AM4096 – 12 bit angular magnetic encoder IC
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Data sheet AM4096D02_09 Issue 9, 30th November 2021 AM4096 – 12 bit angular magnetic encoder IC The AM4096 uses Hall sensor technology for sensing the magnetic field. A circular array of sensors detects the perpendicular component of the magnetic field. The signals are summed then amplified. Sine and cosine signals are generated when the magnet rotates. The sine and cosine signals are factory calibrated for optimum performance. From the sine and cosine values the angular position is calculated with a fast 12 bit interpolator. The calculated position is then output in various digital and analogue formats. An inbuilt voltage regulator ensures stable conditions for the core of the chip and a more flexible power supply voltage. All inputs and outputs are related to the external supply voltage. The AM4096 has many different setting options which are defined by the contents of internal registers. The zero position can be also set with an external pin. The settings of the chip are stored in an integrated EEPROM. The registers and the EEPROM can be accessed through a serial two wire interface TWI. With its compact size the AM4096 is especially suitable for different applications, including motor motion control and commutation, robotics, camera positioning, various encoder applications, battery powered devices and other demanding high resolution applications. Contactless angular position encoding over 360° Presetable zero position High speed operation to 60,000 rpm Power save mode for low current consumption Integrated EEPROM Output options: • Incremental • Serial SSI • Serial two wire interface (TWI) • UVW commutation output • Linear voltage • Tacho • Analogue sin

Block diagram Analogue part Digital part Hall array & front end amplifier Clock Data Differential amplifier Analog differential RefP RefN Sin positive Sin negative Cos positive Cos negative U V W Linear voltage AM4096 Zero Fig. 1: AM4096 block diagram Vddd Vddd Vext Vext Vdda Vdda Agnd Agnd RefP RefP Vout/Tout Vout/Tout Zero Zero Data Data Clock Clock

Lower reference input for voltage output Upper reference input for voltage output Commutation output W/Cosine negative output Zeroing input Commutation output V/Sine positive output TWI serial interface data line TWI serial interface clock line Linear voltage output/Tacho output Power save mode input Factory test Commutation output U/Sine negative output Factory test Tacho direction output/Cosine positive output Factory test Factory test Factory test Cosine analogue output for filtering Sine analogue output for filtering Digital power supply 3.0 / 3.3 V Power supply input 5 V Analogue power...

Pin description Some pins have more than one function. The function of those pins can be selected over two wire serial interface and stored in the chip. All digital pins have a pull-down resistor except PSM pin. Name Data a digital output for serial SSI communication the quadrature incremental reference mark output the quadrature incremental output B is the quadrature incremental output A the commutation digital output W or analogue differential buffered Cosine negative output the commutation digital output V or analogue differential buffered Sine positive output the commutation digital...

Technical specifications Absolute maximum ratings TA = 22 °C unless otherwise noted. Parameter Supply voltage Input current (latch-up immunity) Electrostatic discharge Operating junction temperature Storage temperature range Moisture sensitivity level * Human Body Model Operating range conditions Parameter Temperature range Temperature range for EEPROM write Supply voltage Supply current Power-up time Interpolator delay Sensors delay Filtering delay Oscillator Oscillator frequency Oscillator frequency temperature drift fosc power supply dependence Digital outputs Saturation voltage hi (Vext...

AM4096 programming The AM4096 can be programmed over the two-wire serial interface (TWI) which is compatible with I2C protocol with a 400 kbps bit rate speed. The TWI protocol allows the to interconnect up to 128 individually addressable devices using only two bi-directional bus lines, one for clock (SCL) and one for data (SDA). The only external hardware needed to implement the bus is a single pull-up resistor for each of the TWI bus lines. All devices connected to the bus have individual addresses, and mechanisms for resolving bus contention are inherent in the TWI protocol. Vext The TWI...

The AM4096 device acts as a slave and supports two modes: 1. Master transmits to slave. This mode is used to write to the AM4096 address space. The 16 bit data word is divided into two 8 bit data frames. The ACK acknowledges are provided by the slave. Fig. 6: Write data packet After the EEPROM write packet (memory address 00 h – 1 Fh) the slave device can not be addressed for a time of 20 ms. In this time the slave is performing the internal EEPROM write process. If the device is addressed, no ACK is returned. 2. Combined format mode is used to read the AM4096 address space. If the EEPROM...

Data sheet AM4096D02_09 Description of user-programmable parameters: Parameter Note Interpolator power can be switched off, if only analogue outputs are used. Interpolator power Interpolator delay It must always be set to 1. Currently it is not allowed to use value 0. Internal power down rate See power save mode description. Internal power down See power save mode description. Regulator voltage Device address Incremental output can be disabled if not used. Interpolator may not work properly when sinusoidal differential analogue outputs are on. Selects the output on pins U/NSin, V/PSin,...

3/5 V operation mode The AM4096 can operate with power supply voltage from 3 V to 5.5 V. The outputs and inputs are supplied with the external voltage. The core of the chip is always powered with the regulated voltage from the LDO voltage regulator. The voltage of the regulator can be selected with the “Reg35” parameter between 3 V and 3.3 V. When the external power supply is from 3 V to 3.3 V the regulator voltage should be set to 3 V. When the external power supply voltage is from 3.3 V to 5.5 V the regulator voltage should be set to 3.3 V. Outputs direction The direction of the outputs...