Datasheet

12
LTC1422
1422fb
Power N-Channel and Sense Resistor Selection
The decision of which external power N-Channel to use is
dependent on its maximum current rating and the maxi-
mum allowed current times R
DS(ON)
drop across the
transistor. Table 1 lists some transistors that are available.
Table 2 lists some current sense resistors that can be
used with the circuit breaker. Since this information is
subject to change, please verify the part numbers with the
manufacturer. Table 3 lists the web sites of several manu-
facturers.
Table 1. N-Channel Selection Guide
CURRENT LEVEL (A) PART NUMBER DESCRIPTION MANUFACTURER
0 to 2 MMDF3N02HD Dual N-Channel SO-8 ON Semiconductor
R
DS(ON)
= 0.1Ω
2 to 5 MMSF5N02HD Single N-Channel SO-8 ON Semiconductor
R
DS(ON)
= 0.025Ω
5 to 10 MTB50N06V Single N-Channel DD Pak ON Semiconductor
R
DS(ON)
= 0.028Ω
10 to 20 MTB75N05HD Single N-Channel DD Pak ON Semiconductor
R
DS(ON)
= 0.0095Ω
Table 2. Sense Resistor Selection Guide
CURRENT LIMIT VALUE PART NUMBER DESCRIPTION MANUFACTURER
1A LR120601R050 0.05Ω 0.25W 1% Resistor IRC-TT
2A LR120601R025 0.025Ω 0.25W 1% Resistor IRC-TT
2.5A LR120601R020 0.02Ω 0.25W 1% Resistor IRC-TT
3.3A WSL2512R015F 0.015Ω 1W 1% Resistor Vishay-Dale
5A LR120601R010 0.01Ω 0.25W 1% Resistor IRC-TT
10A WSR2R005F 0.005Ω 2W 1% Resistor Vishay-Dale
Table 3. Manufacturers’ Web Sites
MANUFACTURER WEB SITE
TEMIC Semiconductor www.temic.com
International Rectifier www.irf.com
ON Semiconductor www.onsemiconductor.com
Harris Semiconductor www.semi.harris.com
IRC-TT www.irctt.com
Vishay-Dale www.vishay.com
APPLICATIONS INFORMATION
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