LT3420
PRODUCTIONPhotoflash Capacitor Chargers with Automatic Refresh
- Part Models
- 8
- 1ku List Price
- Starting From $4.21
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
Documentation
Data Sheet 1
User Guide 3
Design Note 1
Technical Articles 2
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) | ||
| LT3420EDD#TRPBF | 10-Lead DFN (3mm x 3mm w/ EP) | ||
| LT3420EDD-1#PBF | 10-Lead DFN (3mm x 3mm w/ EP) | ||
| LT3420EDD-1#TRPBF | 10-Lead DFN (3mm x 3mm w/ EP) | ||
| LT3420EMS#PBF | 10-Lead MSOP | ||
| LT3420EMS#TRPBF | 10-Lead MSOP | ||
| LT3420EMS-1#PBF | 10-Lead MSOP | ||
| LT3420EMS-1#TRPBF | 10-Lead MSOP |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Jun 5, 2024 - 24_0003 Epoxy Change from Henkel 8290 to 8290A for MSOP Package (2) |
||
| 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 |
||
| 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/SoftwareTools & Simulations
LTspice 1
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.
Evaluation Kits
LT3420EMS-1 | Strobe Capacitor Charger, High Voltage Supply, Vbatt = 1.8V - 6V, Vcc = 2.3V - 6V, Strobe Cap = 320V
Resources
LT3420EMS-1 | Strobe Capacitor Charger, High Voltage Supply, Vbatt = 1.8V - 6V, Vcc = 2.3V - 6V, Strobe Cap = 320V
Resources
LT3420EMS | Strobe Capacitor Charger, High Voltage Supply, Input = 1.8V to 16V, VOUT = 300V
Resources
LT3420EMS | Strobe Capacitor Charger, High Voltage Supply, Input = 1.8V to 16V, VOUT = 300V
Resources
LT3420EMS | Strobe Capacitor Charger, High Voltage Supply, 1.8V to 10V Input, 320VOUT
Resources
LT3420EMS | Strobe Capacitor Charger, High Voltage Supply, 1.8V to 10V Input, 320VOUT