The new SD400 family combines the flexibility of free programmable standard interface products with the advantages of an optimized custom specific solution.
For fast prototyping, a tool kit is offered allowing sensor interface configuration and firmware development. Special SD400 versions with E²PROM enable customer’s firmware design. Alternatively, SensorDynamics may provide the complete ready-to-use firmware to be tested at the customer’s site. In the final customized product the E²PROM is replaced by metal-mask ROM for cost minimization and highest reliability.
Two versions out of the SD400 family are available and can be adapted to customer’s needs.
First version has a specialized Eddy current interface, designed for contactless displacement measurement. Besides the interface chip, only a sensing coil plus a few passive components are needed for the application circuit. A metal target facing the coil completes the distance measuring system which is best suited to work under harsh environments, e.g. in transmission cases at temperatures up to 150°C.
Second version provides two differential analog input channels. Wheatstone bridge type sensors as thermocouples, AMR-, GMR-, piezoresistive pressure-, water flow- and strain gauge sensors can be adapted easily to the interface chip as well as single-ended sensors. It is also suitable for battery management where fast and simultaneous acquisition of voltage and current is necessary.
For both versions several interface options are available such as PWM, LIN, SPI or UART.
Typical applications are:
Position sensing in automotive applications based on Eddy current or AMR/ GMR principle like clutch-, brake-and accelerator-pedals, gear shifters and suspension control;
Position sensing under harsh environment up to 150°C like in valves, transmission- and transfer-cases based on Eddy current principle;
Liquid- and gas-flow sensing based on MEMS sensors;
Indirect force sensing based on strain gauge sensors;
Pressure measuring based on piezoresistive MEMS sensors;
Battery charge-state and health monitoring.
Fail-safe and further Features:
SensorDynamics, being the leader in fail-safe solutions, has recognized the critical market need for AEC-Q100 certified sensor interfaces including monitoring circuitries that make them absolutely fail-safe. The monitoring comprises the external sensors as well as all analog and digital circuitry of the sensor interface chip. Fail-safe functions and alarm thresholds can be adapted to customer’s needs. All design solutions involved in achieving fail-safe are in accordance with IEC 61508 and upcoming ISO 26262 recommendations and a result of thorough FMEAs (Failure Mode Effect Analysis).
SD400 family offers a unique combination of outstanding features:
Ambient operating temperature range -40 to +150°C;
Supply voltage range 3.9 V to 33V with peaks up to 50V;
Comprehensive hard-wired fail-safe features;
Final ASIC with metal-mask programmed memory for highest reliability;
Proven 8051 CPU core running at 20MHz;
Two full 14-bit Sigma-Delta ADCs for simultaneous data acquisition;
Eddy current sensor interface;
Integration of additional analog and digital blocks on customer demand;
Two sleep-modes with wake-up on external signal or sensor signal change.
Fabrication:
SensorDynamics uses the semiconductor fab of ST-Microelectronics for ASIC production. The component is QFN64L (9 mm x 9 mm), packaged and tested by ASE in Korea. SensorDynamics’ own quality and logistics specialists are responsible for the entire manufacturing process.
