TI TSC2008非常低功耗触摸屏控制方案

TI公司的TSC2008是非常低功耗触摸屏控制器,工作电压可低至1.2V,能用单节锂电池进行供电. TSC2008包括有完整的超低功耗12位A/D电阻型触摸屏转换器,有驱动器和控制逻辑,以便用来测量触摸压力,支持SPI串行总线和数据传输,SPI速率高达25MHz,12位分辨率时的有效吞吐量速率为10kHz,可用于手机,PDA,GPS和媒体播放器,手提仪表,POS终端以及多屏触摸系统.本文介绍了TSC2008的主要特性,方框图,典型应用电路以及TSC2008EVM评估板电路图和材料清单(BOM).

The TSC2008 is a very low-power touch screen controller designed to work with power-sensitive, handheld applications that are based on advanced low-voltage processors. It works with a supply voltage as low as 1.2V, which can be supplied by a single-cell battery. It contains a complete, ultra-low power, 12-bit, analog-to-digital (A/D) resistive touch screen converter, including drivers and the control logic to measure touch pressure.

In addition to these standard features, the TSC2008 offers preprocessing of the touch screen measurements to reduce bus loading, thus reducing the consumption of host processor resources that can then be redirected to more critical functions.
The TSC2008 supports an SPI serial bus and data transmission. It offers programmable resolution of 8 or 12 bits to accommodate different screen sizes and performance needs.
The TSC2008 is available in a 12-lead,(1,555 ±0,055mm) x (2,055 ±0,055mm) 3 x 4 array, wafer chip-scale package (WCSP), and a 16-pin, 4 x 4 QFN(1) package. The TSC2008 is characterized for the -40°C to +85°C industrial temperature range.

TSC2008主要特性:
4-Wire Touch Screen Interface
Single 1.2V to 3.6V Supply/Reference
Ratiometric Conversion
Effective Throughput Rate:
Up to 20kHz (8-Bit) or 10kHz (12-Bit)
Preprocessing to Reduce Bus Activity
High-Speed SPI (up to 25MHz)
Simple Command-Based User Interface:
TSC2046 Compatible
8- or 12-Bit Resolution
On-Chip Temperature Measurement
ouch Pressure Measurement
Digital Buffered PENIRQ
On-Chip, Programmable PENIRQ Pull-up
Auto Power-Down Control
Low Power (12-Bit, 8.2kHz Eq Rate):
30.4µA at 1.2V, fSCLK = 5MHz
35.5µA at 1.8V, fSCLK = 10MHz
44.6µA at 2.7V, fSCLK = 10MHz
Power-On, Software, and SureSet Resets
Enhanced ESD Protection:
±8kV HBM
±1kV CDM
±25kV Air Gap Discharge
±15kV Contact Discharge
1.5 x 2 WCSP-12 and 4 x 4 QFN-16(1) PackagesRGV (QFN) package available Q1, 2009.U.S. Patent No. 6246394; other patents pending.
应用:
Cellular Phones
PDA, GPS, and Media Players
Portable Instruments
Point-of-Sale Terminals
Multi-Screen Touch Control Systems



图1.TSC2008方框图



图2.TSC2008典型应用电路图

TSC2008EVM评估板
The TSC2008EVM is in the Texas Instruments modular EVM form factor, which allows direct evaluation of the performance and operating characteristics of the TSC2008 and eases software development and system prototyping. This EVM is compatible with the 5-6K Interface Board (SLAU104) from Texas Instruments and additional third-party boards such as the NI Speedy-33 from National Instruments Corporation.
(www.ni.com)
The TSC2008EVM-PDK is a complete evaluation/demonstration kit, which includes a USB-based motherboard called the USB-MODEVM interface board and evaluation software for use with a personal computer running Microsoft Windows operating systems.

TSC2008EVM评估板主要特性:
Full-featured evaluation board for the TSC2008 4-wire resistive touch screen controller (TSC).
Modular design for use with a variety of DSP and microcontroller interface boards.
TSC2008EVM评估板电路图



图3.TSC2008EVM评估板电路图(1)



图4.TSC2008EVM评估板电路图(2)



图5.TSC2008EVM评估板电路图(3)
TSC2008EVM评估板材料清单(BOM):



USB-MODEVM 材料清单(BOM):