LTC3214.pdf 데이터시트 (총 12 페이지) - 파일 다운로드 LTC3214 데이타시트 다운로드

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FEATUREtSaSheet4U.com DESCRIPTIOLED50C0mhaArgCLeTaCPm3u2em1rap4Low Noise Constant Frequency Operation*
aHigh Efficiency: Up to 94%
.DMulti-Mode Operation: 1x, 1.5x or 2x Boost Modes
wAutomatic Mode Switching
wHigh Output Current: Up to 500mA
wTiny Application Circuit (3mm × 3mm DFN Package,
mAll Components <1mm High)
oAutomatic Soft-Start
.cOutput Disconnect
Open, Shorted LED Protection
No Inductors
UInternal 110mLED Current Sense Resistor
t43mm × 3mm 10-Lead DFN Package
APPLICATIOUS eeLED Torch/Camera Light Supply for Cell Phones,
hPDAs and Digital Cameras
SGeneral Lighting and/or Flash/Strobe Applications
The LTC®3214 is a low noise, high current charge pump
DC/DC converter capable of driving high current LEDs at
up to 500mA from a 2.9V to 4.5V input. Low external
parts count (two flying capacitors, one programming
resistor and two bypass capacitors at VIN and CPO) make
the LTC3214 ideally suited for small, battery-powered
applications.
Built-in soft-start circuitry prevents excessive inrush cur-
rent during start-up. High switching frequency enables the
use of small external capacitors.
Output current level is programmed by an external resis-
tor. LED current is regulated using an internal 110m
sense resistor. Automatic mode switching optimizes effi-
ciency by monitoring the voltage across the charge pump
and switching modes only when dropout is detected. The
part is available in a low profile 3mm x 3mm 10-lead DFN
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.
TYPICAL APPLICATIO .DataC1
2.2µF
C2
2.2µF
ww2.9V TO 4.5V
CIN
m2.2µF
w www.DataSheet4U.c1oDISABLE ENABLE
C1+ C1C2+ C2
VIN CPO
LTC3214
ILED
EN
ISET
0.11
RSET
3214 TA01a
LED: AOT2015
LED
ILED
UP TO
500mA
CCPO
4.7µF
Efficiency vs VIN
100
100mA 200mA
90 300mA
80
70
60 50mA
50
40
30
20
10 LED = AOT2015
VF = 2.9V TYP AT 100mA
0
2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5
VIN (V)
3214 TA01b
3214f

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LTC3214
ABSOLUTE AXI U RATI GS
(Note 1)
VIN to GND ............................................... –0.3V to 5.5V
CPO to GND ............................................. –0.3V to 5.5V
EN ................................................... –0.3V to VIN + 0.3V
ICPO, IILED (Note 2) ............................................. 600mA
CPO Short-Circuit Duration ............................ Indefinite
Storage Temperature Range ................. –65°C to 125°C
Operating Temperature Range (Note 3) .. –40°C to 85°C
UW U
PACKAGE/ORDER I FOR ATIO
TOP VIEW
C2+ 1
C1+ 2
CPO 3
ILED 4
ISET 5
10 C1
9 GND
11 8 C2
7 VIN
6 EN
DD PACKAGE
10-LEAD (3mm × 3mm) PLASTIC DFN
TJMAX = 125°C, θJA = 43°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB GND
ORDER PART NUMBER DD PART MARKING
LTC3214EDD
LBVQ
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 specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = 3.6V, CIN = C1 = C2 = 2.2µF, CCPO = 4.7µF.
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Input Power Supply
VIN Operating Voltage
IVIN Operating Current
IVIN Shutdown Current
LED Current
ICPO = 0mA, 1x Mode
ICPO = 0mA, 1.5x
ICPO = 0mA, 2x Mode
EN = LOW
2.9
4.5
980
4.8
6.7
2.5 7.5
V
µA
mA
mA
µA
LED Current Ratio (ILED/ISET)
ILED Dropout Voltage (VILED)
Mode Switching Delay (LED Warmup Time)
ILED = 150mA to 500mA
Mode Switch Threshold, ILED = 200mA
2715 2950 3190 mA/mA
40 mV
2.5 ms
LED Current On Time
Charge Pump (CPO)
EN to LED Current On
100 µs
Charge Pump Output Clamp Voltage
5V
1x Mode Output Impedance
0.70
1.5x Mode Output Impedance
3.2
2x Mode Output Impedance
4
CLK Frequency
EN
VIN = 3V
0.6 0.9 1.2
MHz
High Level Input Voltage (VIH)
Low Level Input Voltage (VIL)
Input Current (IIH)
Input Current (IIL)
VEN = 3.6V
1.4
0.4
14.4 20
–1
1
V
V
µA
µA
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LTC3214
ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = 3.6V, CIN = C1 = C2 = 2.2µF, CCPO = 4.7µF.
PARAMETER
ISET
VISET
IISET
CONDITIONS
ISET = 50µA
MIN TYP MAX UNITS
1.18 1.21 1.24
184
V
µA
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be 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. Max current for continuous operation is
300mA.
Note 3: The LTC3214E is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the –40°C to 85°C ambient
operating temperature range are assured by design, characterization and
correlation with statistical process controls.
TYPICAL PERFOR A CE CHARACTERISTICS (TA = 25°C unless otherwise specified)
ILED Dropout Voltage
vs LED Current
0.12
0.10
0.08
0.06
0.04
0.02
0
0 100 200 300 400 500
LED CURRENT (mA)
3216 G01
1x Mode Charge Pump Open-Loop
Output Resistance vs Temperature
1.0 ICPO = 100mA
0.9
VIN = 2.9V
0.8 VIN = 3.6V
0.7
VIN = 4.5V
0.6
0.5
0.4
–40
–15 10 35 60
TEMPERATURE (°C)
85
3216 G03
ILED vs RSET
600
500
400
300
200
100
0
0 50 100 150 200 250 300 350 400
RSET (k)
1573 G02
2x Mode Charge Pump
Open-Loop Output Resistance
(2VIN – VCPO)/ICPO vs Temperature
5
4
3
2
1 VIN = 3.6V
CIN = C1 = C2 = 2.2µF
CCPO = 4.7µF
0
–40 –15 10
35
TEMPERATURE (°C)
60 85
3216 G05
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LTC3214
TYPICAL PERFOR A CE CHARACTERISTICS (TA = 25°C unless otherwise specified)
Input Shutdown Current
vs Input Voltage
4.5
4.0
3.5
3.0 TA = 25°C
2.5
TA = –40°C
TA = 85°C
2.0
1.5
1.0
0.5
0
2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5
INPUT VOLTAGE (V)
3214 G06
Oscillator Frequency
vs Supply Voltage
910
900 TA = –40°C
890 TA = 25°C
880 TA = 85°C
870
860
850
840
830
2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5
SUPPLY VOLTAGE (V)
3214 G07
Efficiency vs VIN
100
100mA 200mA
90 300mA
80
70
60 50mA
50
40
30
20
10 LED = AOT2015
VF = 2.9V TYP AT 100mA
0
2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5
VIN (V)
3215 G08
ISET/ILED Current Ratio
vs ILED Current
3300
3200
3100
3000
2900
25°C
85°C
–40°C
2800
2700
0
100 200 300 400
ILED CURRENT (mA)
500
3214 G09
ILED Current vs Input Voltage
600
500
7.15k
400
300
11.8k
200
17.4k
36.6k
100
72.2k
0
2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5
VIN (V)
3214 G10
1.5x Mode CPO Output Ripple
2x Mode CPO Output Ripple
VCPO
50mV/DIV
VIN = 3.6V
500ns/DIV
ICPO = 200mA
3214 G11
VCPO
50mV/DIV
A/C COUPLED
VIN = 3.6V
ICPO = 400mA
500ns/DIV
3214 G12
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LTC3214
PI FU CTIO S
C2+, C1+, C2, C1(Pins 1, 2, 8, 10): Charge Pump Flying
Capacitor Pins. A 2.2µF X5R or X7R ceramic capacitor
should be connected from C1+ to C1and from C2+ to
C2.
CPO (Pin 3): Output. CPO is the output of the charge
pump. This pin may be enabled or disabled using the EN
input. A 4.7µF X5R or X7R ceramic capacitor is required
from CPO to GND.
ILED (Pin 4): Input. ILED is the LED current sense pin. The
LED is connected between CPO (anode) and ILED (cath-
ode). The current into the ILED pin is set by a resistor
connected to the ISET pin and regulated internally.
ISET (Pin 5): LED Current Programming Resistor Pin. A
resistor connected between this pin and GND is used to set
the LED current level.
EN (Pin 6): Input. The EN pin is used to enable the part and
bring it into shutdown mode. An internal 250kresistor
pulls this pin to GND when left floating.
VIN (Pin 7): Power. Supply voltage for the LTC3214. VIN
should be bypassed with a 2.2µF to 4.7µF low impedance
ceramic capacitor to GND.
GND (Pin 9): Charge Pump Ground. This pin should be
connected directly to a low impedance ground plane.
Exposed Pad (Pin 11): Control Signal Ground. This pad
must be soldered to a low impedance ground plane for
optimum thermal and electrical performance.
BLOCK DIAGRA
2
C1+
10
C1
1
C2+
8
C2
OSCILLATOR
VIN
7
EN
6
CONTROL
LOGIC
250k
GND
9
+
MODE
CONTROL
CPO
3
VOLTAGE
CLAMP
VREF
CURRENT
SOURCE
CONTROL
VIN ILED 4
580.11
ISET
5
GND
11
3214 BD
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