90-00123-A0

Features • Complete Touchscreen Module: • • • • – Projected Capacitive Multi Touch Controller – 4.3in LCD – 4 Capacitive “Navigation” Keys – 200 bytes non-volatile serial EEPROM Touch: – Microchip maXTouch™ mXT336T Touch Controller – Supports up to 10 touches Display: – 480x272 resolution – Himax HX8257-A driver IC – 30 ms response time – White LED backlight Navigation Keys: – Microchip AT42QT1070 QTouch™ Button Sensor IC Cover Panel: – 2mm Soda Lime PDA TM4301B: 4.3in PCAP Touch Module P/N: 90-00123-A0 90-00123-B1 90-00123-B1 includes MEB Adapter for Microchip PIC32MZ MEB II Kit Doc: 111-00221-A1 TM4301B Visit http://www.pdaatl.com/tm4301b for the latest information on the TM4301B   Contents 1 2 Module Overview 1.1 PCB Connections 4 1.2 Host Interface J1 5 1.3 Touch Interface Connector J2 6 1.4 Module Interface Connector S-J1 6 1.5 Navigation Button Connector J3 & J4 7 1.6 Display Flex Connector J5 8 1.7 Touch Sensor Flex Connector S-J2 9 Overview of the 4.3in PCAP Touch Module Introduction 10 2.2 Understanding Unfamiliar Concepts 11 2.3 LCD Panel 11 2.4 maXTouch Capacitive Touchscreen Controller 11 2.5 2.5.1 2.6 11 QTouch Capacitive Button Controller 12 QTouch Controller Interface Getting Started 12 12 13 Hardware Connections 13 3.1.1 Microchip XPRO Kits 13 3.1.2 Microchip PIC32MZ Kits 13 3.2 Software 15 3.2.1 MPLab Harmony Framework 15 3.2.2 Linux Kernel / Android 15 3.2.3 Advanced Software Framework 15 3.2.4 Microchip Software Packages 15 3.3  2 maXTouch Controller Interface Serial EEPROM 3.1 4 10 2.1 2.4.1 3 4 Using the Touch Module 15 3.3.1 Navigation Keys 15 3.3.2 Evaluating the Touch Module 15 Specifications 17 4.1 Mechanical Specifications 17 4.2 Absolute Maximum Specifications 19 4.3 Recommended Operating Conditions 19 4.4 DC Specifications 19 4.5 I2C-compatible Bus Specifications 20 PDA TM4301B: 4.3in PCAP Touch Module Doc:111-00221-A1 PDA TM4301B: 4.6 5 LCM Specification 4.3in PCAP Touch Module 20 4.6.1 LCM Parameters 20 4.6.2 LCM Absolute Maximum Specifications 21 4.6.3 LCM DC Specifications 21 4.6.4 LCM Optical Characteristics 21 4.6.5 LCM Timing 22 4.7 Power Consumption 22 4.8 Part Number 22 I2C Basics (I2C-compatible Operation) 23 5.1 Interface Bus 23 5.2 Transferring Data Bits 23 5.3 START and STOP Conditions 23 5.4 Address Byte Format 24 5.5 Data Byte Format 24 5.6 Combining Address and Data Bytes into a Transmission 25 6 Revision History 26 7 Notes 27   3 1 Module Overview 1.1 PCB Connections The TM4301B is composed two PCBs: a Module PCB (10-01111-A0) and a Sensor PCB (10-01093-B0). The reference designators shown below for various connectors will use an “S” prefix when the connector is located on the sensor PCB (for example “S-J1”). Reference designators without a prefix are located on the Module PCB. Host Pin 1 J1 DS24B 33 J2 Module Pin 1 Interface Pin 1 Touch Interface Pin 1 S-J1 ATMEL M XT336T J5 Display Flex S-J2 Touch Sensor Flex Pin 1 Figure 1 - PCB Connectors NOTE: Insert flex in Connector J6 with contacts facing DOWN. The following notations are used for pin descriptions: I Input only O Output only, push-pull MXT EE maXTouch touchscreen Serial EEPROM OD Open drain output P Ground or power QT LCD QTouch Button Controller LCD Panel NOTE: Except where noted otherwise, inputs and output are defined from the standpoint of the Touch Module PCB.  4 PDA TM4301B: 4.3in PCAP Touch Module Doc:111-00221-A1 PDA TM4301B: 4.3in PCAP Touch Module 1.2 Host Interface J1 Connector J1 implements Microchip’s “XPRO LCD” connector found on various Xplained and Xplained Pro evaluation kits. Connector J1 connects to the host provides interface between the host and (1) the MaXTouch Touch Controller, (2) the QTouch Button Controller, (3) LCD Panel, and (4) serial EEPROM. Suggested Flex: Wurth Electronics #687 650 100 002, Description: 0.5mm pitch 50 position FFC, Length 100mm Type  26 I LCD_DATA_19 27 P GND  28 I LCD_DATA_20  LCD_DATA_1  29 I LCD_DATA_21  LCD_DATA_2  30 I LCD_DATA_22  I LCD_DATA_3  31 I LCD_DATA_23  7 P GND 32 P GND 8 I LCD_DATA_4  33 I PCLK  9 I LCD_DATA_5  34 I VSYNC  10 I LCD_DATA_6  35 I HSYNC  11 I LCD_DATA_7  36 I DE  12 P GND 37 - N/C 13 I LCD_DATA_8  38 - N/C 14 I LCD_DATA_9  39 - N/C 15 I LCD_DATA_10  40 - N/C 16 I LCD_DATA_11  41 I DISP Type 1 I/O 2 P GND 3 I LCD_DATA_0 4 I 5 I 6 17 P Description One-Wire Interface GND 42 I Description EE Pin Pin QT LCD MXT EE QT LCD MXT Flex should be inserted with contacts facing DOWN.   2   2  I C SDA 18 I LCD_DATA_12  43 I/O I C SCL  19 I LCD_DATA_13  44 O ~MXT_CHG  20 I LCD_DATA_14  45 O ~QT_CHG 21 I LCD_DATA_15  46 I LCD_PWM 22 P GND 47 I ~RESET 23 I LCD_DATA_16  48 P +5Vdc 24 I LCD_DATA_17  49 P +5Vdc 25 I LCD_DATA_18  50 P GND       5 1.3 Touch Interface Connector J2 Connector J2 connects to the Sensor PCB and carries signals between the host and the MaXTouch Touch Controller. Flex should be inserted with contacts facing DOWN. Pin 1 Type O Pin Type 2 Description 5 P GND 2 I C SCL Description 2 I/O I C SDA 5 P AVDD 3 O ~MXT_RESET 8 - N/C 4 I ~MXT_CHG 9 - N/C 5 P VDD 10 P GND 1.4 Module Interface Connector S-J1 Connector J1 located on the Sensor PCB connects to the Module PCB and carries signals between the MaXTouch Touch Controller and the host NOTE: Inputs and output are defined from the standpoint of the Sensor PCB. Flex should be inserted with contacts facing UP. Pin 1  6 Type O Pin Type 2 Description 5 P GND 2 I C SCL Description 2 I/O I C SDA 5 P AVDD 3 O ~MXT_RESET 8 - N/C 4 I ~MXT_CHG 9 - N/C 5 P VDD 10 P GND PDA TM4301B: 4.3in PCAP Touch Module Doc:111-00221-A1 PDA TM4301B: 4.3in PCAP Touch Module 1.5 Navigation Button Connector J3 & J4 Optionally connects to the Navigation Button PCB and carries signals between the host and the QTouch Controller used to detect input on the Nav buttons. While navigation buttons can be used in place, the module PCB was designed to allow removal and optional ‘remote’ use of the buttons. The button PCB can be separated by carefully cutting the PCB along the scoring, ensuring cut traces (top and bottom) are not shorted. Populate connectors J3 (on the module PCB) and J4 (on the Nav button PCB) and connect using a flex cable. Suggested Connector: TE 1734839-6 Suggested Flex: Wurth Electronics #687 606 LLL 002, Description: 0.5mm pitch 6 position FFC, Length LLLmm Flex should be inserted with contacts facing DOWN. J3 J3 Pin Type 1 P 2 3 4 J4 J4 Pin Type VDD 6 P O ~QT_RESET 5 I I ~QT_CHG 4 O O I C SCL 2 3 I 2 I C SDA 2 I/O GND 1 P 5 I/O 6 P Description   7 1.6 Display Flex Connector J5 Connector J5 connects to the LCD panel flex and carries signals between the host and the LCD Panel. NOTE: Pin 1 on the Module PCB aligns to pin 40 on the LCM flex. Flex should be inserted with contacts facing UP.  8 Pin Type 1 - 2 3 Description Pin Type Description N/C 21 O LCD_DATA_15 / G7 - N/C 22 O LCD_DATA_14 / G6 - N/C 23 O LCD_DATA_13 / G5 4 - N/C 24 O LCD_DATA_12 / G4 5 P GND 25 O LCD_DATA_11 / G3 6 - N/C 26 O LCD_DATA_10 / G2 7 O DE 27 O LCD_DATA_9 / G1 8 O VSYNC 28 O LCD_DATA_8 / G0 9 O HSYNC 29 O LCD_DATA_23 / R7 10 O DISP 30 O LCD_DATA_22 / R6 11 O PCLK 31 O LCD_DATA_21 / R5 12 P GND 32 O LCD_DATA_20 / R4 13 O LCD_DATA_7 / B7 33 O LCD_DATA_19 / R3 14 O LCD_DATA_6 / B6 34 O LCD_DATA_18 / R2 15 O LCD_DATA_5 / B5 35 O LCD_DATA_17 / R1 16 O LCD_DATA_4 / B4 36 O LCD_DATA_16 / R0 17 O LCD_DATA_3 / B3 37 P +3.3Vdc 18 O LCD_DATA_2 / B2 38 P GND 19 O LCD_DATA_1 / B1 39 P LED+ 20 O LCD_DATA_0 / B0 40 P LED- PDA TM4301B: 4.3in PCAP Touch Module Doc:111-00221-A1 PDA TM4301B: 4.3in PCAP Touch Module 1.7 Touch Sensor Flex Connector S-J2 Connector S-J2 connects to the touch sensor flex and carries signals used by the maXTouch controller to detect input on the touch sensor. Pin Type 1 P 15 14 Description Pin Type Description GND 21 I/O X4 I/O X23 35 I/O X3 I/O X22 34 I/O X2 13 I/O X21 33 I/O X1 12 I/O X20 32 I/O X0 11 I/O X19 31 I/O S0 10 I/O X18 30 I/O Y0 9 I/O X17 29 I/O Y1 8 I/O X16 28 I/O Y2 7 I/O X15 27 I/O Y3 6 I/O X14 26 I/O Y4 5 I/O X13 25 I/O Y5 4 I/O X12 24 I/O Y6 3 I/O X11 23 I/O Y7 2 I/O X10 22 I/O Y8 16 I/O X9 36 I/O Y9 17 I/O X8 37 I/O Y10 18 I/O X7 38 I/O Y11 19 I/O X6 39 I/O Y12 20 I/O X5 40 I/O Y13   9 2 Overview of the 4.3in PCAP Touch Module 2.1 Introduction The 4.3in PCAP Touch Module is a touchscreen module offering best-in-class projected capacitance multi-touch functionality combined with a 4.3in LCD panel. The module is configured for development and evaluation with several Microchip PIC32- and ARM-based evaluation solutions as well as development and integration with a custom host system. For convenience, this module features Atmel’s “Xplained Pro LCD” connector (J1) for use with Xplained and Xplained Pro/Ultra evaluation hardware. In addition, a “MEB adapter” board is available in the 90-00123-B1 assembly for connecting to PIC32 kits. See Section 3.1.2.1 for details. As shown in Figure 2 below, several sub-system components are accessible to maximize effective integration. TM4301B - Touch Module Capacitive Touchscreen Controller Nav Keys J2 J2 J1 mX336T QT1070 Sensor PCB Capacitive Button Controller J5 LCD Panel Module PCB Touch sensor HOST J1 DS24B33 Serial EEPROM Figure 2 - Functional Block Diagram  10 PDA TM4301B: 4.3in PCAP Touch Module Doc:111-00221-A1 PDA TM4301B: 4.3in PCAP Touch Module 2.2 Understanding Unfamiliar Concepts Throughout this document, the functionality of the module sub-system will be outlined and summarized. However, the user is encouraged to refer to the resources and documents below in order to gain a more thorough understanding of each sub-system. 2 • For a basic overview of I C communication, refer to Section 5 of this document • Microchip maXTouch mXT336T (http://www.microchip.com/.../maxtouch) • Microchip QTouch QT1070 Datasheet (https://www.microchip.com/.../AT42QT1070) • Maxim DS24B33 Datasheet (www.maximintegrated.com) In addition, when developing or evaluating with the Microchip ARM-based EK’s, it is recommended that the user visit www.at91.com which contains a broad range of resources for the EK’s and the ARM devices they feature. 2.3 LCD Panel The module provides the host with a direct connection (Connector J1) to the LCD panel interface (Connector J5). Aside from generating supply voltages for the LED backlight and providing backlight control to the host, no display panel control is performed by the module. 2.4 maXTouch Capacitive Touchscreen Controller The module touch screen interface is based on the Microchip maXTouch mXT336T Touch Controller and operates using the touch sensor at Connector S-J2. The touch controller scans the touch sensor and will signal the host with an active low interrupt signal (~MXT_CHG on Connector J1) when new touch data is available. Data communication with the maXTouch controller is 2 2 2 2 performed over a shared I C interface (I C SCL and I C SDA on J1). The I C address of the touch controller is 0x4A. NOTE: The TM4301B has pull-up resistors on the maXTouch ~CHG_mxt interrupt signal located at R8 on 2 2 the sensor PCB. There are no external pull-ups on the I C SCL and I C SDA signals – the host must provide pull-up for these signals. 2.4.1 maXTouch Controller Interface Details of the maXTouch communication protocol are beyond the scope of this document. provided in Section 3.2 below to facilitate evaluation and initial development. However information is This module is pre-loaded with a configuration already optimized for this touch sensor and panel, so the developer need only focus on interfacing with the device. When developing the maXTouch controller interface during evaluation and host development, care should be taken to avoid changing the maXTouch configuration or committing changes to NV storage on the maXTouch controller. To get started with host interface development, the user is strongly encouraged to leverage existing code available from the resources outlined in Sections 3.2.   11 2.5 QTouch Capacitive Button Controller The module’s “nav key” interface is based on the Microchip QT1070 7-Channel Capacitive Sensor Driver. The button controller scans the 4 capacitive nav keys (K1, K2, K3 and K4) and will signal the host with an active low interrupt signal (~QT_CHG on Connector J1) when a touch event has occurred. Data communication with the 2 2 2 2 QT1070 controller is performed over a shared I C interface (I C SCL and I C SDA on J1). The I C address of the button controller is 0x1B and cannot be changed. NOTE: The TM4301B has pull-up resistors on the QTouch ~CHG interrupt signal located at R8. There are 2 2 no external pull-ups on the I C SCL and I C SDA signals – the host must provide pull-up for these signals. 2.5.1 QTouch Controller Interface Details of the QTouch communication protocol are beyond the scope of this document. to review the QT1070 Datasheet (https://www.microchip.com/.../AT42QT1070). The user is encouraged 2.6 Serial EEPROM The module includes a DS24B33 Serial EEPROM providing 512 bytes of non-volatile storage. Data communication with the EEPROM is performed over a One-Wire Interface. The EEPROM is not used by another subsystem on the touch module and can be freely used by the host system for any purpose. For example, Microchip ARM-based EK’s running Linux or Android operating systems use the pre-programmed contents of the EEPROM to identify this module type. NOTE: The user should take care if choosing to overwrite the pre-programmed EEPROM contents. As noted above, certain builds of Linux or Android provided by Microchip and targeted for the Microchip ARM-based EKs use the EEPROM contents to identify the module and may no longer recognize the module. The user is advised to back up the EEPROM contents before overwriting. The serial EEPROM communicates via a one-wire interface (“One-Wire Interface” on J5 or J6). DS24B33 Datasheet (www.maximintegrated.com) for details.  12 PDA TM4301B: 4.3in PCAP Touch Module Refer to the Doc:111-00221-A1 PDA TM4301B: 4.3in PCAP Touch Module 3 Getting Started This module was designed to install on a variety of Microchip ARM-based EK’s including the SAMA5D3 Xplained, SAMA5D4 Xplained Ultra, SAMA5D2 Xplained Ultra and the SAMV71 Xplained Ultra among others. Hardware connectivity with Microchip PIC32MZ kits is also supported. With example projects and prebuilt Linux and/or Android images available for many of these evaluation platforms, this provides the fastest way to evaluate the performance of the touchscreen and display using a familiar, full-featured OS or lightweight bare-metal code. The following sections provide basic information related to using and evaluating the Touch Module. Visit Precision Design Associates website ( www.pdaatl.com ) or Microchip’s AT91 Community website ( www.at91.com ) for more information related to this touch module or guidance appropriate for your specific EK. 3.1 Hardware Connections The module interfaces with host hardware or an evaluation board via the flex connector, J1. following sections and refer to the specific kit documentation for more information. See details in the 3.1.1 Microchip XPRO Kits The host interface connector, J1, matches the “XPRO LCD” interface found on many Xplained or Xplained Ultra kits. The module connected directly as described in Section 1.2. 3.1.2 Microchip PIC32MZ Kits This touch module can interface with a Microchip PIC32MZ Multimedia Expansion Board (MEB) II (http://www.microchip.com/developmenttools/ProductDetails/DM320005-5) through the use of the “MEB Adapter” P/N 10-01120-A0 (contact PDA for details, included in the 90-00123-B1 assy). A flex cable connected to J1 on the touch module PCB is connected to J2 on the MEB Adapter. Figure 3 – TM4301B w/ MEB Adapter The board-to-board connecter (J2) on the MEB Adapter connects to the Display Connector J4 on the MEB II PCB. The through holes can be used to secure the MEB adapter to the touch module and the PEM nut standoffs can be used to secure the touch module to the MEB II PCB.   13 3.1.2.1 MEB Adapter Display Connector J1 The board-to-board connector (J1) on the MEB adapter matches the MEB II display connector. II documentation for more information. Refer to the MEB Type GND 31 I LCD_DATA_21  P GND 32 I LCD_DATA_5  3 - N/C 33 I LCD_DATA_22  4 - N/C 34 I LCD_DATA_6  5 P GND 35 I LCD_DATA_23  6 P GND 36 I LCD_DATA_7  7 P +3.3Vdc 37 I PCLK  8 P +3.3Vdc 38 I/O 9 I LCD_DATA_12  39 I VSYNC  10 I LCD_DATA_8  40 I HSYNC  11 I LCD_DATA_13  41 I DE  12 I LCD_DATA_9  42 - N/C 13 I LCD_DATA_14  43 O ~MXT_CHG 14 I LCD_DATA_10  44 I I C SCL 15 I LCD_DATA_15  45 - N/C 16 I LCD_DATA_11  46 I/O 17 I LCD_DATA_16  47 I LCD_PWM  18 I LCD_DATA_0  48 I DISP 1  19 I LCD_DATA_17  49 P GND 20 I LCD_DATA_1  50 P GND 21 I LCD_DATA_18  51 P +5Vdc 22 I LCD_DATA_2  52 P +5Vdc 23 I LCD_DATA_19  53 O ~QT_CHG 24 I LCD_DATA_3  54 I SCK (not used) 25 I LCD_DATA_20  55 I ~RESET 26 I LCD_DATA_4  56 I MOSI (not used) 27 P GND 57 O MISO (not used) 28 P GND 58 I SS (not used) 29 P +3.3Vdc 59 P GND 30 P +3.3Vdc 60 P GND EE Pin QT Description LCD 2 MXT P EE 1 Description QT Type LCD Pin MXT Mating connector: Hirose DF12(3.0)-60DP-0.5V(86)  One-wire interface  2 2 I C SDA        NOTE 1: Touch Module “DISP” signal is connected to MEB “LCD_Reset”. When driven low, the display is in standby mode.  14 PDA TM4301B: 4.3in PCAP Touch Module Doc:111-00221-A1 PDA TM4301B: 4.3in PCAP Touch Module 3.2 Software Several options exist when developing for the touch module whether targeting a custom host or a Microchip EK. 3.2.1 MPLab Harmony Framework Microchip’s MPLab IDE ( http://www.microchip.com/mplab/mplab-ide-home ) is an IDE and collection of tools that can be used when developing for Microchips silicon. The MPLAB Harmony Integrated Software Framework ( http://www.microchip.com/mplab/mplab-harmony ) is a collection of reusable modules for the PIC32 family of microcontrollers. Refer to the links above for specific support. 3.2.2 Linux Kernel / Android The Linux Kernel (www.kernel.org) has included basic support for maXTouch touch devices since version 2.6.36. The mainline driver has undergone considerable evolution since then. Microchip hosts the AT91 community website with resources dedicated to developing on their EKs for Android ( www.at91.com/android4sam/ ) and Linux ( www.at91.com/linux4sam/ ) Finally, Microchip maintains an up-to-date driver (www.github.com/atmel-maxtouch/linux) which includes numerous out-of-cycle improvements to the mainline Linux Kernel maXTouch driver. 3.2.3 Advanced Software Framework The Advanced Software Framework (asf.microchip.com) contains examples of code for interfacing with devices in the maXTouch family of touch controllers. The capabilities of various maXTouch devices may differ, but the basic communication protocol is common and can be applied to this module. 3.2.4 Microchip Software Packages Many of Microchip’s Xplained kits have corresponding “Software packages” available ( www.microchip.com/design-centers/32-bit/softpacks ) with example projects which can be built using MPLAB, Atmel START or Atmel Studio (and/or other) toolchains. Many of these software packages include examples directly supporting or written for the PDA TMxxxx modules. 3.3 Using the Touch Module 3.3.1 Navigation Keys When using this module with one of the standard Android demo builds, the navigation keys function as shown in Table 3-1 below: Table 3-1 - Navigation Key Function (Android) Key K1 K2 K3 K4 Navigation Function Back Menu Home Power / Sleep 3.3.2 Evaluating the Touch Module For effective evaluation of the module – the touch sensor and the LCD panel in particular – the user is encouraged to try the following applications and tools depending on the host OS.   15 3.3.2.1 Android The following Android apps available from Google Play: TouchTest by Moonblink Dotty by Gerry Steele Multitouch Visible Test by Battery Powered Games Screen Test by Amberfog 3.3.2.2 Linux The user can perform simple touch / drawing test using the ts_test utility that is part of tslib.  16 PDA TM4301B: 4.3in PCAP Touch Module Doc:111-00221-A1 PDA TM4301B: 4.3in PCAP Touch Module 4 Specifications For complete specifications, refer to the datasheets listed in section 2.2 for the various sub-system components outlined in sections 2.3 through 2.6. 4.1 Mechanical Specifications Contact PDA for drawings and CAD models available. 119.6 ±0.15mm (Cover Panel) 7.1mm 2.0mm 0.18mm 102.67±0.15mm (Sensor Substrate Outline) 0.7mm Side View 96.0±0.2mm Backprint Viewable 95.04mm (LCD Active) 58.54mm (Touch Active) 26 mm 5.1mm 66.46±0.1 5mm (Sensor Substrate Outline) 98.04mm (Touch Active) 54.9±0.2mm Backprint Viewable 53.86mm (LC D Active) 0.78mm 0.08mm PIN 1 0.3mm PIN 40 82.16±0.15mm (Cover Panel) Front View 25.5 mm 20.5 mm Figure 4 - Sensor Only Dimensions Sensor Assy (P/N: 90-00089-A0) may be purchased individually. Minimum order quantities apply. Contact PDA for details.   17 116.84mm (PCB) 60.96mm (PCB) 50.55mm 66.7mm (LCM) DS2 4B33 ATMEL M XT336T 105.0mm (LCM) Figure 5 – Module Dimensions  18 PDA TM4301B: 4.3in PCAP Touch Module Doc:111-00221-A1 PDA TM4301B: 4.3in PCAP Touch Module 4.2 Absolute Maximum Specifications Parameter Value Operating temp 0 C to + 70 C Storage temp -40 C to + 85 C Vdd -0.5 to +6V Max continuous pin current, any control or drive pin ±40 mA Voltage forced onto any pin -0.5V to (Vdd + 0.5) Volts o o o o CAUTION: Stresses beyond those listed under Absolute Maximum Specifications may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification are not implied. Exposure to absolute maximum specification conditions for extended periods may affect device reliability. 4.3 Recommended Operating Conditions Parameter Value Vin 5.0V ±5 percent Supply ripple + noise ±20 mV 4.4 DC Specifications Vin = 5.0V, Vdd=3.3Vdc, Ta = recommended range, unless otherwise noted Parameter Description Min Typ Max Units Notes VIL Low input logic level - 0.5 – 0.3 Vdd V 1.8V