Parameter conversion for stability of digitally controlled converter
A method of digitally controlling a DC-DC converter includes detecting an output of the DC-DC converter; comparing the output to a target value to determine an error value; calculating a control parameter based on the error value in which an output control target is a linear function of the control parameter; converting the control parameter to a converter control parameter; and based on the converter control parameter, generating a pulse signal to control a power switch of the DC-DC converter.
1 . A method of digitally controlling a DC-DC converter, the method comprising:
detecting an output of the DC-DC converter;
comparing the output to a target value to determine an error value;
calculating a control parameter based on the error value in which an output control target is a linear function of the control parameter;
converting the control parameter to a converter control parameter; and
based on the converter control parameter, generating a pulse signal to control a power switch of the DC-DC converter; wherein
calculating the control parameter includes using equations that provide either proportional-integral-derivative control or proportional-integral control.
2 . The method of claim 1 , wherein the output control target is an output voltage, an output current, or an output power.
3 . The method of claim 1 , wherein the DC-DC converter is a boost DC-DC converter.
4 . The method of claim 1 , wherein
the converter control parameter is a duty of the power switch of the DC-DC converter; and
the control parameter is provided by an equation:
1
1
-
Duty
where Duty is the duty of the power switch of the DC-DC converter.
5 . The method of claim 1 , wherein
the output of the DC-DC converter is a function f(z) of a control parameter z; and
the control parameter z is provided by
z
=
f
-
1
(
x
)
A
where A is an arbitrary value and f (z) is a linear function defined by
f ( z )= A·x.
6 . The method of claim 1 , wherein the pulse signal provides duty control, on-time control, off-time control, frequency control, or phase-shift control.
7 . A digital controller comprising:
a terminal configured to receive a detected signal; and
a terminal configured to provide a pulse signal; wherein
the digital controller is configured and/or programmed to, when the digital controller is included in a DC-DC converter:
compare the detected signal to a target value to determine an error value;
calculate a control parameter based on the error value in which an output control target is a linear function of the control parameter;
convert the control parameter to a converter control parameter; and
based on the converter control parameter, generate the pulse signal, wherein
calculating the control parameter includes using equations that provide either proportional-integral-derivative control or proportional-integral control.
8 . The digital controller of claim 7 , wherein the DC-DC converter is a boost DC-DC converter.
9 . The digital controller of claim 7 , wherein
the converter control parameter is a duty of a power switch of the DC-DC converter; and
the control parameter is provided by an equation:
1
1
-
Duty
where Duty is the duty of the power switch of the DC-DC converter.
10 . The digital controller of claim 7 , wherein
an output of the DC-DC converter is a function f(z) of a control parameter z; and
the control parameter z is provided by
z
=
f
-
1
(
x
)
A
where A is an arbitrary value and f(z) is a liner function defined by
f ( z )= A·x.
11 . A DC-DC converter comprising:
an output;
a power switch; and
the digital controller of claim 7 connected to the power switch.
12 . The DC-DC converter of claim 11 , wherein the detected signal is received from the output of the DC-DC converter.
13 . The DC-DC converter of claim 12 , wherein the output is an output voltage, an output current, or an output power.