IC CHARGER PHOTOFLASH 10-DFN

LT3485EDD-2#PBF

Manufacturer Part NumberLT3485EDD-2#PBF
DescriptionIC CHARGER PHOTOFLASH 10-DFN
ManufacturerLinear Technology
LT3485EDD-2#PBF datasheet
 

Specifications of LT3485EDD-2#PBF

ApplicationsPhotoflash Capacitor Charger, XenonCurrent - Supply5mA
Voltage - Supply1.7 V ~ 10 VOperating Temperature-40°C ~ 85°C
Mounting TypeSurface MountPackage / Case10-DFN
Lead Free Status / RoHS StatusLead free / RoHS Compliant  
1
Page 1
2
Page 2
3
Page 3
4
Page 4
5
Page 5
6
Page 6
7
Page 7
8
Page 8
9
Page 9
10
Page 10
11
12
13
14
15
16
17
18
19
20
Page 1/20

Download datasheet (340Kb)Embed
Next
FEATURES
Integrated IGBT Driver
Voltage Output Monitor
Uses Small Transformers: 5.8mm × 5.8mm × 3mm
Operates from Two AA Batteries, Single Cell Li-Ion
or Any Supply from 1.8V up to 10V
No Output Voltage Divider Needed
No External Schottky Diode Required
Charges Any Size Photoflash Capacitor
Available in 10-Lead (3mm × 3mm) DFN
Fast Charge Time
VERSION
INPUT CURRENT (mA)
LT3485-3
750
LT3485-0
500
LT3485-2
350
LT3485-1
225
V
= V
= 3.6V
IN
BAT
100µF capacitor, 320V. *50µF capacitor
U
APPLICATIO S
Digital Camera and Cell Phone Flash Charger
U
TYPICAL APPLICATIO
LT3485-0 Photoflash Charger Uses High Efficiency 3mm Tall Transformers
DANGER HIGH VOLTAGE – OPERATION BY HIGH VOLTAGE TRAINED PERSONNEL ONLY
V
BAT
1:10.2
2 AA OR
1
4
1 TO 2 Li-Ion
4.7µF
2
5
SW
V
BAT
DONE
CHARGE
GND
LT3485-0
V
TO
CC
V
V
IN
MONT
5V
MICRO
IGBTPWR
0.22µF
IGBTIN
IGBTOUT
Photoflash Capacitor
Chargers with Output Voltage
Monitor and Integrated IGBT Drive
DESCRIPTIO
®
The LT
3485 family of photoflash chargers are highly inte-
grated ICs containing complete charger and IGBT drive
functions. The patented control technique of the LT3485-x
allows it to use extremely small transformers. Output voltage
detection requires no external circuitry. The turns ratio of the
transformer controls the final charge voltage. While charging,
the output voltage on the capacitor may be monitored by a
microcontroller from the monitor pin. Each device contains an
on-chip high voltage NPN power switch, which can withstand
negative voltages on the switch pin without an external
Schottky diode. The device features a V
CHARGE TIME (sec)
the use of two AA cells to charge the capacitor. The internal
2.5
circuitry operates from the V
3.7
primary current limit of 1.4A, whereas the LT3485-3, LT3485-2,
5.5
and LT3485-1 have current limits of 2A, 1A and 0.7A respec-
4.0*
tively. These different current limits result in tightly controlled
input currents.
The CHARGE pin gives full control of the part to the user.
Driving CHARGE low puts the part in shutdown. The DONE pin
indicates when the part has completed charging. The LT3485
series of parts are housed in a leadless (3mm × 3mm) DFN
package.
, 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 6636021.
320V
1M
150µF
A
2.2µF
PHOTOFLASH
600V
CAPACITOR
TRIGGER
T
FLASHLAMP
1
3
2
C
IGBT
3485 TA01
LT3485-0/LT3485-1/
LT3485-2/LT3485-3
U
pin, which allows
BAT
pin. The LT3485-0 has a
IN
LT3485-0 Charging Waveform
V
OUT
50V/DIV
AVERAGE
INPUT CURRENT
0.5A/DIV
V
= 3.6V
1s/DIV
IN
C
= 100µF
OUT
34850123fb
3485 TA02
1

LT3485EDD-2#PBF Summary of contents

  • Page 1

    ... The LT3485 series of parts are housed in a leadless (3mm × 3mm) DFN package. , 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 6636021. ...

  • Page 2

    ... EXPOSED PAD (11) IS GND, MUST BE SOLDERED TO PCB ORDER PART NUMBER LT3485EDD-0 LT3485EDD-1 LT3485EDD-2 LT3485EDD-3 Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: Consult LTC Marketing for parts specified with wider operating temperature ranges. ...

  • Page 3

    ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T PARAMETER Switch Leakage Current CHARGE Input Voltage High CHARGE Input Voltage Low Minimum Charge Pin Low Time DONE Output Signal High DONE Output Signal Low DONE Leakage Current IGBT Input Voltage ...

  • Page 4

    LT3485-0/LT3485-1/ LT3485-2/LT3485 TYPICAL PERFOR A CE CHARACTERISTICS curves use the circuit of Figure 9, LT3485-2 use the circuit of Figure 10 and LT3485-3 use the circuit of Figure 11 unless otherwise noted. LT3485-0 Charging Waveform V OUT 50V/DIV ...

  • Page 5

    W U TYPICAL PERFOR A CE CHARACTERISTICS curves use the circuit of Figure 9, LT3485-2 use the circuit of Figure 10 and LT3485-3 use the circuit of Figure 11 unless otherwise noted. LT3485-0 Efficiency 2.5V ...

  • Page 6

    LT3485-0/LT3485-1/ LT3485-2/LT3485 TYPICAL PERFOR A CE CHARACTERISTICS curves use the circuit of Figure 9, LT3485-2 use the circuit of Figure 10 and LT3485-3 use the circuit of Figure 11 unless otherwise noted. LT3485-0 Switching Waveform V SW 10V/DIV ...

  • Page 7

    CTIO S CHARGE (Pin 1): Charge Pin. A low (<0.3V) to high (>1V) transition on this pin puts the part into power delivery mode. Once the target voltage is reached, the part will stop charging ...

  • Page 8

    LT3485-0/LT3485-1/ LT3485-2/LT3485 CTIO AL BLOCK DIAGRA DONE V MONT SAMPLE AND HOLD CHARGE ONE- 1 SHOT IGBT DRIVER IN POWER 7 IGBTIN IGBT ...

  • Page 9

    U OPERATIO The LT3485-0/LT3485-1/LT3485-2/LT3485-3 are designed to charge photoflash capacitors quickly and efficiently. The operation of the part can be best understood by referring to Figure 1. When the CHARGE pin is first driven high, a one shot sets both ...

  • Page 10

    LT3485-0/LT3485-1/ LT3485-2/LT3485 APPLICATIO S I FOR ATIO Choosing the Right Device (LT3485-0/LT3485-1/LT3485-2/LT3485-3) The only difference between the four versions of the LT3485 is the peak current level. For the fastest possible charge time, use the LT3485-3. The LT3485-1 ...

  • Page 11

    ... SW pin, the parasitic capacitance of the transformer would become large. This will adversely affect the charge time of the photoflash circuit. Linear Technology has worked with several leading mag- netic component manufacturers to produce pre-designed flyback transformers for use with the LT3485-0/LT3485- 1/LT3485-2/LT3485-3 ...

  • Page 12

    LT3485-0/LT3485-1/ LT3485-2/LT3485 APPLICATIO S I FOR ATIO The peak current of the diode is simply LT3485-3 PK-SEC N 1 LT3485-0 PK-SEC LT3485-2 ...

  • Page 13

    U U APPLICATIO S I FOR ATIO GATE EMITTER Figure 6. IGBT Gate the capacitance closest to the terminal goes low but the capacitance further from the terminal remains high. This causes a small portion of the device to handle ...

  • Page 14

    LT3485-0/LT3485-1/ LT3485-2/LT3485 APPLICATIO S I FOR ATIO Board Layout The high voltage operation of the LT3485-0/LT3485-1/ LT3485-2/LT3485-3 demands careful attention to board layout. You will not get advertised performance with careless layout. Figure 7 shows the recommended com- ...

  • Page 15

    U TYPICAL APPLICATIO 2. Figure 8. LT3485-0 Photoflash Charger Uses High Efficiency 4mm Tall Transformer Figure 9. LT3485-1 Photoflash Charger Uses High Efficiency 3mm Tall Transformer T1 1:10.2 V BAT ...

  • Page 16

    LT3485-0/LT3485-1/ LT3485-2/LT3485-3 U TYPICAL APPLICATIO 2. Figure 10. LT3485-2 Photoflash Charger Uses High Efficiency 4mm Tall Transformer Figure 11. LT3485-3 Photoflash Charger Uses High Efficiency 3mm Tall Transformer 16 T1 ...

  • Page 17

    U TYPICAL APPLICATIO 2. Figure 12. LT3485-0 Photoflash Circuit Uses Tiny 3mm Tall Transformer Figure 13. Charge Time with TDK Transformers (Figures 11, 12, 13, 14 and 15) T1 1:10.2 V BAT 1. ...

  • Page 18

    LT3485-0/LT3485-1/ LT3485-2/LT3485-3 U TYPICAL APPLICATIO 2. Figure 14. LT3485-1 Photoflash Circuit Uses Tiny 3mm Tall Transformer Figure 15. LT3485-2 Photoflash Circuit Uses Tiny 3mm Tall Transformer 18 T1 1:10.2 V ...

  • Page 19

    ... SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights Package 10-Lead Plastic DFN (3mm × ...

  • Page 20

    ... DC/DC Converter for CCD Bias LT3463/LT3463A Dual Boost (250mA)/Inverting (250mA/400mA) DC/DC Converter for CCD Bias LT3484-0/LT3484-1/ Photoflash Capacitor Chargers LT3484-2 ThinSOT is a trademark of Linear Technology Corporation. Linear Technology Corporation 20 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● ...