Document 484-1
For National Semiconductor
LM5115 DC Controller IC
Shielded Power Inductor
The D1787-AL was developed for use with the National
Semiconductor LM5115 Secondary Side Post Regulator
Controller and LM5025 Primary Side Controller. This flat
wire power inductor offers extremely low dc resistance
and very high current ratings (up to 23 Arms). The flat
core allows for exceptional heat dissipation and provides
an excellent surface for pick and place operation.
This inductor is ideal for power supply applications where
high current handling is essential and is perfect for low-
voltage dc-dc converters. Custom inductance values are
also possible.
Request free evaluation samples by contacting Coilcraft
or visiting www.coilcraft.com.
Core material Ferrite
Core and winding loss See www.coilcraft.com/coreloss
Terminations RoHS tin-silver (96.5/3.5) over copper
Weight 34.9 g
Ambient temperature –40°C to +85°C with (40°C rise) Irms current.
Maximum part temperature +125°C (ambient + temp rise). Derating.
Storage temperature Component: –40°C to +125°C.
Tape and reel packaging: –40°C to +80°C
DCR
SRF
typ2
Part
number
Inductance1 max
Isat3 Irms4
±±10 ꢀ(µH ꢀmOhmsH ꢀMµzH
ꢀAH
ꢀAH
D1787-AL
33.0
2.8
9.0
8.0
23.0
Resistance to soldering heat Max three 40 second reflows at
+260°C, parts cooled to room temperature between cycles
1. Inductance measured at 100 kHz, 0.1 Vrms, 0 Adc using Coilcraft
SMD-D fixture in Agilent/HP 4284A impedance analyzer.
2. SRF measured using Agilent/HP 8753D network analyzer and Coilcraft
SMD-D test fixture.
3. DC current at which the inductance drops 20% (typ) from its value with-
out current. Click for temperature derating information.
Moisture Sensitivity Level ꢀMSLH 1 (unlimited floor life at <30°C /
85% relative humidity)
Failures in Time ꢀFITH / Mean Time Between Failures ꢀMTBFH
38 per billion hours / 26,315,789 hours, calculated per Telcordia SR-332
Packaging 25 pieces per tray
PCB washing Tested to MIL-STD-202 Method 215 plus an additional
aqueous wash. See Doc787_PCB_Washing.pdf.
4. Current that causes a 40°C rise from 25°C ambient.This information is
for reference only and does not represent absolute maximum ratings.
Click for temperature derating information.
5. Electrical specifications at 25°C.
Refer to Doc 362 “Soldering Surface Mount Components” before soldering.
Temperature Rise vs Current
50
45
40
35
30
25
20
15
10
5
0
0
5
10
15
20
25
30
35
Current (Arms)
Document 484-1 Revised 09/10/15