l6599atn STMicroelectronics, l6599atn Datasheet - Page 14

• Manufacturer Part Number: l6599atn
• Description: Improved High-voltage Resonant Controller
• Manufacturer: STMicroelectronics

Application information
14/31
Figure 5.
The following approximate relationships hold for the minimum and the maximum oscillator
frequency respectively:
Equation 1
After fixing CF in the hundred pF or nF range (consistent with the maximum source
capability of the RF
the value of RF
entire range needed for regulation, from the minimum value f
and maximum load) to the maximum value f
load):
Equation 2
A different selection criterion is given for R
used (see
Section 6.2: Operation at no load or very light
Oscillator internal block diagram
min
and RF
min
f
min
pin and trading this off against the total consumption of the device),
=
3
RF
max
⋅
CF
min
is selected so that the oscillator frequency is able to cover the
Doc ID 15534 Rev 1
1
⋅
=
RF
3
min
⋅
CF
1
⋅
;
f
min
Fmax
f
max
max
;
in case burst-mode operation at no-load is
=
(at maximum input voltage and minimum
RF
3
⋅
max
CF
⋅
=
(
load).
RF
f
f
max
RF
min
1
min
min
min
−
//
(at minimum input voltage
1
RF
max
)
L6599AT