L6566A STMicroelectronics, L6566A Datasheet - Page 33

• Manufacturer Part Number: L6566A
• Description: IC CTRLR OVP UVLO 16SOIC
• Manufacturer: STMicroelectronics

Specifications of L6566A

• 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)
• Output Current: 800 mA
• Output Power: 750 mW
• Input Voltage: 8 V to 23 V
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: SMD/SMT
• Duty Cycle (max): 75 %
• Universal Input Mains Range: 90÷264Vac - Frequency 45 ÷ 65 Hz
• Output Voltage: 19 V@4 A continuous operation
• Mains Harmonics: Acc. to EN61000-3-2 Class-D
• St-by Mains Consumption: Less than 0.25 W @265Vac
• Overall Efficiency: Better than 86%
• Emi: According to EN55022-Class-B
• Safety: According to EN60950
• Low Profile Design: 25 mm maximum height
• Pcb Single Layer: single side, 70 μm, CEM-1, 78x174 mm, Mixed PTH/SMT
• 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

L6566A
5.10
Figure 20. Operation after latched disable activation: timing diagram
Soft-start and delayed latched shutdown upon overcurrent
At device start-up, a capacitor (Css) connected between the SS pin (14) and ground is
charged by an internal current generator, I
clamped. During this ramp, the overcurrent setpoint progressively rises from zero to the
value imposed by the voltage on the VFF pin 15, (see “
latch and voltage feedforward blocks on page 27
gradually, hence controlling the start-up inrush current. The time needed for the overcurrent
setpoint to reach its steady state value, referred to as soft-start time, is approximately:
Equation 9
During the ramp (i.e. until V
are disabled.
The soft-start pin is also invoked whenever the control voltage (COMP) saturates high,
which reveals an open-loop condition for the feedback system. This condition very often
occurs at start-up, but may be also caused by either a control loop failure or a converter
overload/short circuit. A control loop failure results in an output overvoltage that is handled
by the OVP function of the L6566A (see next section). In case of QR operation, a short
circuit causes the converter to run at a very low frequency, then with very low power
capability. This makes the self-supply system that powers the device unable to keep it
Vcc
Vcc_PFC
(pin 16)
AC_OK
(pin 6)
Vcc
(pin 8)
(pin 5)
(pin 4)
ON
Vcc
V
Vcc
Vcc
DIS
GD
HVstart
-0.5
restart
4.5V
Vin
Vth
OFF
ON
HV generator is turned on
T
SS
SS
= 2 V) all the functions that monitor the voltage on pin COMP
=
Css
I
SS
1
V
csx
Input source is removed here
V (
SS1
VFF
, from zero up to about 2 V where it is
)
”); MOSFET’s conduction time increases
=
Css
I
SS
HV generator turn-on is disabled here
1
Section 5.6: PWM comparator, PWM
⎛
⎜ ⎜
⎝
1
−
V
VFF
3
Disable latch is reset here
⎞
⎟ ⎟
⎠
Application information
Restart is quicker
t
t
t
t
t
t
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