L6599 STMicroelectronics, L6599 Datasheet - Page 26

• Manufacturer Part Number: L6599
• Description: High-voltage resonant controller
• Manufacturer: STMicroelectronics

Specifications of L6599

• Dimensions (l/w/h): 132 mm / 52 mm / 22 mm
• Universal Ac Mains Range: 90 VAC to 264 VAC
• High Output Power: 90 W (4.74 A, 19 VDC)
• Very Low Output Noise And Ripple: less than 300 m VP-P
• Very Low Standby Power: less than 0.5 W at 264 V
• Hiccup Mode: Auto recovery with SCP
• Latch Mode: OVP acts while VOUT > 29 VDC

Application information
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Figure 32. Soft-start and delayed shutdown upon overcurrent timing diagram
This function is realized with pin 2 (DELAY), by means of a capacitor C
resistor R
OCP comparator, in addition to discharging C
sources 150 µA from the DELAY pin and charges C
the OCP comparator and the internal current source will be repeatedly activated and C
will be charged with an average current that depends essentially on the time constant of the
current sense filtering circuit, on C
discharge due to R
typically much longer.
This operation will go on until the voltage on C
There is not a simple relationship that links T
determine C
order of 100 ms.
Once C
continuously regardless of the OCP comparator's output, and the 150 µA current source is
continuously on, until the voltage on C
with T
close to f
As the voltage on C
pulled low. Also the internal generator is turned off, so that C
discharged by R
which will take:
PFC_STOP
Primary
Current
DELAY
ISEN
Vout
Vcc
Css
MP
START-UP
Delay
start
is expressed in ms and C
0.8V
3.5V
0.3V
Delay
2V
0A
2V
Delay
is charged at 2 V the internal switch that discharges C
(see
SOFT-START
connected to ground. As the voltage on the ISEN pin exceeds 0.8 V the first
Delay
T
experimentally. As a rough indication, with C
ss
Chapter 7.3:
Delay
Delay
. The IC will restart when the voltage on C
OPERATION
T
NORMAL
can be neglected, considering that the associated time constant is
STOP
is 3.5 V, the device stops switching and the PFC_STOP pin is
=
Soft-start) to minimize the energy inside the resonant circuit.
LOAD
OVER
R
Delay
Delay
SS
and the characteristics of the resonant circuit; the
OPERATION
T
Delay
NORMAL
MP
⋅
in µF. During this time the L6599 runs at a frequency
C
=
Delay
reaches 3.5 V. This phase lasts:
10 C
SH
SS
Delay
⋅
OVERLOAD
ln
, turns on an internal current generator that
to C
T
Delay
3.5
------- -
0.3
SH
reaches 2 V, which defines the time T
Delay
Delay
≈
2.5R
. During an overload/short-circuit
, thus it is more practical to
T
MIN. POWER
MP
Delay
Delay
Delay
Delay
⋅
SHUTDOWN
C
will now be slowly
Delay
T
SS
= 1 µF T
STOP
will be less than 0.3V,
is forced low
Delay
SH
and a parallel
will be in the
SOFT-START
L6599
Delay
SH
t
t
t
t
t
t
t
.