3.2.3

Output Current measurement

Pin 33, Iout. PFC Output current. The measurement of this current allows to implement the following functions.

•

Load feedforward. The input current reference is modified proportionally to the load, in order to give a faster

response versus load transient.

•

Channels power management. Each channel can be enabled or disabled based on output current level. For

example, up to 50% of the load, only one channel may be enabled, above 50% two channel configurations

can be selected,

3.2.4

Output voltage sensing

Pin 34, Vout. Output Voltage sensing. This feedback input is connected via a voltage divider to the boost output

voltage. The voltage divider will give the Vout_fb to Digital Voltage Control Block and it’s used in order to

implements the following functions.

•

Output voltage regulation.

•

Over voltage protection

In Figure 8 the block scheme of Vin Iout and Vout is reported.

Figure 8. Vin, Iout and Vout Measurement

3.2.5

Channel current measurement

Pin 35 Pin 36. ICH[0], ICH[1]: channel current measurements. These pins measure the currents flowing in each

channel. The signal coming from sensing resistors is sent to a low pass filter and finally it’s connected to Pin 35

and Pin 36. The low pass filter must be sized so that its passband is about ten times lower than the switching

frequency of the single channel. The result of this measurement is internally used to perform the current balance

between the two channels.

STNRGPF02, STNRGPF12

Measurements section

DS12895 - Rev 2

page 9/43