TTP224B-SQBN 2015/12/21 page 1 of 9 version 1.0 4 keys touch pad detector ic outline z the TTP224B-SQBN tontouch tm ic is capacitive sensing design specifically for touch pad controls. the device built in regulator for touch sensor. stable sensing method can cover diversity conditions. human interfaces control panel links through non-conductive dielectric material. the main application is focused at replacing of the mechanical switch or button. the assp can independently handle the 4 touch pads with 4 direct output pins characteristic z operating voltage 2.4v ~ 5.5v z built-in regulator for touch sensor z operating current, @vdd=3v no load at low power mode typical 2.5ua, at fast mode typical 13ua z @vdd=3v operating voltage : the response time about 160ms at low power mode, 60ms at fast mode z sensitivity can adjust by the capacitance 1~50pf outside for each touch pad z provides fast mode and low power mode selection by pad option (lpmb pin) z provides direct mode or toggle mode cmos output or open drain output active high or active low by pad option (tog/od/ahlb pin) z have the maximum on time about 16sec/infinite by pad option(mot0 pin) z provides single-key and multi-key functions by pad option (sm pin) z after power-on have about 0.5sec stable-time, during the time do not touch the key pad, and the function is disabled z auto calibration for life z the re-calibration period is about 1 sec within 8 sec after power-on. when key has been touched within 8 sec or key has not been touched more than 8 sec after power-on, then the re-calibration period change to 4 sec applications z wide consumer products z button key replacement
TTP224B-SQBN 2015/12/21 page 2 of 9 version 1.0 block diagram pin description pin no pin name type pad description 1 tp0 i/o touch pad input pin 2 tp1 i/o touch pad input pin 3 tp2 i/o touch pad input pin 4 tp3 i/o touch pad input pin 5 ahlb i-pl output active high or low option, default: 0 6 vdd p positive power supply 7 tog i-pl output type option, default: 0 8 lpmb i-pl low power/fast mode option, default: 0 9 mot0 i-ph key maximum on time option, default: 1 10 vss p negative power supply, ground 11 od i-ph output open-drain option, default: 1 12 sm i-ph single/multi key option, default: 1 13 tpq3 o direct output for tp3 touch input pin 14 tpq2 o direct output for tp2 touch input pin 15 tpq1 o direct output for tp1 touch input pin 16 tpq0 o direct output for tp0 touch input pin pin type z i cmos input only z i-ph cmos input and pull-high resister z o cmos push-pull output z i-pl cmos input and pull-low resister z i o cmos i o z od open drain output, have no diode p rotective circuit z p power ground mot0 lpmb tog sm ahlb od control circuit function option timing counter & control key-on & timing circuit system oscillator regulator circuit tp0 tp3 tp2 tp1 tpq3 tpq2 tpq1 tpq0 circuit sensor oscillator circuit touch detecting detecting circuit reference sensor & circuit driver & mode output
TTP224B-SQBN 2015/12/21 page 3 of 9 version 1.0 electrical characteristics z absolute maximum ratings z dc / ac characteristics test condition at room temperature = 25 parameter symbol conditions rating unit operating temperature t op -40 +85 storage temperature t stg -50 +125 supply voltage vdd ta=25 c vss-0.3 vss+5.5 v input voltage v in ta=25 c vss-0.3 vdd+0.3 v human body mode esd 5 kv note vss symbolizes for system ground parameter symbol test condition min typ max unit operating voltage vdd internal regulator enable 2.4 5.5 v internal regulator output vreg 2.2 2.3 2.4 v i opl vdd=3v, at low power mode(regulator enable) 2.5 ua operating current i opf vdd=3v, at fast mode (regulator enable) 13.0 ua input ports v il input low voltage 0 0.2 vdd input ports v ih input high voltage 0.8 1.0 vdd output port sink current i ol vdd=3v, v ol =0.6v 8 ma output port source current i oh vdd=3v, v oh =2.4v -4 ma input pin pull-high resistor r ph vdd=3v 30k ohm input pin pull-low resistor r pl vdd=3v 25k ohm vdd=3v at fast mode 60 output response time t r vdd=3v at low power mode 160 ms
TTP224B-SQBN 2015/12/21 page 4 of 9 version 1.0 function description . sensitivity adjustment the total loading of electrode size and capacitance of connecting line on pcb can affect the sensitivity. so the sensitivity adjustment must according to the practical application on pcb. the TTP224B-SQBN offers some methods for adjusting the sensitivity outside 1. by the electrode size under other conditions are fixed. using a lar ger electrode size can increase sensitivity. otherwise it can decrease sensitivity. but the electrode size must use in the effective scope 2. by the panel thickness under other conditions are fixed. using a thinner panel can increase sensitivity. otherwise it can decrease sensitivity. but the panel thickness must be below the maximum value 3. by the value of cs0~cs3 please see the down figure under other conditions are fixed. add the capacitors cs0~cs3 can fine tune the sensitivity for single key, that lets all ke y?s sensitivity identical. when do not use any capacitor to vss, the sensitivity is most sensitive. when adding the values of cs0~cs3 will reduce sensitivity in the useful range 1 Q cs0~cs3 Q 50pf sm od mot0 tog lpmb ahlb vss tpq0 tpq3 tpq2 tpq1 cs3 cs2 cs1 cs0 electrode k3 k0 k1 k2 tp3 tp2 tp1 vdd vdd tp0
TTP224B-SQBN 2015/12/21 page 5 of 9 version 1.0 . output mode by tog od ahlb pin option the TTP224B-SQBN outputs tpq0~tpq3 has direct mode active high or low by ahlb pin option, has toggle mode by tog pin option and has open drain(have diode protective circuit) mode by od pin option tog od ahlb pin tpq0 tpq3 option features remark 0 1 0 direct mode, cmos output active high default 0 1 1 direct mode, cmos output active low 0 0 0 direct mode, open drain output active high 0 0 1 direct mode, open drain output active low 1 1 0 toggle mode, cmos output, power on state=0 1 1 1 toggle mode, cmos output, power on state=1 1 0 0 toggle mode, power on state high-z, active high 1 0 1 toggle mode, power on state high-z, active low . key operating mode by sm pin option the TTP224B-SQBN has the single-key and multi-key functions by sm pin option sm option features remark 1 multi-key mode default 0 single key mode multi-key mode the tp0-tp3 can be detected 2 keys or above 2 keys at the same time single-key mode the tp0-tp3 can be detected 1 key only at the same time, when any key be detected, the other 3 keys can not be detected
TTP224B-SQBN 2015/12/21 page 6 of 9 version 1.0 . maximum key on duration time by mot0 pin option if some objects cover in the sense pad, and causing the change quantity enough to be detected. to prevent this, the TTP224B-SQBN sets a timer to monitor the detection. the timer is the maximum on duration time. when the detection is over the timer, the system will return to the power-on initial state, and the output becomes inactive until the next detection mot0 option features remark 1 infinite disable maximum on time default 0 maximum on time about 16 sec . fast and low power mode select by lpmb pin option the TTP224B-SQBN has fast mode and low power mode to be selected. it depends on the state of lpmb pin. when the lpmb pin is connected to vdd, the TTP224B-SQBN runs in fast mode. when the lpmb pin is opened or connected to vss, the TTP224B-SQBN runs in low power mode. in the fast mode response time is faster, but the current consumption will be increased. in the low power mode it will be saving power, but will be slowing response time for first touch. when it awaked in fast mode, the response time is the same the fast mode. in this mode when detecting key touch, it will switch to fast mode. until the key touch is released and will keep a time about 8sec. then it returns to low power mode. the states and timing of two modes please see below figure. low power mode timing diagram: fast mode timing diagram: lpmb option features remark 1 fast mode 0 low power mode default
TTP224B-SQBN 2015/12/21 page 7 of 9 version 1.0 application circuit 104 c1 k3 k2 k1 k0 cs3 cs2 cs1 cs0 16 tp0 15 tpq0 14 tpq1 13 tpq2 tpq3 12 sm 11 vss od 10 9 mot0 lpmb tog vdd 8 7 6 5 tp3 ahlb 4 3 tp2 2 tp1 1 low power mode option features open fast mode vdd fast and low power mode: lpmb infinite(disable maximum on time) maximum on time 16sec option features open vss mot0 option table: single key mode multi-key mode option features sm open maximum key on duration time: vss key operation mode: tog toggle mode, power on state high-z, active low toggle mode, cmos output, power on state =1 toggle mode, power on state high-z, active high toggle mode, cmos output, power on state =0 open open open vdd vdd vdd vdd vdd vss vss vss open open open vss vdd vdd open open open open vdd open open direct mode, open drain active low output direct mode, open drain active high output direct mode, cmos active low output direct mode, cmos active high output od ahlb pad tpq0~tp3 option features output mode: p. s . 1. on pcb, the length of lines from t ouch pad to ic pin shorter is better. and the lines do not parallel and cross with other lines. 2. the power supply must be stable. if the supply voltage drift or shift quickly, maybe causing sensitivity anomalies or false detections. 3. the material of panel covering on the pcb can not include the metal or the electric element. the paints on the surfaces are the same. 4. the c1 capacitor must be used between v dd and vss; and should be ro uted with very short tracks to the device?s vdd and vss pins (TTP224B-SQBN). 5. the capacitance cs0~cs3 can be used to adjus t the sensitivity. the value of cs0~cs3 use smaller, then the sensitivity will be better. the sensitivity adjustment must according to the practical application on pcb. the range of cs0~cs3 value are 1~50pf. 6. the sensitivity adjustment capacitors cs0~cs3 must use smaller temperature coefficient and more stable capacitors. such are x7r, npo for ex ample. so for touch application, recommend to use npo capacitor, for reducing that the te mperature varies to affect sensitivity.
TTP224B-SQBN 2015/12/21 page 8 of 9 version 1.0 package outline package type: qfn-16
TTP224B-SQBN 2015/12/21 page 9 of 9 version 1.0 package configuration TTP224B-SQBN package type qfn-16 mot0 lpmb tog vdd ahlb tp3 tp2 tp1 tp0 tpq2 tpq1 tpq0 tpq3 od sm vss 13 14 15 16 9 12 10 11 8 7 6 5 4 3 2 1 ordering information TTP224B-SQBN package type chip type wafer type TTP224B-SQBN no support no support
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