L6566ATR STMicroelectronics, L6566ATR Datasheet - Page 31

• Manufacturer Part Number: L6566ATR
• Description: IC CTRLR OVP UVLO 16SOIC
• Manufacturer: STMicroelectronics

Specifications of L6566ATR

• Output Isolation: Isolated
• Frequency Range: 93 ~ 107kHz
• Voltage - Input: 8 ~ 23 V
• Power (watts): 750mW
• Operating Temperature: -40°C ~ 150°C
• Package / Case: 16-SOIC (0.154", 3.90mm Width)
• For Use With: 497-8834 - BOARD DEMO FOR L6563/LL6566A497-6452 - BOARD EVAL FOR L6566B497-6451 - BOARD EVAL FOR L6566B497-6450 - BOARD EVAL FOR L6566B497-6449 - BOARD EVAL FOR L6566A
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6296-2

L6566A
5.8
Figure 18. Hiccup-mode OCP: timing diagram
PFC interface
The device is specifically designed to minimize converter’s losses under light or no-load
conditions, and a special function has been provided to help the designer meet energy
saving requirements even in power-factor-corrected systems where a PFC pre-regulator
precedes the isolated DC-DC converter.
Actually EMC regulations require compliance with low-frequency harmonic emission limits
at nominal load; no limit is envisaged when the converter operates with a light load. Then
the PFC pre-regulator can be turned off, thus saving the no-load consumption of this stage
(0.5÷1 W).
To do so, the L6566A provides the Vcc_PFC pin (6): this pin is internally connected to the
Vcc pin (5) via a PNP transistor, normally closed, that opens when the voltage V
below V
FF operation is selected. This pin is intended for supplying the PFC controller of the pre-
regulator as shown in
IC will stop if an external failure causes the pin to be overloaded for too long time or shorted
to ground.
OCP latch
Vcc_PFC
Vcc_OK
(pin 6)
(pin 5)
(pin 7)
(pin 4)
Vcc
Vcc
COMPO
V
GD
Vcc
Vcc
CS
restart
OFF
ON
, a threshold internally set at a value depending on whether QR operation or
1.5 V
Figure 16 on page 28
Secondary diode is shorted here
. The switch is thermally protected, so that the
Application information
COMP
t
t
t
t
t
t
falls
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