STEVAL-ISA041V1 STMicroelectronics, STEVAL-ISA041V1 Datasheet - Page 7
![BOARD EVAL STP12IE95F4](/photos/9/13/91341/steval-isa041v1_sml.jpg)
STEVAL-ISA041V1
Manufacturer Part Number
STEVAL-ISA041V1
Description
BOARD EVAL STP12IE95F4
Manufacturer
STMicroelectronics
Series
VIPER™r
Specifications of STEVAL-ISA041V1
Main Purpose
AC/DC, Primary Side
Outputs And Type
1, Isolated
Power - Output
125W
Voltage - Output
19V
Current - Output
6.6A
Voltage - Input
240 ~ 400VDC
Regulator Topology
Flyback
Frequency - Switching
55kHz
Board Type
Fully Populated
Utilized Ic / Part
L6565, STP12IE95F4
Product
Power Management Modules
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
497-8410
L6565
APPLICATION INFORMATION
Quasi-resonant operation in offline flyback converters lies in synchronizing MOSFET's turn-on to the transform-
er's demagnetization. Detecting the resulting negative-going edge of the voltage across any winding of the
transformer can do this. The L6565 is provided with a dedicated pin that allows doing the job with a very simple
interface, just one resistor.
Variable frequency operation - as a result of different operating conditions in terms of input voltage and output
current - is inherent in such functionality. The system always works close to the boundary between DCM (Dis-
continuous Conduction Mode) and CCM (Continuous Conduction Mode) operation of the transformer. The op-
eration is then identical to that of the so-called self-oscillating or Ringing Choke Converter (RCC).
Detailed Device Description
Internal Supply Block (see fig. 12)
A linear voltage regulator supplied by V
(pin 8) generates an internal 7V rail used for supplying the entire IC,
cc
except for the gate driver that is supplied directly from Vcc. In addition, a bandgap circuit generates a precise
internal reference (2.5V±1% @ 25°C) used by the control loop to ensure a good regulation with primary feed-
back technique.
In figure 12 it is also shown the undervoltage lockout (UVLO) comparator with hysteresis used to enable the
chip as long as the Vcc voltage is high enough to ensure a reliable operation.
Figure 12. L6565 internal supply block
+V
in
Vcc
8
-
+
UVLO
LIN.
REF.
REG.
2.5V
7V bus
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