E & E Magnetic Products Limited
POWER TRANSFORMER
Flyback Transformer for PoE
Providing Power to PoE devices with up to 13 Watts
S
CHEMATICS
Flyback transformers designed for PoE (IEEE802.3af)
powered devices with up to 13 Watts
Designed for 250kHz switching frequency with input of
36 - 72V
Low Leakage Inductance
Hipot voltage: 1500Vrms
Operating temperature -40°C to +125°C.
RoHS compliant version is available
Custom design is also available
E
LECTRICAL
S
PECIFICATION @
25°C
Part
Number
835-00835F
835-00836F
835-00837F
835-00838F
835-00839F
835-00840F
835-00841F
Turns Ratio
Pri : Sec
1 : 0.07
1 : 0.08
1 : 0.11
1 : 0.15
1 : 0.35
1 : 0.57
1 : 0.67
Pri : Bias
1 : 0.36
1 : 0.33
1 : 0.36
1 : 0.35
1 : 0.35
1 : 0.35
1 : 0.33
Inductance
at 0A
(uH
±
10
%)
45
35
40
40
35
37
37
Inductance Leakage
at Ipk
Inductance
(uH Min)
(nH Max)
40.5
31.5
36.0
36.0
31.5
33.3
33.3
7.9
4.2
3.4
1.9
0.6
0.4
0.4
DCR
(mOhm Max)
Pri
195
95
138
130
95
85
86
Sec
5
5
7
9
17
25
49
Bias
195
150
180
165
150
385
370
Ipk
(A)
Secondary
Output
Vout=1.8V,7.2A
Vout=2.5V,5.2A
Vout=3.3V,3.9A
Vout=5.0V,2.6A
Vout=12V,1.1A
Vout=19.5V,0.67A
Vout=24V,0.54A
2.3
2.2
2.2
2.1
2.0
2.0
2.0
Notes:
1. Inductance is measured at 250kHz, 0.3Vrms.
2. Peak primary current, Ipk, is drawn at minimum input voltage.
3. DCR for the primary and for the secondary are with the windings connected in parallel.
4. Leakage Inductance is for the primary winding with the secondary winding shorted.
5. Turns ratio are with the primary and the secondary windings connected in parallel.
6. Output of the secondary is with the windings connected in parallel. Bias winding output is 12V, 20mA.
7. Operating temperature range: -40°C to +125°C. The part temperature (ambient temperature + temperature rise)
should not exceed the upper limit of the operating temperature under worst case operating conditions. Circuit design,
component placement, PWB trace size and thickness, airflow and other cooling provisions all affect the part
temperature. Part temperature should be verified in the end application.
1/F.,Harbour View,No.12 Science Park East Avenue,Phase II,Hong Kong Science Park,Shatin,N.T.,HK . Tel: (852) 2954 3333 . Fax: (852) 2954 3304
1
PX001(01)
Revised in 12/03
E & E Magnetic Products Limited
POWER TRANSFORMER
Flyback Transformer for PoE
Providing Power to PoE devices with up to 13 Watts
M
ECHANICAL
D
IMENSIONS
.492
12.50
.089
2.26
.675
MAX
17.15
.098
2.50
12
7
EE
.865
21.97 MAX
.900
22.86
835-008xx
(DATE)
.060
1.52
Pin 1
location
1
6
.028
0.71
Recommended
Pad Layout
.012
±
.008
0.30
±
0.20
.330
8.38 MAX
REFERENCE OR
GAUGE PLANE
.098
±
.010
2.50
±
0.25
.492
±
.010
12.50
±
0.25
.050-.080
1.27-2.03
Notes:
8. All dimensions are specified in
inches
with higher precedence in inches.
mm
9. U
nless otherwise specified, all tolerances are
±
.010
.
0.25
.004
max.
10.
Coplanarity:
0.10
Weight (in gram)
Tape & Reel
:
:
6.2 typ.
250 / reel
S
CHEMATICS
1
2
Pri
11
12
8
7
Sec
6
5
10
Bias
3
FOR MORE INFORMATION, PLEASE CONTACT
HEADQUARTER
1/F.,Harbour View,No.12 Science Park East Avenue,,
Phase II,Hong Kong Science Park,Shatin,N.T.,HK
Tel: (852) 2954 3333
Fax: (852) 2954 3304
Email: eempl@eleceltek.com
Website: Http://www.eemagnetic.com
Information herein is for reference only and subject to change without notice. It does not constitute any representation, warranty or commitment of the company in respect
of the products in any aspect. All logos, brands and product names mentioned herein are trademarks or registered trademarks of their respective owners. The company
does not assume any liability arising out of the application or use of any product or circuit described herein. Copyrights 2012, E & E Magnetic Products Limited.
1/F.,Harbour View,No.12 Science Park East Avenue,Phase II,Hong Kong Science Park,Shatin,N.T.,HK . Tel: (852) 2954 3333 . Fax: (852) 2954 3304
2
PX001(01)
Revised in 12/03