FT3168

Self-Capacitance Touch Controller

Preliminary
Jun.18th, 2021

Version :0.6

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FT3168

Table of Contents

PAGE

TABLE OF CONTENTS .......................................................................................................................................................................................... 3

INTRODUCTION ............................................................................................................................................................................................... 4

FEATURES ....................................................................................................................................................................................................... 4

1. OVERVIEW .................................................................................................................................................................................................. 5
1.1. TYPICAL APPLICATIONS................................................................................................................................................................ 5

2. FUNCTIONAL BLOCK DESCRIPTION....................................................................................................................................................... 5

2.1. ARCHITECTURE OVERVIEW.................................................................................................................................................................. 6
2.1.1AFE AND AFE CONTROLLER ................................................................................................................................................................. 6
2.1.2MCU ..................................................................................................................................................................................................... 6
2.1.3OPERATION MODES ............................................................................................................................................................................... 6
2.1.4Watchdog Timer ........................................................................................................................................................................... 6
2.1.5 PMU ............................................................................................................................................................................................ 6
2.2. OPERATING MODE .............................................................................................................................................................................. 6
2.2.1. Active Mode .............................................................................................................................................................................. 6
2.2.2. Monitor Mode ............................................................................................................................................................................ 6
2.2.3. Sleep Mode ............................................................................................................................................................................... 6
2.3. HOST INTERFACE ................................................................................................................................................................................ 7
2.3.1. I2C Interface Timing................................................................................................................................................................... 7
3. ELECTRICAL SPECIFICATIONS ............................................................................................................................................................... 8
3.1. ABSOLUTE MAXIMUM RATINGS ............................................................................................................................................................ 8
3.2. DC CHARACTERISTICS ........................................................................................................................................................................ 9
3.3. AC CHARACTERISTICS ........................................................................................................................................................................ 9
3.4. POWER ON AND RESET SEQUENCE ................................................................................................................................................... 10
3.5. IO PORT CIRCUIT .......................................................................................................................................................................... 13

4. PIN CONFIGURATION .............................................................................................................................................................................. 14

5. ACKAGE INFORMATION ......................................................................................................................................................................... 16
5.1. PACKAGE INFORMATION OF QFN3X3_24L PACKAGE ........................................................................................................................ 16

DISCLAIMER .................................................................................................................................................................................................. 17

6. REVISION HISTORY ................................................................................................................................................................................. 18

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INTRODUCTION

The FT3168is a single-chip capacitance touch panel controller IC with a built-in 16-bitenhancedMicro-controller unit (MCU). It adopts the

self-capacitance technology, which supports multi-touch. In conjunction with a self-capacitance touch panel, The FT3168implementthe

user-friendly input function and is widely used in various industry application and other touch application.

FEATURES

 Self-Capacitive Sensing Techniques support single point touch and gesture or two-point touch.

 Absolute X and Y coordinates or gesture

 1 point and gestures / 2 points supported

 Supports up to 16 channels of sensors

 Auto-Calibration: Insensitive to background capacitance and environmental variations

 High immunity to RF and Power interferences

 Excellent waterproof performance

 Support single film material TP and triangle pattern without additional shield

 Fast Report Rate: up to 100Hz

 Serial interfaces: I2Cslave, up to 400Kbps

 Built-in 16-bit enhanced MCU

 Built-in 1.4V and 1.8V LDO Regulators

 Built-in 30MHz and 35KHz Oscillator

 Internal accuracy ADC and smooth filters

 Power Supply Mode

 Power Supply:2.8V-3.6V

 independent IOVCC:1.8V-3.6V

 High efficient power management with 3 Operating Modes

 Active Mode

 Monitor Mode

 Sleep Mode

 Operating Temperature Range: -40°C to +85°C

 Package:

 QFN3*3*0.55mm 0.35mm/pitch

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1.OVERVIEW
1.1. TYPICAL APPLICATIONS
FT3168 accommodates a wide range of applications with a set of buttons up to a 2D touch sensing device, their typical applications are

listed below.

 Mobile phones, smart phones

 Smart watch
 Wrist Band
 GPS
 Game consoles
 POS (Point of Sales) devices
 Portable MP3 and MP4 media players
 Digital cameras
 MIDs

FT3168 support up to 1.4-inch Touch Panel; users may find out their target IC from the specs listed in the following table:

Panel Package
Model Name Touch Panel Size
Channel Type Pin Size
FT3168 16 QFN3X3 25 3mm×3mm ≤2 inch

2.FUNCTIONAL BLOCK DESCRIPTION

Figure 2-1FunctionBlock Diagram of FT3168

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2.1. Architecture Overview

2.1.1AFE and AFE Controller

The main function for the AFE and AFE controller is to interface with the touch panel. It scans the panel by sending AC signals to the panel

and processes the received signals from the panel. So it supports both driver and Sensor functions.Key parameters to configure this circuit

can be sent via serial interfaces.

2.1.2MCU
For MCU, larger program and data memories are supported. Furthermore, a Flash Memory is implemented to store programs and some key

parameters.Complex signal processing algorithms are implemented by MCU to detect the touches reliablyand efficiently. Communication

protocol software is also implemented on this MCU to exchange data and control information with the host processor.

2.1.3Operation Modes
 SDA/SCL:I2C Interface for data exchange with host.

 INT: Interrupt signal to inform the host processor that touch data is ready for read.

 RESETB: External Hardware reset for FT3168; low is active.

2.1.4Watchdog Timer
Watchdog timer is implemented to ensure the robustness of the chip.

2.1.5 PMU
PMU is power manage unit, to generate voltage power / reference for internal circuit.

2.2. Operating Mode

FT3168 operates in the following three modes:

2.2.1. Active Mode

In this mode, FT3168 actively scans the panel. The default scan rate is 60 frames per second. The host processor can configure

FT3168to speed up or to slow down.

2.2.2. Monitor Mode

 In this mode, the FT3168 is scanning the touch sensor at a lower scan rate, which is user programmable. The purpose of this

mode is to detect whether there is a touch on the screen. If a touch is detected, the FT3168 will switch to active mode

immediately. In the case of mobile phone applications, the display is typically “on” in this mode.

 In Monitor mode, the FT3168 does not perform full touch tracking. It only looks for a valid touch. No coordinates or sensor image

are calculated or reported.

2.2.3. Sleep Mode

FT3168 is not scanning the touch sensor. The analog circuits are turned off and the MCU stopped. The FT3168will wake up and respond

to“RESETB” or“Wakeup”signal from host processor. The display is typically off in this mode.

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2.3. Host Interface

FT3168 communicates to the host through the I2C interface and follows the I2C protocol. I2C bus utilize the SCL and SDA, a two-wire

synchronous communication interface and can operate at a maximum bit rate of 400kbps. FT3168 can be part of a single-slave or a

multi-slave environment.

When FT3168 is in Monitor mode or Sleep mode, host will not be able to communicate with the touch IC via I2Cafter accessing any other

slave device on the same bus. In order to maintain I2C communication during Monitor/Sleep mode between host and touch IC in them

multi-slave environment, the FT3168 firmware will clear I2C state machine periodically. Wake up status via a touch event could also change

FT3168 from Monitor/Sleep mode to Active mode and clear the I2C state machine, hence ensuring the touch FT3168’s I2C function properly.

Figure 2-2 HOST Interface of FT3168

2.3.1. I2C Interface Timing

The I2C is always configured in the Slave mode. The data transfer format is shown in Figure 2-3

Figure 2-3I2C Serial Data Transfer Format

Figure 2-4I2C Master Write, Slave Read

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Figure 2-5I2C Master Read, Slave Write

Table 2-1 lists the meanings of the mnemonics used in the above figures.

Table 2-1 Mnemonics Description

Mnemonics Description

S I2C Start or I2C Restart

A[6:0] Slave address

R/W READ/WRITE bit, ‘1’ for read, ‘0’for write

A(N) ACK(NACK)
STOP: the indication of the end of a packet (if this bit is missing, S will indicate the end of the current packet
P
and the beginning of the next packet)

I2C Interface Timing Characteristics is shown in Table 2-2.

Table 2-2 I2C Timing Characteristics

Standard Mode Fast Mode

Parameter Unit
Min Max Min Max

SCL frequency (fast mode support) 0 100 0 400 KHz

Clock low period 4.7 - 1.3 - us

Clock high period 4.0 - 0.6 - us

Bus free time between a STOP and START condition 4.7 - 1.3 - us

Hold time (repeated) START condition 4.0 - 0.6 - us

Data setup time 250 - 100 - ns

Setup time for a repeated START condition 4.7 - 0.6 - us

Setup Time for STOP condition 4.0 - 0.6 - us

3.ELECTRICAL SPECIFICATIONS

3.1. Absolute Maximum Ratings

Table 3-1 Absolute Maximum Ratings

Item Symbol Value Unit Note

Power Supply Voltage AVDD - AVSS -0.3 ~ +3.6 V 1, 2

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IOVCC
(Internal generated when external IOVCC power 1.75~1.85 V 1
is not existed)
I/O Communication Voltage
IOVCC
(Internal LDO IOVCC is turned off when external 1.6~3.6 V 1
IOVCC power is existed)

Operating Temperature Topr -40 ~ +85 ℃ 1

Storage Temperature Tstg -55 ~ +150 ℃ 1

Notes

1. If used beyond the absolute maximum ratings, FT3168 may be permanently damaged. It is strongly recommended that the device be

used within the electrical characteristics in normal operations. If exposed to the condition not within the electrical characteristics, it may

affect the reliability of the device.

2. Make sure AVDD (high) ≥AVSS (low).

3.2. DC Characteristics

Table 3-2 DC Characteristics (Ta=-40~105℃)

Item Symbol Test Condition Min. Typ. Max. Unit Note

Input high-level voltage VIH 0.7 × IOVCC - IOVCC V

Input low -level voltage VIL -0.3 - 0.3 × IOVCC V

Output high -level voltage VOH IOH=－0.1mA 0.7 × IOVCC - - V

Output low -level voltage VOL IOH=0.1mA - - 0.3 × IOVCC V

I/O leakage current ILI Vin=0~AVDD -1 - 1 μA

Current consumption AVDD=2.8V

Iopr - 1.5 - mA
（Normal operation mode） Ta=25℃ MCLK=15MHz
Current consumption AVDD=2.8V
Imon - 30 - μA
（Monitor mode） Ta=25℃ MCLK=15MHz
Current consumption AVDD=2.8V
Islp - 10 - μA
（Sleep mode） Ta=25℃
Power Supply voltage AVDD 2.8 - 3.6 V

3.3. AC Characteristics

Table 3-3 AC Characteristics of Oscillators

Item Symbol Test Condition Min Typ. Max Unit Note

OSC clock fosc1 AVDD= 2.8V；Ta=25℃ -1% 30 +1% MHz

Table 3-4 AC Characteristics of sensor

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Item Symbol Test Condition Min Typ. Max Unit Note

Sensor acceptable clock ftx AVDD= 2.8V；Ta=25℃ 0 100 300 KHz

Sensor output rise time Ttxr AVDD= 2.8V；Ta=25℃ - 100 - nS

Sensor output fall time Ttxf AVDD= 2.8V；Ta=25℃ - 80 - nS

3.4. Power ON and Reset Sequence

The GPIO such as INT and I2C are advised to be low before powering on. Reset should be pulled down to be low before powering on. INT

signal will be sent to the host after initializing all parameters and then start to report points to the host. If power down, the voltage of supply

must be below 0.3V and Trst is more than 5ms.

Figure 3-1 Power on time

Figure 3-2 Power down requirement

Figure 3-3Power on Sequence (for external IOVCC supply exist)

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Notes*: external IOVCC supply should be in a floating state when it is not on to avoid unexpected leakage.

Figure 3-4Power on Sequence (for external IOVCC supply not exist)

Reset time must be enough to guarantee reliable reset, the time of starting to report point after resetting approach to the time of starting to

report point after powering on.

Trsi
Trst

AVDD

RESET

INT

I2C

Figure 3-5 Reset Sequence

The following is the power down sequence.

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Figure 3-6 Power down Sequence (for external IOVCC)

Figure 3-7 Power down Sequence (for internal IOVCC)

Table 3-5Power on/Reset/Wake Sequence Parameters

Parameter Description Min Max Units

Tris Rise time from 0.1VDD to 0.9VDD - 3 ms

Tpor Time of internal POR ready after AVDD power on 1 - ms

Tio1 Time of IOVCC rising after AVDD power on 1 - ms

Tio2 Time of external IOVCC supply after AVDD power on or time of 1 - ms

external IOVCC supply before AVDD power down

Tpon Time of starting to report point after powering on 70 - ms

Tprt* Time of RESETB being low after power on 3 - ms

Trsi Time of starting to report point after resetting 70 - ms

Trst* Reset time 5 - ms

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Notes*: reset time should not to be too long, because when reset is low, all the control logic would be fixed to be the default value, and the

system state is fixed to be a default state.

3.5. IO PORT CIRCUIT

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4.PIN CONFIGURATION

Table 4-1 Pin Definition of FT3168

Name Pin No. Type Description

S0 1 I/O Capacitance sensor
S1 2 I/O Capacitance sensor
S2 3 I/O Capacitance sensor
S3 4 I/O Capacitance sensor
S4 5 I/O Capacitance sensor
S5 6 I/O Capacitance sensor
S6 7 I/O Capacitance sensor
S7 8 I/O Capacitance sensor
S8 9 I/O Capacitance sensor
S9 10 I/O Capacitance sensor
S10 11 I/O Capacitance sensor
S11 12 I/O Capacitance sensor
S12 13 I/O Capacitance sensor
S13 14 I/O Capacitance sensor
S14 15 I/O Capacitance sensor
S15 16 I/O Capacitance sensor
VREF 17 PWR Generated internal reference voltage. A 1μF ceramic capacitor to ground is required.
AVDD 18 PWR Analog power supply, A 1μF ceramic capacitor toground is required
IOVCC 19 PWR I/O power supply
SCL 20 I/O I2C clock input
SDA 21 I/O I2C data input and output
INT 22 I/O External interrupt to the host
RSTN 23 I External Reset, Low is active
DVDD 24 PWR Digital power supply. A 1μF ceramic capacitor toground is required.
GND 25 PWR Power ground. The pin that needs to be connected to the ground is exposed die attach pad.

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Figure 4-1 FT3168 Package Diagram

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5.ACKAGE INFORMATION

5.1. Package Information of QFN3X3_24L Package

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DISCLAIMER

The information appearing in this publication is believed to be accurate.

Integrated circuits sold by FocalTech Systems are covered by the warranty and patent indemnification provisions stipulated in the terms of
sale only. FocalTech Systems makes no warranty, express, statutory implied or by description regarding the information in this publication or
regarding the freedom of the described chip(s) from patent infringement. FURTHERMORE, FocalTech Systems MAKES NO WARRANTY
OF MERCHANTABILITY OR FITNESS FOR ANY PURPOSE.FocalTech Systems reserves the right to halt production or alter the
specifications and prices at any time without notice. Accordingly, the reader is cautioned to verify that the data sheets and other information
in this publication are current before placing orders. Products described herein are intended for use in normal commercial applications.
Applications involving unusual environmental or reliability requirements, e.g. military equipment or medical life support equipment, are
specifically not recommended without additional processing by FocalTech Systems for such applications. Please note that application
circuits illustrated in this document are for reference purposes only.

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6.REVISION HISTORY

Date Revision # Description Page Auditor

Jan. 23th,2019 0.1 Original. All Jack.huang,
张金磊，李瑞兴，
杜洪洋，李华
Aug.20th,2019 0.2 Update sleep mode current consumption 11 李华
Otc.18th,2019 0.3 Modify Figure 3-2, Figure 3-4, Figure 3-5.
Update Tpon and Trsi parameters minimum value. 12,13,15 李华、李瑞兴
Add Figure 4-1 Package Diagram
Nov.22th,2019 0.4 Update OSC frequency 4,5,10 李瑞兴
And modify Table2-2 9 李华
Jul.03th,2020 0.5 Modify IC support touch panel size
Modify IIC interface description 李华，张金磊，黄
5,7,11,12
Update Power on sequence diagram 飚
Update Power on/Reset/Wake Sequence Parameters
Jun.18th,2021 0.6 Update power down sequence 12、13 李瑞兴

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