Shivaki STV-24LEDGR7, Service Manual

Page: 52 / 175

D-class power amplifier
R2A15120FA
PRELI
MINAR
Y
some
param
etric lim
its are
subjec
t to ch
ange.
CONFIDENTIAL
11-4. Carrier I/O control
Operating by external
oscillator.
Input
(Triangular wave form)
Connected to the
AVCC
Slave
mode
Operating by the clock
signal of internal oscillator.
Output
(Triangular wave form)
Resistor connected
ROSC to RREF
Master
mode
Operating condition State of
terminal CLK
ROSC condition Setting
IC1:Master
ROSC
CLK
OSC
Example for Multi-channel
Rosc
AVCC
IC2:Slave
AVCC
CLK
ROSC
OSC
+
+
11-5. Carrier frequency
A standard clock (carrier) of the PWM signal generation is adjustable by controlling external resistor
connected to terminal ROSC.
Carrier I/O condition is controllable by external condition of terminal ROSE.
Carrier frequency can be set from 400kHz to 600kHz by terminal ROSC(34pin).
The recommended carrier frequency is 500kHz.
(Please be careful following condition.PWM function might be unstable if the condition of low carrier
frequency and high power supply voltage occurs.)
200
300
400
500
600
700
800
0 10 20 30 40 50 60
Resistance R[kΩ]
C
ar
ri
er
f
re
quen
cy
(
K
H
z)
27k 18k
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