特点
Highly Integrated IC Reduces Solution Size
Uses Small Transformers:
5.8mm x 5.8mm x 3mm
Fast Photoflash Charge Times:
4.6s for LT3468 (0V to 320V, 100μF, V
IN
= 3.6V)
5.7s for LT3468-2 (0V to 320V, 100μF, V
IN
= 3.6V)
5.5s for LT3468-1 (0V to 320V, 50μF, V
IN
= 3.6V)
Controlled Input Current:
500mA (LT3468)
375mA (LT3468-2)
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
典型应用
典型应用
描述
The LT?3468/LT3468-1/LT3468-2 are highly integrated 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.
*U.S. Patent # 6, 518, 733