LTC3210-1
MAIN/CAM LED Controller
with 64-Step Brightness Control
in 3mm
×
3mm QFN
DescripTion
The LTC
®
3210-1 is a low noise charge pump DC/DC con-
verter designed to drive four MAIN LEDs and one high
current CAM LED for camera lighting. The LTC3210-1
requires only four small ceramic capacitors and two cur-
rent set resistors to form a complete LED power supply
and current controller.
Built-in soft-start circuitry prevents excessive inrush cur-
rent during start-up and mode changes. High switching
frequency enables the use of small external capacitors.
Independent MAIN and CAM full-scale current settings
are programmed by two external resistors.
Shutdown mode and current output levels are selected
via two logic inputs. ENM and ENC are toggled to adjust
the LED currents via internal counters and DACs. A 6-bit
linear DAC (64 steps) provides high resolution brightness
control for the MAIN display.
The charge pump optimizes efficiency based on the volt-
age 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 LTC3210-1 is available in a 3mm × 3mm ×
0.75mm 16-lead QFN package.
FeaTures
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Low Noise Charge Pump Provides High Efficiency
with Automatic Mode Switching
Multimode Operation: 1x, 1.5x, 2x
Individual Full-Scale Current Set Resistors
Up to 500mA Total Output Current
Single Wire EN/Brightness Control for MAIN and
CAM LEDs
64:1 Linear Brightness Control Range for
MAIN Display
Four 25mA Low Dropout MAIN LED Outputs
One 400mA Low Dropout CAM LED Output
Low Noise Constant-Frequency Operation
Low Shutdown Current: 3µA
Internal Soft-Start Limits Inrush Current During
Startup and Mode Switching
Open/Short LED Protection
No Inductors
3mm × 3mm × 0.75mm 16-Lead Plastic QFN Package
Multi-LED Light Supply for Cell Phones/DSCs/PDAs
applicaTions
n
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property
of their respective owners.
Typical applicaTion
C2
2.2µF
C3
2.2µF
MAIN
C4
2.2µF
CAM
100
90
V
BAT
V
BAT
LTC3210-1
MLED1
MLED2
ENM
ENC
ENM
ENC
RM
30.1k
1%
RC
24.3k
1%
MLED3
MLED4
GND CLED
32101 TA01
4-LED MAIN Display
Efficiency vs V
BAT
Voltage
EFFICIENCY (P
LED
/P
IN
) (%)
C1P
C1
2.2µF
C1M C2P
C2M
CPO
80
70
60
50
40
30
20 4 LEDs AT 9mA/LED
10 (TYP V
F
AT 9mA = 3V, NICHIA NSCW100)
T
A
= 25°C
0
3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4
V
BAT
(V)
32101 TA01b
32101fd
LTC3210-1
absoluTe maximum raTings
(Note 1)
pin conFiguraTion
TOP VIEW
V
BAT
C1M
C2M
12 GND
17
11 CLED
10 ENC
9
5
MLED2
6
MLED3
7
MLED4
8
RM
RC
C2P
C1P 1
CPO 2
ENM 3
MLED1 4
16 15 14 13
V
BAT
, CPO to GND ........................................ –0.3V to 6V
ENM, ENC ...................................–0.3V to (V
BAT
+ 0.3V)
I
CPO
(Note 2) ....................................................... 600mA
I
MLED1-4
.................................................................35mA
I
CLED
(Note 2)...................................................... 500mA
CPO Short-Circuit Duration .............................. Indefinite
Operating Temperature Range (Note 3) ...–40°C to 85°C
Storage Temperature Range .................. –65°C to 125°C
T
JMAX
= 125°C, θ
JA
= 68°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
UD PACKAGE
16-LEAD (3mm 3mm) PLASTIC QFN
orDer inFormaTion
LEAD FREE FINISH
LTC3210EUD-1#PBF
LTC3210EPD-1#PBF
TAPE AND REEL
LTC3210EUD-1#TRPBF
LTC3210EPD-1#TRPBF
PART MARKING
LCBT
LCXT
PACKAGE DESCRIPTION
16-Lead (3mm × 3mm) Plastic QFN
16-Lead (3mm × 3mm) Plastic UTQFN
TEMPERATURE RANGE
–40°C to 85°C
–40°C to 85°C (OBSOLETE)
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
PARAMETER
V
BAT
Operating Voltage
I
VBAT
Operating Current
V
BAT
Shutdown Current
MLED1, MLED2, MLED3, MLED4 Current
LED Current Ratio (I
MLED
/I
RM
)
LED Dropout Voltage
LED Current Matching
MLED Current, 6-Bit Linear DAC
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C.V
BAT
= 3.6V, C1 = C2 = C3 = C4 = 2.2µF RM = 30.1k, RC = 24.3k,
,
ENM = high, unless otherwise noted.
CONDITIONS
l
MIN
2.9
TYP
0.4
2.5
4.5
MAX
4.5
UNITS
V
mA
mA
mA
I
CPO
= 0, 1x Mode, LSB Setting
I
CPO
= 0, 1.5x Mode
I
CPO
= 0, 2x Mode
ENM = ENC = Low
I
MLED
= Full-Scale
Mode Switch Threshold, I
MLED
= Full-Scale
Any Two Outputs
1 ENM Strobe (FS)
63 ENM Strobes (FS/63)
l
3
481
535
75
0.5
20
0.318
6
589
µA
A/A
mV
%
mA
mA
l
32101fd
LTC3210-1
elecTrical characTerisTics
PARAMETER
Unused MLED Detection
Test Current
Threshold Voltage
CLED Current
LED Current Ratio (I
CLED
/I
RC
)
LED Dropout Voltage
CLED Current, 3-Bit Linear DAC
Charge Pump (CPO)
1x Mode Output Voltage
1.5x Mode Output Voltage
2x Mode Output Voltage
1x Mode Output Impedance
1.5x Mode Output Impedance
2x Mode Output Impedance
CLOCK Frequency
Mode Switching Delay
CPO Short-Circuit Detection
Threshold Voltage
Test Current
ENC, ENM
V
IL
V
IH
I
IH
I
IL
ENC, ENM Timing
t
PW
t
SD
t
EN
RM, RC
V
RM
, V
RC
I
RM
, I
RC
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. Assumes an
operating duty cycle of ≤10% under absolute maximum conditions
for durations less than 10 seconds. Maximum current for continuous
operation is 300mA.
l
l
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
BAT
= 3.6V, C1 = C2 = C3 = C4 = 2.2µF RM = 30.1k, RC = 24.3k,
,
ENM = high, unless otherwise noted.
CONDITIONS
MLED Tied to CPO
V
CPO
– V
MLED
I
CLED
= Full-Scale
Mode Switch Threshold, I
CLED
= Full-Scale
1 ENC Strobe (FS)
7 ENC Strobes (FS/7)
I
CPO
= 0mA
I
CPO
= 0mA
I
CPO
= 0mA
V
BAT
= 3.4V, V
CPO
= 4.6V (Note 4)
V
BAT
= 3.2V, V
CPO
= 5.1V (Note 4)
l
l
MIN
4
0.5
6930
TYP
MAX
16
1.5
UNITS
µA
V
A/A
mV
mA
mA
V
V
V
Ω
Ω
Ω
l
7700
500
380
54
V
BAT
4.55
5.05
0.55
3.15
3.95
0.8
0.4
8470
MHz
ms
0.4
10
1.3
30
0.4
V
mA
V
V
µA
µA
ns
CPO = 0V, ENM = ENC = Low
l
1.4
10
–1
200
50
50
1.16
150
150
1.20
250
250
1.24
80
15
20
1
ENM = ENC = 3.6V
ENM = ENC = 0V
Minimum Pulse Width
Low Time to Shutdown (ENC, ENM = Low)
Current Source Enable Time
(ENC, ENM = High) (Note 5)
l
l
l
l
l
µs
µs
V
µA
Note 3: The LTC3210E-1 is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 4: 1.5x mode output impedance is defined as (1.5V
BAT
– V
CPO
)/I
OUT
.
2x mode output impedance is defined as (2V
BAT
– V
CPO
)/I
OUT
.
Note 5: If the part has been shut down then the initial enable time is about
100µs longer due to the bandgap enable time.
32101fd
LTC3210-1
Typical perFormance characTerisTics
Dropout Time from Shutdown
CPO
1V/DIV
EN
2V/DIV
5.1V
1X
2X
CPO
1V/DIV
ENC
2V/DIV
T
A
= 25°C unless otherwise stated.
Dropout Time When Enabled
5.1V
1X
2X
V
CPO
50mV/DIV
AC-
COUPLED
1.5x CPO Ripple
V
BAT
= 3.6V
I
CPO
= 200mA
C
CPO
= 2.2µF
1.5X
1.5X
MODE
RESET
MODE
RESET
ENM = HIGH
500µs/DIV
32101 G01
250µs/DIV
32101 G02
500ns/DIV
32101 G03
2x CPO Ripple
V
BAT
= 3.6V
I
CPO
= 200mA
C
CPO
= 2.2µF
SWITCH RESISTANCE ( )
V
CPO
20mV/DIV
AC-
COUPLED
0.70
0.65
0.60
0.55
0.50
0.45
32101 G04
1x Mode Switch Resistance
vs Temperature
I
CPO
= 200mA
OPEN-LOOP OUTPUT RESISTANCE ( )
3.8
1.5x Mode Charge Pump Open-Loop
Output Resistance vs Temperature
(1.5V
BAT
– V
CPO
)/I
CPO
V
BAT
= 3V
V
CPO
= 4.2V
3.6 C2 = C3 = C4 = 2.2µF
3.4
3.2
3.0
2.8
2.6
2.4
–40
–15
10
35
60
85
32101 G06
V
BAT
= 3.3V
V
BAT
= 3.6V
V
BAT
= 3.9V
500ns/DIV
0.40
–40
–15
10
35
TEMPERATURE (°C)
60
85
32101 G05
TEMPERATURE (˚C)
1.5x Mode CPO Voltage
vs Load Current
4.8
4.6
CPO VOLTAGE (V)
4.4
4.2
4.0
3.8
3.6
C2 = C3 = C4 = 2.2µF
V
BAT
= 3.3V
V
BAT
= 3.4V
V
BAT
= 3.5V
V
BAT
= 3.6V
OPEN-LOOP OUTPUT RESISTANCE ( )
4.6
2x Mode Charge Pump Open-Loop
Output Resistance vs Temperature
(2V
BAT
– V
CPO
)/I
CPO
2x Mode CPO Voltage
vs Load Current
5.2
5.1
5.0
CPO VOLTAGE (V)
4.9
4.8
4.7
4.6
4.5
4.4
4.3
V
BAT
= 3.5V
V
BAT
= 3.4V
V
BAT
= 3.3V
V
BAT
= 3.2V
V
BAT
= 3.1V
V
BAT
= 3V
0
100
300
400
200
LOAD CURRENT (mA)
500
32101 G09
V
BAT
= 3V
V
CPO
= 4.8V
4.4 C2 = C3 = C4 = 2.2µF
4.2
C2 = C3 = C4 = 2.2µF
V
BAT
= 3.6V
4.0
3.8
3.6
3.4
3.2
–40
–15
10
35
60
85
32101 G08
V
BAT
= 3.2V
V
BAT
= 3.1V
V
BAT
= 3V
0
100
200
300
400
LOAD CURRENT (mA)
500
32101 G07
4.2
TEMPERATURE (˚C)
32101fd
LTC3210-1
Typical perFormance characTerisTics
500
CLED PIN DROPOUT VOLTAGE (mV)
T
A
= 25°C, unless otherwise stated.
Oscillator Frequency
vs V
BAT
Voltage
T
A
= 25°C
CLED Pin Dropout Voltage
vs CLED Pin Current
V
BAT
= 3.6V
MLED PIN DROPOUT VOLTAGE (mV)
120
100
MLED Pin Dropout Voltage
vs MLED Pin Current
V
BAT
= 3.6V
850
840
830
FREQUENCY (kHz)
820
810
800
790
780
770
0
2
4
6 8 10 12 14 16 18 20
MLED PIN CURRENT (mA)
32101 G11
400
300
80
60
40
20
0
T
A
= 85°C
T
A
= –40°C
200
100
0
50
100
150 200 250 300 350
CLED PIN CURRENT (mA)
400
760
2.7
3.0
3.3
3.6
3.9
V
BAT
VOLTAGE (V)
4.2
4.5
32101 G10
32101 G12
5.0
V
BAT
SHUTDOWN CURRENT (µA)
4.5
4.0
3.5
3.0
2.5
2.0
V
BAT
Shutdown Current
vs V
BAT
Voltage
T
A
= 25°C
V
BAT
CURRENT (µA)
800
780
760
740
720
700
680
660
640
620
600
1x Mode No Load V
BAT
Current
vs V
BAT
Voltage
RM = 33.2k
RC = 24.3k
SUPPLY CURRENT (mA)
20
1.5x Mode Supply Current
vs I
CPO
(IV
BAT
– 1.5I
CPO
)
V
BAT
= 3.6V
15
T
A
= –40°C
10
T
A
= 85°C
5
1.5
2.7
3.0
3.9
3.6
3.3
V
BAT
VOLTAGE (V)
4.2
4.5
2.7
3.0
3.6
3.9
3.3
V
BAT
VOLTAGE (V)
4.2
4.5
0
0
100
300
400
200
LOAD CURRENT (mA)
500
32101 G15
32101 G13
32101 G14
20
2x Mode Supply Current
vs I
CPO
(IV
BAT
– 2I
CPO
)
V
BAT
= 3.6V
400
360
CLED PIN CURRENT (mA)
320
280
240
200
160
120
80
40
CLED Pin Current
vs CLED Pin Voltage
V
BAT
= 3.6V
SUPPLY CURRENT (mA)
15
10
5
0
0
100
300
400
200
LOAD CURRENT (mA)
500
32101 G16
0
0
0.2
0.6
0.8
0.4
CLED PIN VOLTAGE (V)
1
32101 G17
32101fd
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