QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 749
MULTIDISPLAY LED CONTROLLER
1
LTC3206
DESCRIPTION
Demonstration circuit 749 is a multi-display LED con-
troller featuring the LTC3206.
The LTC3206 is a highly integrated multi-display LED
controller. This device contains a high efficiency, low
noise fractional step-up/step-down charge pump to
provide power for a main and sub white LED display,
plus an RGB color LED display. The LTC3206 re-
quires only four small ceramic capacitors plus two
resistors to form a complete 3-panel LED power sup-
ply and a current controller.
Maximum currents for the main/sub and RGB dis-
plays are set independently with a single resistor.
Current for each LED is controlled with an internal
current source. Dimming control for all displays is
achieved via a 2-wire I
2
C interface. The RGB or Sub
panel may be disabled with the ENRGB/S pin. Sixteen
dimming states exist for the main panel, sub panel,
and the red, green, and blue LEDs resulting in up to
4096 color combinations.
The LTC3206 charge pump optimizes efficiency based
on VIN and LED forward voltage conditions. The part
powers-up in step-down mode and automatically
switches to step-up mode once the first LED current
source begins to enter dropout. The charge pump can
also be programmed to be in step-up mode using the
I
2
C interface. Internal circuitry prevents inrush cur-
rent and excess input noise during start-up and mode
switching.
QUICK START PROCEDURE
Demonstration circuit 749 is easy to setup to evalu-
ate the performance of the LTC3206. Refer to Figure
1 for the proper measurement equipment setup and
follow the procedure below.
1.
Connect DC749 to the DC590 USB Serial Control-
ler using the supplied 14-conductor ribbon cable
as shown in Figure 1. Refer to the DC590 Quick
Start guide for software installation details.
2.
Attach the supplied USB cable to your computer
and then to the DC590 controller board.
3.
Run the QuickEvalTM program. The program de-
tects the DC749 and displays the LTC3206 con-
trol window (shown in Figure 2).
4.
Attach a 2.7 – 4.5V power source to the VIN and
GND turrets of the DC749 demo board. This is
the V
IN
power supply for the LTC3206 (see appli-
cation schematic).
QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 749
MULTIDISPLAY LED CONTROLLER
2
Figure 1. Proper Measurement Equipment Setup
USING THE LTC3206 QUICKEVAL SOFTWARE
The program provides brightness controls for the
Main, Sub, and RGB LEDs. The two check boxes
allow the Charge Pump to be forced on and the
ENRGB/S pin to be toggled. The three pairs of ra-
dio buttons allow the selection of either the RGB or
Sub panel to be disabled with the ENRGB/S pin,
AUX1 and/or AUX2 to be either Main or Sub LEDs.
There are four demo buttons and a CIE Chromaticity
diagram which allows direct selection of colors.
The LEDS OFF button resets all LEDs to zero, stops
and resets any demonstration in progress. An ad-
dress select button allows the I
2
C address to be
changed from 00 to FF, however the I
2
C address of
the LTC3206 is preset to a hexadecimal address of
36.
MAIN and SUB control – These are vertical slide
controls which adjust the main and sub LEDs out-
put from 0% to 100% by clicking on the up and
down arrows, a higher or lower tick, or by clicking
and dragging the slide pointer.
RED, GREEN, and BLUE controls – These are verti-
cal slide controls which allow individual adjustment
of the red, green, and blue LEDs to make any of the
QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 749
MULTIDISPLAY LED CONTROLLER
3
4096 colors available. The hex code and color are
displayed in small boxes below each of the sliders.
They too are adjusted by clicking on the up and
down arrows, a higher or lower tick, or by clicking
and dragging the slide pointer.
CIE Chromaticity diagram – Colors can be selected
by clicking on a specific color in the diagram. The
Gammut box, when checked, displays the Chroma-
ticity coordinates of the Nichia NSCM315C RGB
diode forming a triangle or
gammut
of all the colors
which can be produced by that diode.
Force Charge Pump On check box – When this box
is selected the charge pump is forced on. The
charge pump is automatically selected while the
Rainbow and Light Cycle demos are activated, but
returns to its original state when the demos are de-
selected.
ENRGB/S check box – When this box is selected,
the ENRGB/S pin is high. When it is deselected the
pin is low and either the RGB or the Sub panel is
disabled depending on the selection of the
ENRGB/S radio buttons.
ENRGB/S option buttons – If RGB Control is se-
lected, the RGB display will be disabled when the
ENRGB/S box is deselected. If the Sub Control is
selected, the Sub panel will be disabled when the
ENRGB/S box is deselected.
AUX1 & AUX2 Main/Sub option buttons – If the
Main button is selected, the applicable LED will
change illumination with the Main brightness con-
trol. If the Sub button is selected, the applicable
LED will change illumination with the Sub bright-
ness control. The LTC3206’s maximum current set-
tings for the Main, Sub, and RGB panels are set by
R2 and R3 (see the attached DC749 schematic.) R2
= R3 = 15.8K, which set the maximum current to
15mA.
Demo Buttons – These buttons can be selected to
run 4 different demonstrations. Demo 1 and Demo
2 cycle through the brightness levels of the LEDs
using a feathering technique. Demo 4 randomly
changes colors also using the feathering technique.
The feathering technique is done by alternating be-
tween adjacent brightness levels at high speeds
with a duty cycle to produce a certain intensity level
between the two brightness levels (virtual step).
These demos use 7 virtual steps between each
brightness level giving it a total of 120 brightness
levels (8 X 15).
LEDS OFF button – This button will turn the bright-
ness levels to zero on all of the LEDs and will turn
off and reset any active demo.
Select I2C Address button – Typically, the LTC3206
is preprogrammed with the hexadecimal I
2
C address
of 36, however, a different I
2
C address may be spe-
cial ordered. In this event the appropriate I
2
C ad-
dress will need to be selected. To do this, select the
Select I2C Address button. This button will display
UPDATE ADDRESS and the address selection box
will become active. Select the appropriate hexa-
decimal address in the address selection box. Then
select the Select I2C Address button to activate the
new address.
QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 749
MULTIDISPLAY LED CONTROLLER
4
Figure 2. LTC3206 Control Window
5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
Vin
2.7V to 4.5V
NOTES: UNLESS OTHERWISE SPECIFIED
1%
5%
5%
5%
1%5%
5%
DC749A LTC3206EUF
Multidisplay LED Controller
LINEAR TECHNOLOGY CORPORATION
1630 McCarthy Blvd.
Milpitas, CA. 95035
Phone : (408) 954-8400 Fax : (408) 434-0507
Custom
1 1Friday, July 30, 2004
Title
Size Document Number Rev
Date: Sheet of
J3
Gnd 1
TP1
SMT 1
D7
LED
WHITE
21
J6
M3
1
J19
ENRGB/S
1
R2
15.8K
J5
M2
1
J20
DVCC
1
D8
LED
WHITE
21
C3
4.7uF
6.3V
D5
LED
WHITE
21
D6
LED
WHITE
21
R3
15.8K
D4
LED
WHITE
21
J7
M4
1
J11
B
1
D1
LED
WHITE
21
C1
2.2uF
6.3V
C6
4.7uF
6.3V
C7
0.1uF
10V
U2
24LC025
1
6
3
4
5
2
7
8
A0
SCLK
A2
Vss
SDA
A1
WP
Vcc
D2
LED
WHITE
21
J9
A1 1
J12
G
1
REDGRNBLU
D9
LED
COLOR
2
13
4
R1
82
R7
5.1K
C2
2.2uF
6.3V
C5
0.1uF
10V
J13
R
1
J8
A2 1
R4
47K
R6
5.1K
J10
S1 1
U1
LTC3206EUF
4
1
8
7
6
5
2
3
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
C1-
SUB1
SDA
DVCC
C2+
C1+
SUB2
C2-
SCL
ENRGB/S
IMS
IRGB
SGND
CPO
VIN
RED
GREEN
BLUE
MAIN4
MAIN3
MAIN2
MAIN1
AUX1
AUX2
PGND
TP2
SMT 1
J14
CPO
1
J4
M1 1
J21
S2 1
J17
SDA 1
D3
LED
WHITE
21
J1
HD2X7
1
3
5
7
9
11
13
2
4
6
8
10
12
14
+
+
+
+
+
+
+
+
+
+
+
+
+
+
C4
0.1uF
10V
J16
IRGB
1
R5
5.1K
J18
SCL 1
J15
IMS
1
J2
1
Linear Technology Corporation
LTC3206EUF
Bill Of Material
Demo Bd. #749A
6/20/2005
Item Qty Reference Part Description Manufacture / Part #
1 3 C4,C5,C7 CAP., CHIP X5R 0.1uF 10V 10% AVX, 0402ZD104K 0402
2 2 C1,C2 CAP., CHIP X5R 2.2uF 6.3V 20% TAIYO YUDEN, JMK107BJ225MA 0603
3 2 C3,C6 CAP., CHIP X5R 4.7uF 6.3V TDK C1608X5R0J475M
4 2 J2,J3 TURRET TESTPOINT .064" MILL-MAX, 2308-02
5 8 D1-D8 LED, SMT WHITE NICHIA, NSCW100
61
D9 LED, SMT COLOR RGB NICHIA, NSCM315C
7 1 J1 SOCKET, 2X7 2MM STRAIGHT MOLEX/WALDOM 87331-1420
8 1 R1 RES., CHIP 82 OHM 5% AAC CR05-820JM 0402
9 3 R5,R6,R7 RES., CHIP 5.1K 5% AAC CR05-512JM 0402
10 2 R2,R3 RES., CHIP 15.8K 1% PANASONIC, ERJ-2RKF1582X 0402
11 1 R4 Res., CHIP 47K 5% AAC CR05-473JM 0402
12 1 U2 IC., SERIAL EEPROM MICROCHIP 24LC025 TSSOP8
13 1 U1 IC., MULTIDISPLAY LED CONTROLLER LINEAR TECHNOLOGY, LTC3206EUF
14 0 TP1,TP2 OPT
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