L6699D STMicroelectronics, L6699D Datasheet - Page 6

• Manufacturer Part Number: L6699D
• Description: AC/DC Switching Converters Enhanced High Volt Res CTRL 600V
• Manufacturer: STMicroelectronics
• Type: High Voltage Controllersr

Specifications of L6699D

• Product Category: AC/DC Switching Converters
• Output Voltage: 13.3 V
• Input / Supply Voltage (max): 8.85 V
• Input / Supply Voltage (min): 16 V
• Switching Frequency: 235 kHz
• Supply Current: 3 mA
• Operating Temperature Range: - 25 C to + 125 C
• Mounting Style: SMD/SMT
• Package / Case: SO-16
• Number Of Outputs: 1
• Output Current: 800 mA

Pin connections
4
6/38
Pin connections
Figure 2.
Table 4.
N.
1
2
3
DELAY
Name
C
CF
SS
Pin connections (top view)
Pin functions
Soft-start. This pin connects an external capacitor to GND and a resistor to
RF
for the frequency shift that occurs as the chip starts up (soft-start). An internal
switch discharges this capacitor every time the chip turns off (V
LINE < 1.25 V, DIS > 1.85 V, ISEN > 1.5 V, DELAY > 2 V) to make sure it is soft-
started next. Additionally the switch is activated when the voltage on the current
sense pin (ISEN) exceeds 0.8 V or when the converter is working too close to,
or in, the capacitive-mode operation.
Delayed shutdown upon overcurrent. A capacitor and a resistor are connected
from this pin to GND to set both the maximum duration of an overcurrent
condition before the IC stops switching and the delay after which the IC restarts
switching. Every time the voltage on the ISEN pin exceeds 0.8 V the capacitor
is charged by 350 µA current pulses and is slowly discharged by the external
resistor. If the voltage on the DELAY pin reaches 2 V, the soft-start capacitor is
completely discharged so that the switching frequency is pushed to its
maximum value and the 350 µA current source is kept always on. As the
voltage on the DELAY pin exceeds 3.5 V the IC stops switching and the internal
generator is turned off, so that the voltage on the pin decays because of the
external resistor. The IC is soft-restarted as the voltage drops below 0.3 V. In
this way, under short-circuit conditions, the converter works intermittently with
very low input average power.
If the voltage on the ISEN pin exceeds 1.5 V, the L6699 is immediately stopped
and the 350 µA current source is kept on until the voltage on the DELAY pin
reaches 3.5 V. Then, the generator is turned off and the voltage on the pin
decays because of the external resistor. Also in this case the IC is soft-restarted
as the voltage drops below 0.3 V.
Timing capacitor. A capacitor connected from this pin to GND is charged and
discharged by internal current generators programmed by the external network
connected to pin 4 (RF
converter.
min
(pin 4) that set both the initial oscillator frequency and the time constant
Doc ID 022835 Rev 2
min
) and determines the switching frequency of the
Function
CC
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L6699