EC11E quadrature rotary encoder pinout

The EC11E family contains two passive rotation contacts in quadrature. Selected models add a separate momentary push switch.

EC11E without push switch

5 contacts Current package

Alps Alpine · 11 mm body with three electrical terminals and two dummy terminals.

EC11E without push switch

Catalog mounting-side view. The two dummy terminals sit opposite the A, C, B row. Scroll the map to reach all contacts.

Contact · Outputs

Phase B switch contact. Its transitions are offset from phase A.

Alps Alpine EC11E catalog, drawings 1–3

Pin	Signal	Direction	Function
A	A Contact	Contact	Phase A switch contact. Pull up through an external resistor.
C	C Contact common	Contact common	Common contact for the two rotation phases. Connect to signal ground for the pull-up circuit.
B	B Contact	Contact	Phase B switch contact. Its transitions are offset from phase A.
D1	DUMMY Dummy terminal	Dummy terminal	Dummy solder terminal. It has no assigned electrical function.
D2	DUMMY Dummy terminal	Dummy terminal	Dummy solder terminal. It has no assigned electrical function.

A and B are passive switches to C. Decode the order of the transitions and filter contact bounce.

Parameter	Limit	Conditions and source
Rotation contact rating10 mA at 5 V DC	10 mA at 5 V DC	Resistive load; specified operating-current range is 1–10 mA. Alps Alpine EC11E09204A4 specifications
Chattering and bounce3 ms and 2 ms maximum	3 ms and 2 ms maximum	Catalog sliding-noise test at R = 5 kΩ. Alps Alpine EC11E09204A4 sliding-noise test

These maps cover the flat-shaft EC11E variants listed by Alps Alpine. The drawings identify mechanical support tabs and dummy terminals separately.

Alps Alpine EC11E catalog, drawings 1–3· Drawings, model table, output phase and application notes.
Alps Alpine EC11E09204A4 specifications· Electrical ratings, switching waveform and sliding noise.
Source register· Document revisions, applicable order codes, consulted sections and available file checksums.