On

Figure 169. Start-Up Response of LED Circuit. Many Switching Cycles Elapse before Current Flows in LEDs Because of C1 Charging

L1 = MURATA-ERIE LQH3C100K04 D1 = MOTOROLA MBR0520L , C2 = CERAMIC

D2, D3 = LUMEX SSL-X100133SRC/4 "MEGA-BRITE" RED LED OR PANASONIC LNG992CF9 HIGH BRIGHTNESS BLUE LED

Figure 169. Start-Up Response of LED Circuit. Many Switching Cycles Elapse before Current Flows in LEDs Because of C1 Charging

Figure 168. Single-Cell LED Driver Supplies 25mA to LED String. Two Red LEDs Can Be Replaced by One Blue LED

AN ULTRALOW QUIESCENT CURRENT, 5V BOOST REGULATOR

by Sam Nork

Many battery-powered applications require an auxiliary 5V supply to power infrequently used circuitry, such as smart card readers, wireless i.d. tags, or the like. Keeping the 5V supply permanently active is desirable, since this eliminates timing delays and inrush currents due to supply start-up. The downside is that most 5V boost converters consume an unacceptable amount of quiescent current under no-load conditions. This problem is addressed by the SHDN features of the LTC1516 micropower, chargepump DC/DC converter. Toggling the SHDN pin of the LTC1516 allows the 5V supply to remain in regulation with a typical no-load input current of less than 5|A When the 5V output load is enabled, the part can supply up to 50mA of load current.

0.22|iF

10|F

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DIY Battery Repair

DIY Battery Repair

You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.

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