收藏本站
APPLICATION INFORMATION
R =
In this application, the bias resistor can be se-
lected by:
V FB
B
I LED (TOTAL)
where I LED(TOTAL) is the total operating current
of all the white LEDs.
To use SP6683 as a voltage source for fixed
voltage applications, a voltage divider is need to
program the output voltage, as shown in the figure
above. The output voltage is set by the ratio of
the two resistors and the feedback control volt-
age as shown by:
V OUT = ( 1 + R 5 ) ? V FB
R 6
Brightness Control Using PWM
Dimming control can be achieved by applying a
PWM control signal to the EN/PWM pin. The
brightness of the white LEDs is controlled by
increasing and decreasing the duty cycle of the
PWM signal. While operating frequency range
is from 60Hz to 700Hz, the recommended maxi-
The SP6683-03ER has the discharge MOSFET
disabled ensuring that the output node is at high
impedance during shutdown. This can be useful
if the system is feeding LED current from an-
other source while the SP6683 is in shutdown.
The SP6683-LV offers a lower reference volt-
age that allows to reduce efficiency loss occur-
ring in the current sense resistor. This part is
ideal for driving single LEDs for Flash applica-
tions.
Reducing Component Count
It is possible to reduce the number of external
components by shorting pins 2 & 9 and omitting
the flying capacitor. In this mode, the charge
pump operates in a "quasi" doubler mode. This
reduces efficiency but does allow for one less
external capacitor. This circuit is recommended
only when Input and Output Voltages have
similar range, which is very common when
driving white LEDs from a Li-Io battery.
mum brightness frequency range is from 60Hz
to 200Hz. A repetition rate of at least 60Hz is
required to prevent flicker.
Vin
2.7V~4.2V
C1
2.2uF
1 Vout C2P 10
2 C1P C1N 9
SP6683
3 Vin GND 8
4 Vmode
C2N 7
5 FB
EN/PWM 6
C3
1uF
6.3V/0603
LED1
C4
2.2uF
6.3V/0603
Io=Vfb/Rb
6.3V/0603
EN/PWM
Rb
1.5 ?
Three Options for Optimization
The SP6683 family includes three options that
allow the user to optimize the LED driving
circuit. The SP6683 includes an on-board dis-
charge switch that ensures that V OUT is com-
pletely discharged in shutdown. This feature is
very useful in systems using PWM dimming,
when the SP6683 is periodically turned on and
off. The discharge switch ensures that the fall-
ing and rising edges of the LED current have
similar durations.
Flying Cap Removed
1% / 0603
Date: 3/31/06 RevG
SP6683 1X/1.5X Charge Pump LED Driver for Flash or Backlight
9
? Copyright 2006 Sipex Corporation
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
SP6685EB EVAL BOARD FOR SP6685
SP6686EB EVAL BOARD FOR SP6686
SP6699EB EVAL BOARD FOR SP6699
SP6887EB EVAL BOARD FOR SP6887
SP7121EB EVAL BOARD FOR SP7121
SP7122BEB EVAL BOARD FOR SP7122B
SP7600EB EVAL BOARD FOR SP7600
SP7601EB EVAL BOARD FOR SP7601
相关代理商/技术参数
SP6685 制造商:EXAR 制造商全称:EXAR 功能描述:700mA Buck/Boost Charge Pump LED Driver
SP6685_06 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:700mA Buck/Boost Charge Pump LED Driver
SP6685EB 功能描述:电源管理IC开发工具 Eval Board for SP6685 Series RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
SP6685ER 制造商:Exar Corporation 功能描述:LASER DIODE/LED DRIVER, 10 Pin, Plastic, LCC
SP6685ER/TR 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:700mA Buck/Boost Charge Pump LED Driver
SP6685ER-L 功能描述:电荷泵 Camera Flash RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 输出电压:- 1.5 V to - 5.5 V, 3 V to 11 V 输出电流:100 mA 电源电流:1 mA 最大工作温度:+ 70 C 封装 / 箱体:SOIC-8 Narrow 封装:Tube
SP6685ER-L/TR 功能描述:电荷泵 700mA For Camera Flash RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 输出电压:- 1.5 V to - 5.5 V, 3 V to 11 V 输出电流:100 mA 电源电流:1 mA 最大工作温度:+ 70 C 封装 / 箱体:SOIC-8 Narrow 封装:Tube
SP6685ERTR 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Charge Pump LED Driver For Camera Flash