Document
DM117
Version : A.001 Issue Date : 2007/9/18 File Name : SP-DM117-A.001.doc Total Pages: 22
8-bit Constant Current LED Driver with Error Detection
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SILICON TOUCH TECHNOLOGY INC.
9-7F-1, Prosperity Road I, Science Based Industrial Park, Hsin-Chu, Taiwan 300, R.O.C.
Tel:886-3-5645656 Fax:886-3-5645626
SILICON TOUCH TECHNOLOGY INC.
DM117
DM117
8-bit Constant Current LED Driver
with Error Detection
General Description
DM117 is a constant-current sink driver specifically designed for LED display applications. The device incorporates shift registers, data latches, and constant current circuitry on the silicon CMOS chip. The maximum output current value of all 8 channels is adjustable by a single external resistor. Its built-in open/short detection and thermal alarm circuits help users detect LED failures and overheating. There are two methods to communicate the error messages to the system. One is through serial output data to indicate which channel has failure. The other is by means of dedicated Alarm pin.
Features
z Constant-current outputs: 5mA to 90mA adjustable by one external resistor z Maximum output voltage: 17V z Maximum clock frequency: 25MHz z Built-in real-time LED open/short detection: real-time monitor or smart detection modes z Fast detecting response: 0.1us (min.) z Over temperature protection:
Alarm((junction temperature > 110°C)
Shutdown (junction temperature >180°C) z Power supply voltage: 3.3V to 5.5V
Applications
z Indoor/Outdoor LED Video Display z LED Variable Message Signs (VMS) System
Package
z PDIP20, SSOP20
8-bit Constant Current LED Driver with Error Detection
Version:A.001
、、, Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 1
SILICON TOUCH TECHNOLOGY INC.
Block Diagram
DM117
8-bit Constant Current LED Driver with Error Detection
Version:A.001
、、, Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 2
SILICON TOUCH TECHNOLOGY INC.
Pin Connection
DM117
Pin Description
PIN No. 1 2
3
PIN NAME VCC
EN
FUNCTION
Supply voltage terminal.
Output enable terminal: ‘H’ for all outputs are turned off , ‘L’ for all outputs are active.
LAT
Input terminal of data strobe. Data on shift register goes through at the rising edge of LAT (edge trigger). Otherwise, data is latched.
4 5 6
7~14
CLK DAI OS
OUT0~7
Synchronous clock input terminal for serial data transfer. Data is sampled at the rising edge of DCK.
Serial data input terminal.
Input open/short detection selection: ‘H’ for LED short detection mode ‘L’ for LED open detection mode. ‘Edge’*1 for smart detection mode.
Sink constant-current outputs (open-drain)
15
DAO
Serial data output terminal.
16 ALARM Output open drain terminal: (connected to a pull-high resistor)
Serial data output trigger mode selection:
17 SDO
‘H’ means data is shifted out on synchronization to falling edge of CKO
‘L’ means data is shifted out on syn.