L6599D STMicroelectronics, L6599D Datasheet - Page 19

• Manufacturer Part Number: L6599D
• Description: IC RESONANT CONVRTR CTRLR 16SOIC
• Manufacturer: STMicroelectronics
• Type: Phase Shift Resonant Controllersr

Specifications of L6599D

• Applications: Resonant Converter Controller
• Voltage - Supply: 8.85 V ~ 16 V
• Current - Supply: 3.5mA
• Operating Temperature: 0°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Number Of Outputs: Single
• Output Current: 800 mA (Max)
• Switching Frequency: 500 KHz
• Operating Supply Voltage: 8.85 V to 16 V
• Maximum Operating Temperature: + 150 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Supply Voltage Range: 8.85V To 16V
• Digital Ic Case Style: SOIC
• No. Of Pins: 16
• Operating Temperature Range: -40°C To +150°C
• Svhc: No SVHC (15-Dec-2010)
• Base Number: 6599
• Device Type: Power
• Rohs Compliant: Yes
• For Use With: 497-10542 - BOARD EVAL BASED ON L6599497-8429 - BOARD ADAPTER L6599/STP12NM50N497-8265 - BOARD EVAL BASED ON L6599497-5857 - DEMO BOARD FOR L6599497-5856 - DEMO BOARD FOR L6599497-5497 - EVAL BOARD FOR L6599497-5496 - EVAL BOARD FOR L6599
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Input: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

L6599
Essentially, RF
burst-mode operation. Once fixed f
Note that, unlike the f
f
the transformer's peak currents are low enough not to cause audible noise.
Resonant converter's switching frequency, however, depends also on the input voltage;
hence, in case there is quite a large input voltage range with the circuit of
value of Pout
arrangement shown in
added to the voltage applied to the STBY pin. Due to the strongly non-linear relationship
between switching frequency and input voltage, it is more practical to find empirically the
right amount of correction R
careful in choosing the total value R
the LINE pin voltage (see
Whichever circuit is in use, its operation can be described as follows. As the load falls below
the value Pout
the voltage on the STBY pin (V
gate-drive outputs low, so that both MOSFETs of the half-bridge leg are in OFF-state. The
voltage V
stop and, as it exceeds 1.3V, the IC will restart switching. After a while, V
again in response to the energy burst and stop the IC. In this way the converter will work in a
burst-mode fashion with a nearly constant switching frequency. A further load decrease will
then cause a frequency reduction, which can go down even to few hundred hertz. The timing
diagram of
A small capacitor (typically in the hundred pF) from the STBY pin to ground, placed as close
to the IC as possible to reduce switching noise pick-up, will help get clean operation.
To help the designer meet energy saving requirements even in power-factor-corrected
systems, where a PFC pre-regulator precedes the DC-DC converter, the device allows that
the PFC pre-regulator can be turned off during burst-mode operation, hence eliminating the
no-load consumption of this stage (0.5
because EMC regulations on low-frequency harmonic emissions refer to nominal load, no
limit is envisaged when the converter operates with light or no load.
To do so, the device provides pin 9 (PFC_STOP): it is an open collector output, normally
open, that is asserted low when the IC is idle during burst-mode operation. This signal will
be externally used for switching off the PFC controller and the pre-regulator as shown in
Figure 27
first.
max
is associated to some load Pout
STBY
When the L6599 is in UVLO the pin is kept open, to let the PFC controller start
Figure 26
B
B
will now increase as a result of the feedback reaction to the energy delivery
max
would change considerably. In this case it is recommended to use the
the frequency will try to exceed the maximum programmed value f
will define the switching frequency f
max
illustrates this kind of operation, showing the most significant signals.
Figure 25
considered in the previous section
Chapter 7.6: Line sensing
A
/ (R
STBY
where the information on the converter's input voltage is
A
max
+ R
) will go below 1.25V. The IC will then stop with both
A
B
RF
+ R
greater than the minimum one. Pout
, RF
B
÷
max
) needed to minimize the change of Pout
B
1 W). There is no compliance issue in that
max
=
much greater than R
3
-- -
8
will be found from the relationship:
⋅
-------------------- -
f
---------- - 1
f
RF
max
min
min
–
function).
max
above which the L6599 will enter
("Chapter 7.1:
C
to minimize the effect on
Application information
STBY
B
Figure 24
Oscillator"), here
will be such that
will go down
B
. Just be
max
the
and
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