AN1439

Design specification

7/17

Figure 2.

STEVAL-ISC001V1: PCB layout, silk + bottom layer (top view)

Q1

STP5NK80ZFP

1.9

Ω/ 800 V, TO220FP, ST

NTC1

SSN550

NTC 10

Ω, Vishay or equivalent

F1

T2A250V

2 A, 250 V ELU

PCB

---

FR-4, Cu single layer 35 µm, 95.8 x 64.7 mm

1.

If not otherwise specified, all resistors are 1%, ¼ W Q1 and D7 are both provided with a 40 °C/W heatsink

SK95/25/SA from Fischer Elektronik.

Table 2.

STEVAL-ISC001V1 evaluation board: bill of material (continued)

Symbol

Value

Note

Table 3.

STEVAL-ISC001V1: transformer specification (part number 558179, supplied by Albe

s.r.l.)

Core

E25/13/7, N67 material or 3C85 or equivalent

Bobbin

Vertical mounting, 10 pins

Air gap

≈ 1 mm for an inductance 1-3 of 740 µH

Leakage inductance

< 20 µH (at 60 kHz) pins 1-3 with 4,5,7,8,9,10 shorted

Windings Spec & build

Pin

start/end

Winding

Wire

Turns

Notes

1/2

Pri1

AWG26

40

Innermost winding

7/9

Sec1

2xAWG23

8

Pins 7-8 will be shorted on the PCB

8/10

Sec2

2xAWG23

8

Pins 9-10 will be shorted on the PCB

2/3

Pri2

AWG26

40

Pin2 will be cut for safety

4/5

Aux

AWG32

8

Evenly spaced