ICE2PCS02_11 INFINEON [Infineon Technologies AG], ICE2PCS02_11 Datasheet - Page 7

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ICE2PCS02_11

Manufacturer Part Number
ICE2PCS02_11
Description
Standalone Power Factor Correction (PFC) Controller in Continuous Conduction Mode (CCM) with Input Brown-Out Protection
Manufacturer
INFINEON [Infineon Technologies AG]
Datasheet
3
3.1
The ICE2PCS02/G is a 8 pin control IC for power factor
correction converters. It comes in both DIP and DSO
packages and is suitable for wide range line input
applications from 85 to 265 VAC. The IC supports
converters in boost topology and it operates in
continuous conduction mode (CCM) with average
current control.
It is a design derivative from the ICE2PCS01/G with the
differences in the supporting functions, namely the
input brown-out detection and internal fixed switching
frequency 65kHz.
The IC operates with a cascaded control; the inner
current loop and the outer voltage loop. The inner
current loop of the IC controls the sinusoidal profile for
the average input current. It uses the dependency of
the PWM duty cycle on the line input voltage to
determine the corresponding input current. This means
the average input current follows the input voltage as
long as the device operates in CCM. Under light load
condition, depending on the choke inductance, the
system may enter into discontinuous conduction mode
(DCM) resulting in a higher harmonics but still meeting
the Class D requirement of IEC 1000-3-2.
The outer voltage loop controls the output bus voltage.
Depending on the load condition, OTA1 establishes an
appropriate voltage at VCOMP pin which controls the
amplitude of the average input current.
The IC is equipped with various protection features to
ensure safe operating condition for both the system
and device.
3.2
An internal under voltage lockout (UVLO) block
monitors the VCC power supply. As soon as it exceeds
11.8V and both voltages at pin 6 (VSENSE) >0.6V and
pin 4 (VINS) >1.5V, the IC begins operating its gate
drive and performs its Startup as shown in Figure 3.
.
Figure 3
Version 2.4
IC's
State
V
CC
11.8 V
OFF
General
Power Supply
State of Operation respect to VCC
Start
Up
AND (V
(V
Functional Description
VSENSE
Operation
VINS
Normal
> 0.6 V)
> 1.5 V)
OR (V
(V
Open loop/
VSENSE
Standby
VINS
< 0.6 V)
< 0.8 V)
AND (V
(V
Operation
Normal
VSENSE
VINS
> 0.6 V)
> 1.5 V)
11.0 V
OFF
t
7
If VCC drops below 11V, the IC is off. The IC will then
be consuming typically 300mA, whereas consuming
10mA during normal operation.
The IC can be turned off and forced into standby mode
by pulling down the voltage at pin 6 (VSENSE) to lower
than 0.6V. In this standby mode, the current
consumption is reduced to 300mA. Other condition that
can result in the standby mode is when a Brown-out
condition occurs, ie pin 4 (VINS) <0.71V.
3.3
Figure 4 shows the operation of voltage loop’s OTA1
during startup. The VCOMP pin is pull internally to
ground via switch S1 during UVLO and other fault
conditions (see later section on “System Protection”).
During power up when V
rated level, OTA1 sources an output current, maximum
30mA into the compensation network at pin 5 (VCOMP)
causing the voltage at this pin to rise linearly. This
results in a controlled linear increase of the input
current from 0A thus reducing the stress on the
external component.
Figure 4
As V
value, VCOMP voltage is level-shifted by the window
detect block as shown in Figure 5, to ensure there is
fast boost up output voltage.
When V
sourcing current drops and so does the level shift of the
window detect block is removed. The normal voltage
loop then takes control.
OUT
OUT
(
has not reached within 5% from the rated
Start-up
C4
R6
Startup Circuit
R3 + R4
R4
approaches its rated value, OTA1’s
VSENSE
VCOMP
x V
C5
OUT
Functional Description
)
OUT
ICE2PCS02/G
S1
is less than 83% of the
ICE2PCS02/G
OTA1
protect
CCM-PFC
3V
22 Mar 2010

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