LT3468/LT3468-1/LT3468-2

1

346812fa

FEATURES

DESCRIPTIO

APPLICATIO S

5.8mm × 5.8mm × 3mm

500mA (LT3468)

375mA (LT3468-2)

225mA (LT3468-1)

■

Supports Operation from Single Li-Ion Cell, or Any

Supply from 2.5V up to 16V

■

No Output Voltage Divider Needed

Photoflash Capacitor

Chargers in ThinSOT

TM

The LT

ICs designed to charge photoflash capacitors in digital and

film cameras. A patented control technique* allows for the

use of extremely small transformers. Each device contains

an on-chip high voltage NPN power switch. Output voltage

detection* is completely contained within the device,

eliminating the need for any discrete zener diodes or

resistors. The output voltage can be adjusted by simply

changing the turns ratio of the transformer. The LT3468

has a primary current limit of 1.4A, the LT3468-2 has a 1A

limit, and the LT3468-1 has a 0.7A limit. These different

current limit levels result in well controlled input currents

of 500mA for the LT3468, 375mA for the LT3468-2 and

225mA for the LT3468-1. Aside from the differing current

limit, the three devices are otherwise equivalent.

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

LT3468 series of parts are available in tiny low profile

(1mm) SOT-23 packages.

DANGER HIGH VOLTAGE – OPERATION BY HIGH VOLTAGE

TRAINED PERSONNEL ONLY

LT3468 Photoflash Charger Uses

High Efficiency 4mm Tall Transformer

LT3468

CHARGE

GND

SW

+

DONE

DONE

CHARGE

4.7µF

100k

1:10.2

VIN

2.5V TO 8V

320V

1

2

4

5

346812 TA01

100µF

LT3468 Charging Waveform

3468 G01

1s/DIV

50V/DIV

AVERAGE

INPUT

CURRENT

1A/DIV

TYPICAL APPLICATIO

, LTC and LT are registered trademarks of Linear Technology Corporation.

ThinSOT is a trademark of Linear Technology Corporation.

All other trademarks are the property of their respective owners.

*Protected by U.S. Patents, including 6518733.