VIPER16HN STMicroelectronics, VIPER16HN Datasheet - Page 17

• Manufacturer Part Number: VIPER16HN
• Description: IC OFFLINE CONV PWM OTP 7DIP
• Manufacturer: STMicroelectronics
• Series: VIPer™ plusr

Specifications of VIPER16HN

• Output Isolation: Either
• Frequency Range: 103 ~ 127kHz
• Voltage - Input: 11.5 ~ 23.5 V
• Voltage - Output: 800V
• Power (watts): 12W
• Operating Temperature: -40°C ~ 150°C
• Package / Case: 8-DIP (0.300", 7.62mm), 7 Leads
• Output Voltage: 800 V
• Output Power: 1 W
• Input Voltage: - 0.3 V
• Switching Frequency: 115 KHz
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: Through Hole
• Duty Cycle (max): 80 %
• Number Of Outputs: 1
• For Use With: 497-9006 - BOARD EVAL BASED ON VIPER16497-8836 - EVAL BOARD FOR VIPER16HD497-8835 - EVAL BOARD FOR VIPER16HD ISO PSU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-8545-5

VIPER16
14
Automatic auto restart after overload or short-circuit
The overload protection is implemented in automatic way using the integrated up-down
counter. Every cycle, it is incremented or decremented depending if the current logic detects
the limit condition or not. The limit condition is the peak drain current, I
Table 8 on page 7
Figure 13 on page
equal to the level I
be disabled the power MOSFET switch ON. It will be activated again, through the soft start,
after the t
values on
In case of overload or short-circuit event, the power MOSFET switching will be stopped after
a time that depends from the counter and that can be as maximum equal to t
protection will occur in the same way until the overload condition is removed, see
and
repetition rate, so that it works safely with extremely low power throughput and avoiding the
IC overheating in case of repeated overload events. If the overload is removed before the
protection tripping, the counter will be decremented cycle by cycle down to zero and the IC
will not be stopped.
Figure 25. Timing diagram: OLP sequence (IC externally biased)
Figure 26. Timing diagram: OLP sequence (IC internally biased)
V
Figure 26 on page
I
Dlim_bm
DDCSon
V
I
DRAIN
V
DDon
DD
V
I
Dlim_bm
DDCSon
V
I
DRAIN
RESTART
V
DDon
Table 8 on page
* The time t
DD
SHORT CIRCUIT
OCCURS HERE
* The time t
SHORT CIRCUIT
OCCURS HERE
t
1
*
1
t
time, see the
can be lower or equal to the time t
1
Dlim
*
or the one set by the user through the R
9. After the reset of the counter, if the peak drain current is continuously
1
can be lower than or equal to the time t
, the counter will be incremented till the fixed time, t
t
RESTART
17. This protection ensures restart attempts of the converter with low
t
RESTART
7.
Doc ID 15232 Rev 4
Figure 25
t
SS
t
SS
t
Automatic auto restart after overload or short-circuit
OVL
t
OVL
OVL
and
OVL
t
t
RESTART
RESTART
Figure 26 on page 17
t
SS
t
SS
t
OVL
t
OVL
LIM
resistor, as reported in
SHORT CIRCUIT
REMOVED HERE
t
RESTART
SHORT CIRCUIT
REMOVED HERE
t
RESTART
and the mentioned time
Dlim ,
t
OVL
SS
t
reported on
SS
, after that will
OVL
. The
time
time
Figure 25
time
time
17/24