MAX8685A/MAX8685C/MAX8685D/MAX8685F 19-0728 Rev 4 2/09 Xenon Photoflash Charger with IGBT Driver and Voltage Monitor General Description Features 2s to Charge 100F to 300V The MAX8685 family charges high-voltage photoflash capacitors quickly, while limiting peak drain from the Integrated IGBT Driver battery, through an efficient flyback switching regulator. Voltage-Monitor Output* The internal n-channel MOSFET improves efficiency Short-/Open-Circuit Protection over competing bipolar designs by lowering switch- voltage dropout. An integrated insulated gate bipolar Controlled Inrush Current transistor (IGBT) driver enables flash discharge and Programmable Input Current Limit Up to 2A reduces external component count. The device (MAX8685A) or 2.6A (MAX8685F)* includes an open-drain DONE output to indicate when Programmable Input Voltage-Overload Protection* the photoflash voltage has reached regulation. The Extended Battery Life with Input-Voltage device automatically refreshes the output voltage every Monitoring* 16s, thus efficiently maintains the capacitor charge level with minimum battery drain. Internal 2.6A Switch Robust Architecture Allows Use of Low-Cost The MAX8685A/MAX8685F feature an undervoltage Transformers input (UVI) monitor. UVI monitors the supply voltage and suspends switching if the input voltage drops High Accuracy Not Dependent on Transformer below a programmed threshold. The MAX8685A/ Turns Ratio MAX8685F also feature a voltage-monitor output that Automatic Refresh Mode Draws Minimal provides a scaled replica of the output voltage. The Quiescent Current voltage-monitor output is used for interfacing with a Charge-Done Indicator microprocessors internal A/D converter to assist in 3mm x 3mm, 14-Pin TDFN Package implementing red-eye reduction. (MAX8685A/MAX8685F) The MAX8685C/MAX8685D, with fixed peak-primary 2mm x 3mm, 8-Pin TDFN Package current limits of 1A and 1.6A, respectively, are offered in (MAX8685C/MAX8685D) a 2mm x 3mm, 8-pin TDFN package. The MAX8685A/ *MAX8685A/MAX8685F only. MAX8685F, with resistor-programmable current limits of up to 2A (max) and 2.6A (max), respectively, are offered Ordering Information in a 3mm x 3mm, 14-pin TDFN package. All devices operate over the -40C to +85C temperature range. PART PIN-PACKAGE T O P MA R K Typical Operating Circuit 14 TDFN - E P MAX8685AETD+ ADD 3mm x 3mm V BATT 8 TDFN - E P +1.5V +300V MAX8685CETA+ AAE 1:15 2mm x 3mm TO +10V 8 TDFN - E P MAX8685DETA+ AAF + 2mm x 3mm XENON 14 TDFN - E P FLASH MAX8685FETD+ ADY V CC ISET UVI LX 3mm x 3mm TUBE +2.5V TO +5.5V - V SEC CC Note: All devices are specified over the -40C to +85C operating temperature range. ISET FB +Denotes a lead(Pb)-free/RoHS-compliant package. EP= Exposed paddle. MAX8685A MAX8685F Applications MTR GND V CCT +2.5V Digital Cameras V CCT PGND TO Film Cameras +5.5V IGBT Cell-Phone Cameras TRIG GATE Personal Media Players Pin Configurations appear at end of data sheet. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim s website at www.maxim-ic.com. EVALUATION KIT AVAILABLEXenon Photoflash Charger with IGBT Driver and Voltage Monitor ABSOLUTE MAXIMUM RATINGS LX to PGND ............................................................-0.3V to +40V Continuous Power Dissipation EN, ISET, MTR, to GND ..............................-0.3V to (V + 0.3V) 8-Pin TDFN (derate 16.7mW/C above T = +70C) CC A UVI to GND.............................................................-0.3V to +12V (multilayer PCB) ........................................................1333mW V , V , FB, DONE to GND.................................-0.3V to +6V 14-Pin TDFN (derate 18.5mW/C above T = +70C) CC CCT A GATE, TRIG to PGND (MAX8685A/MAX8685F) (single-layer PCB) .....................................................1481mW ..............................................................-0.3V to (V + 0.3V) 14-Pin TDFN (derate 24.4mW/C above T = +70C) CCT A GATE, TRIG to EP (multilayer PCB) ........................................................1951mW (MAX8685C/MAX8685D).......................-0.3V to (V + 0.3V) Operating Temperature Range ...........................-40C to +85C CC PGND to GND (Note 1) .........................................-0.3V to +0.3V Junction Temperature Range ............................-40C to +150C SEC Current................................................................... 200mA Storage Temperature Range .............................-65C to +150C Current into DONE............................................................10mA Lead Temperature (soldering, 10s) .................................+300C Note 1: For the MAX8685C/MAX8685D, GND and PGND are internally connected to the exposed paddle (EP). All references to GND or PGND refer to the EP in the MAX8685C/MAX8685D. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = V = 3.3V, V = 3.3V (MAX8685A/MAX8685F only) V = 0, R = 93.1k (MAX8685A), R = 120k (MAX8685F) CC EN CCT FB ISET ISET V = 1.5V, T = -40C to +85C, unless otherwise noted.) (Notes 2 and 3) UVI A PARAMETER CONDITIONS MIN TYP MAX UNITS V CC V Voltage Range 2.5 5.5 V CC V rising 2.2 2.3 2.4 CC V Undervoltage Threshold V CC V falling 2.1 2.2 2.3 CC Switching at 300kHz 1.85 mA V Supply Current CC Not switching 60 100 A T = +25C 0.1 1 A V = 5.5V CCT V = 0, EN T = +85C 0.1 V Shutdown Current (MAX8685A/ A CC V = 5.5V, A CC MAX8685F) T = +25C 0.1 1 A V = 0 TRIG V = 0 CCT T = +85C 0.1 A T = +25C 0.1 1 A V Shutdown Current V = 0, V = 5.5V, CC EN CC A (MAX8685C/MAX8685D) V = 0 TRIG T = +85C 0.1 A LX V = 3.3V 0.18 0.4 CC LX On-Resistance I = 190mA LX V = 2.5V 0.2 0.5 CC T = +25C 0.1 1 A LX Off-Leakage V = 10V, V = 0 A LX EN T = +85C 0.1 A R = 93.1k 1.44 1.60 1.76 LX Peak Current Limit ISET T = 0C to +85C A A (MAX8685A Only) ISET = V 2.0 CC R = 120k 1.4625 1.625 1.7875 LX Peak Current Limit ISET T = 0C to +85C A A (MAX8685F Only) ISET = V 2.6 CC MAX8685C 1.0 LX Peak Current Limit T = 0C to +85C A A MAX8685D 1.6 Circuit of Figure 3 or Figure 4, output 90% LX Switching Frequency 300 kHz of final value 2 MAX8685A/MAX8685C/MAX8685D/MAX8685F