C Interface compatible, supporting

　　 Standard Mode(100kHz)

　　 Fast Mode (400kHz)

　　 High-Speed Mode (3.4MHz)

　　 Capacitive input range 0 to 30pF

　　 Capacitive offset compensation 0 to 15pF

　　 Available in 4x4 mm2 24-PQFN package or as die

　　ZSSC3230应用:

　　 Humidity sensors

　　 Pressure sensors, level sensors

　　 Smart, digital, capacitive sensors for energy-efficient solutions

　　 Consumer / white goods (e.g., HVAC)

　　 Medical applications

　　图1. ZSSC3230基本应用框图

　　图2. ZSSC3230框图

　　图3. ZSSC3230隔离C模式

　　图4. ZSSC3230接地C模式

　　评估板ZSSC3230 EVK

　　The ZSSC3230 SSC Evaluation Kit is designed for sensor moduleevaluation, laboratory setup, and module calibration developmentfor the ZSSC3230 Sensor Signal Conditioners (SSC).

　　The main purpose of the ZSSC3230 Evaluation Kit iscommunication between the user’s computer and the ZSSC3230.

　　The computer sends commands and data via its USB port to theZSSC3230 Evaluation Board (ZSSC3230EVB). Themicrocontroller on the ZSSC3230EVB interprets these commandsand relays them to the ZSSC3230 located on the ZSSC3230 SSCEvaluation Board using the I2C communication interface.

　　The microcontroller also forwards any data bytes from theZSSC3230 back to the computer via the USB connection. Thesebytes can be sensor readings to be displayed on the computer bythe software, raw analog-to-digital converter (ADC) data usedduring calibration, or Electrically Erasable Programmable Read-Only Memory (EEPROM) data.

　　评估板ZSSC3230 EVK主要特性:

　　 The I2C communication interface enables quick and easyconfiguration and calibration of the ZSSC3230 using theuser’s computer.

　　 Connections are provided on the ZSSC3230 SSC EvaluationBoard for the user’s sensor module, which can be usedinstead of the Onboard Cap Select Dual In-line Package(DIP) switches on the ZSSC3230EVB.

　　 A set of DIP switches on the ZSSC3230EVB controls acapacitance that simulates a sensor signal ranging from2pF to 30pF, which can be input to the analog front-end ofthe ZSSC3230 for evaluation of basic features or fordemonstrating a “dry-run” calibration.

　　 Clamshell 24-PQFN socket for ZSSC3230 device under test(DUT) facilitates testing multiple DUTs without soldering.

　　 Software is available for download from the IDT web sitewww.IDT.com/ZSSC3230.

　　评估板ZSSC3230 EVK包括:

　　 ZSSC3230EVB SSC Evaluation Board

　　 5 samples of the ZSSC3230 (24-PQFN 4 x 4 mm)

　　 USB cable

　　图5.评估板ZSSC3230 EVK外形图

　　图6.评估板ZSSC3230 EVK概况图

　　评估板ZSSC3230 EVK材料清单: