The interpolation circuit AM-IP4k serves to increase the resolution of incremental position and angular measuring systems with sinusoidal output signals. The input signals are subjected to a AMAC-patented internal gain and offset control and the signal period will be divided from 4 up to 4096 times. The ICs comprise three instrumentation amplifiers with adjustable gain factors. Incremental encoders which possess a voltage interface and measuring bridges up to 1Vpp can be connected directly. Sensors with current interface and photodiode-arrays are adapted by a simple external circuit. The IC operates with both single-ended or differential input signals. The noise of the sensor signals is prevented by a switching analog filter. Additionally, a digital hysteresis can suppress the edge noise of the output signals at low input frequencies and at standstill. The AM-IP4k is the first AMAC interpolator with implemented jitter suppression filter for ABZ outputs. The quality of the signals issued by the sensors is monitored in the ICs. For that purpose it is possible to activate 9 different error signals indicating the type of the error. For the calculation of the position a set of sensor or scale specific coefficients for a 360 degree correction (rotary encoder) and a signal shape correction (both linear and rotary encoder) can be placed in the EEPROM of the IC. In that way, harmonics of the sinusoidal signals or inaccuracies of the measuring scale do not lead to errors in the position value.
The three integrated output interfaces ABZ, SPI, SSI and further features like the multi stage trigger signal processing, integrated timer, integrated multiturn counter, the processing of distance coded reference marks, the possibility to adjust the reference mark as well as adjustment and storage of the zero position make the ICs suitable for direct use in industrial controls or in fast multi-channel positioning measuring systems. With these features the ICs are also prepared for use in absolute positioning measuring systems. The AM-IP4k can be configured according to specific applications using the integrated EEPROM or via the serial interface (SPI).