VIPER26LD STMicroelectronics, VIPER26LD Datasheet - Page 13

• Manufacturer Part Number: VIPER26LD
• Description: Switching Converters, Regulators & Controllers VIPer Plus 800V Fixed freq 60 kHz
• Manufacturer: STMicroelectronics

Specifications of VIPER26LD

• Output Voltage: 800 V
• Output Current: 3 A
• Output Power: 20 W
• Input Voltage: 11.5 V to 23.5 V
• Switching Frequency: 60 KHz
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: SMD/SMT
• Package / Case: SOIC-16 Narrow
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

VIPER26
7
8
Power section
The power section is implemented with an n-channel power MOSFET with a breakdown
voltage of 800 V min. and a typical R
a virtually lossless current sensing and the thermal sensor.
The gate driver of the power MOSFET is designed to supply a controlled gate current during
both turn-ON and turn-OFF in order to minimize common mode EMI. During UVLO
conditions, an internal pull-down circuit holds the gate low in order to ensure that the power
MOSFET cannot be turned ON accidentally.
High voltage current generator
The high voltage current generator is supplied by the DRAIN pin. At the first start up of the
converter, it is enabled when the voltage across the input bulk capacitor reaches the
V
voltage reaches the V
high voltage current generator is turned OFF. The VIPer26 is powered by the external
source. After the start-up, the auxiliary winding or the diode connected to the output voltage
have to power the VDD capacitor with voltage higher than V
on page
consumptions are minimized. In case of fault the switching is stopped and the device is self
biased by the internal high voltage current source; it is activated between the levels V
and V
see
At converter power-down, the V
below V
Figure 22. Power on and power off
DRAIN_START
V
DRAIN_START
Figure 22 on page
V
V
DDCSon
V
V
DDon
I
DRAIN
I
DDch2
DDch1
DDon
V
DDoff
V
I
DD
DDoff
DD
IN
6). During the switching, the internal current source is disabled and the
delivering the current I
threshold (see
threshold, sourcing the I
Power-on
DDon
13.
start-up threshold, the power section starts switching and the
Table 7 on page
Doc ID 17736 Rev 2
DD
DDch2
voltage drops and the converter activity stops as it falls
DS(on)
DDch1
to the V
Normal operation
of 7 Ω . It includes a SenseFET structure to allow
current (see
6).
DD
capacitor during the MOSFET off time,
Table 7 on page
DDCSon
regulation is lost here
threshold (see
V
HV startup is no more activated
Power-off
IN
< V
6); as the V
DRAIN_START
Power section
time
time
time
time
Table 7
DDCSon
DD
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