LT3420EMS-1#PBF Analog Devices

LT3420/LT3420-1 Photoflash Capacitor Chargers with Automatic Refresh FEATURES DESCRIPTIO Charges 220F to 320V in 3.7 Seconds The LT 3420/LT3420-1 charge high voltage photoflash from 5V (LT3420) capacitors quickly and efficiently. Designed for use in both Charges 100F to 320V in 3.5 Seconds digital and film cameras, these devices use a flyback from 5V (LT3420-1) topology to achieve efficiencies up to four times better Charges Any Size Photoflash Capacitor than competing flash modules. A unique adaptive off-time Supports Operation from Two AA Cells or Any control algorithm* maintains current-limited continuous Supply from 1.8V to 16V mode transformer operation throughout the entire charge Controlled Peak Switch Current: 1.4A (LT3420) cycle, eliminating the high inrush current often found in 1.0A (LT3420-1) modules. Controlled Input Current: 840mA (LT3420) The LT3420/LT3420-1 output voltage sensing scheme* 450mA (LT3420-1) monitors the flyback voltage to indirectly regulate the Uses Standard Transformers output voltage, eliminating an output resistor divider or Efficient Flyback Operation (>75% Typical) discrete zener diode. This feature allows the capacitor to Adjustable Output be held at a fully charged state without excessive power Automatic Refresh consumption. Automatic refresh (which can be defeated) Charge Complete Indicator allows the capacitor to remain charged while consuming No High Voltage Zener Diode Required an average input current of about 2mA, at a user-defined No Output Voltage Divider Required refresh rate. A logic high on the CHARGE pin initiates Small 10-Lead MSOP Package charging, while the DONE pin signals that the capacitor is Small 10-Lead (3mm 3mm) DFN Package fully charged. U The LT3420/LT3420-1 are available in 10-Lead MSOP and APPLICATIO S (3mm 3mm) DFN packages. Digital Camera Flash Unit , LTC and LT are registered trademarks of Linear Technology Corporation. All other Film Camera Flash Unit trademarks are the property of their respective owners. *Protected by U.S. Patents including 6518733. High Voltage Power Supplies TYPICAL APPLICATIO T1 1:10 T1 V (3mm TALL) V 1:12 BAT BAT 320V 320V 1.8V TO 6V 1.8V TO 6V 5 8 4 5,6 INPUT CURRENT C1 C1 D1 INPUT CURRENT D1 4.7F 450mA 4.7F 350mA 3,4 3 6 1 60.4k 51.1k 2 3 6 2 3 6 C3 C3 V R SW V R SW BAT FB BAT FB 100F + 220F + V 4 4 CC 7 V 7 CC V SEC 330V CC V SEC 330V CC 2.5V TO 6V 2.5V TO 10V C2 C2 PHOTOFLASH PHOTOFLASH 4.7F LT3420-1 4.7F LT3420 CAPACITOR CAPACITOR 9 9 CHARGE CHARGE CHARGE CHARGE 1 1 8 8 R DONE REF R DONE DONE DONE REF C GND GND T C T 10 5 10 5 2k 2k 0.1F 0.1F C1, C2: 4.7F, X5R or X7R, 6.3V C1, C2: 4.7F, X5R or X7R, 10V DANGER HIGH VOLTAGE C3: RUBYCON 100F PHOTOFLASH CAPACITOR C3: RUBYCON 220F PHOTOFLASH CAPACITOR OPERATION BY HIGH VOLTAGE 3420 F02 3420 F01 T1: TDK SRW10EPC-U01H003 FLYBACK TRANSFORMER TRAINED PERSONNEL ONLY T1: KIJIMA MUSEN SBL-5.6S-2 D1: VISHAY GSD2004S SOT-23 D1: VISHAY GSD2004S SOT-23 DUAL DIODE. DIODES CONNECTED IN SERIES DUAL DIODE. DIODES CONNECTED IN SERIES Figure 1. High Charge Rate LT3420 Photoflash Circuit Figure 2. Small Size LT3420-1 Photoflash Circuit 3420fb 1 U ULT3420/LT3420-1 ABSOLUTE AXI U RATI GS (Note 1) DONE Voltage .......................................................... 16V V Voltage .............................................................. 16V CC Current into DONE Pin .......................................... 1mA V Voltage ............................................................ 16V BAT Maximum Junction Temperature .......................... 125C SW Voltage (Note 2) Operating Ambient Temperature Range LT3420 ................................................................ 38V (Note 3) .............................................. 40C to 85C LT3420-1............................................................ 50V Storage Temperature Range ................. 40C to 125C SEC Current ...................................................... 200mA Lead Temperature (Soldering, 10 sec) R Current ........................................................... 3mA FB (For MS Package only) ..................................... 300C R Voltage ........................................................... 2.5V REF CHARGE Voltage...................................................... 16V CT Voltage .............................................................. 1.5V PACKAGE/ORDER INFORMATION ORDER PART ORDER PART TOP VIEW NUMBER NUMBER TOP VIEW 10 R 1 C REF T R 1 10 C REF T V 2 9 CHARGE LT3420EDD BAT LT3420EMS V 2 9 CHARGE BAT R 3 11 8 DONE FB LT3420EDD-1 R 3 8 DONE FB LT3420EMS-1 V 4 7 SEC V 4 7 SEC CC CC GND 5 6 SW GND 5 6 SW DD PART MS PACKAGE MS PART MARKING 10-LEAD PLASTIC MSOP DD PACKAGE MARKING 10-LEAD (3mm 3mm) PLASTIC DFN T = 125C, = 100C/W, = 45C/W JMAX JA JC LTYH (4-LAYER BOARD) LBJW T = 125C, = 43C/W, = 3C/W JMAX JA JC LTAJG EXPOSED PAD IS GND (PIN 11) LBJX AND MUST BE SOLDERED TO PCB Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25C. V = V = 3.3V, V = V unless otherwise noted. (Note 3) A CC BAT CHARGE CC PARAMETER CONDITIONS MIN TYP MAX UNITS Minimum Operating Voltage, V 2.2 2.5 V CC Maximum Operating Voltage, V 16 V CC V UVLO Hysteresis 40 mV CC Minimum V Voltage 1.6 1.8 V BAT Maximum V Voltage 16 V BAT V UVLO Hysteresis 275 mV BAT R Threshold Voltage 0.98 1.00 1.02 V REF 0.975 1.025 V R Pin Bias Current V = 0V, Switching 2 4 A REF RREF V = V 0.2V (Note 4) RFB BAT Quiescent Current V = 1.1V, Not Switching 90 130 A RREF Quiescent Current in Shutdown V = 0V, V = 3.3V 0.01 1 A CHARGE IN 3420fb 2 U W U U WWW