LT3468

Features:

 Highly Integrated IC Reduces Solution Size
Uses Small Transformers:
   5.8mm ´ 5.8mm ´ 3mm
 Fast Photoflash Charge Times:
4.6s for LT3468 (0V to 320V, 100mF, VIN = 3.6V)
5.5s for LT3468-1 (0V to 320V, 50mF, VIN = 3.6V)
 Controlled Input Current:
     500mA (LT3468)
     225mA (LT3468-1)
Supports Operation from Single Li-Ion Cell, or Any
   Supply from 2.5V up to 16V
 Adjustable Output Voltage
No Output Voltage Divider Needed
 Charges Any Size Photoflash Capacitor
 Low Profile (1mm) SOT-23 Package

Application

Digital / Film Camera Flash
PDA / Cell Phone Flash
Emergency Strobe


Specifications

VIN Voltage .............................................................. 16V
SW Voltage ................................................ 0.4V to 50V
CHARGE Voltage...................................................... 10V
DONE Voltage .......................................................... 10V
Current into DONE Pin .......................................... ±1mA
Maximum Junction Temperature .......................... 125°C
Operating Temperature Range (Note 2) ...40°C to 85°C
Storage Temperature Range ..................65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C

Description

The LT®3468/LT3468-1 are highly integrated ICs designed
to charge photoflash capacitors in digital and film cameras.
A new 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 while the LT3468-1 has
a 0.7A limit. These different current limit levels result in
well controlled input currents of 500mA for the LT3468
and 225mA for the LT3468-1. Aside from the differing
current limit, the two 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 housed in tiny low profile
(1mm) SOT-23 packages.