A8739EEETR-T Allegro Microsystems Inc, A8739EEETR-T Datasheet
A8739EEETR-T
Specifications of A8739EEETR-T
Related parts for A8739EEETR-T
A8739EEETR-T Summary of contents
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Ultra-Small Mobile Adjustable Xenon Photoflash Features and Benefits ▪ Primary-side output voltage sensing; no resistor divider required ▪ Adjustable switch peak current limit up to 1.5 A with single-wire programming through the CHARGE pin ▪ Option to fine-tune target voltage ...
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... Ultra-Small Mobile Adjustable Xenon Photoflash A8739 Selection Guide Part Number Packing A8739EEETR-T 1500 pieces per reel Absolute Maximum Ratings Characteristic Symbol SW Pin V VIN_DRV, VBAT Pins CHARGE, TRIG, ¯ D ¯ ¯ O ¯ ¯ N ¯ ¯ E ¯ Pins Remaining Pins Operating Ambient Temperature ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 VBAT V – BAT ILIM Reference V ref DS VIN_DRV Decoder CHARGE TRIG Pin-out Diagram DONE 1 8 CHARGE TRIG 2 7 VIN_DRV PAD GATE 3 6 VBAT GND ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 ELECTRICAL CHARACTERISTICS guaranteed from −40°C to 85°C ambient, unless otherwise noted Characteristics VBAT Voltage Range VIN_DRV Voltage Range UVLO Enable Threshold UVLO Hysteresis V Supply Current IN VBAT Pin Supply Current Current Limit Primary-Side ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 ELECTRICAL CHARACTERISTICS specifications guaranteed from −40°C to 85°C ambient, unless otherwise noted Charge Pin Programming ILIM Programming High at CHARGE pin 2 ILIM Programming Low at CHARGE pin 2 Total ILIM Setup Time at ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 UVLO V IN CHARGE SW Target V V OUT DONE TRIG GATE Explanation of Events A: Start charging by pulling CHARGE to high, provided that V B: Charging stops when V C: Start a ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 IGBT drive waveforms are measured at pin, with capacitive load of 6800 pF Rising Signal Symbol Parameter Units/Division TRIGGER GATE ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 Charge Time versus Battery Voltage at Various ILIM Ω, Transformer L BAT 1.5 Efficiency versus Battery Voltage at Various ILIM ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 Final Output Voltage versus Battery Voltage at Various ILIM Ω, Transformer L BAT 328 327 326 325 324 323 322 321 320 1.5 2.0 Note: Output voltage is sensed from the ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 Average Input Current versus Battery Voltage at Various ILIM Ω, Transformer L BAT 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 1.5 Note: Peak switch current is limited by the maximum ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 Output Capacitor Charging at Various Peak Current Limits Test conditions 3 3 BAT Oscilloscope settings: Ch1 = ¯ D ¯ ¯ O ¯ ¯ N ¯ ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 Output Capacitor Charging at Various Battery Voltages Test conditions 3.0 V, ILIM3 (1.36 A Oscilloscope settings: Ch1 = ¯ D ¯ ¯ O ¯ ¯ N ¯ ¯ E ¯ ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 General Operation Overview The charging operation is started by a low-to-high signal on the CHARGE pin, provided that V is above the V IN strongly recommended to keep the CHARGE pin at logic low ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 As soon as a sufficient voltage has built up at the output capaci- tor, the IC enters Fast-Charging mode. In this mode, the next switching cycle starts after the secondary side current has stopped ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 ILIM Programming The peak current limit can be programmed to sixteen differ- ent levels, from 100% to 29%, with programming through the CHARGE pin. An internal digital circuit decodes the input clock signals, which ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 Output Voltage Adjustment The target output voltage of the A8739 is primarily determined by the transformer turns ratio 31.5 (V) × N OUT Typically N = 10, so the output voltage ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 Transformer Design 1. The transformer turns ratio, N, determines the output voltage 31.5 × N – OUT d where 31.5 is the typical value ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 Input Capacitor Selection Ceramic capacitors with X5R or X7R dielectrics are recom- mended for the input capacitor During initial Timer mode IN the device operates with 18 μs off-time. The resonant period ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 Layout Guidelines Key to a good layout for the photoflash capacitor charger circuit is to keep the parasitics minimized on the power switch loop (transformer primary side) and the rectifier loop (secondary side). Use ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 Recommended layout: C4 Schematic 0.1uF DONE CHARGE Top side Bottom side Top components Capacitor Charger with IGBT Driver VBAT C2 10uF R10 6 5 A8739 20k VBAT VIN_DRV GATE 1 2 ...
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Ultra-Small Mobile Adjustable Xenon Photoflash A8739 Package EE 8-Contact DFN/MLP with Exposed Thermal Pad D 9X 0.08 C 0.25 ±0.05 0.325 ±0.050 Copyright ©2009-2010, Allegro MicroSystems, Inc. The products described here are manufactured under one or more U.S. patents or ...