NCP1395A ONSEMI [ON Semiconductor], NCP1395A Datasheet - Page 20

• Manufacturer Part Number: NCP1395A
• Description: High Performance Resonant Mode Controller
• Manufacturer: ONSEMI [ON Semiconductor]

Brown−Out Protection
resonant converter from low DC input voltages. Below a
given level, the controller blocks the output pulses, above
it, it authorizes them. The internal circuitry, depicted by
Figure 42, offers a possibility to observe the high−voltage
Configuration with an Offset Current Source
The Brown−Out circuitry (BO) offers a way to protect the
Rupper
Rlower
Figure 45. The Internal Brown−Out
−4.00
−8.00
4.00
3.00
2.00
1.00
16.0
12.0
8.00
4.00
8.00
4.00
Vbulk
0
0
0
1
vct
IBO
BO
2
56.2u
Vdd
clock
+
VBO
ON/OFF
5
+
−
difference
Figure 44. Typical Oscillator Waveforms
BO
65.9u
http://onsemi.com
250
NCP1395A/B
50.0
450
350
150
time in seconds
16.0
12.0
8.00
4.00
20
0
Figure 46. Simulation Results for 350/250 ON/OFF Levels
75.7u
1
(HV) rail. A resistive divider made of Rupper and Rlower,
brings a portion of the HV rail on pin 7. Below the turn−on
level, a current source IBO is off. Therefore, the turn−on
level solely depends on the division ratio brought by the
resistive divider.
vin
20.0u
Vin
2
vcmp
351 volts
60.0u
BO
85.4u
time in seconds
100u
140u
95.1u
250 volts
180u
1
2
5
2
1