ELM407 Datasheet | ELM

Description The ELM407 is an 8 pin integrated circuit that is used to convert the output from a rotary encoder into three signals (chip select, clock and up/down) that can be used to control various devices. The low power CMOS technology used ensures that only a very small current is required over the entire 2.0 to 5.5 volt operating range. There is no need for external filtering or debounce circuits with the ELM407, as this is all performed within the integrated circuit. After debouncing the encoder signals, the ELM407 determines the direction of shaft rotation, and then generates the appropriate outputs. A write sequence can also be generated if the Write Enable input is at a high level when the outputs are generated. The ELM407 provides 4x decoding of a rotary encoder signal. If your application requires 2x decoding, please see the ELM406 (it is identical to the ELM407 in every respect, except that it provides 2x decoding). Features - - - - - - - - Low power CMOS design Wide supply range - 2.0 to 5.5 volts plete debouncing of the encoder inputs No external filtering needed 4x decoding Can generate a write sequence Startup delay timer High current drive outputs Connection Diagram PDIP and SOIC (top view) VDD A 1 2 3 4 8 7 6 5 VSS CS Clk U/D Applications - - - - Digital audio potentiometer controls Variable voltage or temperature circuits Positioning controls Tuning circuits B Write Enable Block Diagram Debounce Circuit Direction Decoding Debounce Circuit Output Logic CS Clk U/D Rotary Encoder Write Enable ELM407DSA Elm Electronics - Circuits for the Hobbyist .elmelectronics. 1 of 10 Free Datasheet http://../ Pin Descriptions VDD (pin 1) This pin is the positive supply pin, and should always be the most positive point in the circuit. Internal circuitry connected to this pin is used to provide power on reset of the internal logic, so an external reset signal is not required. Refer to the Electrical...