LINEAR TECHNOLOGY LTC3220, LTC3220-1 Technical data

LTC3220/LTC3220-1

360mA Universal

18-Channel LED Driver

FEATURES

n

Eighteen 20mA Universal Current Sources with

64-Step Linear Brightness Control

n

Independent On/Off, Brightness Level, Blinking and

Gradation Control for Each Current Source Using

2

2-Wire I

n

Low Noise Multi-Mode Charge Pump (1x, 1.5x, 2x)

C Interface

Provides Up to 91% Effi ciency

n

Slew Limited Switching Reduces Conducted and

Radiated Noise (EMI)

n

Up to 360mA Total Output Current

n

Internal Current Reference

n

Single Reset Pin for Asynchronous Shutdown and

Reset of All Data Registers

n

Two I2C Addresses Are Available (LTC3220: 0011100,

LTC3220-1: 0011101)

n

Automatic or Forced Mode Switching

n

Internal Soft-Start Limits Inrush Current

n

Short-Circuit/Thermal Protection

n

4mm × 4mm Ultrathin (0.55mm) 28-Lead QFN

Package

APPLICATIONS

n

Video Phones with QVGA+ Displays

n

Keypad Lighting

n

General/Miscellaneous Lighting

DESCRIPTION

The LTC3220/LTC3220-1 are highly integrated multi-display
LED drivers. These parts contain a high effi ciency, low noise
charge pump to provide power to up to eighteen universal
LED current sources. The LTC3220/LTC3220-1 require
only fi ve small ceramic capacitors to form a complete
LED power supply and current controller.

The LED currents are set by an internal precision cur­rent reference. Independent dimming, on/off, blinking
and gradation control for all universal current sources
is achieved via the I
are available to adjust brightness levels independently for
each universal LED current source.

The LTC3220/LTC3220-1 charge pump optimizes effi ciency
based on the voltage across the LED current sources. The
part powers up in 1x mode and will automatically switch
to boost mode whenever any enabled LED current source
begins to enter dropout. The fi rst dropout switches the
parts into 1.5x mode and a subsequent dropout switches
the LTC3220/LTC3220-1 into 2x mode. The parts reset to
1x mode whenever a data bit is updated via the I

L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 6411531.

2

C serial interface. 6-bit linear DACs

2

C port.

TYPICAL APPLICATION

C2

2.2μFC32.2μF

C1P

C1M

C2P

V

IN

DV

CC

I2C

RESET

C1

2.2μF

0.1μF

V

IN

LTC3220-1

DV

CC

SCL/SDA

RST

LTC3220

ULED1-18

GND

C2M

CPO

C4

4.7μF
18

RGB1

6-LED Main, 4 RGB LEDs

RGB2 RGB3 RGB4 MAIN

3220 TA01

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1

LTC3220/LTC3220-1

(Notes 1, 4)

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

ULED1-ULED18 to GND ............................... –0.3V to 6V

SDA, SCL, RST............................–0.3V to (DV

(Continuous) (Note 2) ..................................360mA

I

CPO

I

ULED1-18

(Note 2) ..................................................25mA

CPO Short-Circuit Duration .............................. Indefi nite

Operating Temperature Range (Note 3)

LTC3220E/LTC3220E-1 ........................ –40°C to 85°C

LTC3220I/LTC3220I-1 ........................ –40°C to 125°C

Storage Temperature Range ...................–65°C to 150°C

+ 0.3V)

CC

PIN CONFIGURATION ABSOLUTE MAXIMUM RATINGS

TOP VIEW

CPO

C1P

C2P

RST

VINC1M

C2M

28 27 26 25 24 23

1

ULED1

ULED2

2

ULED3

3

ULED4

4

ULED5

5

ULED6

6

ULED7

7

8 9

28-LEAD UTQFN (4mm s 4mm)

T

EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB

JMAX

29

11 12 13 14

10

CC

SCL

DV

ULED8

ULED9

PF PACKAGE

= 125°C, θJA = 37°C/W

SDA

22

ULED10

ULED11

21

20

19

18

17

16

15

ULED18

ULED17

ULED16

ULED15

ULED14

ULED13

ULED12

ORDER INFORMATION

LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE

LTC3220EPF#PBF LTC3220EPF#TRPBF 3220T 28-Lead UTQFN (4mm × 4mm) –40°C to 85°C

LTC3220EPF-1#PBF LTC3220EPF-1#TRPBF 2201T 28-Lead UTQFN (4mm × 4mm) –40°C to 85°C

LTC3220IPF#PBF LTC3220IPF#TRPBF 3220T 28-Lead UTQFN (4mm × 4mm) –40°C to 125°C

LTC3220IPF-1#PBF LTC3220IPF-1#TRPBF 2201T 28-Lead UTQFN (4mm × 4mm) –40°C to 125°C

Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based fi nish parts.

For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifi cations, go to: http://www.linear.com/tapeandreel/

ELECTRICAL CHARACTERISTICS

The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at TA = 25°C. VIN = 3.6V, DVCC = 3V, RST = high, C1 = C2 = C3 = 2.2μF, C4 = 4.7μF,
unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

Operating Voltage

V

IN

Operating Current I

I

VIN

UVLO Threshold 1V

DV

CC

Operating Voltage

DV

CC

UVLO Threshold 1.5 V

V

IN

= 0, 1x Mode

CPO

I

= 0, 1.5x Mode

CPO

I

= 0, 2x Mode

CPO

l

2.9 5.5 V
580

2.4

3.2

l

1.5 5.5 V

μA
mA
mA

2

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LTC3220/LTC3220-1

ELECTRICAL CHARACTERISTICS

The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

Shutdown Current

V

IN

Shutdown Current

DV

CC

Universal LED Current, 6-Bit Linear DACs, ULED = 1V

Full-Scale LED Current
Minimum (I
Minimum Programmable Current ULED Data Register Programmed to

LED Current Matching Any Two Outputs, 50% of FS 1.5 %
LED Dropout Voltage I
Blink Rate Period REG19, D3 and D4 1.25

ULED Up/Down Gradation Ramp Times REG19, D1 and D2 0.24

Gradation Period REG19, D1 and D2 0.313

General Purpose Output Mode (GPO) I

V

OL

LED Turn-On Delay From Stop Bit, Part Enabled 4 μs

Charge Pump (CPO)

1x Mode Output Impedance 0.6 Ω

1.5x Mode Output Impedance V
2x Mode Output Impedance V
CPO Regulation Voltage 1.5x Mode, I

Clock Frequency

CPO Short-Circuit Detection

Threshold Voltage
Test Current CPO = 0V

SDA, SCL, RST

V

IL

V

IH

I

IH

I

IL

V

OL

Digital Output Low (SDA) I

RST Timing Reset Pulse Duration 10 ns

Serial Port Timing (Notes 6, 7)

f
t

SCL

BUF

Clock Operating Frequency 400 kHz
Bus Free Time Between Stop and Start

Condition

t

HD,STA

t

SU,STA

t

SU,STO

Hold Time After (Repeated) Start Condition 0.6 μs
Repeated Start Condition Setup Time 0.6 μs
Stop Condition Setup Time 0.6 μs

) LED Current Step 0.314 mA

LSB

= 25°C. VIN = 3.6V, DVCC = 3V, RST = high, C1 = C2 = C3 = 2.2μF, C4 = 4.7μF,

A

l

l

l

18 20 22 mA

3.2 7 μA
1μA

0.395 mA

0b00000001

= FS 120 mV

LED

2.5

0.48

0.96

0.410

0.625

1.25

= 1mA, Single Output Enabled 5 mV

OUT

= 3V, V

IN

= 3V, V

IN

2x Mode, I

SDA, SCL, RST = DV
SDA, SCL, RST = 0V

PULLUP

= 4.2V (Note 5) 3.6 Ω

CPO

= 4.8V (Note 5) 4.1 Ω

CPO

CPO

CPO

= 3mA

= 20mA

= 20mA

CC

l

0.65 0.85 1.05 MHz

l

0.4 1.3 V

l

10 30 mA

l

l

0.7 • DV

l

–1 1 μA

l

–1 1 μA

l

4.5

5.03

CC

0.12 0.4 V

0.820

1.640

0.3 • DV

CC

1.3 μs

Sec
Sec

Sec
Sec
Sec

Sec
Sec
Sec

V
V

V
V

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3

LTC3220/LTC3220-1

ELECTRICAL CHARACTERISTICS

The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

t

HD,DAT(OUT)

t

HD,DAT(IN)

t

SU,DAT

t

LOW

t

HIGH

t

f

t

r

t

SP

Data Hold Time 0 900 ns
Input Data Hold Time 0 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 Rise Time 20 300 ns
Spike Supression Time 50 ns

= 25°C. VIN = 3.6V, DVCC = 3V, RST = high, C1 = C2 = C3 = 2.2μF, C4 = 4.7μF,

A

Note 1: Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.

Note 2: Based on long term current density limitations.
Note 3: The LTC3220E/LTC3220E-1 are guaranteed to meet performance

specifi cations from 0°C to 85°C. Specifi cations over the –40°C to 85°C
operating temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3220I/LTC3220I-1

Note 4: These devices include overtemperature protection that is intended
to protect the devices during momentary overload conditions. Junction
temperatures will exceed 125°C when overtemperature protection is
active. Continuous operation above the specifi ed maximum operating
junction temperature may result in device degradation or failure.

Note 5: 1.5x mode output impedance is defi ned as (1.5V
2x mode output impedance is defi ned as (2V

Note 6: All values are referenced to V

and VIL levels.

IH

Note 7: Guaranteed by design.
are guaranteed to meet performance specifi cations over the full –40°C to
125°C operating temperature range.

TYPICAL PERFORMANCE CHARACTERISTICS

TA = 25°C unless otherwise noted.

Mode Switch Dropout Times 1.5x Mode CPO Ripple 2x Mode CPO Ripple

2s

V

CPO

20mV/DIV

AC COUPLED

V

CPO

20mV/DIV

AC COUPLED

V

CPO

1V/DIV

1.5s

1s

– V

)/I

CPO

OUT

.

CPO

)/I

IN

OUT

.

– V

IN

4

= 3.6V 250μs/DIV

V

IN

3220 G01

V
I
C

IN

CPO

CPO

= 3.6V

= 200mA

= 4.7μF

500ns/DIV

3220 G02

V
I
C

IN

CPO

CPO

= 3.6V

= 200mA

= 4.7μF

500ns/DIV

3220 G03

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LTC3220/LTC3220-1

TYPICAL PERFORMANCE CHARACTERISTICS

1x Mode Switch Resistance
vs Temperature

0.80

0.75

0.70

0.65

0.60

0.55

0.50

0.45

SWITCH RESISTANCE (Ω)

0.40

0.35

0.30

VIN = 3.6V

–25 –10 20 35 50 65 80 95 110

–40

5

TEMPERATURE (°C)

VIN = 3.3V

VIN = 3.9V

2x Mode Charge Pump Open-Loop
Output Resistance vs Temperature

4.9

4.7

4.5

4.3

4.1

3.9

3.7

3.5

3.3

OPEN-LOOP OUTPUT RESISTANCE (Ω)

3.1

2.9
–25 –10 35205 50 65 80 110 125

–40

TEMPERATURE (°C)

125

3220 G04

95

3220 G07

1.5x Mode Charge Pump Open-Loop
Output Resistance vs Temperature

4.5

4.3

4.1

3.9

3.5

3.3

3.1

2.9

2.7

OPEN-LOOP OUTPUT RESISTANCE (Ω)

2.5
–40

–25 –10 5 6520 35 50 80 95 110

TEMPERATURE (°C)

2x Mode CPO Voltage vs I

5.2

5.1

5.0

4.9

4.8

4.7

4.6

CPO VOLTAGE (V)

4.5

4.4

4.3

4.2

60

0

120

3.3V-3.6V

180 240

I

(mA)

CPO

TA = 25°C unless otherwise noted.

1.5x Mode CPO Voltage vs I

4.8

4.6

4.4

3220 G05

125

4.2

CPO VOLTAGE (V)

4.0

3.8

3.6

3V

3.1V

0

60

Oscillator Frequency

CPO

3.2V

3.1V

300

3V

360

3220 G08

vs VIN Voltage

810

800

790

780

770

760

FREQUENCY (kHz)

750

740

730

TA = 85°C

2.9

3.55

3.2V

3.3V

3.4V

120 180 240

I

(mA)

CPO

TA = 25°C

TA = –45°C

TA = 125°C

4.2

VIN VOLTAGE (V)

3.6V

300 360

4.85

CPO

3.5V

3220 G06

5.5

3220 G09

VIN Shutdown Current
vs VIN Voltage

7.5

6.5

5.5

4.5

3.5

SHUTDOWN CURRENT (μA)

IN

V

2.5

1.5

2.9

TA = 85°C

3.55 4.2 4.85 5.5
VOLTAGE (V)

TA = 125°C

TA = –40°C

TA = 25°C

3220 G10

DVCC Current vs DVCC Voltage

3.0

RST = SDA = DV

2.5

2.0

1.5

CURRENT (μA)

CC

1.0

DV

0.5

0

1.5

CC

f

= 400kHz

SCL

f

= 100kHz

SCL

2.5 3.5 4.5 5.5
DVCC VOLTAGE (V)

f

SCL

= 10kHz

3220 G11

1x Mode No Load VIN Current
vs V

Voltage

2.9

IN

3.55 4.2 4.85 5.5
VIN VOLTAGE (V)

610

605

600

595

CURRENT (μA)

IN

590

V

585

580

3220 G12

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5

LTC3220/LTC3220-1

TYPICAL PERFORMANCE CHARACTERISTICS

1.5x Mode VIN Current vs I
(I

– 1.5I

VIN

16

14

12

10

8

CURRENT (mA)

6

IN

V

4

2

0

0

60 120 240

CPO

)

I

CPO

ULED Current vs Input Code

25

20

15

10

ULED CURRENT (mA)

5

0

009

180

(mA)

CPO

360

300

3220 G13

24

1B

12

INPUT CODE (HEX)

2D

2x Mode VIN Current vs I
(I

– 2I

VIN

14

12

10

8

6

CURRENT (mA)

IN

V

4

2

0

0

36

3220 G16

CPO

60 120

3F

)

180 300

I

(mA)

CPO

CPO

240 360

100

ULED EFFICIENCY (PLED/PIN) (%)

TA = 25°C unless otherwise noted.

ULED Pin Current
vs ULED Pin Voltage

25

20

15

10

ULED PIN CURRENT (mA)

5

0

3220 G14

0.05

0

18-LED ULED Display Effi ciency

Voltage

vs V

IN

90

80

70

60

50

40

30

20

10

0

2.9
VIN VOLTAGE (V)

4.5253.875 5.175

0.1

ULED PIN VOLTAGE (V)

5.54.23.55 4.853.225

3220 G17

0.15

0.2

3220 G15

PIN FUNCTIONS

ULED1-ULED18 (Pins 1-9,13-21): Current Source Outputs
for Driving LEDs. The LED current can be set from 0mA
to 20mA in 64 steps via software control and internal
6-bit linear DAC. Each output can be disabled by setting
the associated data register REG1 to REG18 low. ULED1

2

to ULED18 can also be used as I

C controlled open-drain
general purpose outputs. Connect unused outputs to
ground.

6

(Pin 10): Supply Voltage for All digital I/O lines. This

DV

CC

pin sets the logic reference level of the LTC3220/LTC3220-1.

will reset the data registers when set below the

DV

CC

undervoltage lockout threshold. A 0.1μF X5R or X7R
ceramic capacitor should be connected to ground.

2

SCL (Pin 11): I
referenced to DV

C Clock Input. The logic level for SCL is

.

CC

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