Additional Resources: Product Page date 08/05/2021 page 1 of 9 SERIES: AMT22 DESCRIPTION: MODULAR ABSOLUTE ENCODER FEATURES patented capacitive ASIC technology low power consumption full duplex Serial Peripheral Interface (SPI) 12 or 14-bit absolute position with multi-turn capability checksum bits for error detection configuration and firmware updates via AMT Viewpoint software digitally settable zero position (single-turn versions only) compact modular package with locking hub for ease of installation radial and axial cable connections -40 ~ 105C operating temperature ELECTRICAL parameter conditions/description min typ max units power supply VDD 3.8 5 5.5 V 1 start-up time 200 ms current consumption with unloaded output 16 mA input low level 0.8 V input high level 2.0 5.5 V output low level 0.8 V output high level 3.3 V Note: 1. Encoder must be stationary during start-up. ABSOLUTE POSITION CHARACTERISTICS parameter conditions/description min typ max units resolution 12 or 14-bit accuracy 0.2 degrees settable via AMT Viewpoint GUI or SPI (single-turn versions absolute zero position only) multi-turn multi-turn and single-turn versions available 2 turns counter signed binary number 14 bits 12-bit 25 s absolute position update rate 14-bit 100 s Notes: 2. Multi-turn encoders only. MECHANICAL parameter conditions/description min typ max units motor shaft length 9 mm motor shaft tolerance NOM +0/-0.015 mm weight 15.7 g axial play 0.3 mm rotational speed (at each 12-bit position resolution 8,000 RPM resolution) 14-bit position resolution 4,000 RPM cuidevices.comAdditional Resources: Product Page CUI Devices SERIES: AMT22 DESCRIPTION: MODULAR ABSOLUTE ENCODER date 08/05/2021 page 2 of 9 ENVIRONMENTAL parameter conditions/description min typ max units operating temperature -40 105 C humidity non-condensing 85 % vibration 10~500 Hz, 5 minute sweep, 2 hours on each XYZ 5 G shock 3 pulses, 6 ms, 3 on each XYZ 200 G RoHS yes SERIAL INTERFACE parameter conditions/description min typ max units protocol Serial Peripheral Interface Mode 0 frame size 8 bit data rate 2 MHz 3 transceiver SPI driven by PIC18F14K22 4 T data shifted to output buffer 2.5 s CLK T time between bytes 2.5 s B T time between reads 40 s CS T time before CS can be released 3 s R Notes: 3. See Microchip documentation for more details. 4. This is the time it takes to load the most current position into the SPI buffer which prevents multiple read/response commands from being required. Figure 1 Timing Waveform T CS T T B CLK CHIP SELECT T R 6 6 5 7 8 1 5 7 8 23 4 23 4 1 SCLK D7 D5 D4 D3 D2 D1 MISO K1 K0 D14 D13 D12 D11 D10 D9 D8 D6 C7 C6 C5 C4 C3 C0 C6 C5 C4 C3 C2 C1 C1 C2 C1 C7 MOSI First Command Char Second Command Char Values K1 and K0 in the response are checkbits. The checkbits are odd parity over the odd and even bits in the position response shown in the equation below. The checkbits are not part of the position, but are used to verify its validity. The lower 14 bits are the encoder position. Example: Full response: 0x61AB 14-bit position: 0x21AB (8619 decimal) Checkbit Formula Odd: K1 = (H5 H3 H1 L7 L5 L3 L1) Even: K0 = (H4 H2 H0 L6 L4 L2 L0) From the above response 0x61AB: Odd: 0 = (1 0 0 1 1 1 1) = correct Even: 1 = (0 0 1 0 0 0 1) = correct For 12-bit applications L0 and L1 are always 0. Because the low two bits are 0, 12-bit data will need right-shifted two bits. The checkbit calculation remains the same and unaffected. cuidevices.com