OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

LT3420EMS#PBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P20
LT3420/LT3420-1
1
3420fb
, 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 6518733.
APPLICATIO S
U
FEATURES
DESCRIPTIO
U
TYPICAL APPLICATIO
U
■
Digital Camera Flash Unit
■
Film Camera Flash Unit
■
High Voltage Power Supplies
■
Charges 220µF to 320V in 3.7 Seconds
from 5V (LT3420)
■
Charges 100µF to 320V in 3.5 Seconds
from 5V (LT3420-1)
■
Charges Any Size Photoflash Capacitor
■
Supports Operation from Two AA Cells or Any
Supply from 1.8V to 16V
■
Controlled Peak Switch Current: 1.4A (LT3420)
1.0A (LT3420-1)
■
Controlled Input Current: 840mA (LT3420)
450mA (LT3420-1)
■
Uses Standard Transformers
■
Efficient Flyback Operation (>75% Typical)
■
Adjustable Output
■
Automatic Refresh
■
Charge Complete Indicator
■
No High Voltage Zener Diode Required
■
No Output Voltage Divider Required
■
Small 10-Lead MSOP Package
■
Small 10-Lead (3mm × 3mm) DFN Package
Photoflash Capacitor
Chargers with Automatic Refresh
The LT
®
3420/LT3420-1 charge high voltage photoflash
capacitors quickly and efficiently. Designed for use in both
digital and film cameras, these devices use a flyback
topology to achieve efficiencies up to four times better
than competing flash modules. A unique adaptive off-time
control algorithm* maintains current-limited continuous
mode transformer operation throughout the entire charge
cycle, eliminating the high inrush current often found in
modules.
The LT3420/LT3420-1 output voltage sensing scheme*
monitors the flyback voltage to indirectly regulate the
output voltage, eliminating an output resistor divider or
discrete zener diode. This feature allows the capacitor to
be held at a fully charged state without excessive power
consumption. Automatic refresh (which can be defeated)
allows the capacitor to remain charged while consuming
an average input current of about 2mA, at a user-defined
refresh rate. A logic high on the CHARGE pin initiates
charging, while the DONE pin signals that the capacitor is
fully charged.
The LT3420/LT3420-1 are available in 10-Lead MSOP and
(3mm × 3mm) DFN packages.
Figure 1. High Charge Rate LT3420 Photoflash Circuit
V
BAT
1.8V TO 6V
INPUT CURRENT
≈350mA
3420 F01
+
V
CC
CHARGE
DONE
SEC
R
REF
LT3420
V
BAT
R
FB
SW
C
T
GND
C2
4.7µF
0.1µF
C1
4.7µF
V
CC
2.5V TO 10V
CHARGE
DONE
51.1k
T1
1:12
320V
3,4
5,6
8
1
2k
D1
C1, C2: 4.7µF, X5R or X7R, 10V
C3: RUBYCON 220µF PHOTOFLASH CAPACITOR
T1: TDK SRW10EPC-U01H003 FLYBACK TRANSFORMER
D1: VISHAY GSD2004S SOT-23
DUAL DIODE. DIODES CONNECTED IN SERIES
C3
220µF
330V
PHOTOFLASH
CAPACITOR
4
9
8
10 5
1
7
632
DANGER HIGH VOLTAGE
OPERATION BY HIGH VOLTAGE
TRAINED PERSONNEL ONLY
Figure 2. Small Size LT3420-1 Photoflash Circuit
3420 F02
+
V
CC
CHARGE
DONE
SEC
R
REF
LT3420-1
V
BAT
R
FB
SW
C
T
GND
C2
4.7µF
0.1µF
C1
4.7µF
V
BAT
1.8V TO 6V
INPUT CURRENT
≈450mA
V
CC
2.5V TO 6V
CHARGE
DONE
60.4k
T1
1:10
(3mm TALL)
320V
3
4
5
6
2k
D1
C1, C2: 4.7µF, X5R or X7R, 6.3V
C3: RUBYCON 100µF PHOTOFLASH CAPACITOR
T1: KIJIMA MUSEN SBL-5.6S-2
D1: VISHAY GSD2004S SOT-23
DUAL DIODE. DIODES CONNECTED IN SERIES
C3
100µF
330V
PHOTOFLASH
CAPACITOR
4
9
8
10 5
1
7
632
2
LT3420/LT3420-1
3420fb
1
2
3
4
5
R
REF
V
BAT
R
FB
V
CC
GND
10
9
8
7
6
C
T
CHARGE
DONE
SEC
SW
TOP VIEW
MS PACKAGE
10-LEAD PLASTIC MSOP
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Operating Voltage, V
CC
● 2.2 2.5 V
Maximum Operating Voltage, V
CC
16 V
V
CC
UVLO Hysteresis 40 mV
Minimum V
BAT
Voltage 1.6 1.8 V
Maximum V
BAT
Voltage 16 V
V
BAT
UVLO Hysteresis 275 mV
R
REF
Threshold Voltage 0.98 1.00 1.02 V
● 0.975 1.025 V
R
REF
Pin Bias Current V
RREF
= 0V, Switching 2 4 µA
V
RFB
= V
BAT
– 0.2V (Note 4)
Quiescent Current V
RREF
= 1.1V, Not Switching 90 130 µA
Quiescent Current in Shutdown V
CHARGE
= 0V, V
IN
= 3.3V 0.01 1 µA
Consult LTC Marketing for parts specified with wider operating temperature ranges.
V
CC
Voltage .............................................................. 16V
V
BAT
Voltage ............................................................ 16V
SW Voltage (Note 2)
LT3420 ................................................................ 38V
LT3420-1............................................................ 50V
SEC Current ...................................................... ±200mA
R
FB
Current ........................................................... ±3mA
R
REF
Voltage ........................................................... 2.5V
CHARGE Voltage...................................................... 16V
CT Voltage .............................................................. 1.5V
ABSOLUTE AXI U RATI GS
W
WW
U
(Note 1)
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= V
BAT
= 3.3V, V
CHARGE
= V
CC
unless otherwise noted. (Note 3)
T
JMAX
= 125°C, θ
JA
= 100°C/W, θ
JC
= 45°C/W
(4-LAYER BOARD)
TOP VIEW
DD PACKAGE
10-LEAD (3mm × 3mm) PLASTIC DFN
10
9
6
7
8
4
5
3
2
1
C
T
CHARGE
DONE
SEC
SW
R
REF
V
BAT
R
FB
V
CC
GND
11
ORDER PART
NUMBER
LT3420EDD
LT3420EDD-1
T
JMAX
= 125°C, θ
JA
= 43°C/W, θ
JC
= 3°C/W
EXPOSED PAD IS GND (PIN 11)
AND MUST BE SOLDERED TO PCB
PACKAGE/ORDER INFORMATION
W
U
U
DD PART
MARKING
LBJW
LBJX
ORDER PART
NUMBER
MS PART MARKING
LTYH
LTAJG
LT3420EMS
LT3420EMS-1
DONE Voltage .......................................................... 16V
Current into DONE Pin .......................................... ±1mA
Maximum Junction Temperature .......................... 125°C
Operating Ambient Temperature Range
(Note 3) .............................................. –40°C to 85°C
Storage Temperature Range ................. – 40°C to 125°C
Lead Temperature (Soldering, 10 sec)
(For MS Package only) ..................................... 300°C
LT3420/LT3420-1
3
3420fb
V
BAT
(V)
2
TIME (s)
3420 G03
453
6
10
8
6
4
2
0
V
OUT
CHARGED
FROM
50V TO 320V
T
A
= 25°C
FIGURE 1 CIRCUIT
UNLESS OTHERWISE
NOTED.
C
OUT
= 220µF
C
OUT
= 100µF
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: Rated breakdown with LT3420 in power delivery mode and power
switch off.
Note 3: The LT3420/LT3420-1 are guaranteed to meet performance
specifications from 0°C to 70°C. Specifications over the –40°C to 85°C
PARAMETER CONDITIONS MIN TYP MAX UNITS
Primary Side Current Limit LT3420 (Note 5) 1.20 1.4 1.60 A
LT3420-1 (Note 5) 0.75 0.9 1.05 A
Secondary Side Current Limit LT3420 (Note 5) 20 40 50 mA
LT3420-1 (Note 5) 5 15 25 mA
Leakage Blanking Pulse Width LT3420 200 ns
LT3420-1 0 ns
Refresh Timer Charge/Discharge Current V
CT
= 0.75V 1.5 2.5 3.5 µA
Refresh Timer Upper Threshold 0.9 1.0 1.1 V
Refresh Timer Lower Threshold 0.45 0.5 0.55 V
Switch V
CESAT
LT3420, SW = 1A (Note 5) 220 340 mV
LT3420-1, SW = 0.5A (Note 5) 130 230 mV
Switch Leakage Current V
SW
= 38V (LT3420), V
SW
= 50V (LT3420-1) 0.01 1 µA
CHARGE Input Voltage High 1.5 V
CHARGE Input Voltage Low 0.2 V
CHARGE Pin Bias Current V
CHARGE
= 3V 4.5 15 µA
V
CHARGE
= 0V 0.01 0.1 µA
DONE Output Signal High 100k from V
CC
to DONE 3.3 V
DONE Output Signal Low 33µA into DONE Pin 100 200 mV
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= V
BAT
= 3.3V, V
CHARGE
= V
CC
unless otherwise noted. (Note 3)
operating temperature range are assured by design, characterization and
correlation with statistical process controls.
Note 4: Bias current flows out of R
FB
pin.
Note 5: Current limit and V
CESAT
guaranteed by design and/or correlation
to static test for DD package.
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Output Voltage in Refresh Mode,
LT3420
Output Voltage in Refresh Mode,
LT3420
Charge Time, LT3420
TEMPERATURE (°C)
–50
V
OUT
(V)
100
3420 G01
050
335
330
325
320
315
310
305
300
295
–25 25 75 125
FIGURE 1 CIRCUIT
V
CC
= 3.3V
V
BAT
= 3.3V
V
IN
(V)
2.5
V
OUT
(V)
3420 G02
4.03.53.0 5.55.04.5 6.0
FIGURE 1 CIRCUIT
V
CC
= V
IN
V
BAT
= V
IN
T
A
= 25°C
335
330
325
320
315
310
305
300
295
Graphs apply to both the LT3420 and LT3420-1 unless otherwise noted.
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P20

LT3420EMS#PBF

Mfr. #:
Buy LT3420EMS#PBF
Manufacturer:
Analog Devices / Linear Technology
Description:
Switching Voltage Regulators 1.4A Photoflash Capacitor Charger
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet