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UA7902 Flyback Transformer

for Silicon Labs Si88xx 5kV DC-DC Converter

RoHS compliant AEC-Q flag
  • UA7902 was developed for use with Silicon Labs Si88xx isolated dc-dc-converter reference designs. Learn more about these miniature transformers for digital isolators.
  • 5000 Vrms, one minute isolation (hipot), from primary to secondary
  • Designed to meet reinforced insulation class with 8 mm creepage and clearance.
  • Ultra-miniature flyback tranformer, measures only 10.0 × 17.07 × 5.97 mm
  • AEC-Q200 Grade 1 (−40°C to +125°C)
  • Low leakage inductance, only 971 nH
Buy Now:
Count Unit price
1 $3.89
350 $3.06
700 $2.65
1400 $2.09
2100 $1.79
4000 $1.62

For high volume or non-stock items, request a quote.

. in stock, ready to ship today.
Request a Sample:

Typical Application

Works with Silicon Labs Si88xxx

Input Voltage Output Power Fsw
7 V 24 V 5 V , 0.4 A 2 W 250 kHz

Specifications

Electrical specifications at 25°C.

Part number 1 Inductance
at 0A (µH) 2
(Tolerance: ±5%)
Isat (A) 3 DCR max (Ω) 4 Leakage
Inductance
max (µH) 5
Turns Ratio Isolation
Voltage (Vrms) 6
Pri Sec Pri : Sec
UA7902-AL_ 25.0 1.3 0.075 0.106 0.971 1 : 0.33 5000
Notes
  1. When ordering, please specify packaging code: e.g.UA7902-ALD
  2. Inductance is for the primary, measured on an Agilent/HP 4284 at 250 kHz, 0.1 Vrms, 0 Adc.
  3. DC current that causes an inductance drop of 30% (typ) from its value without current.
  4. DCR for secondary is for the windings connected in parallel.
  5. Leakage inductance measured between pins 1 and 3 at 250 kHz, 0.1Vrms, 0 Adc with all secondary pins shorted.
  6. Isolation (hipot) measured between windings for one minute.

Termination:

  • RoHS-compliant. 260°C compatible. RoHS tin-silver-copper (95.5/3.8/0.7) over tin over nickel over phos bronze.

Packaging:

  • 13" reel, machine-ready 
    EIA-481 embossed plastic tape (700 parts 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.
Environmental
Environmental:
RoHS compliant
Ambient temperature range:
–40°C to +125°C
Storage temperature range:
Component: –40°C to +160°C
Tape and reel packaging: –40°C to +80°C
Maximum part temperature:
+160°C
Failures in Time (FIT) / Mean Time Between Failures (MTBF):
38 per billion hours / 26,315,789 hours, calculated per Telcordia SR-332

Schematics

ua7902s.gif
Secondary windings to be connected
in parallel on PC board.

Physical characteristics

ua7902d.gif

dims_inches_mm.gif

Tape and Reel specification

tapereel_pl.gif

 
Parts per reel Reel dimensions (mm) Tape dimensions (mm) Orientation
13" (330 mm) A B C D E W P Po P1 H T part_or_f.gif
700 330 100 13 38,4 32,4 32 16 4 2 5,72 0,4

General specification

Core Material:
Ferrite
Weight:
1.1 g
Packaging:
700 per 13″ reel Plastic tape: 32 mm wide, 0.40 mm thick, 16 mm pocket spacing, 5.72 mm pocket depth

Soldering/Washing

Moisture Sensitivity Level (MSL):
1 (unlimited floor life at <30°C / 85% relative humidity)
Resistance to soldering heat:
Max three 40 second reflows at +260°C, parts cooled to room temperature between cycles
Refer to Soldering Coilcraft Components before soldering.
PCB Washing:
Tested to MIL-STD-202 Method 215 plus an additional aqueous wash. More info.