L6599 STMicroelectronics, L6599 Datasheet - Page 30

• 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
30/36
This concern applies to converters designed with a high resonance frequency (indicatively,
> 150 kHz), so that they run at high frequency also at full load. Otherwise, the converter will
run at high frequency only at light load, where the current flowing in the MOSFETs of the
half-bridge leg is lower, so that, generally, an R
to check this point anyway and the following equation is useful to compute the drop on the
bootstrap driver:
where Q
bootstrap DMOS (150, typ.) and T
about half the switching period minus the dead time T
a total gate charge of 30 nC, the drop on the bootstrap driver is about 3 V at a switching
frequency of 200 kHz:
If a significant drop on the bootstrap driver is an issue, an external ultra-fast diode can be
used, thus saving the drop on the R
g
is the gate charge of the external power MOS, R
V
Drop
V
Drop
=
I
=
Ch
------------------------------------------------------ - 150
2.5 10
arg
charge
e
⋅
DS(on)
r
(
DS
30 10
–
)ON
is the ON-time of the bootstrap driver, which equals
6
⋅
–
of the internal DMOS.
0.3 10
+
–
9
V
⋅
DS(on)
F
=
–
------------------- - R
T
6
Ch
Q
rise is not an issue. However, it is wise
D
arg
g
. For example, using a MOSFET with
+
e
0.6
DS(on)
(
DS
=
)ON
2.7V
+
is the on-resistance of the
V
F
L6599