ON Semiconductor Fairchild FDD850N10LD, User Manual

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© 2013 Fairchild Semiconductor Corporation 3 FEBFDD850N10LD_CS001
• Rev. 1.0.0
This user guide supports the evaluation kit for the FDD850N10LD. It should be used in
conjunction with the FDD850N10LD datasheets as well as Fairchild’s application notes
and technical support team. Please visit Fairchild’s website at
www.fairchildsemi.com .
1. Introduction
This document describes the proposed solution for a driving of LED application using the
BoostPak (FDD850N10LD) for boost topology. The input voltage range is 20.4 V –
27.6 V and there is a single-channel DC output with a constant current of 640 mA at
55 V. This document contains a general description of FDD850N10LD, the converter
specification, a schematic, the bill of materials, and the typical operating characteristics.
1.1. Description
The N-channel MOSFET and NP diode are combined in one 5-lead D-Pak package
produced using Fairchild Semiconductor’s PowerTrench
®
process tailored to minimize on-
state resistance while maintaining superior switching performance. The diode is a hyper-
fast rectifier with low forward-voltage drop and excellent switching performance
.
Using the
BoostPak FDD850N10LD in low-power LED backlight driving applications results in
lower profile and cost savings by reducing part count, weight, and PCB size as well as
improving reliability due to lower leakage current than Schottky Barrier Diode (SBD).
1.2. Features

Lower Conduction Resistance :
-
R
DS(on)
= 61 mΩ (Typ.) at V
GS
= 10 V, I
D
= 12 A
-
R
DS(on)
= 64 mΩ (Typ.) at V
GS
= 5.0 V, I
D
= 12 A

Low Gate Charge (Typ. 22.2 nC)

Low C
rss
(Typ. 42 pF)

Fast Reverse Recovery Time: t
rr
(Typ.) = 11 ns at I
F
= 5 A, di/dt = 200 A/µs

Fast Switching

100% Avalanche Tested

Improved dv/dt Capability

RoHS Compliant
1.3. FDD850N10LD Diagrams
Figure 1. Pin Descriptions Figure 2. Block Diagram