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Thanks to some very helpful folks in another thread, I've selected a buck regulator for a microprocessor project that draws on automotive current, i.e., reducing 12v to 5v with about 2amps of power. I have selected the TPS62133AQRGTRQ1 IC (automotive rated) and have found a viable regulator circuit schematic for my application. The schematic calls for an inductor coil rated at 2.2 uH and 35 mOhm. It specifies a specific inductor manufacturer/partnumber (Abracon Corporation ASPI-0530HI-2R2M-T2), but I'd like to search out suitable replacements. I can find LOTS of 2.2 uH inductors... but none so far are rated at 35 mOhm. Many inductor specs seem not even to include Ohms (although surely their respective datasheets would if you dig in to each one.) So my question is, how much variance in rated Ohms is typically acceptable... if there even is a "typical" range. I'm probably and intermediate amateur when it comes to electrical theory, but I can imagine that ohms would be related to current, i.e., higher resistance, less amps. If that's right, then I would reckon that I'd need to find a coil that's pretty similar, i.e., not from off from .035 ohms. Am I in the ball park?

Here is the schematic:

enter image description here

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Below 35mΩ is better. A little above is okay too. It will only affect your efficiency.

You can use TI's Webbench and it will give you alternative choices when going into the BOM.

Generally he higher the amp rating the lower the DCR. Larger gauge wire has more cross sectional area and therefore lower resistance.

Sometimes a large amperage inductor is required for high efficiency even though the current requirement is much less than the the the inductors rated current.

I did a quick search and found 50 (including duplicates) 2.2µH inductors at or below 35mΩ

"Manufacturer Part Number"  "Manufacturer"  "Description"   "Unit Price (USD)"  "Packaging" "Series"    "Part Status"   "Type"  "Material - Core"   "Inductance"    "Tolerance" "Current Rating"    "Current - Saturation"  "Shielding" "DC Resistance (DCR)"   "Q @ Freq"  "Frequency - Self Resonant" "Ratings"   "Operating Temperature" "Frequency - Test"  "Mounting Type" "Size / Dimension"  "Height - Seated (Max)"
74404054022 "Wurth Electronics Inc."    "FIXED IND 2.2UH 3.8A 19 MOHM SMD"  1.22    "Cut Tape (CT)" "WE-LQS"    "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.8A"  "5.3A"  "Shielded"  "19 mOhm"   -0  "77MHz" -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.197"" L x 0.197"" W (5.00mm x 5.00mm)"   "0.157"" (4.00mm)"
"TYS50402R2N-10"    "Laird-Signal Integrity Products"   "FIXED IND 2.2UH 3.8A 19 MOHM SMD"  0.53    "Cut Tape (CT)" "TYS5040"   "Active"    -0  -0  "2.2µH" "±30%"  "3.8A"  "4.9A"  "Shielded"  "19 mOhm Max"   -0  "50MHz" -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.197"" L x 0.197"" W (5.00mm x 5.00mm)"   "0.165"" (4.20mm)"
"CLF6045T-2R2N-CA"  "TDK Corporation"   "FIXED IND 2.2UH 4A 19.5 MOHM SMD"  1.16    "Cut Tape (CT)" "CLF-CA"    "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "4A"    "3.9A"  "Shielded"  "19.5 mOhm Max" -0  -0  "AEC-Q200"  "-40°C ~ 105°C" "100kHz"    "Surface Mount" "0.244"" L x 0.232"" W (6.20mm x 5.90mm)"   "0.189"" (4.80mm)"
"CLF6045T-2R2N-D"   "TDK Corporation"   "FIXED IND 2.2UH 4A 15 MOHM SMD"    1.29    "Cut Tape (CT)" "CLF-D" "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "4A"    "3.9A"  "Shielded"  "19.5 mOhm Max" -0  -0  "AEC-Q200"  "-40°C ~ 105°C" "100kHz"    "Surface Mount" "0.244"" L x 0.232"" W (6.20mm x 5.90mm)"   "0.177"" (4.50mm)"
"ASPI-0628-2R2N-T1" "Abracon LLC"   "FIXED IND 2.2UH 3.7A 20 MOHM SMD"  0.43    "Cut Tape (CT)" "ASPI-0628" "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.7A"  "4.2A"  "Shielded"  "20 mOhm"   -0  -0  -0  "-25°C ~ 120°C" "100kHz"    "Surface Mount" "0.236"" L x 0.236"" W (6.00mm x 6.00mm)"   "0.110"" (2.80mm)"
"PA4322.222NLT" "Pulse Electronics Corporation" "FIXED IND 2.2UH 2.08A 20 MOHM" 1.18    "Cut Tape (CT)" "PA4322"    "Active"    "Wirewound" -0  "2.2µH" "±20%"  "2.08A" "1.76A" "Shielded"  "20 mOhm Max"   -0  -0  -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.201"" L x 0.201"" W (5.10mm x 5.10mm)"   "0.122"" (3.10mm)"
"B82472G6222M"  "EPCOS (TDK)"   "FIXED IND 2.2UH 3A 20 MOHM SMD"    1.31    "Cut Tape (CT)" "B82472G6"  "Active"    "Wirewound" "Ferrite"   "2.2µH" "±20%"  "3A"    "2.8A"  "Shielded"  "20 mOhm Max"   -0  -0  -0  "-55°C ~ 125°C" "100kHz"    "Surface Mount" "0.287"" L x 0.287"" W (7.30mm x 7.30mm)"   "0.138"" (3.50mm)"
"SRU5018-2R2Y"  "Bourns Inc."   "FIXED IND 2.2UH 2.3A 20.5 MOHM"    0.68    "Cut Tape (CT)" "SRU5018"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "2.3A"  "2.1A"  "Shielded"  "20.5 mOhm" "10 @ 7.96MHz"  "130MHz"    -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.205"" L x 0.205"" W (5.20mm x 5.20mm)"   "0.079"" (2.00mm)"
"SRU5028-2R2Y"  "Bourns Inc."   "FIXED IND 2.2UH 3.2A 21 MOHM SMD"  0.68    "Cut Tape (CT)" "SRU5028"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.2A"  "2.5A"  "Shielded"  "21 mOhm"   "10 @ 7.96MHz"  "130MHz"    -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.205"" L x 0.205"" W (5.20mm x 5.20mm)"   "0.118"" (3.00mm)"
"SRN5040-2R2Y"  "Bourns Inc."   "FIXED IND 2.2UH 3.5A 21 MOHM SMD"  0.36    "Cut Tape (CT)" "SRN5040"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.5A"  "4.6A"  "Semi-Shielded" "21 mOhm Max"   "20 @ 7.96MHz"  "40MHz" -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.197"" L x 0.197"" W (5.00mm x 5.00mm)"   "0.157"" (4.00mm)"
"AIUR-03-2R2M"  "Abracon LLC"   "FIXED IND 2.2UH 3.2A 21 MOHM TH"   0.52    "Bulk"  "AIUR-03"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±10%"  "3.2A"  "6.5A"  "Unshielded"    "21 mOhm Max"   "20 @ 7.96MHz"  "100MHz"    -0  "-25°C ~ 85°C"  "7.96MHz"   "Through Hole"  "0.354"" Dia (9.00mm)"  "0.472"" (12.00mm)"
"NRS5030T2R2NMGJ"   "Taiyo Yuden"   "FIXED IND 2.2UH 3.5A 23 MOHM SMD"  0.41    "Cut Tape (CT)" "NRS"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.5A"  "4.2A"  "Shielded"  "23 mOhm"   -0  "46MHz" -0  "-25°C ~ 120°C" "100kHz"    "Surface Mount" "0.193"" L x 0.193"" W (4.90mm x 4.90mm)"   "0.122"" (3.10mm)"
"74404043022A"  "Wurth Electronics Inc."    "FIXED IND 2.2UH 3.83A 23 MOHM" 0.89    "Cut Tape (CT)" "WE-LQS"    "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.83A" "2.28A" "Shielded"  "23 mOhm"   -0  "104MHz"    -0  "-40°C ~ 125°C" -0  "Surface Mount" "0.157"" L x 0.157"" W (4.00mm x 4.00mm)"   "0.098"" (2.50mm)"
"SPD42R-222M"   "API Delevan Inc."  "FIXED IND 2.2UH 1.35A 23 MOHM" 3.19    "Cut Tape (CT)" "SPD42R"    "Active"    "Wirewound" "Ferrite"   "2.2µH" "±20%"  "1.35A" "1.35A" "Shielded"  "23 mOhm Max"   -0  "77MHz" -0  "-55°C ~ 125°C" "100kHz"    "Surface Mount" "0.185"" L x 0.185"" W (4.70mm x 4.70mm)"   "0.115"" (2.92mm)"
"SLF6045T-2R2N3R3-3PF"  "TDK Corporation"   "FIXED IND 2.2UH 3.3A 18 MOHM SMD"  1.09    "Cut Tape (CT)" "SLF"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.8A"  "3.3A"  "Shielded"  "23.4 mOhm Max" -0  -0  -0  "-40°C ~ 105°C" "100kHz"    "Surface Mount" "0.236"" L x 0.236"" W (6.00mm x 6.00mm)"   "0.189"" (4.80mm)"
"ASPI-0615FS-2R2N-T2"   "Abracon LLC"   "FIXED IND 2.2UH 2.9A 24 MOHM SMD"  0.74    "Cut Tape (CT)" "ASPI-0615FS"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "2.9A"  "3.5A"  "Shielded"  "24 mOhm"   -0  -0  -0  "-25°C ~ 120°C" "100kHz"    "Surface Mount" "0.236"" L x 0.236"" W (6.00mm x 6.00mm)"   "0.087"" (2.20mm)"
"SRU6025-2R2Y"  "Bourns Inc."   "FIXED IND 2.2UH 3.4A 24 MOHM SMD"  0.79    "Cut Tape (CT)" "SRU6025"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.4A"  "2.35A" "Shielded"  "24 mOhm Max"   "8 @ 7.96MHz"   "65MHz" -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.256"" L x 0.244"" W (6.50mm x 6.20mm)"   "0.110"" (2.80mm)"
"PA4300.222NLT" "Pulse Electronics Corporation" "FIXED IND 2.2UH 2.3A 24.7 MOHM"    0.94    "Cut Tape (CT)" "PA4300"    "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "2.3A"  -0  "Shielded"  "24.7 mOhm Max" -0  -0  -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.240"" L x 0.240"" W (6.10mm x 6.10mm)"   "0.118"" (3.00mm)"
"PA4301.222NLT" "Pulse Electronics Corporation" "FIXED IND 2.2UH 3.15A 24.7 MOHM"   0.98    "Cut Tape (CT)" "PA4301"    "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.15A" -0  "Shielded"  "24.7 mOhm Max" -0  -0  -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.283"" L x 0.283"" W (7.20mm x 7.20mm)"   "0.118"" (3.00mm)"
"B82462G4222M"  "EPCOS (TDK)"   "FIXED IND 2.2UH 2.55A 25 MOHM" 1.67    "Cut Tape (CT)" "B82462G4"  "Active"    "Wirewound" "Ferrite"   "2.2µH" "±20%"  "2.55A" "2.6A"  "Shielded"  "25 mOhm Max"   -0  -0  "AEC-Q200"  "-55°C ~ 150°C" "100kHz"    "Surface Mount" "0.248"" L x 0.248"" W (6.30mm x 6.30mm)"   "0.118"" (3.00mm)"
"SRN6045-2R2Y"  "Bourns Inc."   "FIXED IND 2.2UH 3.5A 25.1 MOHM"    0.43    "Cut Tape (CT)" "SRN6045"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.5A"  "6A"    "Shielded"  "25.1 mOhm Max" "15 @ 7.96MHz"  "35MHz" -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.236"" L x 0.236"" W (6.00mm x 6.00mm)"   "0.177"" (4.50mm)"
"NRS6028T2R2NMGJ"   "Taiyo Yuden"   "FIXED IND 2.2UH 3.7A 26 MOHM SMD"  0.4 "Cut Tape (CT)" "NRS"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.7A"  "4.2A"  "Shielded"  "26 mOhm Max"   -0  "68MHz" -0  "-25°C ~ 125°C" "100kHz"    "Surface Mount" "0.236"" L x 0.236"" W (6.00mm x 6.00mm)"   "0.110"" (2.80mm)"
"SRN6028-2R2Y"  "Bourns Inc."   "FIXED IND 2.2UH 3.7A 26 MOHM SMD"  0.39    "Cut Tape (CT)" "SRN6028"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.7A"  "4.2A"  "Semi-Shielded" "26 mOhm Max"   "12 @ 7.96MHz"  "56MHz" -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.236"" L x 0.236"" W (6.00mm x 6.00mm)"   "0.110"" (2.80mm)"
"NRS6028T2R2NMGJV"  "Taiyo Yuden"   "FIXED IND 2.2UH 3.7A 26 MOHM SMD"  0.42    "Cut Tape (CT)" "NRS"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.7A"  "4.2A"  "Shielded"  "26 mOhm Max"   -0  "68MHz" "AEC-Q200"  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.236"" L x 0.236"" W (6.00mm x 6.00mm)"   "0.110"" (2.80mm)"
"NR6028T2R2N"   "Taiyo Yuden"   "FIXED IND 2.2UH 3.7A 26 MOHM SMD"  0.36    "Cut Tape (CT)" "NR"    "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.7A"  "4.2A"  "Shielded"  "26 mOhm Max"   -0  "68MHz" -0  "-25°C ~ 120°C" "100kHz"    "Surface Mount" "0.236"" L x 0.236"" W (6.00mm x 6.00mm)"   "0.110"" (2.80mm)"
"AIUR-02H-2R2M" "Abracon LLC"   "FIXED IND 2.2UH 3.2A 26 MOHM TH"   0.56    "Bulk"  "AIUR-02H"  "Active"    "Wirewound" "Ferrite"   "2.2µH" "±20%"  "3.2A"  "6.3A"  "Unshielded"    "26 mOhm Max"   "15 @ 7.96MHz"  -0  -0  "-25°C ~ 85°C"  "7.96MHz"   "Through Hole"  "0.830"" Dia (21.08mm)" "0.830"" (21.10mm)"
"LQH66SN2R2M03L"    "Murata Electronics North America"  "FIXED IND 2.2UH 3.3A 19 MOHM SMD"  2.42    "Cut Tape (CT)" "LQH66" "Active"    "Wirewound" "Ferrite"   "2.2µH" "±20%"  "3.3A"  -0  "Shielded"  "26.6 mOhm Max" -0  "80MHz" -0  "-40°C ~ 80°C"  "1MHz"  "Surface Mount" "0.248"" L x 0.248"" W (6.30mm x 6.30mm)"   "0.197"" (5.00mm)"
"SRR1005-2R2M"  "Bourns Inc."   "FIXED IND 2.2UH 3.1A 27 MOHM SMD"  0.87    "Cut Tape (CT)" "SRR1005"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±20%"  "3.1A"  "6.1A"  "Shielded"  "27 mOhm Max"   "25 @ 7.96MHz"  "90MHz" -0  "-40°C ~ 125°C" "1kHz"  "Surface Mount" "0.500"" L x 0.394"" W (12.70mm x 10.00mm)" "0.205"" (5.20mm)"
"CDRH5D16F/LDNP-2R2NC"  "Sumida America Components Inc."    "FIXED IND 2.2UH 3.8A 27 MOHM SMD"  1.09    "Cut Tape (CT)" "CDRH5D16F/LD"  "Active"    -0  "Ferrite"   "2.2µH" "±25%"  "3.8A"  "1.8A"  "Shielded"  "27 mOhm Max"   -0  -0  -0  "-40°C ~ 105°C" "100kHz"    "Surface Mount" "0.205"" L x 0.205"" W (5.20mm x 5.20mm)"   "0.071"" (1.80mm)"
7440430022  "Wurth Electronics Inc."    "FIXED IND 2.2UH 2.5A 28 MOHM SMD"  1.44    "Cut Tape (CT)" "WE-TPC"    "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "2.5A"  "2.35A" "Shielded"  "28 mOhm Max"   -0  "100MHz"    -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.189"" L x 0.189"" W (4.80mm x 4.80mm)"   "0.118"" (3.00mm)"
"SRR4028-2R2Y"  "Bourns Inc."   "FIXED IND 2.2UH 2.5A 28 MOHM SMD"  0.7 "Cut Tape (CT)" "SRR4028"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "2.5A"  "2.05A" "Shielded"  "28 mOhm Max"   "9.24 @ 7.96MHz"    "111MHz"    -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.189"" L x 0.189"" W (4.80mm x 4.80mm)"   "0.118"" (3.00mm)"
"TYS60202R2N-10"    "Laird-Signal Integrity Products"   "FIXED IND 2.2UH 2.75A 28 MOHM" 0.56    "Cut Tape (CT)" "TYS6020"   "Active"    -0  -0  "2.2µH" "±30%"  "2.75A" "3.75A" "Shielded"  "28 mOhm Max"   -0  "61MHz" -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.236"" L x 0.236"" W (6.00mm x 6.00mm)"   "0.087"" (2.20mm)"
"SLF7055T-2R2N3R5-3PF"  "TDK Corporation"   "FIXED IND 2.2UH 3.5A 21.7 MOHM"    1.17    "Cut Tape (CT)" "SLF"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.5A"  "5.3A"  "Shielded"  "28.2 mOhm Max" -0  -0  -0  "-40°C ~ 105°C" "100kHz"    "Surface Mount" "0.276"" L x 0.276"" W (7.00mm x 7.00mm)"   "0.228"" (5.80mm)"
"NR5040T2R2N"   "Taiyo Yuden"   "FIXED IND 2.2UH 3.5A 28.6 MOHM"    0.45    "Cut Tape (CT)" "NR"    "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.5A"  "4.6A"  "Shielded"  "28.6 mOhm Max" -0  "42MHz" -0  "-25°C ~ 120°C" "100kHz"    "Surface Mount" "0.193"" L x 0.193"" W (4.90mm x 4.90mm)"   "0.161"" (4.10mm)"
"NRS5040T2R2NMGJV"  "Taiyo Yuden"   "FIXED IND 2.2UH 3.7A 28.6 MOHM"    0.57    "Cut Tape (CT)" "NRS"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.7A"  "5A"    "Shielded"  "28.6 mOhm Max" -0  "42MHz" "AEC-Q200"  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.193"" L x 0.193"" W (4.90mm x 4.90mm)"   "0.161"" (4.10mm)"
"SRN4026-2R2Y"  "Bourns Inc."   "FIXED IND 2.2UH 2.1A 29 MOHM SMD"  0.36    "Cut Tape (CT)" "SRN4026"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "2.1A"  "2.1A"  "Semi-Shielded" "29 mOhm Max"   "9 @ 7.96MHz"   "60MHz" -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.157"" L x 0.157"" W (4.00mm x 4.00mm)"   "0.098"" (2.50mm)"
"4922R-05L" "API Delevan Inc."  "FIXED IND 2.2UH 3.7A 29 MOHM SMD"  3.32    "Cut Tape (CT)" "4922R" "Active"    "Wirewound" "Ferrite"   "2.2µH" "±15%"  "3.7A"  "3.7A"  "Unshielded"    "29 mOhm Max"   -0  -0  -0  "-55°C ~ 125°C" "1kHz"  "Surface Mount" "0.505"" L x 0.240"" W (12.82mm x 6.09mm)"  "0.230"" (5.84mm)"
"NRS5030T2R2NMGJV"  "Taiyo Yuden"   "FIXED IND 2.2UH 3.5A 29.9 MOHM"    0.57    "Cut Tape (CT)" "NRS"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "3.5A"  "4.2A"  "Shielded"  "29.9 mOhm Max" -0  "46MHz" "AEC-Q200"  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.193"" L x 0.193"" W (4.90mm x 4.90mm)"   "0.118"" (3.00mm)"
"ASPI-4030S-2R2N-T" "Abracon LLC"   "FIXED IND 2.2UH 2.95A 30 MOHM" 0.49    "Cut Tape (CT)" "ASPI-4030S"    "Active"    "Wirewound" "Nickel Zinc Ferrite"   "2.2µH" "±30%"  "2.95A" "4.9A"  "Shielded"  "30 mOhm"   -0  "52MHz" -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.157"" L x 0.157"" W (4.00mm x 4.00mm)"   "0.118"" (3.00mm)"
74408943022 "Wurth Electronics Inc."    "FIXED IND 2.2UH 3A 30 MOHM SMD"    2.09    "Cut Tape (CT)" "WE-SPC"    "Active"    "Wirewound" "Ferrite"   "2.2µH" "±20%"  "3A"    "4.6A"  "Shielded"  "30 mOhm Max"   -0  "85MHz" -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.189"" L x 0.189"" W (4.80mm x 4.80mm)"   "0.161"" (4.10mm)"
"CDMT40D20HF-2R2NC" "Sumida America Components Inc."    "FIXED IND 2.2UH 3.5A 30.8 MOHM"    1.76    "Cut Tape (CT)" "CDMT"  "Active"    -0  -0  "2.2µH" "±30%"  "3.5A"  "5.6A"  "Unshielded"    "30.8 mOhm Max" -0  -0  -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.163"" L x 0.163"" W (4.15mm x 4.15mm)"   "0.083"" (2.10mm)"
"AIAP-01-2R2K-T"    "Abracon LLC"   "FIXED IND 2.2UH 2.6A 31 MOHM TH"   0.38    "Cut Tape (CT)" "AIAP-01"   "Active"    "Wirewound" -0  "2.2µH" "±10%"  "2.6A"  -0  "Unshielded"    "31 mOhm Max"   -0  "130MHz"    -0  "-40°C ~ 105°C" "7.9MHz"    "Through Hole"  "0.130"" Dia x 0.360"" L (3.30mm x 9.14mm)" -0
"5300-05-RC"    "Bourns Inc."   "FIXED IND 2.2UH 2.6A 31 MOHM TH"   0.94    "Bulk"  5300    "Active"    "Wirewound" "Ferrite"   "2.2µH" "±10%"  "2.6A"  "2A"    "Unshielded"    "31 mOhm Max"   -0  "130MHz"    -0  "-55°C ~ 105°C" "7.96MHz"   "Through Hole"  "0.160"" Dia x 0.500"" L (4.06mm x 12.70mm)"    -0
"SD25-2R2-R"    "Eaton" "FIXED IND 2.2UH 2.93A 31.1 MOHM"   1.97    "Cut Tape (CT)" "SD"    "Active"    "Wirewound" "Ferrite"   "2.2µH" "±20%"  "2.93A" "2.8A"  "Shielded"  "31.1 mOhm" -0  -0  -0  "-40°C ~ 85°C"  "100kHz"    "Surface Mount" "0.204"" L x 0.204"" W (5.20mm x 5.20mm)"   "0.098"" (2.50mm)"
"CDRH4D28NP-2R2NC"  "Sumida America Components Inc."    "FIXED IND 2.2UH 2.04A 31.3 MOHM"   0.93    "Cut Tape (CT)" "CDRH4D28"  "Active"    -0  "Ferrite"   "2.2µH" "±30%"  "2.04A" -0  "Shielded"  "31.3 mOhm Max" -0  -0  -0  "-40°C ~ 100°C" "100kHz"    "Surface Mount" "0.185"" L x 0.185"" W (4.70mm x 4.70mm)"   "0.118"" (3.00mm)"
"ASPI-0428S-2R2M-T" "Abracon LLC"   "FIXED IND 2.2UH 2.04A 31.3 MOHM"   0.87    "Cut Tape (CT)" "ASPI-0428S"    "Active"    "Wirewound" "Ferrite"   "2.2µH" "±20%"  "2.04A" -0  "Shielded"  "31.3 mOhm Max" -0  -0  -0  "-40°C ~ 85°C"  "100kHz"    "Surface Mount" "0.185"" L x 0.185"" W (4.70mm x 4.70mm)"   "0.118"" (3.00mm)"
74404052022 "Wurth Electronics Inc."    "FIXED IND 2.2UH 3A 31.6 MOHM SMD"  1.33    "Cut Tape (CT)" "WE-LQS"    "Active"    "Wirewound" -0  "2.2µH" "±30%"  "3A"    "3.6A"  "Shielded"  "31.6 mOhm" -0  "88MHz" -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.197"" L x 0.197"" W (5.00mm x 5.00mm)"   "0.079"" (2.00mm)"
"TYS50202R2N-10"    "Laird-Signal Integrity Products"   "FIXED IND 2.2UH 2.9A 32 MOHM SMD"  0.53    "Cut Tape (CT)" "TYS5020"   "Active"    -0  -0  "2.2µH" "±30%"  "2.9A"  "3.2A"  "Shielded"  "32 mOhm Max"   -0  "57MHz" -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.197"" L x 0.197"" W (5.00mm x 5.00mm)"   "0.079"" (2.00mm)"
"SRU3017-2R2Y"  "Bourns Inc."   "FIXED IND 2.2UH 1.7A 35 MOHM SMD"  0.68    "Cut Tape (CT)" "SRU3017"   "Active"    "Wirewound" "Ferrite"   "2.2µH" "±30%"  "1.7A"  "980mA" "Shielded"  "35 mOhm"   "8 @ 7.96MHz"   "100MHz"    -0  "-40°C ~ 125°C" "100kHz"    "Surface Mount" "0.138"" L x 0.130"" W (3.50mm x 3.30mm)"   "0.079"" (2.00mm)"
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  • \$\begingroup\$ Thanks for the explanation, @misunderstood, that makes sense. I'll go with a coil at or below 35 MOHM. I only just recently discovered webbench but love it. \$\endgroup\$ – bcrimmins May 9 '17 at 15:40
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from spec" A high switching frequency of typically 2.5 MHz allows the use of small inductors and provides fast transient response."

    1. The main issue is self heating and temperature rise which is affected by copper area to PCB near part.

Derating is important from max continuous current rating as it affects max Efficiency and waste heat causing a gradual drop in inductance with rising T which in turn causes slightly more current. Good margin prevents thermal runaway for unexpected surge loads.

So it depends on your specs for efficiency and Trise and Imax(L) = Iout + 1/2 ripple current.

You can easily increase DCR by 25% but more requires care with PCB copper area and free flowing convection air so if L is DC rated for >200% of 2A load this should result in safe parts but not optimal efficiency.

Some of these are compatible parts if you also consider Isat, SRF and case size. enter image description here

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  • \$\begingroup\$ Thanks, @tony. That really helps me understand things better. You've got me thinking that I should over build and under utilize the power supply. Since the circuit I'm building is drawing from essentially a 400+ amp 12v battery, my little 2 amp circuit load is a gnat on an elephant's rump. Follow up question for you: if I built out the power supply as a 4 amp regulator but only ever drew a maximum of <2 amps, would the current drain on the car battery be more than if I build it with a 2 amp regulator? Does a regulator circuit draw much current if there's not load? Thanks again! \$\endgroup\$ – bcrimmins May 9 '17 at 5:08
  • \$\begingroup\$ The datasheet gives an example of quiescent current < 25uA which looks pretty good. Normally battery loads from memory stored accessories are < a few mA total. They call this IC a 3A regulator due to the RdsOn losses. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 May 9 '17 at 12:12
  • \$\begingroup\$ I learned a lot from these responses. Thanks for the great explanations! \$\endgroup\$ – bcrimmins May 15 '17 at 14:27
  • \$\begingroup\$ great explanations deserve more attention from points for others to find, but I dont care. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 May 15 '17 at 15:23
  • \$\begingroup\$ Is there a way for me to give points? I would be happy to do so, but I'm new to this forum and so I don't think I have up-vote privileges yet. \$\endgroup\$ – bcrimmins May 15 '17 at 21:09

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