| iC-PVL is an ultra low power magnetic encoder, used for linear and off-axis multiturn position sensing. On main power failure, iC-PVL switches automatically to battery supply and continues scanning the position.
iC-PVL operates with pole wheels or linear scales with a pole width of 1.0 mm up to 5.0 mm. Due to various operating modes, iC-PVL can work with iC-Haus singleturn encoders (e.g. iC-MU, iC-MN, iC-LGC, iC-LNB, iC-MHM, etc.), as stand-alone SSI or incremental encoder, or links to embedded controllers via I2C.
The Hall signal processing stage is designed for ultra low power applications and can be configured to support angular accelerations up to 180 000 rad/s2 with 16 magnetic periods per revolution. The maximum magnetic signal frequency is 8 000 Hz. This corresponds to a rotational frequency of 30 000 rpm for magnetic scales with 16 pole pairs. With higher demands on acceleration, the power consumption increases. The maximum supported acceleration is configurable, therefore an optimal trade-off between power consumption and supported acceleration can be individually chosen to meet the demands of the target application.
iC-PVL reads its configuration from an external EEPROM via an I2C interface with multimaster support. Among others, the bit length for multiturn and synchronization data, the interface mode, the maximum supported acceleration and the usage of error or parity bits can be configured. The configuration read-in is triggered by the preset pin PRE. A pulse on this pin resets the device and reads a new configuration from the EEPROM. The multiturn counter is preset to a configurable value (default 0).
The configuration RAM and multiturn counter value are protected against bit errors by an 8 bit CRC. Additionally, an error is generated on excessive speed or acceleration. An integrated battery monitor is used to signalize an empty battery as error. If an error is detected, it is displayed at output NERR and via the error bit in the SSI communication protocol. Additionally, a low battery voltage is indicated at output NWRN. Optionally, this warning can be transmitted in the serial data stream.
Besides linear position encoding, the iC-PVL is also used for off-axis scanning of magnetic pole wheels. In these applications, a certain number of magnetic north-south field periods may be interpreted as one mechanical revolution. The FlexCount® circuitry offers this functionality. By electrically emulating the characteristics of a gear box, a transmission is freely programmable. For instance, 1-256 magnetic periods can be interpreted as one mechanical revolution.
The iC-PVL multiturn encoder comes in a space-saving QFN16 package. This allows its integration in existing encoder systems or the design of smaller encoders.