Microchip HT12-100SAs/12ST25 handleiding

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Handleiding

Introduction

This manual has been written for users of the Microchip TSHARC-12S touch screen micro-controller. The

TSHARC touch screen controller chips and software described within this document are assumed to be used with

four, five or eight wire analog resistive

touch screen products manufactured by a variety of touch screen

manufacturers. Touch screens between manufacturers vary with regards to light transmission, sensitivity, contact

resistance, capacitance and other electrical characteristics. Because touch screen quality and electrical

characteristics may vary between touch screen technologies and manufacturers the actual, overall performance

may vary between touch screen overlay manufacturers’ products.

A great deal of attention has been paid to eliminate potential problems with various touch screen manufacturers.

We have identified substantial specification variance within each manufacturer and between manufacturers touch

screens. While most of the manufactures we tested did fall within a functional specification, it is important to

request electrical and mechanical specifications from your touch screen overlay manufacturer to insure uniform

quality and performance. The specification details that should be provided by your touch screen overlay supplier

include lead to lead resistance, sheet resistance, and linearity of ITO.

Product Description

The TSHARC-12S controller board chip supports PS/2 and RS232 communications and for any manufacturers’ 4,

5 or 8 wire analog resistive touch sensors. Non-standard stock options are also available, including TTL

communication and SPI. For further information about these options, please contact Microchip Technology.

TSHARC-12S Core Features

• RoHS Compliant

• Standard and Industrial-Rated Available

o Standard 0C to +70C

o Industrial -40C to +85C

• Power-up Timer (PWRT)

• Brown Out Detect

• Brown out Voltage: 2.7v

• Oscillator Start-up Timer (OST)

• Watchdog Timer (WDT)

• SSOP and SOIC Packages Available

• True 12-bit ratio metric analog to digital converter

• Supported Communication Types

o 4 byte RS232 and PS/2

o SPI and TTL available. Please contact Microchip for this option

• Supports all manufacturers analog resistive touch screens.

o 4 wire

o 5 wire

o 8 wire

• Touch Screen Resistance Specification is 50 – 2k ohm sheet resistance lead to lead.

Electrical Characteristics (Absolute Maximum Ratings)

Ambient temperature under bias (Operating) .......................................................................................... -65°C to +150°C

Storage temperature ............................................................................................................................... -55°C to +125°C

Voltage on any pin with respect to VSS ……………………………………….. .......................................... -0.3V to (VDD + 0.3V)

Voltage on V

DD with respect to VSS ......................................................................................................... -0.3V to +7.5V

Total power dissipation (Note 1) ...............................................................................................................................1.0W

Maximum current out of VSS pin ...........................................................................................................................300 mA

Maximum current into V

DD pin ..............................................................................................................................250 mA

Input clamp current, I

IK (VI < 0 or VI > VDD)...................................................................................................................... ±20 mA

Output clamp current, I

OK (VO < 0 or VO > VDD) .............................................................................................................. ±20 mA

Maximum output current sunk by any I/O pin..........................................................................................................25 mA

Maximum output current sourced by any I/O pin ....................................................................................................25 mA

Maximum current sunk by all ports .......................................................................................................................200 mA

Maximum current sourced by all ports ..................................................................................................................200 mA

Note 1: Power dissipation is calculated as follows: Pdis = V

DD x {IDD – © IOH} + © {(VDD – VOH) x IOH} + ©(VOL x IOL)

2: Voltage spikes below V

SS at the MCLR/VPP/RE3 pin, inducing currents greater than 80 mA, may cause latch-up.

Thus, a series resistor of approximately 75 Ohms should be used when applying a “low” level to the MCLR/VPP/ RE3 pin,

rather than pulling this pin directly to V

SS.

Bekijk gratis de handleiding van Microchip HT12-100SAs/12ST25, stel vragen en lees de antwoorden op veelvoorkomende problemen, of gebruik onze assistent om sneller informatie in de handleiding te vinden of uitleg te krijgen over specifieke functies.