date 10/2010 page 1 of 6 PART NUMBER: AMT203 THE AMT203 is a high performance absolute encoder based on capacitive sensing technology. The AMT203 utilizes a custom ASIC to create absolute position over a single turn. This encoder is12 bit and communicates via an SPI serial bus for working as a slave to an external microprocessor. Incremental A,B and Index signals are provided for higher speed operation. Incremental A,B signals with a single index pulse per 360 deg are provided for higher speed operation. DESCRIPTION: 12 BIT ABSOLUTE ENCODER FEATURES - 12 bit (4096 positions) SPI communication Small Size 37mm Incremental Line count up to 1024 Single pulse index Capacitive ASIC technology Modular locking hub design for ease of installation - SPI adjustable settings - ‘One Touch’ zero position ELECTRONIC SPECIFICATIONS parameter conditions/description power supply min nom max units 4.5 5 5.5 V 8 10 mA current consumption output resolution 4,096 quadrature resolution 96, 192, 200, 250, 384, 400, 500, 512, 768, 800, 1000, 1024 incremental output signals Quadrature A, B signals and Index Z incremental output waveform square wave incremental outputs output voltage - sourcing to +5 V @ -32 mA output voltage - sinking to ground @ -32 mA SPI output natural binary SPI bus PIC 16F690 (see datasheet) incr. 3.8 SPI resolution accuracy 0.55 V V 12 bit 2 incr. MECHANICAL SPECIFICATIONS parameter conditions/description min nom SPI speed mounting options max units 8,000 RPM max units A) 2 each M1.6 on 16 mm (0.63”) bolt circle B) 2 each #4 on 19.05 mm (0.75”) bolt circle C) 2 each M1.6 or M2 on 20 mm (0.787”) bolt circle D) 3 each M1.6 or M2 on 20.9 mm (0.823”) bolt circle with washers in option B holes E) 3 each M1.6 or M2 on 22 mm (0.866”) bolt circle F) 4 each M1.6 or M2 on 25.4 mm (1”) bolt circle ENVIRONMENTAL SPECIFICATIONS parameter conditions/description min operating temperature -40 humidity vibration 1.5mm, 3 directions, 2 hours 20050 SW 112th Ave. Tualatin, Oregon 97062 10 phone 503.612.2300 nom 125 °C 85 %RH 55 Hz fax 503.612.2380 www.cui.com date 10/2010 page 2 of 6 PART NUMBER: AMT203 12 BIT ABSOLUTE ENCODER DESCRIPTION: AMT203-V KIT In order to provide maximum flexibility for our customers, the AMT203 series is provided in kit form standard. This allows the user to implement the encoder into a range of applications using one sku#, reducing engineering and inventory costs. SLEEVES 8mm 1/4 inch (6.35mm) 6mm 5mm 3/16 inch (4.76mm) 4mm 1/8 inch (3.175mm) 3mm 2mm Blue Snow Red1 Green1 Yellow1 Gray60 Purple1 Orange Light Sky Blue TOOL A BASE TOOL C TOP COVER SHAFT ADAPTER CUSTOM CONFIG KEY For customers that prefer a specific AMT203 configuration, please reference the custom configuration key below. AMT203 - XXXX - XXXX Resolution (ppr): 0096 0192 0200 0250 0400 0500 0512 0640 1024 20050 SW 112th Ave. Tualatin, Oregon 97062 Sleeve Bore Diameter: 2000 = 2 mm 3000 = 3 mm 3175 = 3.175 mm (1/8”) 4000 = 4 mm 4760 = 4.76 mm (3/16”) 5000 = 5 mm 6000 = 6 mm 6350 = 6.35 mm (1/4”) 8000 = 8 mm phone 503.612.2300 fax 503.612.2380 www.cui.com date 10/2010 page 3 of 6 PART NUMBER: AMT203 DESCRIPTION: 12 BIT ABSOLUTE ENCODER ENCODER INTERFACE PINOUT CONNECTOR 1 FUNCTION # 14 13 12 11 10 9 8 7 6 5 4 3 2 1 SPI T_Bit N/A X N/A A N/A B B MOSI 5 V+ SCK GND MISO CSB N/A 7 5 3 1 14 12 10 8 6 4 2 13 11 9 DETAIL B SCALE 4 : 1 Demo Board Side Encoder Side 1' 0.25" (304.8) Samtec ISDF-07-D Demo Board Cable 28 AWG 10 conductor 1.27 mm pitch (Cable available without Demo Board Connector) 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2380 www.cui.com date 10/2010 page 4 of 6 PART NUMBER: AMT203 12 BIT ABSOLUTE ENCODER DESCRIPTION: 10.34 0.407 R15.49 0.610 15.30 0.602 15.33 0.604 37.39 1.472 28.58 1.125 10.93 0.430 A (3 PLCS) 22.00 0.866 2.00 0.079 (4 PLCS) 21.45 0.844 R2.10 0.083 12.60 0.496 19.05 0.750 2.95 0.116 (2 PLCS) TOLERANCE: ±0.05mm UNLESS OTHERWISE SPECIFIED 1.70 0.067 (2 PLCS) 0.55 RoHS 20.90 0.823 DETAIL A SCALE 4 : 1 25.48 1.003 16.00 0.630 5.30mm 18.60mm AMT203 ABS US Patent No. 6892590 SCALE 5:1 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 R1.20mm fax 503.612.2380 www.cui.com date 10/2010 page 5 of 6 PART NUMBER: AMT203 DESCRIPTION: 12 BIT ABSOLUTE ENCODER APPLICATION NOTES Encoder operational mode • Initialization mode: At power up the encoder goes through an initiation and stabilization procedure. This includes microprocessor stabilization and the program for combining Coarse and Fine channel of the encoder for getting the absolute start position. This takes less than 0.1 seconds. • Tracking mode: Only the Fine channel is active and the MCU internal position register is updated with data from Fine: – MCU 12 bit position register is updated from Fine every 48 μs. – For accurate position update without above time delay, outputs for incremental A quad B or Count and Up/Dwn from the Fine channel are provided. These outputs are operational up to 8000 RPM and there is no speed error. There is an acceleration error dependent on an internal filter constant of about 100 μs. – When using the incremental output there also is an Index output available, with one index pulse per turn. Serial Peripheral Interface Commands The SPI or Serial Peripheral Interface Bus is a standard interface promoted by Motorola and Microchip among others. It consists of 4 signals: MOSI: Master Out Slave In MISO: Master In Slave Out SCK: Serial Clock CSB: Chip Select (active low) SPI BUS The SPI bus runs full duplex and transfers multiples of 8 bits in a frame. The SPI type is the most common (CPOL=0, CPHA=0), also known as Microwire. Data is captured on the rising edge of SCK and the output data is changed after the falling edge of SCK. MISO LSB MSB Terminology SCK MOSI CSB LSB MSB MSB = most significant byte LSB = least significant byte msb = most significant bit lsb = least significant bit Setup Serial Peripheral Interface Bus (SPI) on AMT203 Figure 7: SPI BUS Timing Diagram The msb data out on MISO is valid soon after CSB goes low. The MOSI data is valid soon after the falling edge of SCK. The Encoder drives data out on MISO as long as CSB is low. Normally, CSB goes low, then after 8 clocks the command is interpreted. CSB high resets the clock counter, and terminates any command sequence. 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2380 www.cui.com date 10/2010 page 6 of 6 PART NUMBER: AMT203 DESCRIPTION: 12 BIT ABSOLUTE ENCODER SPI Commands: The commands are all 8 bits long, the msb is shifted in first, and is the leftmost bit shown in Figure 7. Encoder Protocol Considerations: The Encoder is designed to operate with a high speed SPI link, in full duplex mode. This implies the host can issue commands and read data as quickly as necessary but there has to be an acknowledgement from the slave just before the data is transferred. Essentially the host issues a command, receives zero or more wait sequences (0xA5 or 1010,0101) then the echo of the command followed by an optional payload. So, for example to read the position, the host issues rd_pos (0x10 or 0001,0000), receiving a series of wait sequences (0xA5) then a reflected rd_pos (0x10), then the MSB data followed by the LSB data. It is recommended that the host leave a 20 us gap between reads to avoid extending the read time by forcing wait sequences. Command 0x00: nop_a5 This command is ignored by the Encoder and simply causes the next data to be read. The encoder responds with 0xA5 if there is nothing else to send. Command 0x10: rd_pos This command causes a read of the current position. The sequence is as follows: 1) issue read command, receive idle character 2) issue NOP, receive idle character 0xA5 or 0x10 3) repeat step 2 if it is 0xA5 4) issue NOP and receive MSB position (4 bits valid data) 5) issue NOP and receive LSB position (8 bits valid data) Note that it is possible to overlap commands, so instead of NOP is several steps above the user could start another operation. The read and write FIFOs for the PCI streams are 16 bytes long and it is up to the user to avoid overflow. Command 0x70: set_zero_point This command sets the current position to zero and saves this setting in the EEPROM. The host should send nop_a5 repeatedly after sending this command, the response will be 0xa5 while update is proceeding and 0x80 is the response when update is finished. 20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2380 www.cui.com