●General Description
●The LM8300/8500 is a 4-wire resistive touch screen control ler. The controller samples and drives the touch screen without the need of any external hardware. The built in 10-bit A/D provides a maximum of 500 coordinate pairs per second (cpps). The data sampled from the touch screen is sent out on the UART at a speed of 38400 bps.
●The controller has a power-saving mode which causes the controller to self-power down when no touch is detected on the touch screen for a specified amount of time. In the self-power down mode, the current drawn is typically less than 2 µA. The device resumes normal operation when a touch is detected on the touch screen or communication is detected on the UART. In addition to the self-power down mode, the controller can be disabled by pulling the SHUTDOWN pin low. The controller resumes normal operation when the SHUTDOWN pin is tristated or pulled high.
●The controller has an internal non-volatile memory storage element to store configuration data such as calibration points or controller configurations.
●Features
●KEY FEATURES
●■ Supports 4 wire resistive touch panels
●■ Low power standby current typically less than 2 µA at 5.5V
●■ Maximum speed of 500 coordinate pairs per second
●■ Automatic wake up and return to standby
●■ 10 bit A/D
●■ On-chip touch screen current drivers - no external driver required
●■ UART interface
●■ Controller configurations are stored in the internal non-volatile storage element
●■ Touch pressure can be measured
●APPLICATIONS
●■ Personal Digital Assistants
●■ Smart Hand-Held Devices
●■ Touch Screen Monitors
●■ Point-of-Sales Terminals
●■ KIOSK
●■ Pagers
●■ Cell Phones
