Electronic Components Datasheet Search |
|
SP6687 Datasheet(PDF) 2 Page - Sipex Corporation |
|
SP6687 Datasheet(HTML) 2 Page - Sipex Corporation |
2 / 4 page Dec18,2006 RevB SP6687 Evaluation Board Manual © 2006 Sipex Corporation Page 2 of 4 The SP6687 is a high efficiency charge pump white LED driver. It provides 4 channels of low drop-out voltage current source to regulate the current for 4 white LEDs. For high efficiency, the SP6687 implements a 3 mode charge pump: x1, x1.5, and x2. An external resistor R5 is used to set the current of the white LEDs. SP6687 has an input current regulation to reduce the input ripple. Users can control white LED on/off via three programming bits: CTRL0, CTRL1 and CTRL2. When an external PWM signal is connected to the control pin, the brightness of white LEDs is adjusted by the duty cycle. Each channel can support up to 30mA of current. A current limiting circuit is also included in the SP6687 for short circuit protection. Whenever the output sources a dangerously high current, the current limiting circuit takes over the output regulation circuit and reduces the output current to an acceptable level. This device is available in a 4mm x 4mm, 16 pin QFN package. Capacitor C1 is a decoupling capacitor. Resistors R1 – R4 are used to pull down inputs if they are left floating. Capacitors C2 – C4 are used by the charge pump. USING THE EVALUATION BOARD 1) Powering Up the SP6687 Circuit The SP6687 Evaluation Board can be powered from a 4.5V power supply or from 3 alkaline cells. Connect 4.5V source pin with short lead directly to the “Vin” and -4.5V /GND pin to the “GND” posts. 2) Selecting the Bias Resistor LED current can be adjusted up to 30mA per string with an external resistor R5. The R5 value may be determined as ILED = 440x (Voltage at ISET /R5), where ILED is required LED current, and Voltage at ISET = 1.1V. R5 = 32 k is installed. 3) Selecting the number of illuminated LEDs The number of illuminated LEDs can be selected using CTRL0 – CTRL2 programming bits (see Table 1). Table 1. Programming Table Control Inputs Output Status CTRL2 CTRL1 CTRL0 LED4 LED3 LED2 LED1 0 0 0 OFF OFF OFF ON 0 0 1 OFF OFF ON OFF 0 1 0 OFF ON OFF OFF 0 1 1 ON OFF OFF OFF 1 0 0 OFF OFF ON ON 1 0 1 OFF ON ON ON 1 1 0 ON ON ON ON 1 1 1 OFF OFF OFF OFF |
Similar Part No. - SP6687_06 |
|
Similar Description - SP6687_06 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |