ST STEVAL-ILL015V1 RGB LED调光解决方案

发布时间：2011-12-5 11:50 发布者：1770309616

ST公司的STEVAL-ILL015V1是采用STP24DP05和STM32™ MCU的LED调光演示板,两个STP24DP05可连接16个RGB LED,采用ST1S010的高效开关DC/DC电源,DC电源电压从7.5V到18V,输入电流小于0.7A,LED电流调整.本文介绍了STP24DP05主要特性，典型应用电路图以及STEVAL-ILL015V1 LED调光演示板主要特性，电路图和材料清单．

STEVAL-ILL015V1 - LED dimmer demonstration board based on the STP24DP05 and STM32™ STP24DP05:24-bit constant current LED sink driver with output error detection

The STP24DP05 is a monolithic, low voltage, low current power 24-bit shift register designed for LED panel displays. The device contains a 8 x 3-bit serial-in, parallel-out shift register that feeds a 8 x 3-bit D-type storage register. In the output stage, twenty-four regulated current sources were designed to provide 5-80 mA constant current to drive the LEDs.

The 8 x 3 shift registers data flow sequence order can be managed with two dedicated pins. The STP24DP05 has a dedicated pin to activate the outputs with a sequential delay, that will prevent inrush current during outputs turn-ON.

The device detection circuit checks 3 different conditions that can occur on the output line: short to GND, short to VO or open line.

The data detection results are loaded in the shift registers and shifted out via the serial line output. The detection functionality is activated with a dedicated pin or as alternative, through a logic sequence that allows the user to enter or exit from detection mode.
Through three external resistors, users can adjust the output current for each 8-channel group, controlling in this way the light intensity of LEDs.

The STP24DP05 guarantees a 20 V output driving capability, allowing users to connect more LEDs in series.

The high clock frequency, 25 MHz, makes the device suitable for high data rate transmission. The 3.3 V of voltage supply is useful for applications that interface any micro from 3.3 V.

STP24DP05主要特性:

■ Low voltage power supply down to 3 V

■ 8 x 3 constant current output channels

■ Adjustable output current through external resistors

■ Short and open output error detection

■ Serial data IN/parallel data OUT

■ Shift register data flow registers control

■ Accepts 3.3 V and 5 V micro driver

■ Output current: 5-80 mA

■ 25 MHz clock frequency

■ High thermal efficiency package

图1. STP24DP05方框图

图2. STP24DP05典型应用电路图

采用STP24DP05 LED驱动器和STM32 MCU的STEVAL-ILL015V1 LED调光演示板

This user manual provides instructions for using the STEVAL-ILL015V1 LED dimmer demonstration board based on the STP24DP05 LED driver and the STM32™ microcontroller accelerated by SPI and DMA. This document provides information including hardware setup, description of demonstration firmware functionality, PC interconnection options and evaluation of the STP24DP05 LED driver.

STEVAL-ILL015V1 LED调光演示板主要特性:

● Two STP24DP05 (TQFP48) for connection of 16 RGB LEDs

● 16 RGB high-brightness LEDs

● STM32 microcontroller using internal HS oscillator

● High-efficiency switching DC-DC power supply using the ST1S010

● DC power supply 7.5 - 18 V (undifferentiated polarity, over voltage protection)

● DC input current 0.7 A max., standard supply connector

● LED current regulation

● Controlled by 3 buttons, a knob and a reset/back button

● Available test point for each important signal

● JTAG interface for microcontroller firmware change/update

● Error and over temperature LEDs for each LED driver.

● 3 jumpers allowing disconnection of 3 LEDs from the driver for testing the error
detection mode

● 3 jumpers allowing shorting of 3 LEDs from the driver for testing the error detection
Mode

● Mini USB connector for PC interconnection

The board is distributed with firmware which enables standalone and non standalone
demonstration. Features include:

● LED diagnostic

● Adjustable brightness and color of each individual LED

● Animated text

● GUI (graphical user interface) software for LED diagnostics