D类放大器的原理Eǖ
E E )QXN* E )FNJ* 0
QXNE FNJ0FNDUIE,O E
E
E )QXN*)* 2 QXNE NPTGFU )M G D G *q o NPTGFU WEE WEE E E)g TX *361lI{ 2/6NI{ ) *QXN “ ” 61&3 QXN
E )BCBC* )BC* E E E
VO(t) VDD VDD
TRIANGLE-WAVE OSCILLATOR
GND COUT
t
LF GATE-DRIVE AMPLIFIER + VL CF
RL
+ VO_AVG -
+ VAUDIO -
2/!E
3
QXNE 2MD ) * )W P`BWH *)J BWH * g TX ǖ
3 134WM)u* )BPO BPGG* 3 ǖ
A ON = | A OFF |
)4*
)5*
)6* 564ǖ )2* )7* WP ǖ )8*
1 I L (t) = ∫ VL (t)dt L
WM)u*2 )JBWH* )U TX* 4 ǖ
E
1 L
TSW
∫ V (t)dt = I
L 0
L
(TSW ) - I L (0) = 0
)3*
TRIANGLE-WAVE OSCILLATOR SIGNAL
TSW
INPUT SIGNAL
VDD VO
GND NOTE: FOR CLARITY, SIGNAL PERIODS ARE NOT SHOWN TO SCALE.
3/!
4
EQXN )*
VO (t) VDD TSW
E
Σ . Δ
5 2
t
5 2 20t QXN
IL (t)
tOFF
IAVG tON
t AL (t)
ǖ )9*
VDD -……
