Incremental Encoder Interface for RS-422, HTL, and TTL with Digital Inputs

The MAX14890E incremental encoder receiver contains four differential receivers and two single-ended receivers.

The differential receivers can be operated in RS-422 or differential high-threshold logic (HTL) modes and are optionally configurable for single-ended TTL/HTL operation. The MAX14890E features a wide common mode input range of -20V to +20V in RS-422 mode.

The auxiliary IEC 61131-2 Type-1/Type-3 digital inputs are designed for operation with switches or proximity sensors and can be individually configured for TTL operation.

All receiver input signals are fault protected to voltage shorts in the ±40V range. Per channel fault detection provides warning of irregular conditions such as small differential signals, shorts, opens, overvoltages, and undervoltages.

The MAX14890E features a pin-selectable SPI or parallel-logic interface. SPI control provides detailed diagnostics and individual configurations for receivers.

The MAX14890E is available in a 32-pin TQFN-EP (5mm x 5mm) and operates over the -40°C to +125°C temperature range.

Applications

* Encoder Interfaces * Motor Controllers * Pulse Counters * Servo Control Commutation

* High Flexibility Supports All Encoder Types

* Selectable RS-422/HTL/TTL/DI Receivers

* RS-422 Switching Rates Up to 35Mbps

* TTL Switching Rates Up to 5MHz

* HTL Switching Rates Up to 400kHz

* SPI or Pin-Controlled Operation

* SPI Interface Allows Per-Receiver Configuration

* 1.62V to 5.5V Logic Interface

* Integrated Fault Detection Reduces Down-Time

* Open-Wire and Short-Circuit Detection

* Overvoltage and Undervoltage Fault Detection

* Integrated Protection Ensures Robust Communication

* ±40V Fault Protection Range

* ±20V RS-422 Common Mode Range

* DI Glitch Filters

* ±25kV HBM ESD

* ±7kV Air-Gap per IEC 61000-4-2 ESD

* ±10kV Contact per IEC 61000-4-2 ESD

* -40°C to +125°C Operating Temperature Range