LINEAR TECHNOLOGY LTC3206 Technical data

FEATURES

■

Step-Up/Direct-Connect Fractional Charge Pump
Provides Up to 92% Efficiency

■

Up to 400mA Continuous Output Current

■

Independent Current and Dimming Control for
1-6 LED MAIN, 1-4 LED SUB and RGB LED Displays

■

LED Currents Programmable Using 2-Wire I2C™
Serial Interface

■

1% LED Current Matching

■

Low Noise Constant Frequency Operation*

■

Minimal Component Count

■

Automatic Soft-Start Limits Inrush Current

■

16 Exponentially Spaced Dimming States Provides
128:1 Brightness Range for MAIN and SUB Displays

■

Up to 4096 Color Combinations for RGB Display

■

Low Operating Current: I

■

Tiny, Low Profile 24-Lead (4mm × 4mm × 0.75mm)

= 180µA

VIN

QFN Package

U

APPLICATIO S

■

Cellular Phones

■

Wireless PDAs

■

Multidisplay Handheld Devices

, LTC and LT are registered trademarks of Linear Technology Corporation.

I2C is a trademark of Philips Electronics N.V.
* U.S. Patent 6,411,531

LTC3206

I2C Multidisplay

LED Controller

U

DESCRIPTIO

The LTC®3206 is a highly integrated multidisplay LED con­troller. The part contains a high efficiency, low noise frac­tional step-up/direct-connect charge pump to provide
power for both main and sub white LED displays plus an
RGB color LED display. The LTC3206 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 displays and RGB
display are set independently. Current for each LED is
controlled with an internal current source. Dimming and
ON/OFF control for all displays is achieved via a 2-wire
serial interface. Two auxiliary LED pins can be individually
assigned to either the MAIN or SUB displays. 16 individual
dimming states exist for both the MAIN and SUB displays.
Each of the RED, GREEN and BLUE LEDs have 16 dimming
states as well, resulting in up to 4096 color combinations.

The LTC3206 charge pump optimizes efficiency based on
V

and LED forward voltage conditions. The part powers

IN

up in direct-connect mode and automatically switches to

1.5x 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 LTC3206 is available in a 24-lead (4mm ×
4mm) QFN package.

TYPICAL APPLICATIO

2.2µF 2.2µF

V

IN

2.7V TO

4.5V

I2C SERIAL
INTERFACE

V

IN

2.2µF 2.2µF

2

SERIAL PORT

I

RGB

LTC3206

CPO

MAIN1-4

AUX 1

SUB1-2

AUX 2

RGB

I

MS

4

2

3

U

MAIN DISPLAY SUB DISPLAY RGB ILLUMINATOR

RED GREEN BLUE

3206 TA01a

5-LED Main Display Efficiency

vs Input Voltage

100

90

80

) (%)

70

IN

/P

60

LED

50

40

30

EFFICIENCY (P

20

FIVE LEDs AT 15mA/LED

AT 15mA = 3.2V)

(TYP V

F

10

= 25°C

T

A

0

3.0

3.6

3.3
INPUT VOLTAGE (V)

3.9

4.2

3206 TA01b

3206f

1

LTC3206

24 23 22 21 20 19

7 8 9

TOP VIEW

25

UF PACKAGE

24-LEAD (4mm × 4mm) PLASTIC QFN

10 11 12

13

14

15

16

17

18

6

5

4

3

2

1

SUB1

SUB2

C2

–

C1

–

C1

+

C2

+

BLUE

GREEN

RED

V

IN

CPO

SGND

AUX2

AUX1

MAIN1

MAIN2

MAIN3

MAIN4

DV

CC

SDA

SCL

ENRGB/S

I

MS

I

RGB

ABSOLUTE AXI U RATI GS

(Note 1)

VIN, DVCC, CPO to GND............................... –0.3V to 6V

SDA, SCL, ENRGB/S ................. – 0.3V to (DV

I

(Continuous) (Note 4) ................................ 400mA

CPO

(Pulsed at 10% Duty Cycle) (Note 4)..................... 1A

I

MAIN1-4, ISUB1,2

(Pulsed at 10% Duty Cycle) (Note 4).............. 125mA

I

RED,GREEN,BLUE

(Pulsed at 10% Duty Cycle) (Note 4).............. 125mA

I

, I

MS

CPO Short-Circuit Duration ............................ Indefinite

Operating Temperature Range (Note 2) .. – 40°C to 85°C

Storage Temperature Range ................. –65°C to 125°C

ELECTRICAL CHARACTERISTICS

temperature range, otherwise specifications are at TA = 25°C. VIN = 3.6V, DVCC = 3V unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

Input Power Supply

White LED Current (MAIN1-MAIN4, SUB1, SUB2, AUX1, AUX2)

RGB LED Current (RED, GREEN, BLUE)

Charge Pump (CPO)

2

WW

W

U

UUW

PACKAGE/ORDER I FOR ATIO

ORDER PART

+ 0.3V)

CC

, I

AUX 1, 2

(Note 4) ..................... 100mA

(Note 4) ..................................... 100mA

(Note 4) .................................................. 1mA

RGB

T

= 125°C, θJA = 37°C/W, θJC = 2°C/W

JMAX

EXPOSED PAD IS PGND (PIN 25)

MUST BE SOLDERED TO PCB

Consult LTC Marketing for parts specified with wider operating temperature ranges.

The ● denotes the specifications which apply over the full operating

VIN Operating Voltage ● 2.7 4.5 V

DVCC Operating Voltage ● 1.5 5.5 V

VIN Operating Current I

DVCC Operating Current Serial Port Idle 1 µA

VIN Shutdown Current 7.3 10 µA

DVCC Shutdown Current 1 µA

IMS Servo Voltage 25µA < IMS < 75µA 0.585 0.6 0.615 V

Full-Scale LED Current Ratio (I

LED/IMS

LED Dropout Voltage 1.5x Mode Switch Threshold, I

LED Brightness Range 0.78 100 %

LED Current Matching MAIN-MAIN, MAIN-AUX, SUB-SUB, SUB-AUX 1 %

I

Servo Voltage 25µA < I

RGB

LED Current Ratio (I

) RED, GREEN, BLUE Voltage = 1V 360 400 440 mA/mA

LED/IRGB

RGB LED Dropout Voltage 1.5x Mode Switch Threshold, I

RGB PWM (Duty Factor) Range 0/15 15/15 %

1x Mode Output Impedance 0.68 Ω

1.5x Mode Output Impedance VIN = 3V, V

I

CPO
CPO

= IMS = I
= IMS = I

= 0µA, Direct-Connect Mode 180 µA

RGB

= 0µA, 1.5x Step-Up Mode 3.9 mA

RGB

● 0.582 0.6 0.618 V

) MAIN1-MAIN4, SUB1, SUB2, AUX1, AUX2, Voltage = 1V ● 368 400 432 mA/mA

= 20mA 80 mV

LED

< 75µA 0.585 0.6 0.615 V

RGB

= 20mA 80 mV

LED

= 4.2V (Note 3) 1.90 Ω

CPO

● 0.582 0.6 0.618 V

NUMBER

LTC3206EUF

UF PART

MARKING

3206

3206f

LTC3206

ELECTRICAL CHARACTERISTICS

temperature range, otherwise specifications are at T

The ● denotes the specifications which apply over the full operating

= 25°C. VIN = 3.6V, DVCC = 3V unless otherwise noted.

A

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

CPO Regulation Voltage I

= 20mA, 1.5x Mode 4.75 V

CPO

CLK Frequency 0.68 0.96 1.36 MHz

SDA, SCL, ENRGB/S

V

IL

V

IH

I

IH

I

IL

V

OL

Low Level Input Voltage ● 0.3 • DV

High Level Input Voltage ● 0.7 • DV

Input Current SDA, SCL, ENRGB/S = DV

CC

CC

–1 1 µA

CC

Input Current SDA, SCL, ENRGB/S = 0V –1 1 µA

Digital Output Low (SDA) I

= 3mA ● 0.4 V

PULLUP

Timing Characteristics (Note 5)

t

SCL

t

BUF

t

HD, STA

t

SU, STA

t

SU, STD

t

HD, DAT(OUT)

t

HD, DAT(IN)

t

SU, DAT

t

LOW

t

HIGH

t

f

t

r

t

SP

Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.

Note 2: The LTC3206E is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation

Clock Operating Frequency 400 kHz

Bus Free Time Between Stop and Start Condition 1.3 µs

Hold Time After (Repeated) Start Condition 0.6 µs

Repeated Start Condition Setup Time 0.6 µs

Stop Condition Setup Time 0.6 µs

Data Hold Time 225 900 ns

Input Data Hold Time 0 900 ns

Data Setup Time 100 ns

Clock Low Period 1.3 µs

Clock High Period 0.6 µs

Clock Data Fall Time 20 300 ns

Clock Data RiseTime 20 300 ns

Spike Suppression Time 50 ns

with statistical process controls.
Note 3: 1.5x mode output impedance is defined as (1.5VIN – V

CPO

)/I

OUT

.

Note 4: Based on long term current density limitations.
Note 5: All values are referenced to V

and V

IH

levels.

IL

V

V

UW

TYPICAL PERFOR A CE CHARACTERISTICS

I

LED

2.5mA/DIV

0mA

LED Pin Sink Current
vs LED Pin Voltage

100%

50%

25%

200mV/DIV 3206 G01 I

V

AT CURRENT SOURCE PIN

LED

AC COUPLED

(50mV/DIV)

AC COUPLED

(50mV/DIV)

Input and Output
Charge Pump Noise

CPO

V

IN

= 200mA 500ns/DIV 3206 G02

CPO

VIN = 3.6V

= C

= 1.6µF

C

IN

CPO

LED Pin Dropout Voltage
vs LED Pin Current

500

VIN = 3.6V

= 25°C

T

A

400

300

200

100

LED PIN DROPOUT VOLTAGE (mV)

0

10 30

20

50 90

60

40

LED CURRENT (mA)

70

80

100

3206 GO3

3206f

3

LTC3206

UW

TYPICAL PERFOR A CE CHARACTERISTICS

1.5x Mode Charge Pump Open­1x Mode Switch Resistance
vs Temperature

0.9
I

= 100mA

CPO

0.8

VIN = 3.6V

0.7

0.6

SWITCH RESISTANCE (Ω)

0.5
–40

–15

10

TEMPERATURE (°C)

V

IN

= 3.3V

VIN = 3.9V

35

60

85

3206 G04

Loop Output Resistance vs
Temperature (1.5V

2.50
VIN = 3V

= 4.2V

V

CPO

= C

= C

= C

FLY1

TEMPERATURE (°C)

OUTPUT RESISTANCE (Ω)

2.25

2.00

1.75

1.50

C

IN

CPO

–15 10 35 60

–40

FLY2

– V

IN

= 1.6µF

CPO

)/I

CPO

3206 G05

1.5x Mode CPO Voltage
vs Load Current

4.8

4.7

4.6

4.5

4.4

4.3

4.2

CPO VOLTAGE (V)

4.1

4.0

3.9

85

3.8
0

CIN = C

3.1V

VIN = 3V

100

LOAD CURRENT (mA)

200

CPO

3.2V

= C

3.3V

FLY1 CFLY2

3.6V

300

400

T

A

= 1.6µF

= 25°C

3.5V

3.4V

3206 G06

500

Oscillator Frequency
vs Supply Voltage

1100

1000

TA = –40°C

900

FREQUENCY (kHz)

800

700

2.7

3.0 3.3 3.6 3.9

TA = 25°C

VIN SUPPLY VOLTAGE (V)

1x Mode No Load Supply Current
vs Input Voltage

300

TA = 25°C

= I

= 0µA

I

MS

RGB

250

200

SUPPLY CURRENT (µA)

150

TA = 85°C

4.2 4.5

3206 G07

DVCC Shutdown Current
vs Input Voltage

0.5
VIN = 3.6V

0.4

TA = –40°C

3.0

TA = 25°C

3.3 3.6 3.9
DVCC VOLTAGE (V)

SHUTDOWN CURRENT (µA)

DV

0.3

0.2

CC

0.1

0

2.7

1.5x Mode Supply Current
vs I

(IIN – 1.5I

CPO

10

VIN = 3.6V

= 25°C

T

A

8

6

4

SUPPLY CURRENT (mA)

2

CPO

)

TA = 85°C

4.2 4.5

3206 G08

VIN Shutdown Current
vs Input Voltage

10

DVCC = 3V

8

TA = –40°C

6

4

SHUTDOWN CURRENT (µA)

IN

2

V

0

2.7

3.0

TA = 25°C

3.3 3.6 3.9

INPUT VOLTAGE (V)

LED Pin Voltage for Higher LED
Currents

120

VIN = 3.6V

= 25°C

T

A

100

80

60

40

LED CURRENT (mA)

20

IMS, I

IMS, I

IMS, I

IMS, I

IMS, I

TA = 85°C

= 250µA

RGB

= 200µA

RGB

= 150µA

RGB

= 100µA

RGB

= 50µA

RGB

4.2 4.5

3206 G09

4

100

2.7

3.0 3.3 3.6 3.9
INPUT VOLTAGE (V)

4.2 4.5

3206 G10

0

0

100 150 200

50

LOAD CURRENT (mA)

250 300

3206 G11

0

0

0.4 0.6 0.8

0.2
LED PIN VOLTAGE (V)

1.0

3206 G12

3206f

LTC3206

U

UU

PI FU CTIO S

SUB1, SUB2 (Pins 1, 2): Current Source Outputs for the
SUB Display White LEDs. The current for the SUB display
is controlled by the resistor on the I
SUB display can be set to exponentially increasing bright­ness levels from 0.78% to 100% of full-scale. See Table 1.

C1+, C1–, C2+, C2– (Pins 5, 4, 6, 3): Charge Pump Flying
Capacitor Pins. A 2.2µF X7R or X5R ceramic capacitor
should be connected from C1

+

to C2–.

C2

DV

(Pin 7): This pin sets the logic reference level of the

CC

SDA, SCL and ENRGB/S pins.

SDA (Pin 8): Input Data for the I2C Serial Port. Serial data
is shifted in one bit per clock to control the LTC3206 (see
Figures 3 and 4). The logic level for SDA is referenced to
DVCC.

SCL (Pin 9): Clock Input for the I2C Serial Port (see Figures
3 and 4). The logic level for SCL is referenced to DVCC.

ENRGB/S (Pin 10): This pin is used to enable and disable
either the RED, GREEN and BLUE current sources or the
SUB display depending on which is programmed to re­spond via the I2C port. Once ENRGB/S is brought high, the
LTC3206 illuminates the RGB or SUB display with the
color combination or intensity that was previously pro­grammed via the I2C port. The logic level for ENRGB/S is
referenced to DVCC.

IMS (Pin 11): This pin controls the maximum amount of
LED current in both the MAIN and SUB LED displays. The
IMS pin servos to 0.6V when there is a resistor to ground.
The full scale (100%) currents in the MAIN and SUB
display LEDs will be 400 times the current at the IMS pin.

I

(Pin 12): This pin controls the amount of LED current

RGB

at the RED, GREEN and BLUE LED pins. The I
servos to 0.6V when there is a resistor to ground. The
current in the RED, GREEN and BLUE LEDs will be 400
times the current at the I
scale.

+

pin when programmed to full

RGB

pin.The LEDs on the

MS

to C1– and another from

pin

RGB

CPO (Pin 14): Output of the Charge Pump. This output
should be used to power white, blue and “true” green
LEDs. Red LEDs can be powered from V
or X7R low impedance (ceramic) 2.2µF charge storage
capacitor is required on CPO.

VIN (Pin 15): Supply Voltage for the Charge Pump. The V
pin should be connected directly to the battery and by­passed with a 2.2µF X5R or X7R ceramic capacitor.

RED, GREEN, BLUE (Pins 16, 17, 18): Current Source
Outputs for the RGB Illuminator LEDs. The currents for the
RGB LEDs are controlled by the resistor on the I
The RGB LEDs can independently be set to any duty cycle
from 0/15 through 15/15 under software control giving a
total of 16 shades per LED and 4096 colors for the
illuminator. See Table 1. The RGB LEDs are modulated at
1/240 the speed of the charge pump oscillator (approxi­mately 4kHz).

MAIN1-MAIN4 (Pins 22, 21, 20, 19): Current Source
Outputs for the Main Display White LEDs. The current for
the main display is controlled by the resistor on the I
pin. The LEDs on the MAIN display can be set to 16
exponentially increasing brightness steps from 0.78% to
100% of full scale. See Table 1.

AUX1, AUX2 (Pins 23, 24): Current source outputs for the
auxiliary white LEDs. The auxiliary current sources can be
individually assigned to be either MAIN display or SUB
display LEDs via the I2C serial port. When either AUX1 and/
or AUX2 are assigned to the MAIN display they will have
the same power setting as the other MAIN LEDs. Likewise,
when either AUX1 and/or AUX2 are assigned to the SUB
display they will have the same power setting as the other
SUB LEDs. The currents for the AUX1 and AUX2 pins are
controlled by the resistor on the IMS pin.

PGND (Pin 25, Exposed Pad): Power Ground for the
Charge Pump. This pin should be connected directly to a
low impedance ground plane.

or CPO. An X5R

IN

pin.

RGB

IN

MS

SGND (Pin 13): Ground for the control logic. This pin
should be connected directly to a low impedance ground
plane.

3206f

5

LTC3206

BLOCK DIAGRA

W

I

I

RGB

SGND

C1+C1–C2+C2

5 4 6 3

960kHz

OSCILLATOR

V

15

IN

1x AND 1.5x CHARGE PUMP

–

PGND

25

CPO

14

–
+

+

–

11

MS

+

–

12

13

ENABLECP

MAIN1

22

MAIN2

21

MAIN3

20

MAIN4

19

AUX1

23

AUX2

24

2

2

SUB1

1

SUB2

2

2

DV

7

ENRGB/S

SDA

SCL

CC

10

8

9

STOP

CONTROL

LOGIC

4 4 4244 4

COMMAND LATCH

I2C SERIAL PORT

PWM

U

OPERATIO

Power Management

To optimize efficiency, the power management section of
the LTC3206 provides two methods of supplying power to
the CPO pin: 1x direct connect mode or 1.5x boost mode.
When any display of the LTC3206 is enabled, the power
management system connects the CPO pin directly to V
with a low impedance switch. If the voltage supplied at V
is high enough to power all of the LEDs with the pro­grammed current, the system will remain in this “direct
connect” mode providing maximum efficiency. Internal

IN
IN

RED

16

GREEN

17

BLUE

18

3206 BD

circuits monitor all current sources for the onset of “drop­out,” the point at which the current sources can no longer
supply programmed current. As the battery voltage falls,
the LED with the largest forward voltage will reach the drop­out threshold first. When any of the LED pins reach the drop­out threshold, the LTC3206 will switch to boost mode and
automatically soft-start the 1.5x boost charge pump. The
constant frequency charge pump is designed to minimize
the amount of noise generated at the VIN supply.

3206f

6

OPERATIO

LTC3206

U

The 1.5x step-up charge pump uses a patented constant
frequency architecture to combine the best efficiency with
the maximum available power at the lowest noise level.

The charge pump of the LTC3206 can be forced to come
on even if no LEDs are programmed for current. Setting bit

2

A3 in the I

C serial port forces the charge pump on (see

Figure 3).

Soft-Start

To prevent excessive inrush current and supply droop
when switching into step-up mode, the LTC3206 employs
a soft-start feature on its charge pump. The current
available to the CPO pin is increased linearly over a period
of about 400µs.

Charge Pump Strength

When the LTC3206 operates in 1.5x boost mode, the
charge pump can be modeled as a Thevenin-equivalent
circuit to determine the amount of current available from
the effective input voltage, 1.5V

and the effective open-

IN

loop output resistance, ROL (Figure 1).

ROL is dependent on a number of factors including the
switching term, 1/(2f

OSC

• C

), internal switch resis-

FLY

tances and the non-overlap period of the switching circuit.
However, for a given ROL, the amount of current available
will be directly proportional to the advantage voltage 1.5V
– V

. Consider the example of driving white LEDs from

CPO

IN

a 3.1V supply. If the LED forward voltage is 3.8V and the
current sources require 100mV, the advantage voltage is

3.1V • 1.5 – 3.8V – 0.1V or 750mV. Notice that if the input
voltage is raised to 3.2V, the advantage voltage jumps to
900mV—a 20% improvement in available strength.

From Figure 1, the available current is given by:

VV

15.–

I

OUT

=

IN CPO

R

OL

R

OL

+

1.5V

IN

–

3206 F01

Figure 1. Equivalent Open-Loop Circuit

+

CPO

–

Typical values of ROL as a function of temperature are
shown in Figure 2.

2.50
VIN = 3V

= 4.2V

V

CPO

= C

= C

= C

C

IN

CPO

2.25

2.00

1.75

OUTPUT RESISTANCE (Ω)

1.50

–40

Figure 2. Typical ROL vs Temperature

FLY1

–15 10 35 60

TEMPERATURE (°C)

FLY2

= 1.6µF

85

3206 F02

I2C Interface

The LTC3206 communicates with a host (master) using
the standard I2C 2-wire interface. The Timing Diagram
(Figure 4) shows the timing relationship of the signals on
the bus. The two bus lines, SDA and SCL, must be high
when the bus is not in use. External pull-up resistors or
current sources, such as the LTC1694 SMBus accelerator,
are required on these lines. The LTC3206 is a receive-only
(slave) device.

Bus Speed

The I2C port is designed to be operated at speeds of up to
400kHz. It has built-in timing delays to ensure correct
operation when addressed from an I2C compliant master
device. It also contains input filters designed to suppress
glitches should the bus become corrupted.

START and STOP Conditions

A bus-master signals the beginning of a communication to
a slave device by transmitting a START condition. A
START condition is generated by transitioning SDA from
high to low while SCL is high. When the master has
finished communicating with the slave, it issues a STOP
condition by transitioning SDA from low to high while SCL
is high. The bus is then free for communication with
another I2C device.

3206f

7

LTC3206

OPERATIO

U

Byte Format

Each byte sent to the LTC3206 must be 8 bits long followed
by an extra clock cycle for the Acknowledge bit to be
returned by the LTC3206. The data should be sent to the
LTC3206 most significant bit (MSB) first.

Acknowledge

The Acknowledge bit is used for handshaking between the
master and the slave. An Acknowledge (active LOW)
generated by the slave (LTC3206) lets the master know
that the latest byte of information was received. The
Acknowledge related clock pulse is generated by the
master. The master releases the SDA line (HIGH) during
the Acknowledge clock cycle. The slave-receiver must pull
down the SDA line during the Acknowledge clock pulse so
that it remains a stable LOW during the HIGH period of this
clock pulse.

Slave Address

The LTC3206 responds to only one 7-bit address which
has been factory programmed to 0011011. The eighth bit
of the address byte (R/W) must be 0 for the LTC3206 to
recognize the address since it is a write only device. This
is equivalent to an 8-bit address where the least significant
bit of the address is always 0. If the correct seven bit
address is given but the R/W bit is 1, the LTC3206 will not
respond.

Bus Write Operation

The master initiates communication with the LTC3206
with a START condition and a 7-bit address followed by the
Write Bit R/W = 0. If the address matches that of the
LTC3206, the LTC3206 returns an Acknowledge. The

master should then deliver the most significant data byte.
Again the LTC3206 acknowledges and the cycle is re­peated two more times for a total of one address byte and
three data bytes. Each data byte is transferred to an
internal holding latch upon the return of an Acknowledge.
After all three data bytes have been transferred to the
LTC3206, the master may terminate the communication
with a STOP condition. Alternatively, a REPEAT-START
condition can be initiated by the master and another chip
on the I2C bus can be addressed. This cycle can continue
indefinitely and the LTC3206 will remember the last input
of valid data that it received. Once all chips on the bus have
been addressed and sent valid data, a STOP condition can
be sent and the LTC3206 will update its command latch
with the data that it had received.

In certain circumstances, the data on the I
become corrupted. In these cases the LTC3206 responds
appropriately by preserving only the last set of complete
data that it has received. For example, assume the LTC3206
has been successfully addressed and is receiving data
when a STOP condition mistakenly occurs. The LTC3206
will ignore this stop condition and will not respond until a
new START condition, correct address, new set of data
and STOP condition are transmitted.

Likewise, if the LTC3206 was previously addressed and
sent valid data but not updated with a STOP, it will respond
to any STOP that appears on the bus independent of the
number of REPEAT-STARTs that have occurred. An ex­ception occurs if a REPEAT-START is given and the
LTC3206 successfully acknowledges its addressed. In
this case, it will not respond to a STOP after the first data
byte is acknowledged. It will, however, respond after the
third data byte is acknowledged.

2

C bus may

8

3206f

UWW

ACK ACK

123

ADDRESS WR

456789123456789123456789123456789

00110 110

00110110

A7 A6 A5 A4 A3 A2 A1 A0

A7 A6 A5 A4 A3 A2 A1 A0 B7 B6 B5 B4 B3 B2 B1 B0

B7 B6 B5 B4 B3 B2 B1 B0

C7 C6 C5 C4 C3 C2 C1 C0

C7 C6 C5 C4 C3 C2 C1 C0

ACK

STOPSTART

SDA

SCL

ACK

FORCE

CHARGE PUMP

ENSUB_ENRGB

AUXSEL1

AUXSEL0

RED

BLUE

GREEN

MAIN

SUB

3206 FO3

t

SU, DAT

t

HD, STA

t

HD, DAT

SDA

SCL

t

SU, STA

t

HD, STA

t

SU, STO

3206 F04

t

BUF

t

LOW

t

HIGH

START

CONDITION

REPEATED START

CONDITION

STOP

CONDITION

START

CONDITION

t

r

t

f

t

SP

RED

GREEN

BLUE

MAIN

SUB

HEX

0

1

2

3

4

5

6

7

8

9

A

B

C

D

E

F

A7

B3

B7

C7

C3

0

0

0

0

0

0

0

0

1

1

1

1

1

1

1

1

A4

B0

B4

C4

C0

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

A6

B2

B6

C6

C2

0

0

0

0

1

1

1

1

0

0

0

0

1

1

1

1

A5

B1

B5

C5

C1

0

0

1

1

0

0

1

1

0

0

1

1

0

0

1

1

4-BIT CODE SUB-RANGE

NA

1/4

1/4

1/4

1/4

1/4

1/4

1/4

1/4

1/4

1/4

1/4

1/2

1/2

1

1

DUTY CYCLE

NA

3.13%

4.42%

6.25%

8.80%

12.50%

17.70%

25.00%

35.35%

50.00%

70.70%

100.00%

70.70%

100.00%

70.70%

100.00%

BRIGHTNESS

LEVEL

OFF

0.78%

1.07%

1.56%

2.25%

3.13%

4.40%

6.25%

8.90%

12.50%

17.70%

25.00%

35.35%

50.00%

70.70%

100.00%

BRIGHTNESS

LEVEL

OFF

1/15(6.7%)

2/15(13.3%)

3/15(20.0%)

4/15(26.7%)

5/15(33.3%)

6/15(40.0%)

7/15(46.7%)

8/15(53.3%)

9/15(60.0%)

10/15(66.6%)

11/15(73.3%)

12/15(80.0%)

13/15(86.7%)

14/15(93.3%)

15/15(100.0%)

MAIN

SUB

AUX

RED

GREEN

BLUE

A0

0

0

1

1

A1

0

1

0

1

AUX1

MAIN

MAIN

SUB

SUB

AUX2

MAIN

SUB

MAIN

SUB

A2

0

1

CONTROL

RGB DISPLAY

SUB DISPLAY

TI I G DIAGRA

LTC3206

Figure 3. Bit Assignments

Table 3. ENRGB/S Assignment

Table 2. Auxilliary LED Pin Assignments

Figure 4. Timing Parameters

Table 1. Serial Port Bit Assignments

3206f

9

LTC3206

WUUU

APPLICATIO S I FOR ATIO

White LED Brightness Control

The White LED displays (MAIN, SUB and AUX) have 16
individual brightness settings. The settings are exponen­tially spaced to compensate for the nearly logarithmic
characteristic of human vision perception. The base of the
power settings is √2 . The off setting (0 power) is a special
case needed for shutdown.

The LTC3206 uses a subranging technique to control the
LED brightness with a combination of both DC level
control and pulse width modulation. Table 1 summarizes
the level control operation. The DC level of the LEDs will be
one of either three sub-range settings, 100%, 50% or 25%
of full scale. For example, if the full scale LED current is
programmed (via the IMS pin) to be 20mA, then the “on”
level of the LED will be either 20mA, 10mA or 5mA
respectively. The power to the LED will be the product of
the subrange (DC current) and the PWM setting. For
example, if an LED power of 2.25% is desired, then the
LTC3206 sets the sub range to 25% and the duty cycle to

8.8%. These settings are designed to optimize the effi­ciency of the dual-mode LTC3206 power management
system while preserving LED color accuracy at low power
levels.

To achieve brightness control by purely DC means, only
the 100%, 50% or 25% power settings should be selected.

The DC current levels of the MAIN, SUB and AUX LEDs are
controlled by a precisely mirrored multiple of the current
at the IMS pin. The IMS pin servos to a fixed level of 0.6V so
the current is programmed simply by adding a resistor
from IMS to ground.

The current that flows during the “on” time will follow the
relationship:

V

IS

= 40006••

LED

where S is the subrange for the given power setting (it will
be either 25%, 50% or 100%, see Table 1) and RMS is the
value of the resistor at the IMS pin.

The average LED current (LED power level) will follow the
relationship:

.

R

MS

D

AVG I

() •.•=−400

LED

06
R

MS

V

15

2

where D is the decimal equivalent of the 4-bit digital code
programmed for the given display (0 to 15).

The PWM frequency is 1/1024 of the frequency of the
charge pump oscillator (typically 938Hz). During PWM,
the LED currents are soft-switched to minimize noise.

AUX LEDs

The AUX1 and AUX2 LEDs can be arbitrarily assigned to
either the MAIN or SUB display. Table 2 summarizes the
assignment possibilities. When an AUX pin is assigned to
a display, it will follow the power level (both DC and PWM)
set for that display.

Unused White LED Pins

The LTC3206 can power up to eight white LEDs (four for
the MAIN display, two for the SUB display and the two
flexible AUX pins), however, it is not necessary to use all
eight in each application.

Any of these LED pins can cause the LTC3206 to switch
from 1x mode to 1.5x charge pump mode if they drop out.
In fact, if an unused LED pin is left unconnected or
grounded, it

will

drop out and force the LTC3206 into

charge pump mode.

To avoid this problem, unused MAIN, SUB or AUX LED
pins can be disabled by connecting them to CPO. Power is
not wasted in this configuration. When the LED pin voltage
is within approximately 1V of CPO, its LED current is
switched off and only a small 10µA test current remains.
Figure 5 shows a block diagram of each of the MAIN, SUB
and AUX LED pins.

CPO

1V

+

+

–

MAIN1-MAIN4

SUB1, SUB2, AUX1, AUX2

–

ENABLE

I

LED

Figure 5. Internal MAIN, SUB and AUX LED Disable Circuit

10µA

3206 F05

3206f

10

WUUU

APPLICATIO S I FOR ATIO

LTC3206

The RED, GREEN and BLUE pins can also enable the
charge pump, however, since they each have individual
disable control they can be left floating or grounded if
unused.

RGB Illuminator Brightness Control

The RED, GREEN and BLUE LEDs can be individually set
to have a linear duty cycle ranging from 0/15 (off) to
15/15 (full on) with 1/15 increments in between. The
combination of 16 possible brightness levels gives the
RGB indicator LED a total of 4096 colors. Table 1 indicates
the decoding of the RED, GREEN and BLUE LEDs.

The full-scale currents in the RED, GREEN and BLUE LEDs
are controlled by the current at the I

pin in a similar

RGB

manner to those in the MAIN, SUB and AUX LEDs. The
I

pin also servos to 0.6V and the RGB LED currents are

RGB

a precise multiple of the I

current. The DC value of the

RGB

RGB display LED currents will follow the relationship:

.

06

R

RGB

V

pin.

RGB

I

RED GREENBLUE

,,

where R

RGB

= 400

is the value of the resistor at the I

The average value of the current in the RED, GREEN and
BLUE LEDs will be:

(see Figure 3 and Table 3) determines which display
ENRGB/S controls. When bit A2 is 0, the ENRGB/S pin
controls the RGB display. If it is set to 1, ENRGB/S controls
the SUB display.

To use the ENRGB/S pin, the I2C port must first be
configured to the desired setting. For example, if ENRGB/S
will be used to control the SUB display, then a non-zero
code must reside in the C3-C0 nibble of the I2C port and bit
A2 must be set to 1 (see Table 1). Now when ENRGB/S is
high (DVCC), the SUB display will be on with the C3-C0
setting. When ENRGB/S is low, the SUB display will be off.
If no other displays are programmed to be on, the entire
chip will be in shutdown.

Likewise, if ENRGB/S will be used to enable the RGB
display, then a non-zero code must reside in one of the
RED, GREEN or BLUE nibbles of the serial port (A4-A7 or
B0-B7), and bit A2 must be 0. Now when ENRGB/S is high
(DVCC), the RGB display will light with the programmed
color. When ENRGB/S is low, the RGB display will be off.
If no other displays are programmed to be on, the entire
chip will be in shutdown.

If bit A2 is set to 1 (SUB display control), then ENRGB/S
will have no effect on the RGB display. Likewise, if bit A2
is set to 0 (RGB display control), then ENRGB/S will have
no effect on the SUB display.

DV

.

AVG I

()••

RED GREENBLUE

,,

= 400

15

06

R

RGB

where D is the decimal equivalent of the 4-bit digital code
programmed for the given LED(0 to 15). Table 1 summa­rizes the RED, GREEN and BLUE LED power settings.

The RED, GREEN and BLUE LEDs are pulse width modu­lated at a frequency of 1/240 of the frequency of the charge
pump oscillator or about 4kHz.

ENRGB/S Pin

The ENRGB/S pin can be used to enable or disable the
LTC3206 without re-accessing the I2C port. This might be
useful to indicate an incoming phone call without waking
the microcontroller. ENRGB/S can be software pro­grammed as an independent control for either the RGB
display or the SUB display. Control bit A2 in the serial port

If the ENRGB/S pin is not used, it should be connected to
DVCC. It should not be grounded or left floating.

VIN, CPO Capacitor Selection

The style and value of capacitors used with the LTC3206
determine several important parameters such as regulator
control-loop stability, output ripple and charge pump
strength. To reduce noise and ripple, it is recommended
that low equivalent series resistance (ESR) multilayer
ceramic capacitors be used on both VIN and CPO. Tanta­lum and aluminum capacitors are not recommended be­cause of their high ESR. The value of the capacitor on CPO
directly controls the amount of output ripple for a given
load current. Increasing the size of this capacitor will
reduce the output ripple. The peak-to-peak output ripple is
approximately given by the expression:

I

V

RIPPLE

P-P

≅

CPO

fC

3•

OSC CPO

3206f

11

LTC3206

WUUU

APPLICATIO S I FOR ATIO

where f
960kHz) and C

is the LTC3206’s oscillator frequency (typically

OSC

is the output charge storage capacitor

CPO

on CPO. Both the style and value of the output capacitor
can significantly affect the stability of the LTC3206. The
LTC3206 uses a linear control loop to adjust the strength
of the charge pump to match the current required at the
output. The error signal of this loop is stored directly on
the output charge storage capacitor. The charge storage
capacitor also serves to form the dominant pole for the
control loop. To prevent ringing or instability, it is impor­tant for the output capacitor to maintain at least 0.6µF of
capacitance over all conditions. Likewise, excessive ESR
on the output capacitor will tend to degrade the loop
stability of the LTC3206. The closed-loop output resis­tance of the LTC3206 is designed to be 0.4Ω. For a 100mA
load current change, the error signal will change by about
40mV. If the output capacitor has 0.4Ω or more of ESR,
the closed-loop frequency response will cease to roll off in
a simple one-pole fashion and poor load transient re­sponse or instability could result. Multilayer ceramic chip
capacitors typically have exceptional ESR performance.
MLCC capacitors combined with a tight board layout, will
yield very good stability. As the value of C

controls the

CPO

amount of output ripple, the value of CIN controls the
amount of ripple present at the input pin (VIN). The input
current to the LTC3206 will be relatively constant while the
charge pump is on either the input charging phase or the
output charging phase but will drop to zero during the
clock nonoverlap times. Since the non-overlap time is
small (~25ns), these missing “notches” will result in only
a small perturbation on the input power supply line. Note
that a higher ESR capacitor such as tantalum will have
higher input noise due to the input current change times
the ESR. Therefore, ceramic capacitors are again recom­mended for their exceptional ESR performance. Input
noise can be further reduced by powering the LTC3206
through a very small series inductor as shown in Figure 6.
A 10nH inductor will reject the fast current notches,
thereby presenting a nearly constant current load to the
input power supply. For economy, the 10nH inductor can
be fabricated on the PC board with about 1cm (0.4") of PC
board trace.

Flying Capacitor Selection

10nH

V

IN

Figure 6. 10nH Inductor Used for Input Noise
Reduction (Approximately 1cm of Wire)

V

IN

2.2µF0.1µF

LTC3206

GND

3206 F06

Warning: A polarized capacitor such as tantalum or alumi­num should never be used for the flying capacitors since
their voltage can reverse upon start-up of the LTC3206.
Ceramic capacitors should always be used for the flying
capacitors.

The flying capacitor controls the strength of the charge
pump. In order to achieve the rated output current it is
necessary to have at least 1µF of capacitance for each of
the flying capacitors. Capacitors of different materials lose
their capacitance with higher temperature and voltage at
different rates. For example, a ceramic capacitor made of
X7R material will retain most of its capacitance from
–40°C to 85°C whereas a Z5U or Y5V style capacitor will
lose considerable capacitance over that range. Z5U and
Y5V capacitors may also have a very poor voltage coeffi­cient causing them to lose 60% or more of their capaci­tance when the rated voltage is applied. Therefore, when
comparing different capacitors, it is often more appropri­ate to compare the amount of achievable capacitance for
a given case size rather than comparing the specified
capacitance value. For example, over rated voltage and
temperature conditions, a 1µF, 10V, Y5V ceramic capaci-
tor in a 0603 case may not provide any more capacitance
than a 0.22µF, 10V, X7R available in the same 0603 case.
The capacitor manufacturer’s data sheet should be con­sulted to determine what value of capacitor is needed to
ensure minimum capacitances at all temperatures and
voltages.

12

3206f

WUUU

GND

V

IN

CPO

3206 F07

PIN 1

APPLICATIO S I FOR ATIO

Table 4 shows a list of ceramic capacitor manufacturers
and how to contact them:

Table 4. Recommended Capacitor Vendors

AVX www.avxcorp.com

Kemet www.kemet.com

Murata www.murata.com

Taiyo Yuden www.t-yuden.com

Vishay www.vishay.com

For very light load applications, the flying capacitors
may be reduced to save space or cost. The theoretical
minimum output resistance of a 1.5x fractional charge
pump is given by:

.–

15 1

VV

R

OL MIN

where f
C

is the value of the flying capacitors. Note that the

FLY

≡ =

()

is the switching frequency (960kHz typ) and

OSC

charge pump will typically be weaker than the theoretical
limit due to additional switch resistance, however for very
light load applications, the above expression can be used
as a guideline in determining a starting capacitor value.

Layout Considerations and Noise

Due to its high switching frequency and the transient
currents produced by the LTC3206, careful board layout is
necessary. A true ground plane and short connections to
all capacitors will improve performance and ensure proper
regulation under all conditions. Figure 7 shows the recom­mended layout configuration.

The flying capacitor pins C1+, C2+, C1– and C2– will have
very high edge rate waveforms. The large dv/dt on these pins
can couple energy capacitively to adjacent printed circuit
board runs. Magnetic fields can also be generated if the
flying capacitors are not close to the LTC3206 (i.e., the loop
area is large). To decouple capacitive energy transfer, a
Faraday shield may be used. This is a grounded PC trace
between the sensitive node and the LTC3206 pins. For a high
quality AC ground, it should be returned to a solid ground
plane that extends all the way to the LTC3206.

IN OUT

IfC

OUT OSC FLY

2

LTC3206

Figure 7. Optimum Single Layer PCB Layout

Power Efficiency

To calculate the power efficiency (η) of a white LED driver
chip, the LED power should be compared to the input
power. The difference between these two number repre­sents lost power whether it is in the charge pump or the
current sources. Stated mathematically, the power effi­ciency is given by:

P

LED

η≡

P

IN

The efficiency of the LTC3206 depends upon the mode in
which it is operating. Recall that the LTC3206 operates as
a pass switch, connecting VIN to CPO until one of the LEDs
drops out. This feature provides the optimum efficiency
available for a given input voltage and LED forward volt­age. When it is operating as a switch, the efficiency is
approximated by:

P

LED

η≡ = ≅

P

IN

since the input current will be very close to the LED
current.

At moderate to high output power, the quiescent current
of the LTC3206 is negligible and the expression above is
valid. For example, with VIN = 3.9V, I
and V

equal to 3.6V, the measured efficiency is 92.2%,

LED

which is very close to the theoretical 92.3% calculation.

•

VI

LED LED

•

VIVV

IN IN

LED

IN

= 20mA • 6 LEDs

OUT

3206f

13

LTC3206

WUUU

APPLICATIO S I FOR ATIO

Once an LED pin drops out, the LTC3206 switches into
step-up mode. Employing the fractional ratio 1.5x charge
pump, the LTC3206 provides more efficiency than would
be achieved with a voltage doubling charge pump.

In 1.5x boost mode, the efficiency is similar to that of a
linear regulator with an effective input voltage of 1.5 times
the actual input voltage. This is because the input current
for a 1.5x fractional charge pump is approximately 1.5
times the load current. In an ideal 1.5x charge pump, the
power efficiency would be given by:

P

η

IDEAL

LED

≡ = ≅

P

Thermal Management

For higher input voltages and maximum output current,
there can be substantial power dissipation in the LTC3206.
If the junction temperature increases above approximately
160°C the thermal shutdown circuitry will automatically
deactivate the output. To reduce the maximum junction
temperature, a good thermal connection to the PC board
is recommended. Connecting the PGND pin (exposed
center pad) to a ground plane and maintaining a solid
ground plane under the device can reduce the thermal
resistance of the package and PC board considerably.

Brightness Control

Although the LTC3206 has many exponentially spaced
brightness settings for the main and sub displays, it is
possible to control the brightness by alternative means.
Figure 8 shows an example of how an external voltage
source can be use to inject a current into the IMS or I
pins to control brightness. For example, if R1 and R2 are
24k, then the LED current would range from 20mA to 0mA
as V

is swept from 0V to 1.2V.

CNTRL

Alternatively, if only digital outputs are available, the
number of settings can be doubled from 15 to 30 by simply

VI

•

LED LED

VIVV

IN

•. .15 15

IN LED

LED

IN

RGB

V

0.6V

CNTRL

–

||

R2

R1

3206 F08

R2

R2

V

CNTRL

R1

LTC3206

I

I

MS

RGB

I

= 400

LED

()

11

12

12k

Figure 8. Alternative Linear Brightness Control

connecting V

to a digital signal. This topology can be

CNTRL

extended to any number of bits and can also be applied to
the RGB display.

Finally, PWM brightness control can be achieved by apply-

LTC3206

I

I

RGB

MS

11

12

12k

Figure 9. Alternative Digital Brightness Control

18.2k

3206 F09

34k

V

DIG

0V TO 0.7V
OR HIGHER

ing a PWM signal to the IMS programming resistor as
shown in Figure 10. The signal should range from 0V (full
on) to any voltage above 0.7V (full off).

LTC3206

I

I

RGB

Figure 10. PWM Brightness Control of the MAIN and SUB Displays

MS

12k

11

12k

12

PWM SIGNAL
0V TO 0.7V OR HIGHER
BRIGHTNESS = 1 – D

3206 F10

14

3206f

TYPICAL APPLICATIO S

2.2µF2.2µF

V

IN

2.7V TO

2.7V TO

4.5V

4.5V

I2C SERIAL
INTERFACE

V

IN

V

IN

2.2µF 2.2µF

LTC3206

MAIN1-4

AUX 1

AUX 2

I

RGB

12k 12k

SUB1-2

RGB

I

MS

2

SERIAL PORT

Main Backlight, Keypad Backlight Plus Motor Controller

2.2µF2.2µF

V

IN

2.2µF 2.2µF

CPO

LTC3206

U

CPO

4-Display Controller

MAIN DISPLAY SUB DISPLAY ILLUMINATOR

4

2

3

MAIN DISPLAY KEYPAD

RED GREEN BLUE

FLASH

CAMERA

LIGHT

3206 TA02

LTC3206

MAIN1-4

AUX 1-2

SUB1-2

R

I

MS

12k 12k

G

I2C SERIAL
INTERFACE

2

SERIAL PORT

I

RGB

PACKAGE DESCRIPTIO

4.50 ± 0.05

3.10 ± 0.05

2.45 ± 0.05
(4 SIDES)

RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS

B

0.25 ±0.05

0.50 BSC

8

U

UF Package

24-Lead Plastic QFN (4mm × 4mm)

(Reference LTC DWG # 05-08-1692)

4.00 ± 0.10
(4 SIDES)

0.70 ±0.05

PACKAGE
OUTLINE

PIN 1
TOP MARK
(NOTE 5)

NOTE:

1. DRAWING PROPOSED TO BE MADE A JEDEC PACKAGE OUTLINE MO-220 VARIATION (WGGD-X)—TO BE APPROVED

2. ALL DIMENSIONS ARE IN MILLIMETERS

3. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE, IF PRESENT

4. EXPOSED PAD SHALL BE SOLDER PLATED

5. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON THE TOP AND BOTTOM OF PACKAGE

6. DRAWING NOT TO SCALE

0.75 ± 0.05

2.45 ± 0.10
(4-SIDES)

0.200 REF

0.00 – 0.05

BATT

VIBRATOR

MOTOR

3206 TA04

BOTTOM VIEW—EXPOSED PAD

R = 0.115

TYP

(4 SIDES)

24

23

0.23 TYP

0.38 ± 0.10

1

2

(UF24) QFN 0603

0.25 ± 0.05

0.50 BSC

3206f

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 represen­tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

15

LTC3206

TYPICAL APPLICATIO

U

5-LED Main Plus Low/High Current Camera Light

2.2µF 2.2µF

V

2.7V TO

4.5V

I2C SERIAL
INTERFACE

IN

FLASH

V

IN

2.2µF 2.2µF

LTC3206

ENRGB/S

2

SERIAL PORT

I

RGB

2.4k 12k

CPO

MAIN1-4

AUX 1

AUX 2

SUB1-2

RGB

I

MS

4

3

3

MAIN DISPLAY

TORCH MODE

FLASH MODE

HIGH CURRENT

CAMERA LED

3206 TA03

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OUT(MAX)

White LED Driver 10-Lead MS

LTC3202 Low Noise, 1.5MHz Regulated Charge Pump Up to 8 White LEDs, VIN: 2.7V to 4.5V, V

OUT(MAX)

White LED Driver 10-Lead MS Package

LTC3205 Multi-Display LED Controller 92% Efficiency, VIN: 2.8V to 4.5V, IQ = 50µA, ISD ≤ 1µA ,

4mm × 4mm QFN Package

LTC3251 500mA (I

Step-Down Charge Pump I

LTC3405/LTC3405A 300mA (I

), 1MHz to 1.6MHz Spread Spectrum 85% Efficiency, VIN: 3.1V to 5.5V, V

OUT

), 1.5MHz Synchronous Step-Down 95% Efficiency, VIN: 2.7V to 6V, V

OUT

≤1µA, 10-Lead MS Package

SD

: 0.9V to 1.6V, IQ = 9µA,

OUT

OUT(MIN)

DC/DC Converter ThinSOT Package

LTC3406/LTC3406B 600mA (I

), 1.5MHz Synchronous Step-Down 95% Efficiency, VIN: 2.5V to 5.5V, V

OUT

OUT(MIN)

DC/DC Converter ThinSOT Package

LTC3440 600mA (I

), 2MHz Synchronous Buck-Boost 95% Efficiency, VIN: 2.5V to 5.5V, V

OUT

OUT(MIN)

DC/DC Converter 10-Lead MS Package

LT3465/LT3465A 1.2MHz/2.7MHz with Internal Schottky Up to 6 White LEDs, VIN: 12.7V to 16V, V

<1µA, ThinSOT Package

I

SD

ThinSOT is a trademark of Linear Technology Corporation.

= 34V, IQ = 1.8mA,

OUT(MAX)

= 1.5V/1.8V, IQ = 180µA,

= 34V, IQ = 1.2mA, IS ≤1µA,

= 34V, IQ = 1.9mA,

= 5V, IQ = 8mA, ISD ≤1µA,

= 5V, IQ = 6.5mA, ISD ≤1µA,

= 5V, IQ = 5mA, ISD ≤1µA,

= 0.8V, IQ = 20µA, ISD ≤1µA,

= 0.6V, IQ = 20µA, ISD ≤1µA,

= 2.5V, IQ = 25µA, ISD ≤1µA,

= 34V, IQ = 1.9mA,

OUT(MAX)

16

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

[phone] ● FAX: [phone] ● www.linear.com

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LT/TP 0604 1K • PRINTED IN USA

© LINEAR TECHNOLOGY CORPORATION 2004