Datasheet A17700 (Allegro)

A17700 Pressure Sensor Interface and Signal Conditioning IC with Polynomial Signal Compensation and Advanced Diagnostics FEATURES AND BENEFITS DESCRIPTION
• Directly interfaces with strain gauge or other transducer The A17700 is a sensor interface IC designed to connect in Wheatstone bridge configuration for low noise and directly to a strain gauge or other sensor in a Wheatstone high accuracy measurements bridge configuration. The A17700 amplifies and converts the • On-chip Poly(4,4) compensation for improved accuracy analog input from the bridge to the digital domain, low-pass over temperature, compensating both IC and bridge filters the signal, and outputs a ratiometric analog signal or • Offering from Poly(1,1) to Poly(4,4) polynomial a digital SENT/PWM protocol. Digital signal processing compensation including any possible degree between 0 functions, including temperature compensation and gain/offset and 4 like Poly(2,4) and Poly(3,3). trim, provide an accurate and linear output. A Manchester • Ratiometric analog output for legacy applications programming interface for configurations is also available. It • High bandwidth option to support fast response time includes on-chip EEPROM technology capable of supporting applications up to 100 read/write cycles for programming of calibration • PWM (Pulse Width Modulated) output with optional parameters. diagnostics to identify fault conditions The A17700 incorporates advanced diagnostic functions to • SENT (Single Edge Nibble Transmission) output support safety-critical application designs. configurable for temperature or diagnostic reporting in addition to pressure data The A17700 is available in a 24-pin 4 mm × 4 mm QFN • Fast SENT provides increased data rates to support fast package with wettable flank and exposed thermal pad. response time applications • Manchester interface for programming through single OUT pin • Internal device temperature available on output via SENT
PACKAGE:
protocol (or volatile registers) 24-pin wettable flank QFN • Suite of diagnostics to allow for safety-critical systems with exposed thermal pad (suffix ES) fault detection ○ Broken wire detection ○ Under- and overvoltage detection ○ Under- and overtemperature detection Continued on next page... Not to scale
A17700
VBRG VCC Regulator POR 100 nF 12-Bit DAC 100 nF VP Coarse Programmable Programmable Offset 16-Bit Digital Filter / Poly(4,4) Gain 1 Amplifier Gain 2 Amplifier Adjust ADC Compensation Block OUT PWM MUX VBRGGND SENT Internal Temperature 12-Bit Sensor ADC Available through SENT output VN Manchester EEPROM Programming GND Interface
Figure 1: Functional Block Diagram
A17700-DS December 4, 2020 MCO-0001009 Document Outline Features and Benefits Description Package Functional Block Diagram Selection Guide Absolute Maximum Ratings Thermal Characteristics Pinout Diagram and Terminal List Operating Characteristics Functional Description Bandwidth Selection Output Response Time Power-On Time Front End Gain Adjustment Front End Differential Offset Adjustment Input Signal Range Calculation Fine Adjustment and Temperature Compensation Output Protocols Digital Output Mode Selection Digital Output Driver Fall Time Selection Broken Wire Detection Diagnostic Features Programming: Manchester Communication Entering Manchester Coding Manchester Interface Message Structure CRC Device Access Shadow Registers Device EEPROM and Register Access Lock EEPROM Map Volatile Registers Map Power Derating Package Outline Drawing