4 Touch Key BS814A-2 + HT48R002 Characteristics Touch Key : BS814A-2 8SOP + HT48R002 Operating Voltage : 2.2V ~ 5.5V Low standby current Auto-calibration Reliable touch key detections High noise rejection Standby and normal operating power modes Maximum key on duration time detection Power supply voltage drop rejection function NMOS output with internal pull high Provide serial interface Sensitivity adjustment using an external capacitor Minimal number of external components 10 MSOP Application Areas Consumer Products, Home Appliances, Industrial Control, Health Care Products, etc. Application Circuit VDD D1 LED D2 LED D3 LED D4 LED VDD C1 10UF P1 C2 0.1UF R1 4.7K U1 4 3 2 1 VDD GND DATA CLOCK 1 2 3 4 5 CN1 VDD PA6 PA5 PA7/RES PA4 VSS PA0 PA1/TMR PA2/INT PA3 R2 4.7K R3 4.7K R4 4.7K 10 9 8 7 6 HT48R002_1OMSOP JP1 1 2 3 4 KEY1 CT1 (0-25)PF U1 1 KEY2 CT2 (0-25)PF KEY3 CT3 (0-25)PF KEY4 GND VDD DATA CLOCK CT4 (0-25)PF 2 3 4 KEY0 VDD KEY1 GND KEY2 OUT1 OUT3 OUT2 BS814A-2 8SOP 8 VDD 7 GND VDD C1 104 BAT1 CR2032 5 DATA 5 CLOCK