LT3484EDCB-1

LT3484-0/LT3484-1/LT3484-2 Photoflash Capacitor Chargers FEATURES ■ ■ ■ DESCRIPTIO ■ ■ ■ ■ ■ ■ Highly Integrated IC in 2mm × 3mm DFN Package Reduces Solution Size Uses Small Transformers: 5.8mm × 5.8mm × 3mm Fast Photoflash Charge Times: 4.6s for LT3484-0 (0V to 320V, 100µF, VIN = 3.6V) 5.7s for LT3484-2 (0V to 320V, 100µF, VIN = 3.6V) 5.5s for LT3484-1 (0V to 320V, 50µF, VIN = 3.6V) Operates from Two AA Batteries, or Any Supply from 1.8V up to 16V Controlled Average Input Current 500mA (LT3484-0) 350mA (LT3484-2) 225mA (LT3484-1) No Output Voltage Divider Needed No External Schottky Diode Required Charges Any Size Photoflash Capacitor Available in 6-Lead 2mm × 3mm DFN Package The LT®3484 family of photoflash capacitor charger ICs is designed for use in digital camera and mobile phone applications where space is at a premium. The LT3484’s patented control technique allows it to use extremely small transformers, and the improved NPN power switch requires no external Schottky diode clamp, reducing solution size. Output voltage detection requires no external circuitry as the transformer turns ratio determines final charge voltage. The devices feature a VBAT pin, which allows the use of 2 alkaline cells to charge the capacitor. The LT3484-0, -2 and -1 have primary current limits of 1.4A, 1A and 0.7A respectively, resulting in tightly controlled average input current of 500mA, 350mA and 225mA respectively. The three versions are otherwise identical. 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 LT3484 series of parts are housed in a tiny low profile 2mm × 3mm DFN package. , LTC and LT 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 LT3484-0 Photoflash Charger Uses High Efficiency 3mm Tall Transformers DANGER HIGH VOLTAGE – OPERATION BY HIGH VOLTAGE TRAINED PERSONNEL ONLY VBAT 2AA OR 1 TO 2 Li-Ion 1:10.2 4.7µF 1 2 VBAT VIN 0.1µF 100k LT3484-0 DONE CHARGE 348412 TA01 LT3484-0 Charging Waveform VIN = 3.6V COUT = 100µF 4 5 320V + SW VCC 5V 150µF PHOTOFLASH CAPACITOR VOUT 50V/DIV AVERAGE INPUT CURRENT 1A/DIV GND U 1s/DIV 3484 TA02 U U 3484012f 1 LT3484-0/LT3484-1/LT3484-2 ABSOLUTE (Note 1) AXI U RATI GS PACKAGE/ORDER I FOR ATIO TOP VIEW DONE 1 CHARGE 2 VIN 3 7 6 VBAT 5 SW 4 SW VIN Voltage .............................................................. 16V VBAT Voltage ............................................................ 16V SW Voltage ................................................... –1V to 50V SW Pin Negative Current ...................................... –0.5A CHARGE Voltage ...................................................... 10V DONE Voltage .......................................................... 10V Current into DONE Pin .......................................... ±1mA Maximum Junction Temperature .......................... 125°C Operating Temperature Range .................–40°C to 85°C Storage Temperature Range ..................–65°C to 150°C DCB6 PACKAGE 6-LEAD (2mm × 3mm) PLASTIC DFN TJMAX = 125°C θJA = 73.5°C/W EXPOSED PAD (PIN 7) IS GND, MUST BE SOLDERED TO PCB ORDER PART NUMBER LT3484EDCB-0 LT3484EDCB-1 LT3484EDCB-2 DCB6 PART MARKING LBTM LBTN LBTP 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. 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 Quiescent Current VCC Voltage Range VBAT Voltage Range Switch Current Limit LT3484-0 LT3484-2 LT3484-1 LT3484-0, ISW = 1A LT3484-2, ISW = 650mA LT3484-1, ISW = 400mA Measured as VSW – VIN 300ns Pulse Width Measured as VSW – VIN VCHARGE = 3V VCHARGE = 0V VIN = VSW = 5V, in Shutdown ● ● ● ● ● ELECTRICAL CHARACTERISTICS CONDITIONS Not Switching VCHARGE = 0V ● ● MIN TYP 5 0 MAX 8 1 16 16 UNITS mA µA V V A A A mV mV mV V mV mV µA µA µA V V V mV nA 2.5 1.7 1.1 0.75 0.45 1.2 0.85 0.55 330 210 150 31 10 31.5 200 60 65 0 0.01 1 1.3 0.95 0.65 430 280 200 32 400 120 100 0.1 1 0.3 Switch VCESAT VOUT Comparator Trip Voltage VOUT Comparator Overdrive DCM Comparator Trip Voltage CHARGE Pin Current Switch Leakage Current CHARGE Input Voltage High CHARGE Input Voltage Low DONE Output Signal High DONE Output Signal Low DONE Leakage Current 100kΩ from VIN to DONE 33µA into DONE Pin VDONE = 3V, DONE NPN Off 3 100 20 200 100 Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. 3484012f 2 U W U U WW W LT3484-0/LT3484-1/LT3484-2 LT3484-0 curves use the circuit of Figure 6, LT3484-1 curves use the circuit of Figure 7 and LT3484-2 use the circuit of Figure 8, TA = 25°C unless otherwise noted. LT3484-0 Charging Waveform VIN = 3.6V COUT = 100µF TYPICAL PERFOR A CE CHARACTERISTICS VIN = 3.6V COUT = 50µF VOUT 50V/DIV AVERAGE INPUT CURRENT 1A/DIV 1s/DIV LT3484-0 Charge Time 10 9 8 CHARGE TIME (s) CHARGE TIME (s) 6 5 4 3 2 1 0 2 100µF CHARGE TIME (s) 7 50µF 3 4 5 VIN (V) 6 LT3484-0 Output Voltage 327 326 325 VOUT (V) VOUT (V) TA = – 40°C TA = 25°C TA = 85°C 324 323 322 321 320 2 3 4 5 VIN (V) 3484 G07 324 323 322 321 320 VOUT (V) 6 UW 3484 G01 LT3484-1 Charging Waveform LT3484-2 Charging Waveform VIN = 3.6V COUT = 100µF VOUT 50V/DIV VOUT 50V/DIV AVERAGE INPUT CURRENT 0.5A/DIV 1s/DIV 3484 G02 AVERAGE INPUT CURRENT 0.5A/DIV 1s/DIV 3484 G03 LT3484-1 Charge Time 10 9 8 7 6 5 4 3 2 1 0 7 8 3484 G04 LT3484-2 Charge Time 10 9 8 50µF 7 6 5 4 3 2 1 0 100µF 50µF 20µF 2 3 4 5 VIN (V) 6 7 8 3484 G05 2 3 4 5 VIN (V) 6 7 8 3484 G06 LT3484-1 Output Voltage 327 326 325 325 324 323 322 321 2 3 4 5 VIN (V) 3484 G08 LT3484-2 Output Voltage 327 326 TA = – 40°C TA = 25°C TA = 85°C TA = – 40°C TA = 25°C TA = 85°C 7 8 6 7 8 2 3 4 5 VIN (V) 6 7 8 3484 G09 3484012f 3 LT3484-0/LT3484-1/LT3484-2 LT3484-0 curves use the circuit of Figure 6, LT3484-1 curves use the circuit of Figure 7 and LT3484-2 use the circuit of Figure 8, TA = 25°C unless otherwise noted. LT3484-0 Switch Current Limit 1.5 0.70 TYPICAL PERFOR A CE CHARACTERISTICS 1.4 CURRENT LIMIT (A) CURRENT LIMIT (A) 0.62 CURRENT LIMIT (A) 100 1.3 1.2 1.1 – 40 – 20 40 20 0 60 TEMPERATURE (°C) LT3484-0 Input Current 800 VIN = 2.4 VIN = 3.6 VIN = 4.2 600 300 400 CURRENT (mA) CURRENT (mA) 400 200 CURRENT (mA) 200 0 0 50 100 150 200 250 300 3484 G13 VOUT (V) LT3484-0 Efficiency 90 85 80 75 90 85 80 75 EFFICIENCY (%) EFFICIENCY (%) 70 65 60 55 50 45 40 50 100 200 150 VOUT (V) VIN = 2.4 VIN = 3.6 VIN = 4.2 250 300 3484 G16 70 65 60 55 50 45 40 50 100 200 150 VOUT (V) VIN = 2.4 VIN = 3.6 VIN = 4.2 250 300 3484 G17 EFFICIENCY (%) 4 UW 80 100 3484 G10 LT3484-1 Switch Current Limit 1.00 LT3484-2 Switch Current Limit 0.66 0.96 0.92 0.58 0.88 0.54 0.84 0.50 – 40 – 20 40 20 0 60 TEMPERATURE (°C) 80 0.80 – 40 – 20 40 20 0 60 TEMPERATURE (°C) 80 100 3484 G11 3484 G12 LT3484-1 Input Current 600 VIN = 2.4 VIN = 3.6 VIN = 4.2 450 LT3484-2 Input Current VIN = 2.4 VIN = 3.6 VIN = 4.2 300 100 150 0 0 50 100 150 200 250 300 3484 G14 0 0 50 100 150 200 250 300 3484 G15 VOUT (V) VOUT (V) LT3484-1 Efficiency 90 85 80 75 70 65 60 55 50 45 40 LT3484-2 Efficiency VIN = 2.4 VIN = 3.6 VIN = 4.2 50 100 200 150 VOUT (V) 250 300 3484 G18 3484012f LT3484-0/LT3484-1/LT3484-2 LT3484-0 curves use the circuit of Figure 6, LT3484-1 curves use the circuit of Figure 7 and LT3484-2 use the circuit of Figure 8, TA = 25°C unless otherwise noted. LT3484-0 Switching Waveform VIN = 3.6V VOUT = 100V TYPICAL PERFOR A CE CHARACTERISTICS VSW 10V/DIV IPRI 1A/DIV 1µs/DIV 3484 G19 LT3484-0 Switching Waveform VIN = 3.6V VOUT = 300V VSW 10V/DIV IPRI 1A/DIV 1µs/DIV SWITCH CURRENT (mA) UW LT3484-1 Switching Waveform VIN = 3.6V VOUT = 100V VSW 10V/DIV IPRI 1A/DIV 1µs/DIV LT3484-2 Switching Waveform VIN = 3.6V VOUT = 100V VSW 10V/DIV IPRI 1A/DIV 3484 G22 1µs/DIV 3484 G21 LT3484-1 Switching Waveform VIN = 3.6V VOUT = 300V LT3484-2 Switching Waveform VIN = 3.6V VOUT = 300V VSW 10V/DIV IPRI 1A/DIV 3484 G20 VSW 10V/DIV IPRI 1A/DIV 1µs/DIV 3484 G23 1µs/DIV 3484 G24 LT3484-0/LT3484-1/LT3484-2 Switch Breakdown Voltage 10 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) 3484 G25 T = 25°C T = –40°C T = 85°C 3484012f 5 LT3484-0/LT3484-1/LT3484-2 PI FU CTIO S DONE (Pin 1): Open NPN Collector Indication Pin. When target output voltage is reached, NPN turns on, pulling Pin 1 low. This pin needs a pull-up resistor or current source. CHARGE (Pin 2): 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 1:8 to 1:12 >500 >1.6 500 >0.8 500 >1.0