air core meterPhilips Semiconductors Automotive Products Application note SA5775 Air core meter driver applications information AN1761 INTRODUCTION The SA5775 is a monolithic Serial Gauge Driver (SGD) which can be used to directly drive Air Core Meters (ACM), typically used in automobile dashboards (Figure 1). The circuit interfaces with the serial bus of a microprocessor, has 10-bit resolution (0.35 degrees) and is guaranteed to be monotonic. Data can be shifted through the part so that several SA5775s can be cascaded with only one chip select line. On-board circuitry protects the circuit from external faults. 2. The permanent magnet ages with a lessening of the magnetic field. This makes it harder for it to pull the needle against the spring. 3. The mechanism is prone to damage due to vibrations ……