ON5250,135 NXP Semiconductors, ON5250,135 Datasheet - Page 10

• Manufacturer Part Number: ON5250,135
• Description: MOSFET RF SOT223 SC-73
• Manufacturer: NXP Semiconductors

Specifications of ON5250,135

• Package / Case: SOT-223 (3 leads + Tab), SC-73, TO-261
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current Rating: -
• Power - Output: -
• Frequency: -
• Gain: -
• Transistor Type: -
• Noise Figure: -
• Current - Test: -
• Voltage - Test: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 934057275135

Philips Semiconductors
Short winding protection
After the leading edge blanking time, the short winding
protection circuit is activated. If the ‘sense’ voltage
exceeds the short winding protection voltage V
converter will stop switching. Once V
UVLO level, capacitor C
supply will restart again. This cycle will be repeated until
the short-circuit is removed (safe restart mode).
The short winding protection will also protect in case of a
secondary diode short-circuit.
OverTemperature Protection (OTP)
An accurate temperature protection is provided in the
circuit. When the junction temperature exceeds the
thermal shutdown temperature, the IC will stop switching.
When V
recharged to the V
Regarding the TEA1533P, this IC will not start switching
again. Subsequently, V
level, etc. Operation only recommences when the V
voltage drops below a level of approximately 4.5 V
(practically when the V
short period).
Regarding the TEA1533AP, when the V
reached, switching starts again (safe restart mode). This
process is repeated as long as the OTP condition exists.
2002 Aug 23
handbook, halfpage
GreenChip
MGU236
CC
100 A
(typ)
drops to UVLO, capacitor C
Fig.9 OPP correction curve.
start
TM
I DEM
level.
II SMPS control IC
mains
CC
VCC
will drop again to the UVLO
has been disconnected for a
will be recharged and the
24 A
(typ)
CC
VCC
start
drops below the
0.52 V
(typ)
0.3 V
(typ)
V sense(max)
will be
level is
swp
, the
CC
10
Control pin protection
If pin CTRL is open-circuit or not connected, a fault
condition is assumed and the converter will stop switching.
Operation will recommence as soon as the fault condition
is removed.
Burst mode standby
Pin CTRL is also used to implement the burst mode
standby. In burst mode standby, the power supply enters
a special low dissipation state. Figure 11 shows a flyback
converter using the burst mode standby function. The
system enters burst mode standby when the
microcontroller activates NPN transistor T1 on the
secondary side.
When the voltage on C
measured by the microcontroller, the opto-coupler is
activated by T1, sending a large current signal to
pin CTRL. In response to this signal, the IC stops
switching and enters a ‘hiccup’ mode. This burst activation
signal should be present for longer than the ‘burst blank’
period (typically 30 s): the blanking time prevents false
burst triggering due to spikes. Figure 12 shows the burst
mode standby signals. The hiccup mode during burst
mode standby operation does not differ from the hiccup
mode at safe restart during a system fault condition (e.g.
output short-circuit). The power is reduced during soft
restart mode.
Burst mode standby operation continues until the
microcontroller stops activating transistor T1. The system
then enters the start-up sequence and begins normal
switching behaviour.
I
burstmode
=
--------------- -
R
V
CTRL
th
TEA1533P; TEA1533AP
+
I
th(on)
micro
exceeds a certain voltage
Product specification