Quadrature contacts
A and B are passive switches to C. Decode the order of the transitions and filter contact bounce.
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 packageEC11E with push switch 5 contacts
30 detents, 15 pulses per revolution, no push switch.
EC11E without push switch pinout
EC11E without push switch
D2 · DUMMY
Dummy solder terminal. It has no assigned electrical function.
All 5 pins
| 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. |
Signal assignments
Electrical limits
| 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 |
Models and documents
These maps cover the flat-shaft EC11E variants listed by Alps Alpine. The drawings identify mechanical support tabs and dummy terminals separately.
- EC11E09204A4
- 18 detents, 9 pulses per revolution, no push switch.
- EC11E15204A3
- 30 detents, 15 pulses per revolution, no push switch.
- EC11E1820402
- 36 detents, 18 pulses per revolution, no push switch.
- 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.