Single Key Touch Sensor using LM2907

Rajkumar Sharma
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SKU: EL119465
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This is a single key device featuring a touch ON (Momentary) output. The project is built using the LM2907 chip. The board provides stable sensing and has a wide working power supply range 5V to 12V DC and consumes 20mA. D1 power LED, D2 function LED.

Touch sensors are used in many applications, from remote controls, LED light controls to appliance control panels. This is a simple solution to replace a mechanical button and can be implemented in a wide variety of applications. The sensor provides a great user experience. It is easy and more convenient to use as it has no moving mechanical parts.

Features

Supply 5V to 12V DC @ 20mA
D1 Power LED
D2 Function LED, indicates when Sense
Sensor Output Normally High – Goes Low when triggered
Sensor Output TTL 5V when Supply 5V, Output 12V When Input Supply 12V
PCB Dimensions 40.48 x 13.02 mm

Schematic

Parts List

NO	QNTY.	REF.	DESC	MANUFACTURER	SUPPLIER	PART NO
1	1	CN1	4 PIN MALE HEADER PITCH 2.54MM	WURTH	DIGIKEY	732-5317-ND
2	1	C1	10uF/16V SMD SIZE 1206	MURATA/YAGEO	DIGIKEY
3	2	C2	0.1uF/50V SMD SIZE 0805	MURATA/YAGEO	DIGIKEY
4	1	C3	DNP
5	1	C5	0.47uF/25V SMD SIZE 1206	MURATA/YAGEO	DIGIKEY
6	2	D1,D2	LED SMD SIZE 0805	LITE ON INC	DIGIKEY	160-1427-1-ND
7	2	R1,R7	1K 5% SMD SIZE 0895	MURATA/YAGEO	DIGIKEY
8	3	R2,R5,R6	10K 5% SMD SIZE 0805	MURATA/YAGEO	DIGIKEY
9	1	R3	120K 5% SMD SIZE 0805	MURATA/YAGEO	DIGIKEY
10	1	R4	0E SMD SIZE 0805	MURATA/YAGEO	DIGIKEY
11	1	U1	LM2907-N-8 SMD SO8	TI	DIGIKEY	LM2907M-8-ND
12	1	C4	0.1uF/50V SMD SIZE 1206	MURATA/YAGEO	DIGIKEY