SMT Flyback Transformer for
Microsemi PoE PD Power Supply

• Developed for use with Microsemi UC3844 Current Mode Controller and LX1752 Buck Regulator
• T1 on PoE PD Power Supply Evaluation Board (AN-37)
• Designed for 36 V to 57 V input; 200 kHz.
• 1500 Vrms isolation from primary, auxiliary and reset to secondary;
  500 Vrms from primary and reset to auxiliary
• RoHS-compliant. 260°C compatible. Tin-silver (96.5/3.5) over tin over nickel over phos bronze terminations

Photo    Pricing    Materials declaration    PDF data sheet

SPECIFICATIONS

Schematic    Dimensions    Tape and reel specifications    3D model

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Part number1 Click for samples	L at 0A2 ±10% (µH)	L at Ipk3 min (µH)	DCR max (Ohms)	Leakage L max (µH)4	Turns ratio			Ipk3 (A)	Output5
					pri : sec	pri : aux	pri : reset
HA3905-CL_	27.0	24.3	0.170 (pri) 0.015 (sec) 0.385 (aux) 0.371 (reset)	1.9	3.75 : 1	1.36 : 1	1 : 1	1.2	5 V, 2.5 A

1	When ordering, please specify termination and packaging codes: e.g. HA3905-CLD
	Termination:	L = RoHS compliant tin-silver over tin over nickel over phos bronze Special order, added cost: T = RoHS tin-silver-copper (95.5/4/0.5) or S = non-RoHS tin-lead (63/37).
	Packaging:	D = 13" reel, machine-ready  EIA-481 embossed plastic tape (175parts per full reel). B = Less than full reel In tape, but not machine-ready. To have a leader and trailer added ($25 charge), use code letter D instead.

2	Inductance is for the primary, measured at 250 kHz, 1.0 Vrms, 0.
3	Ipk: Peak primary current drawn at minimum input voltage.
4	Leakage inductance for the primary is with all secondary pins shorted.
5	Output is with the secondary windings connected in parallel. Auxiliary winding output is 12 V, 20 mA.
6	Ambient temperature range:	–40°C to +125°C
7	Storage temperature range:	Component: –40°C to +125°C T&R packaging: –40°C to +80°C
8	Electrical specifications at 25°C.
Refer to Soldering Coilcraft Components before soldering.