L6911E

6/20

Note that forcing a 50

oscillator.

Figure 1.

Digital to Analog Converter

The built-in digital to analog converter allows the adjustment of the output voltage from 1.050V to 1.825V with

25mV binary steps as shown in the previous table 1. The internal reference is trimmed to ensure the precision

of 1%.

The internal reference voltage for the regulation is programmed by the voltage identification (VID) pins. These

are TTL compatible inputs of an internal DAC that is realised by means of a series of resistors rpoviding a par-

tition of the internal voltage reference. The VID code drives a multiplexer that selects a voltage on a precise

point of the divider. The DAC output is delivered to an amplifier obtaining the VPROG voltage reference (i.e. the

set-point of the error amplifier). Internal pull-ups are provided (realized with a 5

way, to program a logic ”1” it is enough to leave the pin floating, while to program a logic ”0” it is enough to short

the pin to GND.

The voltage identification (VID) pin configuration also sets the power-good thresholds (PGOOD) and the over-

voltage protection (OVP) thresholds.

Soft Start and Inhibit

shown in figure 2.

f

S

200kH z

4.306 10

7

⋅

R

()

-----------------------------

+

=

f

S

200k H z

15 10

7

⋅

R

()

--------------------

+

=

10

10 0

1000

Fr equency [ kH z]

10

100

1000

10000

RT to G N D

RT to V CC= 12 V

RT to V CC= 5V