LTC3207/LTC3207-1
600mA Universal
Multi-Output LED/CAM Driver
FEATURES
■
■
■
■
■
■
■
■
■
■
■
■
■
DESCRIPTION
Low Noise, Multi-Mode Charge Pump (1x, 1.5x, 2x)
Provides Up to 91% Efficiency
Slew Limited Switching Reduces Conducted and
Radiated Noise (EMI)
Up to 600mA Total Output Current
Twelve 28mA Universal Current Sources with
64-Step Linear Brightness Control
425mA CAM LED Current Source with 16-Step
Linear Brightness Control and 2-Second High
Current Safety Timer
Independent On/Off, Brightness Level, Blinking and
Gradation Control for Each Current Source Using
2-Wire I2CTM Interface
Internal Current Reference
Two I2C Addresses are Available
(LTC3207 00110110, LTC3207-1 00110100)
Configurable ENU Pin for Asynchronous LED
On/Off Control
Automatic or Forced Mode Switching
Internal Soft-Start Limits Inrush Current
Short-Circuit/Thermal Protection
4mm × 4mm 24-Pin QFN Plastic Package
The LTC®3207/LTC3207-1 are highly integrated multi-display
LED drivers. The device contains a high-efficiency, low-noise
charge pump to provide power to 12 universal LED current
sources and one camera LED current source. The LTC3207/
LTC3207-1 require only five small ceramic capacitors to
form a complete LED power supply and current controller.
In addition there are two I2C addresses available.
The display 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 I2C serial interface. 6-bit linear DACs are
available for adjusting brightness levels for each universal
LED current source. The CAM current source has a 4-bit
linear DAC to adjust brightness.
The LTC3207/LTC3207-1 charge pumps optimize efficiency
based on the voltage across the LED current sources. The
device powers-up in 1x mode and will automatically switch
to boost mode whenever any enabled LED current source
begins to enter dropout. The first dropout switches the
IC into 1.5x mode and a subsequent dropout switches
the LTC3207/LTC3207-1 into 2x mode. The device resets
to 1x mode whenever a data register is updated via the
I2C port.
APPLICATIONS
■
Video Phones with QVGA+ Displays
, 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.
TYPICAL APPLICATION
4-LED MAIN, 2-LED SUB, Dual RGB and Camera Light
C2
2.2µF
VBAT
C1
2.2µF
DVCC
C3
2.2µF
MAIN
C1P C1M C2P C2M
VBAT
CPO
SUB
RGB
RGB
CAM
C4
4.7µF
LTC3207/LTC3207-1
DVCC
0.1µF
ULED1-12
I2
C
ENABLE DISABLE
LOW HI
2
SCL/SDA
CAM
ENU
CAMHL
12
3207 TA01
GND
3207fc
1
LTC3207/LTC3207-1
ABSOLUTE MAXIMUM RATINGS
PIN CONFIGURATION
(Notes 1, 4)
C2M
C1M
VBAT
ENU
C2P
C1P
TOP VIEW
24 23 22 21 20 19
CPO 1
18 ULED12
ULED1 2
17 ULED11
ULED2 3
16 ULED10
25
ULED3 4
15 ULED9
ULED4 5
14 ULED8
ULED5 6
ULED6
DVCC
SDA
9 10 11 12
SCL
8
CAM
13 ULED7
7
CAMHL
VBAT, DVCC, CPO ........................................... –0.3V to 6V
ULED1 to ULED12, CAM .............................. –0.3V to 6V
SDA, SCL, ENU, CAMHL .............–0.3V to (DVCC + 0.3V)
ICPO
Continuous (Note 3) ........................................350mA
Pulsed at 10% Duty Cycle ................................600mA
ICAM
Continuous (Note 3) ........................................300mA
Pulsed at 10% Duty Cycle ................................460mA
CPO Short-Circuit Duration .............................. Indefinite
Operating Temperature Range (Note 2).... –40°C to 85°C
Storage Temperature Range................... –65°C to 125°C
UF PACKAGE
24-LEAD (4mm × 4mm) PLASTIC QFN
TJMAX = 125°C, θJA = 40°C/W
EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC3207EUF#PBF
LTC3207EUF#TRPBF
3207
24-Lead (4mm × 4mm) Plastic QFN
–40°C to 85°C
LTC3207EUF-1#PBF
LTC3207EUF-1#TRPBF
32071
24-Lead (4mm × 4mm) Plastic QFN
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VBAT = 3.6V, DVCC = 3V, ENU = Hi, CAMHL = LO, C1 = C2 = C3 = 2.2µF,
C4 = 4.7µF, unless otherwise noted.
PARAMETER
CONDITIONS
●
VBAT Operating Voltage
IVBAT Operating Current
MIN
2.9
ICPO = 0, 1x Mode
ICPO = 0, 1.5x Mode
ICPO = 0, 2x Mode
MAX
5.5
0.5
2.9
4.1
DVCC UVLO Threshold
DVCC Operating Voltage
TYP
1.5
VBAT UVLO Threshold
V
5.5
1.5
VBAT Shutdown Current
●
DVCC Shutdown Current
●
3.2
V
mA
mA
mA
1
●
UNITS
V
V
7
µA
1
µA
31
mA
Universal LED Current, 6-Bit Linear DACs, ULED = 1V
Full-Scale LED Current
Minimum (1LSB) LED Current
●
24.2
27.5
0.436
mA
3207fc
2
LTC3207/LTC3207-1
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VBAT = 3.6V, DVCC = 3V, ENU = Hi, CAMHL = LO, C1 = C2 = C3 = 2.2µF,
C4 = 4.7µF, unless otherwise noted.
PARAMETER
CONDITIONS
LED Current Matching
Any Two Outputs, 50% of FS
LED Dropout Voltage
MIN
TYP
MAX
UNITS
2
%
ILED = FS
180
mV
Blink Rate Period
REG15, D6 and D7
1.25
2.5
s
s
ULED Up/Down Gradation Times
REG15, D4 and D5
0.24
●
0.45
0.48
●
0.9
0.96
●
VOL General Purpose Output Mode (GPO)
1.8
IOUT = 1mA, Single Output Enabled
7
s
s
s
s
s
s
mV
CAM LED Current, 4-Bit Linear DAC, CAM = 1V
Full-Scale LED Current
425
mA
Minimum (1LSB) LED Current
29
mA
LED Dropout Voltage
ILED = FS
450
mV
High Current Safety Timer
High Current Mode
2.1
s
Charge Pump (CPO)
1x Mode Output Impedance
0.6
Ω
1.5x Mode Output Impedance
VBAT = 3V, VCPO = 4.2V (Note 5)
3.6
Ω
2x Mode Output Impedance
VBAT = 3V, VCPO = 4.8V (Note 5)
4.1
Ω
CPO Regulation Voltage
1.5x Mode, ICPO = 20mA
2x Mode, ICPO = 20mA
4.55
5.05
V
V
●
CLOCK Frequency
0.65
0.85
1.05
MHz
SDA, SCL, ENU, CAMHL
VIL
●
VIH
●
0.7 • DVCC
0.3 • DVCC
V
V
IIH
SDA, SCL, ENU, CAMHL = DVCC
●
–1
1
µA
IIL
SDA, SCL, ENU, CAMHL = 0V
●
–1
1
µA
VOL
IPULLUP = 3mA
●
0.4
V
400
kHz
0.12
Digital Output Low (SDA)
Serial Port Timing (Notes 6, 7)
tSCL
Clock Operating Frequency
tBUF
Bus Free Time Between Stop and Start Condition
1.3
µs
tHD,STA
Hold Time After (Repeated) Start Condition
0.6
µs
tSU,STA
Repeated Start Condition Setup Time
0.6
µs
tSU,STO
Stop Condition Setup Time
0.6
µs
tHD,DAT(OUT)
Output Data Hold Time
tHD,DAT(IN)
Input Data Hold Time
0
ns
tSU,DAT
Data Setup Time
100
ns
tLOW
Clock Low Period
1.3
µs
tHIGH
Clock High Period
0.6
µs
0
900
ns
3207fc
3
LTC3207/LTC3207-1
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VBAT = 3.6V, DVCC = 3V, ENU = Hi, CAMHL = LO, C1 = C2 = C3 = 2.2µF,
C4 = 4.7µF, unless otherwise noted.
PARAMETER
CONDITIONS
MAX
UNITS
tf
Clock Data Fall Time
MIN
20
300
ns
tr
Clock Data Rise Time
20
300
ns
tSP
Spike Suppression Time
50
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: The LTC3207E/LTC3207E-1 are guaranteed to meet performance
specifications from 0°C to 85°C. Specifications over the –40°C to
85°C ambient operating temperature range are assured by design,
characterization and correlation with statistical process controls.
Note 3: Based on long term current density limitations. Assumes operating
duty cycle of