(VVSENSE > 0.6 V) (VVSENSE < 0.6 V)
If VCC drops below 11V, the IC is off. The IC will then
be consuming typically 300∝A, whereas consuming
The ICE2PCS01/G is a 8 pin control IC for power factor
13mA during normal operation.
correction converters. It comes in both DIP and DSO
The IC can be turned off and forced into standby mode
packages and is suitable for wide range line input
by pulling down the voltage at pin 6 (VSENSE) to lower
applications from 85 to 265 VAC. The IC supports
than 0.6V. The current consumption is reduced to
converters in boost topology and it operates in
continuous conduction mode (CCM) with average
The IC operates with a cascaded control; the inner
current loop and the outer voltage loop. The inner
Figure 4 shows the operation of voltage loop’s OTA1
current loop of the IC controls the sinusoidal profile for
during startup. The VCOMP pin is pull internally to
the average input current. It uses the dependency of
ground via switch S1 during UVLO and other fault
the PWM duty cycle on the line input voltage to
conditions (see later section on “System Protection”).
determine the corresponding input current. This means
During power up when VOUT is less than 83% of the
the average input current follows the input voltage as
rated level, OTA1 sources an output current, maximum
long as the device operates in CCM. Under light load
30∝A, into the compensation network at pin 5
condition, depending on the choke inductance, the
(VCOMP) causing the voltage at this pin to rise linearly.
system may enter into discontinuous conduction mode
This results in a controlled linear increase of the input
(DCM). In DCM, the average current waveform will be
current from 0A thus reducing the stress on the
distorted but the resultant harmonics are still low
enough to meet the Class D requirement of IEC 1000-
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. Important protection features are namely
Open-Loop protection, Current Limitation and Output
An internal under voltage lockout (UVLO) block
monitors the VCC power supply. As soon as it exceeds
11.8V and the voltage at pin 6 (VSENSE) is >0.6V, the
IC begins operating its gate drive and performs its
Startup as shown in Figure 3.
As VOUT has not reached within 5% from the rated
value, VCOMP voltage is level-shifted by the window
detect block as shown in Figure 5, to ensure there is
fast boost up of the output voltage.
When VOUT approaches its rated value, OTA1’s
sourcing current drops and the level shift of the window
detect block is removed. The normal voltage loop then
State of Operation respect to VCC