Digital Control

Analog vs. Digital Control Algorithm
Linear compensation Power stage
Vref 2 3 4
Vout
+ -
K
A
B
0
0
+ A S + A
1
1
+ B S
1
2
+ B
2
S
S
2
+ A
3
+ B
3
S
S
3
+ A
4
+ B
4
S
S
4
κ ( 1+
γS)
1
1+
αS
+ βS
A typical control loop implemented by an analog circuit
Nonlinear
compensation
Operation condition
Adaptive compensation Power stage
Vref
2 3 4
αα
0 + αα
1 S + αα
2 S + αα
3 S + αα
4 S κ κ ( 1 + γγ
S ) Vout
κκ
+
- 2 3 4
β0
+ β1S
+ β 2S
+ β3S
+ β 4S
Software Implementation
A digital control loop implemented by Digtal Signal Controller
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1+
αS
Benefit of digital control:
1) Advanced control algorithm implemented to control complex topologies
2) Optimize feedback loop to meet application requirements
3) Runtime changes to compensation parameters according to operating conditions
1
2
+ βS
2
TM