L6566ATR STMicroelectronics, L6566ATR Datasheet - Page 35

• 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
5.11
OVP block
The OVP function of the L6566A monitors the voltage on the ZCD pin (11) in MOSFET’s
OFF-time, during which the voltage generated by the auxiliary winding tracks converter’s
output voltage. If the voltage on the pin exceeds an internal 5 V reference, a comparator is
triggered, an overvoltage condition is assumed and the device is shut down. An internal
current generator is activated that sources 1 mA out of the VFF pin (15). If the VFF voltage
is allowed to reach 2 Vbe over 5 V, the L6566A will be latched off. See
disable function on page 32
impedance externally connected to pin 15 is so low that the 5+2 V
reached or if some means is provided to prevent that, the device will be able to restart after
the Vcc has dropped below 5 V. Refer to the “Application examples and Ideas” section
(
Figure 22. OVP Function: internal block diagram
Table 7 on page 45
PWM latch
R
S
Q
Q
) for additional hints.
Monostable
M1
to triggering
block
for more details on IC’s behavior under these conditions. If the
2 µs
ZCD
11
40k Ω
5pF
5 V
Monostable
M2
+
-
STROBE
0.5 µs
COUT
OVP
R Q1
S
FF
BE
Application information
threshold cannot be
L6566A
Section 5.9: Latched
counter
2-bit
Counter
reset
Fault
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