QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1204A POSITIVE HIGH VOLTAGE IDEAL DIODE-OR LTC4358 FEATURES *Droop Sharing *Operates 9-75V, Up To 5A Load Current per Chan- *N+1 Redundant Supplies nel *Demo Board Features Two Independent LTC4358 DESCRIPTION Circuits Sharing a Common Ground *0.093-inch Turret Holes Accommodate 12 AWG Demonstration Circuit 1204 showcases the Wire LTC4358 5A ideal diode. The board includes two independent LTC4358 ideal diode circuits with a APPLICATIONS common ground, operating over a 9-28V range. L, LTC, LTM, LT, Burst Mode, OPTI-LOOP, Over-The-Top and PolyPhase are registered *Servers, Routers, Switches, Mass Storage trademarks of Linear Technology Corporation. Adaptive Power, C-Load, DirectSense, Easy Drive, FilterCAD, Hot Swap, LinearView, Module, Micropower SwitcherCAD, Multimode *Solar Panel Isolation Dimming, No Latency , No Latency Delta-Sigma, No R , Operational Filter, PanelProtect, SENSE *Battery Charger Isolation PowerPath, PowerSOT, SmartStart, SoftSpan, Stage Shedding, SwitcherCAD, ThinSOT, UltraFast and VLDO are trademarks of Linear Technology Corporation. Other product names *Battery Isolation may be trademarks of the companies that manufacture the products. PERFORMANCE SUMMARY Specifications are at TA = 25C SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Input Operating Range 9 28 V IN I Maximum Load Current Limited by MOSFET Dissipation 5 A OUT Modifying for More Current Board Layout You cannot modify DC1204A for higher current lev- DC1204A is a 2-layer board. The inputs and outputs els. If currents greater than 5A are needed, use the of the two ideal diode circuits are entirely independ- LTC4357 positive high voltage ideal diode controller ent, sharing only a common ground. Banana jacks featured on DC1203A. are provided for input and output connections tur- rets facilitate connection of voltmeters and scope probes. 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1204A POSITIVE HIGH VOLTAGE IDEAL DIODE-OR LTC4358 Pads are included on the bottom of the board for Thermals use of an optional transient voltage suppressor (TVS or TransZorb) in lieu of a capacitor. The peak The LTC4358CDE is designed and tested to handle clamping voltage must be less than 28V. up to 5A load current. DC1204A can safely carry 5A in each channel, simultaneously. Nevertheless, typi- In practical applications the output is most often cal LTC4358s can handle 7A operating at room bypassed by a large bulk reservoir capacitor. If the temperature with a dissipation of about 1W. Under connections to this capacitor are short, no clamp or these conditions the package temperature rise other bypassing is necessary to protect against out- measures less than 40 degrees Celsius cooled only put spikes when the input is short circuited. by convection currents, permitting operation of DC1204A up to about 75 degrees Celsius air ambi- Basic Operation ent with no air flow. The forward drop at 7A in a 25 degree Celsius air ambient is typically less than Connect two 9-28V power supplies to the input as 150mV. shown in Figure 1, and short VOUT A and VOUT B together. Connect a load to the combined output. By Locally Generated Spikes adjusting the supplies slightly above and below one another, the diode behavior is evident from observ- When bench testing with input short circuits, it is ing the flow of current in each supply. The higher of possible to generate high voltage transients in ex- the two supplies will carry the full load current. cess of the LTC4358 s 28V abs/max rating. A 47 microfarad electrolytic capacitor has been included on the output of each ideal diode to suppress these spikes. 2