Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

SP6682 Datasheet(PDF) 5 Page - Sipex Corporation

Part No. SP6682
Description  High Efficiency Charge Pump Regulator for White LEDs
Download  12 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  SIPEX [Sipex Corporation]
Direct Link  http://www.sipex.com
Logo SIPEX - Sipex Corporation

SP6682 Datasheet(HTML) 5 Page - Sipex Corporation

  SP6682 Datasheet HTML 1Page - Sipex Corporation SP6682 Datasheet HTML 2Page - Sipex Corporation SP6682 Datasheet HTML 3Page - Sipex Corporation SP6682 Datasheet HTML 4Page - Sipex Corporation SP6682 Datasheet HTML 5Page - Sipex Corporation SP6682 Datasheet HTML 6Page - Sipex Corporation SP6682 Datasheet HTML 7Page - Sipex Corporation SP6682 Datasheet HTML 8Page - Sipex Corporation SP6682 Datasheet HTML 9Page - Sipex Corporation Next Button
Zoom Inzoom in Zoom Outzoom out
 5 / 12 page
background image
5
Date: 5/5/04
SP6682 High Efficiency Charge Pump Regulator for White LEDs
© Copyright 2004 Sipex Corporation
0
1
2
3
4
5
6
2.7
3
3.3
3.6
3.9
4.2
Input Voltage (V)
4 LED's @ 30mA
4 LED's @ 15mA
PERFORMANCE CHARACTERISTICS: Continued
Refer to the typical application circuit, TAMB = 25°C, IO = 60mA unless otherwise specified.
0
1
2
3
020
40
6080
100
Duty Cycle,%
100 Hz
500 Hz
General Overview
The SP6682 is a current regulated charge pump
ideal for converting a Li-Ion battery input for
driving white LEDs used in backlighting color
displays in cellular phones, PDAs, digital cam-
eras and MP3 players. The SP6682’s propri-
etary AutoBoost feature enables the IC to auto-
matically transition from X1.5 boost mode to
X2 boost mode based on battery input voltage
for optimal efficiency and performance. The
SP6682 is able to efficiently drive up to six
20mA white LEDs in parallel and maintain a
constant brightness over a very wide operating
voltage range (2.7V to 5.5V). The SP6682 oper-
ates with an internal 600kHz clock, enabling the
use of small external components. Other fea-
tures of SP6682 include PWM dimming control
as well as complete input/out disconnect in
shutdown. In shut down mode the IC draws less
than 1.5
µA current. The output regulation is
achieved by sensing the voltage at the feedback
pin and modulating the switcher between the
charge pump and output capacitor.
Theory of Operation
The SP6682 regulated charge pump block dia-
gram consists of four main blocks (Voltage
Reference, Mode Control, Clock Manager, Start-
up and Charge-Pump Switches) and two com-
parators (VMODE Comparator and VOUT Com-
parator).
1) Voltage Reference. This block provides the
306mV and 1.25V reference voltages needed
for the two comparators.
2) Mode Control. An external voltage divider
connected to the VMODE pin will define an input
voltage to the mode comparator which sets the
logic state of the mode selection outputs to the
X2 or X1.5 modes. VMODE is compared to a
1.25V bandgap voltage. For example, if one
makes a 158K/100K divider, the mode will
change at 2.58 x 1.25 V =3.23V. A comparator-
based cycle by cycle regulation ensures that no
mode change occurs during cycles.
3) Clock Manager. An internal 600 kHz clock
is generated in this block. Depending on the
mode control, the appropriate clock phasing is
generated here and sent to the start-up and
charge-pump switches block.
4) Start-up and Charge Pump Switches. Dur-
ing start-up, until the reference is established,
this block keeps the charge pump inactive. Dur-
ing this period the output stays floating, by
consequence the charge pump drivers are now
referenced to VOUT. Charging of the output will
occur (e.g. when VIN is ramped up to 4.2V, VOUT
ramps only up to about 3V), but not to the value
of VIN, protecting the White LED from experi-
Figure 7. Brightness vs. input voltage
Figure 8. Brightness vs duty cycle
OPERATION


Html Pages

1  2  3  4  5  6  7  8  9  10  11  12 


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
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