ams AG has introduced its first magnetic position sensors fully developed using the automotive industry’s program for ISO26262 safety compliance. The launch of the new sensor series also marks the introduction of ams’s first magnetic position sensor in a system-in-package (SiP) format—a space-saving package that enables lower system costs and allows placement of the sensor device in environments where printed circuit board (PCB)-based packages wouldn't fit.
The AS5170 and AS5171 are ams AG's first magnetic position sensors developed with the goal of ISO26 262 safety compliance. Image source: ams AGThe AS5170 and AS5171 sensors were developed as Safety Element out of Context (SEooC) devices, as defined in the ISO26262 functional safety standard. The AS517x parts are ams’s first magnetic position sensors to provide full data path diagnostics, helping automotive system original equipment manufacturers (OEMs) achieve a higher level of ISO26262 system-level compliance. The diagnostic system built into the AS517x series tests the entire device—from the Hall sensor front end, through the digital signal processing (DSP) engine, to the back-end interfaces and pins.
Qualified to AEC-Q100 Grade 0, the AS517x series sensors measure absolute angle of rotation. 12-bit output resolution enables precise measurements, even for reduced angular excursions down to a minimum arc of 90°. ams considers the devices ideal for a range of safety-critical automotive applications including chassis height, gear shifters, electronic power steering, exhaust gas recirculation, and brake pedal as well as throttle position sensing.
The AS5171 comes in an SiP format, which integrates the sensor die and capacitors in a single, encapsulated three-pin package. The SiP offers improved electrostatic discharge (ESD) and electromagnetic compatibility (EMC) performance, as well as enhanced supply protection. The supply and output pins are protected against over-voltages up to +20V, while the supply pin also offers -20V of protection against reverse polarity.
The SiP eliminates the requirement to mount a position sensor IC on a PCB, thus reducing component count and system cost, and easing assembly into the end product.
The AS5171A comes with an analog output. The AS5171B provides a digital output that may be programmed either as a pulse width modulated (PWM) interface or as a single-edge nibble transmission (SENT)-compliant interface (a digital, unidirectional, interface standard targeting sensor data communications in automotive applications). The analog AS5170A and digital AS5170B ICs are housed in an 8-pin SOIC package.
As with other magnetic position sensors from ams, the AS5170 and AS5171 feature high immunity to stray magnetic fields, enabling unimpaired operation even in the presence of strong fields generated by electric motors, high current-carrying cables and other external devices. In addition to highly reliable performance, such immunity to outside influences reduces system cost by eliminating the need for shielding that other magnetic position sensors require.
The high sensitivity of the Hall sensor front-end in the AS517x devices permits using small, low-cost target magnets and supports a wide magnetic field strength input range of 5-90mT.
The AS5170 and AS5171 magnetic position sensors are available immediately in production volumes. Unit pricing is $2.64 for the AS5170 and $2.87 for the AS5171, in order quantities of 1,000.
