STEVAL-ISA019V2 STMicroelectronics, STEVAL-ISA019V2 Datasheet - Page 13

• Manufacturer Part Number: STEVAL-ISA019V2
• Description: BOARD EVAL SMPS L6565 3PHASE APP
• Manufacturer: STMicroelectronics
• Type: Motor / Motion Controllers & Driversr

Specifications of STEVAL-ISA019V2

• Mfg Application Notes: L6565/STC04IE170HV AppNote
• Main Purpose: AC/DC, Primary Side
• Outputs And Type: 1, Isolated
• Power - Output: 80W
• Voltage - Output: 24V
• Current - Output: 3.33A
• Voltage - Input: 250 ~ 850V
• Regulator Topology: Flyback
• Board Type: Fully Populated
• Utilized Ic / Part: L6565, STC04IE170HV
• Input Voltage: 250 V to 850 V
• Output Voltage: 24 V
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: L6565, STC04IE170HV
• Other names: 497-6339

AN2495
During the conduction time, the junction base-emitter of the ESBT can be seen as a
forward-biased diode. To complete the secondary side load loop, the voltage drop on both
diode D and resistor RB must be added in series with the base of the ESBT. The equivalent
secondary side voltage source is given by:
Equation 22
Since the magnetization inductance cannot be neglected, only I
collector current, is transferred to the secondary. As a result, the magnetization current has
to be first as low as possible. Meanwhile, the value of the magnetization inductance must be
taken into account for the proper calculation of transformer primary turns and turns ratio.
The magnetization voltage drop, that is, the voltage at the primary of the current transformer,
can now be easily calculated:
Equation 23
The magnetization current will be:
Equation 24
The number of primary turns should be increased if I
have a window area large enough to hold all primary and secondary windings. Otherwise it
is necessary to choose a bigger core size. Once both core material and size are fixed, the
turn ratio must be adjusted to get the desiderated I
Equation 25
where I
The insulation between primary and secondary should be considered since the voltage on
the primary side during the off time can surpass 1500 V.
The next step is to select the Zener diode, the capacitor C
performance of the ESBT is related to the initial base peak current and its duration t
which is given approximately by
Equation 26
A suitable value for R
peak, and at the same time, it generates negligible power dissipation.
The value t
frequency. Bear in mind that in practical applications, it should never be lower than 200 ns.
The value of C
Mmax
peak
is the maximum magnetization current.
b
can be determined once the minimum ON time is set based on the operating
can be counted since the values of t
b
is 0.56 Ω. It can eliminate the ringing on the base current after the
Doc ID 13127 Rev 4
V
V
Equation
N
1
S
eff
=
=
I
V
=
Mmax
V
S
t
BEon
I
---- -
I
peak
P
B
•
=
N
--------- -
N
26:
1T
2T
=
I
------------------------------------
–
Cmax
=
=
V
--------------------------- -
V
3R
1
D
2.5
T
L
–
I
---- -
ONmax
–
5
C
b
TP
V
C
C
I
•
Mmax
RB
/I
b
1
-- -
5
peak
Mmax
B
=
≅
ratio according to
0.5 V
2.5V
and R
b
is relatively high. The core must
, and the resistor R
( )
Base driving circuit design
b
P
, a fraction of the total
are known.
Equation 25
b
. The turn-on
peak
below:
13/34
,