preliminary TTP224/TTP224n tontouch tm 2009/8/25 page 1 of 4 ver :2.0 4 key touch pad detector ic general description the TTP224/TTP224n tontouch tm ic is capacitive sensing design specifically for touch pad controls. the device built in regu lator for touch sensor. stable se nsing 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. features ? operating voltage 2.4v~5.5v ? built-in regulator with external enable/disable option ? operating current, @vdd=3v no load at low power mode typical 2.5ua at fast mode typical 9.0ua ? @vdd=3v operating voltage : the response time about 100ms at fast mode, 200ms at low power mode for TTP224 the response time about 60ms at fast m ode, 160ms at low power mode for TTP224n ? sensitivity can adjust by the capacitan ce(0~50pf) outside for each touch pad ? provides fast mode and low power mode selection by pad option(lpmb pin) ? provides direct mode or toggle mode cmos output or open drain output active high or active low by pad option(tog/od/ahlb pin). ? provides 2 output pins tpq0d, tpq2d th at have no diode protection, active low ? have the maximum on time 120sec/64sec/16sec/i nfinite by pad option(mot1, mot0 pin) ? after power-on have about 0.5sec stable-time, during the time do not touch the key pad, and the function is disabled ? auto calibration for life, and th e re-calibration period is about 4.0sec, when key has not be touched. application ? wide consumer products ? button key replacement
preliminary TTP224/TTP224n tontouch tm 2009/8/25 page 2 of 4 ver :2.0 block diagram sm tog ahlb tpq2d tpq0d tpq3 tpq2 tpq1 tpq0 od regen dis13 lpmb tp0 tp3 tp2 tp1 mot1 mot0 vreg regulator circuit control key-on & timing circuit system oscillator control circuit function option timing counter & circuit sensor oscillator circuit touch detecting detecting circuit reference sensor & circuit driver & mode output application circuit tcp224/tcp224n tcp224/tcp224n application (enable internal regulator) c1 104 k0 k1 k2 cs3 k3 cs0 cs1 cs2 tp0 tp1 tpq0d tpq0 tpq1 tpq2d 19 20 21 22 1 2 vdd vreg tog lpmb mot1 mot0 7 6891011 vss dis13 regen od sm tpq3 tpq2 12 13 14 15 16 17 18 ahlb 5 tp2 3 tp3 4
preliminary TTP224/TTP224n tontouch tm 2009/8/25 page 3 of 4 ver :2.0 dis13 vdd vdd vdd vdd vss vss vss vss vdd vdd vdd vdd pad tpq0~tp3 option features open direct mode, cmos active low output open open direct mode, cmos active high output open open open ahlb tog od toggle mode, power on state high-z, active low toggle mode, power on state high-z, active high toggle mode, coms output, power on state=1 toggle mode, coms output, power on state=0 direct mode, open drain active low output direct mode, open drain active high output open open open open open open output mode: vdd option features low power mode fast mode open lpmb vss vss vss vss open open option features maximum on time 64sec maximum on time 16sec infinite(disable maximum on time) maximum on time 120sec open open mot0 mot1 vss option features sm single key mode multi-key mode open pad tpq0d,tpq2d (has no diode protection) option features vdd toggle mode, open drain active low output, power on state high-z open direct mode, open drain active low output, power on state high-z tog vss enable tp1, tp3 open key operation mode: option table: disable tp1, tp3 input keys number select: option features fast and low power mode: maximum key on duration time: ps 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 material of panel covering on the pcb can not include the metal or the electric element. the paints on the surfaces are the same. 3. the c1 capacitor must be used betwe en vdd and vss; and should be routed with very short tracks to the devic e?s vdd and vss pins (TTP224/TTP224n). 4. the capacitance cs0~cs3 can be us ed to adjust the sensitivity. the value of cs0~cs3 use smaller, then the sensitivity will be better. the sensitivity adjustment must according to the practical applicat ion on pcb. the range of cs0~cs3 value are 0~50pf. 5. the sensitivity adjustment capacit ors (cs0~cs3) must use smaller temperature coefficient and more stable capacitors . such are x7r, npo for example. so for touch application, recommend to us e npo capacitor, for reducing that the temperature varies to affect sensitivity.
preliminary TTP224/TTP224n tontouch tm 2009/8/25 page 4 of 4 ver :2.0 tcp224/tcp224n tcp224/tcp224n application (disable internal regulator) c1 104 k0 k1 k2 cs3 k3 cs0 cs1 cs2 tp0 tp1 tpq0d tpq0 tpq1 tpq2d 19 20 21 22 1 2 vdd vreg tog lpmb mot1 mot0 7 6891011 vss dis13 regen od sm tpq3 tpq2 12 13 14 15 16 17 18 ahlb 5 tp2 3 tp3 4 dis13 vdd vdd vdd vdd vss vss vss vss vdd vdd vdd vdd pad tpq0~tp3 option features open direct mode, cmos active low output open open direct mode, cmos active high output open open open ahlb tog od toggle mode, power on state high-z, active low toggle mode, power on state high-z, active high toggle mode, coms output, power on state=1 toggle mode, coms output, power on state=0 direct mode, open drain active low output direct mode, open drain active high output open open open open open open output mode: vdd option features low power mode fast mode open lpmb vss vss vss vss open open option features maximum on time 64sec maximum on time 16sec infinite(disable maximum on time) maximum on time 120sec open open mot0 mot1 vss option features sm single key mode multi-key mode open pad tpq0d,tpq2d (has no diode protection) option features vdd toggle mode, open drain active low output, power on state high-z open direct mode, open drain active low output, power on state high-z tog vss enable tp1, tp3 open key operation mode: option table: disable tp1, tp3 input keys number select: option features fast and low power mode: maximum key on duration time: ps 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 anom alies 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 betwe en vdd and vss; and should be routed with very short tracks to the devic e?s vdd and vss pins (TTP224/TTP224n). 5. the capacitance cs0~cs3 can be us ed to adjust the sensitivity. the value of cs0~cs3 use smaller, then the sensitivity will be better. the sensitivity adjustment must according to the practical applicat ion on pcb. the range of cs0~cs3 value are 0~50pf. 6. the sensitivity adjustment capacit ors (cs0~cs3) must use smaller temperature coefficient and more stable capacitors . such are x7r, npo for example. so for touch application, recommend to us e npo capacitor, for reducing that the temperature varies to affect sensitivity.
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