Document 736
For Linear Technology LT3751
Flyback Transformer Capacitor Charger Controller
• Flyback transformer for the Linear Technology LT3751
Capacitor Charger Controller
• 5 – 24 V input; 5 V, 3.6 A and ±15 V, 1.2A outputs
• 1500 Vrms isolation from primary to secondary windings
Core material Ferrite
Terminations RoHS tin-silver over tin over nickel over phos
bronze. Other terminations available at additional cost.
Weight 25.0 g
Ambient temperature –40°C to +85°C
Storage temperature Component: –40°C to +85°C.
Packaging: –40°C to +80°C
Resistance to soldering heat Max three 40 second reflows at
+260°C, parts cooled to room temperature between cycles
Moisture Sensitivity Level (MSL) 1 (unlimited floor life at <30°C /
85% relative humidity)
Failures in Time (FIT) / Mean Time Between Failures (MTBF)
38 per billion hours / 26,315,789 hours, calculated per Telcordia SR-332
Packaging 24 per tray
PCB washing Only pure water or alcohol recommended
Inductance Inductance
Leakage
Volt-time
product
DCR max (Ohms)3
sec1 sec2 sec3
Part
number
at 0 A1
at Ipk2
inductance4
Turns ratio5
Ipk2
±10% (µH)
min (µH)
pri
max (µH) pri : sec 1 : sec 2 : sec 3 (A) typ (V µsec)
HA3994-AL
7.50
6.75
0.018 0.020 0.031 0.031
0.22
1 : 0.5 : 1.5 : 1.5
5.0
37.5
1. Inductance is measured at 100 kHz, 0.1 Vrms.
2. Peak primary current drawn at minimum input voltage.
3. DCR for the primary is with the windings connected in parallel.
5. Turns ratios are with the primary windings connected in parallel.
6. Electrical specifications at 25°C.
Refer to Doc 362 “Soldering Surface Mount Components” before soldering.
4. Leakage inductance is for both windings of the primary with the
secondary windings shorted.
Dot indicates pin 1
0.108
1
2
1.10
28,2
4
1
2,75
12
1
12
Pri
Sec 1
0.039
1,00
5 – 24 V
5 V, 3.6 A
9
5
11
12
Recommended
Land Pattern
1.053
26,75
0.148
3,75
max
Sec 2
15 V, 1.2 A
0.079
2,00
8
6
0.148
3,75
Sec 3
–15 V, 1.2 A
7
Primary windings to be connected
in parallel on PC board.
0.551
14,0
max
0.004 / 0,10
1.024
26,0
1.35
34,29
max
inches
mm
Dimensions are in
Specifications subject to change without notice.
Please check our website for latest information.
Document736 Revised01/16/09
© Coilcraft, Inc. 2009