3210.indd
LTC3210
1
3210f
FEATURES
DESCRIPTIO
U
TYPICAL APPLICATIO
U
MAIN/CAM LED Controller
in 3mm 3mm QFN
APPLICATIO S
U
The LTC
3210 is a low noise charge pump DC/DC converter
designed to drive four MAIN LEDs and one high current
CAM LED for camera lighting. The LTC3210 requires only
four small ceramic capacitors and two current set resis-
tors 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.
The full-scale current through the LEDs is programmed
via external resistors. ENM and ENC are toggled to adjust
the LED currents via internal counters and DACs. The
part is shut down when both ENM and ENC are low for
150s (typ).
The charge pump optimizes effi ciency 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 en-
ter dropout. The LTC3210 is available in a 3mm 3mm
16-lead QFN package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
*Protected by U.S. Patents, including 6411531.
C1P
C1M
C2P
RM
RC
GND
C2M
CPO
MLED1
MLED2
MLED3
MLED4
CLED
ENM
ENC
V
BAT
LTC3210
V
BAT
C1
2.2
F
C2
2.2
F
C3
2.2
F
30.1k
1%
24.3k
1%
ENM
ENC
C4
2.2
F
3210 TA01
MAIN
CAM
Low Noise Charge Pump Provides High Effi ciency
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 (8 Brightness Steps)
64:1 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: 3A
Internal Soft-Start Limits Inrush Current During
Startup and Mode Switching
Open/Short LED Protection
No Inductors
3mm 3mm 16-Lead Plastic QFN Package
V
BAT
(V)
3.0
EFFICIENCY (P
LED
/P
IN
) (%)
60
80
100
3210 TA01b
40
20
50
70
90
30
10
0
3.6
3.8
3.2
4.0
3.4
4.4
4.2
4 LEDs AT 9mA/LED
(TYP V
F
AT 9mA = 3V, NICHIA NSCW100)
T
A
= 25
C
4-LED MAIN Display
Effi ciency vs V
BAT
Voltage
Multi-LED Light Supply for Cellphones/DSCs/PDAs
LTC3210
2
3210f
(Note 1)
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
.................................................................30mA
I
CLED
(Note 2) ......................................................450mA
CPO Short-Circuit Duration .............................. Indefi nite
Operating Temperature Range (Note 3) ... 40C to 85C
Storage Temperature Range ................... 65C to 125C
16 15 14 13
5
6
7
8
TOP VIEW
UD PACKAGE
16-LEAD (3mm
3mm) PLASTIC QFN
EXPOSED PAD IS GND (PIN 17)
MUST BE SOLDERED TO PCB
9
10
17
11
12
4
3
2
1
C1P
CPO
ENM
MLED1
GND
CLED
ENC
RC
C2P
V
BAT
C1M
C2M
MLED2
MLED3
MLED4
RM
ORDER PART NUMBER
UD PART MARKING
LTC3210EUD
LBXH
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking:
http://www.linear.com/leadfree/
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
T
JMAX
= 125C,
JA
= 68C/W
The
denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25C.V
BAT
= 3.6V, C1 = C2 = C3 = C4 = 2.2F, RM = 30.1k, RC = 24.3k,
ENM = high, unless otherwise noted.
ABSOLUTE AXI U
RATI GS
W
W
W
U
PACKAGE/ORDER I FOR ATIO
U
U
W
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
BAT
Operating Voltage
2.9
4.5
V
I
VBAT
Operating Current
I
CPO
= 0, 1x Mode, MLED LSB Setting
I
CPO
= 0, 1.5x Mode
I
CPO
= 0, 2x Mode
0.375
2.5
4.5
mA
mA
mA
V
BAT
Shutdown Current
ENM = ENC = LOW
3
6
A
MLED1, MLED2, MLED3, MLED4 Current
LED Current Ratio (I
MLED
/I
RM
)
I
MLED
= Full Scale
463
515
567
A/A
LED Dropout Voltage
Mode Switch Threshold, I
MLED
= Full Scale
100
mV
LED Current Matching
Any Two Outputs, I
MLED
= Full Scale
1
%
MLED Current, 3-Bit Exponential DAC
1 ENM Strobe (FS)
2 ENM Strobes
3 ENM Strobes
4 ENM Strobes
5 ENM Strobes
6 ENM Strobes
7 ENM Strobes (FS/64)
20
10
5
2.5
1.25
0.625
0.312
mA
mA
mA
mA
mA
mA
mA
LTC3210
3
3210f
ELECTRICAL CHARACTERISTICS
The
denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25C.V
BAT
= 3.6V, C1 = C2 = C3 = C4 = 2.2F, RM = 30.1k, RC = 24.3k,
ENM = high, unless otherwise noted.
operating temperature range are assured by design, characterization and
correlation with statistical process controls.
Note 4: 1.5x mode output impedance is defi ned as (1.5V
BAT
V
CPO
)/I
OUT
.
2x mode output impedance is defi ned as (2V
BAT
V
CPO
)/I
OUT
.
Note 5: If the part has been shut down then the initial enable time is about
100s longer due to the bandgap enable time.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may become impaired.
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.
Note 3: The LTC3210E is guaranteed to meet performance specifi cations
from 0C to 70C. Specifi cations over the 40C to 85C ambient
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
CLED Current
LED Current Ratio (I
CLED
/I
RC
)
I
CLED
= Full Scale
6750
7500
8250
A/A
LED Dropout Voltage
Mode Switch Threshold, I
CLED
= Full Scale
500
mV
CLED Current, 3-Bit Linear DAC
1 ENC Strobe (FS)
7 ENC Strobes (FS/7)
380
54
mA
mA
Charge Pump (CPO)
1x Mode Output Voltage
I
CPO
= 0mA
V
BAT
V
1.5x Mode Output Voltage
I
CPO
= 0mA
4.55
V
2x Mode Output Voltage
I
CPO
= 0mA
5.05
V
1x Mode Output Impedance
0.5
1.5x Mode Output Impedance
V
BAT
= 3.4V, V
CPO
= 4.6V (Note 4)
3.15
2x Mode Output Impedance
V
BAT
= 3.2V, V
CPO
= 5.1V (Note 4)
3.95
CLOCK Frequency
0.8
MHz
Mode Switching Delay
0.4
ms
ENC, ENM
V
IL
0.4
V
V
IH
1.4
V
I
IH
ENM = ENC = 3.6V
10
15
20
A
I
IL
ENM = ENC = 0V
1
1
A
ENC, ENM Timing
t
PW
Minimum Pulse Width
60
ns
t
SD
Low Time to Shutdown (ENC and ENM = Low)
50
150
250
s
t
EN
Current Source Enable Time
(ENC or ENM = High) (Note 5)
50
150
250
s
RM, RC
V
RM
, V
RC
1.16
1.20
1.24
V
I
RM
, I
RC
70
A
LTC3210
4
3210f
TEMPERATURE (
C)
40
0.40
SWITCH RESISTANCE (
)
0.45
0.50
0.55
0.60
0.65
0.70
15
10
35
60
3210 G05
85
I
CPO
= 200mA
V
BAT
= 3.3V
V
BAT
= 3.9V
V
BAT
= 3.6V
TEMPERATURE (C)
40
3.4
3.6
3.8
60
3210 G06
3.2
3.0
15
10
35
85
2.8
2.6
2.4
OPEN LOOP OUTPUT RESISTANCE (
)
V
BAT
= 3V
V
CPO
= 4.2V
C2 = C3 = C4 = 2.2
F
LOAD CURRENT (mA)
0
3.6
CPO VOLTAGE (V)
3.8
4.0
4.2
4.4
4.6
4.8
100
200
300
400
3210 G07
500
C2 = C3 = C4 = 2.2
F
V
BAT
= 3V
V
BAT
= 3.1V
V
BAT
= 3.2V
V
BAT
= 3.6V
V
BAT
= 3.3V
V
BAT
= 3.4V
V
BAT
= 3.5V
TEMPERATURE (C)
40
4.2
4.4
4.6
60
3210 G08
4.0
3.8
15
10
35
85
3.6
3.4
3.2
OPEN LOOP OUTPUT RESISTANCE (
)
V
BAT
= 3V
V
CPO
= 4.8V
C2 = C3 = C4 = 2.2
F
LOAD CURRENT (mA)
0
CPO VOLTAGE (V)
4.8
5.0
5.2
400
3210 G09
4.6
4.4
4.7
4.9
5.1
4.5
4.3
4.2
100
200
300
500
C2 = C3 = C4 = 2.2
F
V
BAT
= 3V
V
BAT
= 3.1V
V
BAT
= 3.2V
V
BAT
= 3.3V
V
BAT
= 3.4V
V
BAT
= 3.5V
V
BAT
= 3.6V
Dropout Time from Shutdown
Dropout Time When Enabled
1.5x CPO Ripple
2x CPO Ripple
1x Mode Switch Resistance
vs Temperature
1.5x Mode Charge Pump Open-Loop
Output Resistance vs Temperature
(1.5V
BAT
V
CPO
)/I
CPO
1.5x Mode CPO Voltage
vs Load Current
2x Mode Charge Pump Open-Loop
Output Resistance vs Temperature
(2V
BAT
V
CPO
)/I
CPO
2x Mode CPO Voltage
vs Load Current
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
T
A
= 25C unless otherwise stated.
500
s/DIV
CPO
1V/DIV
EN
2V/DIV
3210 G01
1.5X
2X
1X
MODE
RESET
250
s/DIV
CPO
1V/DIV
ENC
2V/DIV
3210 G02
1.5X
2X
1X
MODE
RESET
ENM = HIGH
500ns/DIV
V
CPO
50mV/DIV
AC
COUPLED
3210 G03
V
BAT
= 3.6V
I
CPO
= 200mA
C
CPO
= 2.2
F
500ns/DIV
V
CPO
20mV/DIV
AC
COUPLED
3210 G04
V
BAT
= 3.6V
I
CPO
= 200mA
C
CPO
= 2.2
F
LTC3210
5
3210f
MLED PIN CURRENT (mA)
0
MLED PIN DROPOUT VOLTAGE (mV)
60
80
100
16
3210 G11
40
20
50
70
90
30
10
0
4
2
8
6
12 14
18
10
20
V
BAT
= 3.6V
CLED PIN CURRENT (mA)
50
100
0
CLED PIN DROPOUT VOLTAGE (mV)
200
500
150
250
300
3210 G10
100
400
300
200
350
400
V
BAT
= 3.6V
V
BAT
VOLTAGE (V)
2.7
760
FREQUENCY (kHz)
770
790
800
810
3.9
850
3210 G12
780
3.3
3.0
4.2
3.6
4.5
820
830
840
T
A
= 25
C
T
A
= 40
C
T
A
= 85
C
V
BAT
VOLTAGE (V)
2.7
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
3.6
4.2
3210 G13
3.0
3.3
3.9
4.5
V
BAT
SHUTDOWN CURRENT (
A)
T
A
= 25
C
T
A
= 40
C
T
A
= 85
C
V
BAT
VOLTAGE (V)
2.7
600
V
BAT
CURRENT (
A)
640
680
720
3.0
3.3
3.6
3.9
3210 G14
4.2
760
800
620
660
700
740
780
4.5
RM = 33.2k
RC = 24.3k
LOAD CURRENT (mA)
0
SUPPLY CURRENT (mA)
10
15
400
3210 G15
5
0
100
200
300
500
20
V
BAT
= 3.6V
LOAD CURRENT (mA)
0
SUPPLY CURRENT (mA)
10
15
400
3210 G16
5
0
100
200
300
500
20
V
BAT
= 3.6V
CLED PIN VOLTAGE (V)
0
CLED PIN CURRENT (mA)
240
320
400
0.8
3210 G17
160
80
200
280
360
120
40
0
0.2
0.4
0.6
1
V
BAT
= 3.6V
CLED Pin Dropout Voltage
vs CLED Pin Current
MLED Pin Dropout Voltage
vs MLED Pin Current
Oscillator Frequency
vs V
BAT
Voltage
V
BAT
Shutdown Current
vs V
BAT
Voltage
1x Mode No Load V
BAT
Current
vs V
BAT
Voltage
1.5x Mode Supply Current vs I
CPO
(IV
BAT
1.5I
CPO
)
2x Mode Supply Current vs I
CPO
(IV
BAT
2I
CPO
)
CLED Pin Current
vs CLED Pin Voltage
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
T
A
= 25C unless otherwise stated.
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