LT3420

PRODUCTION

Photoflash Capacitor Chargers with Automatic Refresh

Data Sheet Product Selection Table

Part Models: 8
1ku List Price: Starting From $3.32

Viewing:

Overview

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

The LT3420/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.

*Protected by U.S. Patents including 6518733.

Applications

Digital Camera Flash Unit
Film Camera Flash Unit
High Voltage Power Supplies

Part Models: 8
1ku List Price: Starting From $3.32

Documentation

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.

Part Model	Pin/Package Drawing	Documentation	CAD Symbols, Footprints, and 3D Models
LT3420EDD#PBF	10-Lead DFN (3mm x 3mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT3420EDD#TRPBF	10-Lead DFN (3mm x 3mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT3420EDD-1#PBF	10-Lead DFN (3mm x 3mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT3420EDD-1#TRPBF	10-Lead DFN (3mm x 3mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT3420EMS#PBF	10-Lead MSOP	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT3420EMS#TRPBF	10-Lead MSOP	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT3420EMS-1#PBF	10-Lead MSOP	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT3420EMS-1#TRPBF	10-Lead MSOP	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys

Part Models	Product Lifecycle	PCN

Jun 5, 2024 - 24_0003 Epoxy Change from Henkel 8290 to 8290A for MSOP Package (2)
		PCN24_0003_Form Material_Report Qualification Results Summary Delta Qualification Matrix
LT3420EMS#PBF	PRODUCTION
LT3420EMS#TRPBF	PRODUCTION
LT3420EMS-1#PBF	PRODUCTION
LT3420EMS-1#TRPBF	PRODUCTION
Feb 4, 2020 - 20_0130 Laser Top Mark Conversion for 10-Lead MSOP Packages Assembled in ADPG and UTAC
		PCN20_0130_Form Material_Report
LT3420EMS#PBF	PRODUCTION
LT3420EMS#TRPBF	PRODUCTION
LT3420EMS-1#PBF	PRODUCTION
LT3420EMS-1#TRPBF	PRODUCTION

This is the most up-to-date revision of the Data Sheet.

Software Resources

Can't find the software or driver you need?

Request a Driver/Software

Tools & Simulations

LTspice 1

LT3420 Demo Circuit - High Charge Rate Strobe Capacitor Charger (2.5-6V to 320V)

Models for the following parts are available in LTspice:

LT3420
LT3420-1

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.