L6599 STMicroelectronics, L6599 Datasheet - Page 25

• 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

L6599
The circuit shown in
series to C
operates like a capacitive current divider; C
less and will be a low-loss type, the sense resistor R
and C
If the resistor R
kΩ ), the circuit operates like a divider of the ripple voltage across the resonant capacitor Cr,
which, in turn, is related to its current through the reactance of Cr. Again, C
selected equal to C
(provided it is << R
where the reactance of C
I
Whichever circuit one is going to use, the calculated values of R
considered just a first cut value that needs to be adjusted after experimental verification.
OCP is effective in limiting primary-to-secondary energy flow in case of an overload or an
output short circuit, but the output current through the secondary winding and rectifiers
under these conditions might be so high to endanger converter's safety if continuously
flowing. To prevent any damage during these conditions it is customary to force converter's
intermittent operation, in order to bring the average output current to values such that the
thermal stress for the transformer and the rectifiers can be easily handled.
With the L6599 the designer can program externally the maximum time T
converter is allowed to run overloaded or under short circuit conditions. Overloads or short
circuits lasting less than T
with immunity to short duration phenomena. If, instead, T
protection (OLP) procedure is activated that shuts down the device and, in case of
continuous overload/short circuit, results in continuous intermittent operation with a user-
defined duty cycle.
Crpk
= I
B
Crpkx
will be such that R
A
. Again, C
is small (not above some hundred Ω, just to limit current spiking) the circuit
A
in series to C
A
R
) according to:
Figure 31
/100 or less, this time not necessarily a low-loss type, while R
B
will be such that R
A
SH
B
(X
·C
will not cause any other action, hence providing the system
CA
B
A
can be operated in two different ways. If the resistor R
is in the range of 10 /f
is not small (in this case it will be typically selected in the ten
) and C
R
B
R
B
=
R
=
-------------- -
I
0.8π
Crpkx
(X
-------------- - 1
I
0.8π
Crpkx
B
A
Cr
·C
will be typically selected equal to C
) should be calculated at the frequency where
⋅
B
--------------------------- -
⎛
⎝
is in the range of 10 /f
R
+
2
A
X
------ -
C
+
C
C
B
A
r
min
r
X
will be selected as:
⎞
⎠
2
C
A
.
SH
is exceeded an overload
S
or R
Application information
min
B
should be
.
SH
A
will be typically
that the
R
/100 or
B
A
25/36
in