參數(shù)資料
型號(hào): SP6685ERTR
元件分類: LED驅(qū)動(dòng)器
英文描述: Charge Pump LED Driver For Camera Flash
中文描述: 電荷泵的LED相機(jī)閃光燈驅(qū)動(dòng)器
文件頁(yè)數(shù): 8/10頁(yè)
文件大小: 143K
代理商: SP6685ERTR
8
Date: 12/15/04
SP6685 Charge Pump LED Driver for Camera Flash Copyright 2004 Sipex Corporation
For an example of 200mA Torch mode and
600mA Flash mode, the values R
=
0.25
, V
= 150mV (Flash Mode), and
R
= 88.7K are calculated. The power
obtained in the Flash mode would be:
P
FLASH
= V
FB
*I
OUT
= 150mV*600mA = 90mW.
The typical 0603 surface mount resistor is
rated 1/10 watt continuous power and 1/5
watt pulsed power, more than enough for
this application. For other applications, the
P
can be calculated from the resistor
size selected. The R
resistor is recom-
mended to be size 0603 for most applica-
tions.
COMPONENT SELECTION
The sense resistor R
is determined by
the value needed in the Torch mode for the
desired output current by the equation:
R
= V
FB
/ I
OUT
where V
FB
= 50mV (Torch
Mode)
The SP6685 charge pump circuit requires 3
capacitors: input, output and fly capacitor,
and a 1
μ
F value is typically recommended.
For the input capacitor, a larger value of
2.2
μ
F or 4.7
μ
F will help reduce input volt-
age ripple for applications sensitive to ripple
on the battery voltage. All the capacitors
should be ceramic to obtain low ESR, which
improves bypassing on the input and output
and improves output voltage drive by reduc-
ing output resistance. X5R or X7R Ceramic
capacitors are recommended for most ap-
plications. A selection of recommended
capacitors is included in Table 1. The input
and output capacitors should be located as
close to the V
and V
pins as possible to
obtain best bypassing, and the returns
should be connected directly to the P
pin
or to the thermal pad ground located under
the SP6685. The fly capacitor should be
located as close as possible to the C1 and
C2 pins as possible.
Once the R
resistor has been selected
for Torch mode, the V
voltage can be
selected for Flash mode using the following
equation:
V
= I
*R
(Flash Mode) where I
OUT
is
for Flash Mode
Next, the R
resistor can be selected for
Flash mode using the following equation:
R
SET
= (1.26V/ V
FB
)*11.2K
(Flash Mode)
Part Reference
U1
CIN
COUT, CF
RSET
RSENSE
Part Number
SP6685ER
GRM188R0J475KE19
GRM155R60J105KE19B
-
-
Value
Size
Manufacturers/ Website
Sipex/www.sipex.cpm
Murata/www.murata.com
Murata/www.murata.com
any
any
3x3mm DFN - 10 pin
0603/X5R/0.9mm ht
0402/X5R/0.5mm ht
0402
0603
4.7uF/6.3V
1uF/6.3V
88.7K
0.22ohms
相關(guān)PDF資料
PDF描述
SP6685 Charge Pump LED Driver For Camera Flash
SP6685ER Charge Pump LED Driver For Camera Flash
SP6690 Micro Power Boost Regulator Series White LED Driver
SP6690EB Evaluation Board Manual
SP6690EK Micro Power Boost Regulator Series White LED Driver
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SP6686 制造商:EXAR 制造商全稱:EXAR 功能描述:400mA Buck/Boost Charge Pump LED Driver
SP6686EB 功能描述:LED 照明開(kāi)發(fā)工具 Eval Board for SP6686 Series RoHS:否 制造商:Fairchild Semiconductor 產(chǎn)品:Evaluation Kits 用于:FL7732 核心: 電源電壓:120V 系列: 封裝:
SP6686ER 制造商:Exar Corporation 功能描述:Driver, Other
SP6686ER-L 功能描述:LED照明驅(qū)動(dòng)器 Driver RoHS:否 制造商:STMicroelectronics 輸入電壓:11.5 V to 23 V 工作頻率: 最大電源電流:1.7 mA 輸出電流: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SO-16N
SP6686ER-L/TR 功能描述:LED照明驅(qū)動(dòng)器 400mA Buck/Boost Charge Pump RoHS:否 制造商:STMicroelectronics 輸入電壓:11.5 V to 23 V 工作頻率: 最大電源電流:1.7 mA 輸出電流: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SO-16N