LTC3205EUF Linear Technology, LTC3205EUF Datasheet

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LTC3205EUF

Manufacturer Part Number
LTC3205EUF
Description
IC LED DRVR WT/RGB BCKLGT 24-QFN
Manufacturer
Linear Technology
Type
Backlight, White LED, RGB (Serial Interface)r
Datasheet

Specifications of LTC3205EUF

Topology
PWM, Step-Down (Buck), Step-Up (Boost), Switched Capacitor (Charge Pump)
Number Of Outputs
9
Internal Driver
Yes
Type - Primary
Backlight
Type - Secondary
RGB, White LED
Frequency
600kHz ~ 1.1MHz
Voltage - Supply
2.8 V ~ 4.5 V
Mounting Type
Surface Mount
Package / Case
24-QFN
Operating Temperature
-40°C ~ 85°C
Current - Output / Channel
250mA
Internal Switch(s)
Yes
Efficiency
92%
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Voltage - Output
-

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
LTC3205EUF
Manufacturer:
LINEAR/凌特
Quantity:
20 000
Part Number:
LTC3205EUF#TRPBF
Manufacturer:
LT
Quantity:
5 000
Part Number:
LTC3205EUF#TRPBF
Manufacturer:
LINEAR/凌特
Quantity:
20 000
FEATURES
APPLICATIO S
TYPICAL APPLICATIO
* U.S. Patent 6,411,531
2.8V TO
INTERFACE
4.5V
SERIAL
, LTC and LT are registered trademarks of Linear Technology Corporation.
V
Step-Up/Step-Down Fractional Charge Pump for Up
to 92% Efficiency
Independent Current and Dimming Control for
1-4 LED Main, 1-2 LED Sub and RGB LED Displays
LED Currents Programmable Using 3-Wire Serial
Interface
Up to 250mA of Continuous LED Current
0.7% LED Current Matching
Low Noise Constant Frequency Operation*
Minimal Component Count
Automatic Soft-Start Limits Inrush Current
Four Programmable Dimming States for Main and
Sub Displays
Up to 4096 Color Combinations for RGB Display
Low Shutdown Current: I
Tiny 24-Lead (4mm 4mm) QFN Package
Cellular Phones
Wireless PDAs
Multidisplay Handheld Devices
IN
3
1 F
V
SERIAL PORT
IN
I
1 F
RGB
LTC3205
U
MAIN1-4
SUB1-2
1 F
I
MS
RGB
CPO
2
4
3
CC
< 1 A
MAIN DISPLAY
U
SUB DISPLAY
DESCRIPTIO
The LTC
troller. The part contains a high efficiency, low noise frac-
tional step-up/step-down charge pump to provide power
for both main and sub white LED displays plus an RGB
color LED display. The LTC3205 requires only four small
ceramic capacitors plus two resistors to form a complete
3-display LED power supply and current controller.
Maximum currents for the main/sub and RGB displays are
set independently with a single resistor. Current for each
LED is controlled with an internal current source. Dim-
ming and ON/OFF control for all displays are achieved via
a 3-wire serial interface. Four dimming states exist for the
main and sub displays and 16 dimming states are available
via internal PWM for the red, green and blue LEDs result-
ing in up to 4096 color combinations.
The LTC3205 charge pump optimizes efficiency based on
V
up in step-down mode and automatically switches to step-
up mode once any enabled LED current source begins to
enter dropout. Internal circuitry prevents inrush current and
excess input noise during start-up and mode switching.
The LTC3205 is available in a low profile 24-lead
(4mm 4mm 0.8mm) QFN package.
IN
RED
and LED forward voltage conditions. The part powers
RGB ILLUMINATOR
®
GREEN BLUE
3205 is a highly integrated multidisplay LED con-
3205 TA01a
U
1 F
LED Controller
100
90
80
70
60
50
40
30
20
10
0
3.0
4-LED Main Panel Efficiency
Multidisplay
FOUR LEDs AT 15mA/LED
(TYP V
T
A
= 25 C
F
AT 15mA = 3.2V)
3.3
vs Input Voltage
INPUT VOLTAGE (V)
LTC3205
3.6
3.9
3205 TA01b
1
3205f
4.2

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LTC3205EUF Summary of contents

Page 1

... Up to 4096 Color Combinations for RGB Display Low Shutdown Current: I < Tiny 24-Lead (4mm 4mm) QFN Package U APPLICATIO S Cellular Phones Wireless PDAs Multidisplay Handheld Devices , LTC and LT are registered trademarks of Linear Technology Corporation. * U.S. Patent 6,411,531 U TYPICAL APPLICATIO MAIN DISPLAY IN 2.8V TO ...

Page 2

... Serial Port Idle 25 A < I < MAIN1-MAIN4, SUB1, SUB2 Voltage = MAIN1-MAIN4, SUB1, SUB2 Voltage = MAIN1-MAIN4, SUB1, SUB2 Voltage = 1V MS Any Two MAIN or SUB Outputs 25 A < I < RGB RED, GREEN, BLUE Voltage = TOP VIEW ORDER PART NUMBER LTC3205EUF 18 RED 17 SGND CPO RGB UF PART MARKING 3205 ...

Page 3

ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER Charge Pump (CPO) 1:1 Mode Output Impedance 2:3 Mode Output Impedance CPO Regulation Voltage CLK Frequency D , SCLK, LD, STEPUP, ENRGB IN V Low Level Input Voltage IL ...

Page 4

LTC3205 W U TYPICAL PERFOR A CE CHARACTERISTICS 1:1 Mode Switch Resistance vs Temperature 1 100mA CPO V = 3. 3.9V IN 0.8 0.7 0.6 –15 35 – ...

Page 5

W U TYPICAL PERFOR A CE CHARACTERISTICS Input Supply Voltage Required for Higher LED Currents 3 3 3.5 3.3 3.1 I RGB 2.9 2.7 2 100 125 175 200 225 ...

Page 6

LTC3205 CTIO S V (Pin 16): Supply Voltage for the Charge Pump. The V IN pin should be connected directly to the battery and by- passed with X5R or X7R ceramic capacitor. ...

Page 7

U OPERATIO Power Management To optimize efficiency, the power management section of the LTC3205 provides two methods of supplying power to the CPO pin: 1:1 direct connect mode or 2:3 boost mode. When either the main or sub displays of ...

Page 8

LTC3205 U OPERATIO LTC3205 is in shutdown when DV however, that all of the logic signals that are referenced SCLK, LD, ENRGB and STEPUP) will need below (i.e., ground) ...

Page 9

U OPERATIO Unused MAIN or SUB Display LED Pins Any of the six white LED pins (MAIN1-MAIN4, SUB1 and SUB2) can cause the LTC3205 to switch from 1:1 mode to 2:3 charge pump mode if they drop out ...

Page 10

LTC3205 U U APPLICATIO S I FOR ATIO necessary for LD to load the data once it has shifted into the device. Command data is latched into the command register on the falling edge of the LD signal. The LTC3205 ...

Page 11

U U APPLICATIO S I FOR ATIO lose considerable capacitance over that range. Z5U and Y5V capacitors may also have a very strong voltage coefficient causing them to lose 60% or more of their capacitance when the rated voltage is ...

Page 12

LTC3205 U U APPLICATIO S I FOR ATIO The efficiency of the LTC3205 depends upon the mode in which it is operating. Recall that the LTC3205 operates as a pass switch, connecting V to CPO until one of the LEDs ...

Page 13

U U APPLICATIO S I FOR ATIO If the desired input voltage range is below the data shown in Figure 9, and a precise control of the LED current is desired, then a precision current source may be added to ...

Page 14

LTC3205 U TYPICAL APPLICATIO S All Charge Pump Main, Sub, RGB and Camera Light Controller 15 CPO LTC3205 2 MAIN1 1 MAIN2 24 MAIN3 23 MAIN4 22 SUB1 21 SUB2 18 RED 19 GREEN 20 BLUE I I RGB MS ...

Page 15

... ALL DIMENSIONS ARE IN MILLIMETERS Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 4-LED Main Display Plus 160mA 4-LED Camera Light ...

Page 16

... DC/DC Converter LTC3440 600mA (I ), 2MHz Synchronous Buck-Boost OUT DC/DC Converter LT3465/LT3465A 1.2MHz/2.7MHz with Internal Schottky ThinSOT is a trademark of Linear Technology Corporation. Linear Technology Corporation 16 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 Using the RGB Display as a Camera Light L1 2.2 H ...

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