MC33260DG ON Semiconductor, MC33260DG Datasheet - Page 12

• Manufacturer Part Number: MC33260DG
• Description: IC PFC CONTROLLER DCM 8SOIC
• Manufacturer: ON Semiconductor
• Series: GreenLine™r

Specifications of MC33260DG

• Mode: Discontinuous Conduction (DCM)
• Current - Startup: 100µA
• Voltage - Supply: 11 V ~ 16 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

This circuitry disconnects the Current Sense comparator
from Pin 4 and disables it during the 400 first ns of the power
switch conduction. This prevents the block from reacting on
the current spikes that generally occur at power switch turn
on. Consequently, proper operation does not require any
filtering capacitor on Pin 4.
PROTECTIONS
OCP (Overcurrent Protection)
OVP (Overvoltage Protection)
current (I
is maintained low until this current gets lower than a second
level (I
where:
A LEB (Leading Edge Blanking) has been implemented.
Refer to Current Sense Block.
The feedback current (I
So, the OVP upper threshold is:
R
I
V
Enable
V
ovpH
control
o
Drive
pin1
Gate
5
is the feedback resistor that is connected between
ovpL
Figure 30. Internal Current Thresholds
Pin 1 and the output voltage,
is the internal upper OVP current threshold,
is the Pin 1 clamp voltage.
ovpH
).
V ovpH = V pin1 +
). If it exceeds this value, the gate drive signal
I
uvp
Current Sense
--60 mV
Comparator
Oscillator Sawtooth
--
+
o
) is compared to a threshold
Synchronization
Arrangement

ZCD & OCP
I
regL
R o × I ovpH
Pin Numbers are Relevant to the PDIP- -8 Version
I
regH
I
ovpL

+
I
ovpH
&
--
Figure 29. PWM Latch
http://onsemi.com
OVP, UVP
PWM Latch
Comparator
I
o
12
neglected. The equation can then be simplified:
where I
Consequently, V
parameters specification). This ensures that the OVP
function doesn’t interfere with the regulation one.
UVP (Undervoltage Protection)
than 14% of I
power switch is kept off.
The UVP threshold is:
Practically (V
Maximum On- -Time Limitation
accurately controlled.
Pin Protection
Practically, V
On the other hand, the OVP low threshold is:
The OVP hysteresis prevents erratic behavior.
I
This function detects when the feedback current is lower
This protection is useful to:
As explained in PWM Latch, the maximum on- -time is
All the pins are ESD protected.
 Protect the preregulator from working in too low
 To detect the feedback current absence (in case of a
ovpL
Output_Ctrl
mains conditions.
nonproper connection for instance).
V
control
V uvp ≈ V
S
R
ovpL
is guaranteed to be higher than IregH (refer to
PWM
Latch
V uvp = R o ( MΩ ) × I uvp ( mA ) ( V )
V
V
(V
V ovpL = V pin1 +
ovpH
ref
ovpL
pin2
is the internal low OVP current threshold.
pin1
Q
Q
. In this case, the PWM latch is reset and the
pin1
-- Regulation Output)
pin1
Th--Stdwn
pin1
being neglected),
= R o ( MΩ ) × I
= R o ( MΩ ) × I
that is in the range of 2.5 V, can be
being neglected:
+

R o ( MΩ ) × I uvp ( mA )

R o × I ovpL
ovpH
ovpL
( mA ) ( V )
( mA ) ( V )
Output
Buffer
V
CC


( V )
7