LT3485-1

LT3485-0/LT3485-1/ LT3485-2/LT3485-3 Photoflash Capacitor Chargers with Output Voltage Monitor and Integrated IGBT Drive FEATURES ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO Integrated IGBT Driver Voltage Output Monitor Uses Small Transformers: 5.8mm × 5.8mm × 3mm Operates from Two AA Batteries, Single Cell Li-Ion or Any Supply from 1.8V up to 10V No Output Voltage Divider Needed No External Schottky Diode Required Charges Any Size Photoflash Capacitor Available in 10-Lead (3mm × 3mm) DFN VERSION LT3485-3 LT3485-0 LT3485-2 LT3485-1 INPUT CURRENT (mA) 750 500 350 225 CHARGE TIME (sec) 2.5 3.7 5.5 4.0* Fast Charge Time VIN = VBAT = 3.6V 100µF capacitor, 320V. *50µF capacitor The LT®3485 family of photoflash chargers are highly integrated ICs containing complete charger and IGBT drive functions. The patented control technique of the LT3485-x allows it to use extremely small transformers. Output voltage detection requires no external circuitry. The turns ratio of the transformer controls the final charge voltage. While charging, the output voltage on the capacitor may be monitored by a microcontroller from the monitor pin. Each device contains an on-chip high voltage NPN power switch, which can withstand negative voltages on the switch pin without an external Schottky diode. The device features a VBAT pin, which allows the use of two AA cells to charge the capacitor. The internal circuitry operates from the VIN pin. The LT3485-0 has a primary current limit of 1.4A, whereas the LT3485-3, LT3485-2, and LT3485-1 have current limits of 2A, 1A and 0.7A respectively. These different current limits result in tightly controlled input currents. 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 LT3485 series of parts are housed in a leadless (3mm × 3mm) DFN package. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 6636021. APPLICATIO S ■ Digital Camera and Cell Phone Flash Charger TYPICAL APPLICATIO VBAT 2 AA OR 1 TO 2 Li-Ion 1:10.2 4.7µF 1 2 VBAT DONE CHARGE GND LT3485-0 VCC 5V 0.22µF VIN IGBTPWR IGBTIN IGBTOUT VMONT SW LT3485-0 Photoflash Charger Uses High Efficiency 3mm Tall Transformers DANGER HIGH VOLTAGE – OPERATION BY HIGH VOLTAGE TRAINED PERSONNEL ONLY 320V 4 1M 150µF PHOTOFLASH CAPACITOR 2.2µF 600V TRIGGER T 1 2 TO MICRO 3 C AVERAGE INPUT CURRENT 0.5A/DIV • • 5 A VOUT 50V/DIV FLASHLAMP IGBT 3485 TA01 U LT3485-0 Charging Waveform VIN = 3.6V COUT = 100µF 1s/DIV 3485 TA02 U U 34850123fb 1 LT3485-0/LT3485-1/ LT3485-2/LT3485-3 ABSOLUTE (Note 1) AXI U RATI GS PACKAGE/ORDER I FOR ATIO TOP VIEW CHARGE VBAT VIN SW SW 1 2 3 4 5 11 10 VMONT 9 DONE 8 IGBTPWR 7 IGBTIN 6 IGBTOUT VIN Voltage .............................................................. 10V VBAT Voltage ............................................................ 10V SW Voltage ................................................... –1V to 50V SW Pin Negative Current ...................................... –0.5A CHARGE Voltage ...................................................... 10V IGBTIN Voltage ........................................................ 10V IGBTOUT Voltage ..................................................... 10V DONE Voltage .......................................................... 10V IGBTPWR Voltage .................................................... 10V VMONT Voltage ......................................................... 10V Current into DONE Pin ............................... 0.2mA/–1mA Maximum Junction Temperature .......................... 125°C Operating Temperature Range (Note 2) ... –40°C to 85°C Storage Temperature Range .................. –65°C to 125°C DD PACKAGE 10-LEAD (3mm ´ 3mm) PLASTIC DFN TJMAX = 125°C θJA = 43°C/W EXPOSED PAD (11) IS GND, MUST BE SOLDERED TO PCB ORDER PART NUMBER LT3485EDD-0 LT3485EDD-1 LT3485EDD-2 LT3485EDD-3 DD PART MARKING LBRH LBVN LBVP LBTK Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS PARAMETER Quiescent Current VIN Voltage Range VBAT Voltage Range Switch Current Limit The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = VBAT = VCHARGE = 3V, unless otherwise noted. CONDITIONS Not Switching VCHARGE = 0V ● ● MIN TYP 5 0 2.5 1.7 1.6 1.1 0.75 0.45 1.7 1.2 0.85 0.55 310 210 170 100 31.5 200 45 65 0 MAX 8 1 10 10 1.8 1.3 0.95 0.65 400 300 225 175 32 400 120 100 0.1 UNITS mA µA V V A A A A mV mV mV mV V mV mV µA µA Switch VCESAT VOUT Comparator Trip Voltage VOUT Comparator Overdrive DCM Comparator Trip Voltage CHARGE Pin Current LT3485-3 LT3485-0 LT3485-2 LT3485-1 LT3485-3, ISW = 1.5A LT3485-0, ISW = 1A LT3485-2, ISW = 700mA LT3485-1, ISW = 400mA Measured as VSW – VIN 300ns Pulse Width Measured as VSW – VIN VCHARGE = 3V VCHARGE = 0V ● ● 31 10 34850123fb 2 U W U U WW W LT3485-0/LT3485-1/ LT3485-2/LT3485-3 The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = VBAT = VCHARGE = 3V, unless otherwise noted. PARAMETER Switch Leakage Current CHARGE Input Voltage High CHARGE Input Voltage Low Minimum Charge Pin Low Time DONE Output Signal High DONE Output Signal Low DONE Leakage Current IGBT Input Voltage High IGBT Input Voltage Low IGBT Output Rise Time IGBT Output Fall Time VOUT Monitor Accuracy Monitor Output Current Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. COUT = 4000pF, IGBTPWR = 5V, 10%→90% COUT = 4000pF, IGBTPWR = 5V, 90%→10% SW – VBAT = 20V SW – VBAT = 30V High→Low→High 100kΩ from VIN to DONE 33µA into DONE Pin VDONE = 3V, DONE NPN Off ● ● ELECTRICAL CHARACTERISTICS CONDITIONS VIN = VSW = 5V, in Shutdown MIN ● ● ● TYP 0.01 MAX 1 0.3 UNITS µA V V µs V 1 20 3 140 20 1.5 0.3 450 340 625 940 200 200 100 mV nA V V ns ns mV mV µA 610 920 640 960 Note 2: The LTC3485E-X is guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the –40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. 34850123fb 3 LT3485-0/LT3485-1/ LT3485-2/LT3485-3 LT3485-0 curves use the circuit of Figure 8, LT3485-1 curves use the circuit of Figure 9, LT3485-2 use the circuit of Figure 10 and LT3485-3 use the circuit of Figure 11 unless otherwise noted. LT3485-0 Charging Waveform LT3485-1 Charging Waveform LT3485-2 Charging Waveform TYPICAL PERFOR A CE CHARACTERISTICS VOUT 50V/DIV AVERAGE INPUT CURRENT 1A/DIV VIN = 3.6V COUT = 50µF 0.5s/DIV LT3485-3 Charging Waveform CHARGE TIME (SECONDS) VOUT 50V/DIV 4 3 2 1 INPUT CURRENT (mA) AVERAGE INPUT CURRENT 1A/DIV V = 3.6V IN COUT = 50µF 0.5s/DIV LT3485-1 Input Current 250 400 200 INPUT CURRENT (mA) INPUT CURRENT (mA) INPUT CURRENT (mA) 150 100 50 0 0 50 100 150 200 VOUT (V) 250 300 3485 G07 4 UW 2.5V 3.6V 4.2V VOUT 50V/DIV VOUT 50V/DIV 3485 G01 AVERAGE INPUT CURRENT 0.5A/DIV VIN = 3.6V COUT = 50µF 0.5s/DIV 3485 G02 AVERAGE INPUT CURRENT 0.5A/DIV V = 3.6V IN COUT = 50µF 0.5s/DIV 3485 G03 Charge Time 6 LT3485-0 Input Current COUT = 50µF 600 500 LT3485-1 5 LT3485-2 400 300 200 100 2.5V 3.6V 4.2V 0 50 100 150 200 VOUT (V) 250 300 3485 G06 3485 G04 LT3485-0 0 2 3 4 LT3485-3 5 VIN (V) 6 7 8 1635 G05 0 LT3485-2 Input Current 900 800 300 LT3485-3 Input Current 700 600 500 400 300 200 100 0 0 50 100 150 200 VOUT (V) 250 300 3485 G09 200 100 2.5V 3.6V 4.2V 0 0 50 100 150 200 VOUT (V) 250 300 3485 G08 2.5V 3.6V 4.2V 34850123fb LT3485-0/LT3485-1/ LT3485-2/LT3485-3 LT3485-0 curves use the circuit of Figure 8, LT3485-1 curves use the circuit of Figure 9, LT3485-2 use the circuit of Figure 10 and LT3485-3 use the circuit of Figure 11 unless otherwise noted. LT3485-0 Efficiency 90 90 TYPICAL PERFOR A CE CHARACTERISTICS LT3485-1 Efficiency 80 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 70 60 50 40 50 100 150 200 VOUT (V) 250 LT3485-3 Efficiency 90 322 80 EFFICIENCY (%) VOUT (V) 60 319 VOUT (V) 70 50 40 50 100 150 200 VOUT (V) 250 LT3485-2 Output Voltage 328 327 326 VOUT (V) 325 324 323 322 318 –40°C 25°C 85°C 322 CURRENT LIMIT (mA) VOUT (V) 2 3 4 5 VIN (V) 6 UW 2.5V 3.6V 4.2V 300 3485 G10 LT3485-2 Efficiency 90 80 80 70 70 60 60 50 2.5V 3.6V 4.2V 50 100 150 200 VOUT (V) 250 300 3485 G11 50 2.5V 3.6V 4.2V 50 100 150 200 VOUT (V) 250 300 3485 G12 40 40 LT3485-0 Output Voltage 322 LT3485-1 Output Voltage 321 321 320 320 319 2.5V 3.6V 4.2V 300 3485 G13 318 –40°C 25°C 85°C 2 3 4 5 VIN (V) 6 7 8 3485 G14 318 317 –40°C 25°C 85°C 2 3 4 5 VIN (V) 6 7 8 3485 G15 317 LT3485-3 Output Voltage 2000 LT3485 Switch Current Limits LT3485-3 321 1600 LT3485-0 LT3485-2 800 LT3485-1 400 320 1200 319 –40°C 25°C 85°C 2 3 4 5 VIN (V) 6 7 8 3485 G17 317 7 8 3485 G16 0 –40 –20 40 20 0 60 TEMPERATURE (°C) 80 100 3485 G18 34850123fb 5 LT3485-0/LT3485-1/ LT3485-2/LT3485-3 LT3485-0 curves use the circuit of Figure 8, LT3485-1 curves use the circuit of Figure 9, LT3485-2 use the circuit of Figure 10 and LT3485-3 use the circuit of Figure 11 unless otherwise noted. LT3485-0 Switching Waveform LT3485-1 Switching Waveform LT3485-2 Switching Waveform TYPICAL PERFOR A CE CHARACTERISTICS VSW 10V/DIV IPRI 1A/DIV VIN = 3.6V VOUT = 100V 1µs/DIV 3485 G19 LT3485-3 Switching Waveform VSW 10V/DIV IPRI 2A/DIV VIN = 3.6V VOUT = 100V 1µs/DIV 3485 G22 LT3485-2 Switching Waveform SWITCH CURRENT (mA) VSW 10V/DIV IPRI 1A/DIV VIN = 3.6V VOUT = 300V 1µs/DIV 3485 G25 6 UW VSW 10V/DIV IPRI 1A/DIV VIN = 3.6V VOUT = 100V 1µs/DIV 3485 G20 VSW 10V/DIV IPRI 1A/DIV VIN = 3.6V VOUT = 100V 1µs/DIV 3485 G21 LT3485-0 Switching Waveform LT3485-1 Switching Waveform VSW 10V/DIV VSW 10V/DIV IPRI 1A/DIV VIN = 3.6V VOUT = 300V 1µs/DIV 3485 G23 IPRI 1A/DIV VIN = 3.6V VOUT = 300V 1µs/DIV 3485 G24 LT3485-3 Switching Waveform 10 LT3485-0/LT3485-1/LT3485-2/ LT3485-3 Switch Breakdown Voltage SW PIN IS RESISTIVE UNTIL BREAKDOWN 9 VOLTAGE DUE TO INTEGRATED RESISTORS. THIS DOES NOT INCREASE 8 QUIESCENT CURRENT OF PART 7 6 5 4 3 2 1 0 0 VIN = VCHARGE = 5V 10 20 30 40 50 60 70 80 90 100 SWITCH VOLTAGE (V) 3485 G27 VSW 10V/DIV IPRI 2A/DIV VIN = 3.6V VOUT = 300V 1µs/DIV 3485 G26 T = 25°C T = –40°C T = 85°C 34850123fb LT3485-0/LT3485-1/ LT3485-2/LT3485-3 PI FU CTIO S CHARGE (Pin 1): Charge Pin. A low (1V) transition on this pin puts the part into power delivery mode. Once the target voltage is reached, the part will stop charging the output. Toggle this pin to start charging again. Bringing the pin low (5 100 to 300 8 to 12 >500 >1.6 500 >0.8 500 >1.0 500 >2