Si3056
Si3018/19/10
4. AOUT PWM Output
Figure 18 illustrates an optional circuit to support the pulse width modulation (PWM) output capability of the Si3056
for call progress monitoring purposes. Set the PWME bit (Register 1, bit 3) to enable this mode.
+5 VA
LS1
Q6
NPN
R41
AOUT
C41
Figure 18. AOUT PWM Circuit for Call Progress
Table 13. Component Values—AOUT PWM
Component
LS1
Value
Supplier
Intervox
Speaker BRT1209PF-06
NPN KSP13
Q6
Fairchild
C41
0.1 µF, 16 V, X7R, ±20%
150 Ω, 1/16 W, ±5%
Venkel, SMEC
Venkel, SMEC, Panasonic
R41
Registers 20 and 21 allow the receive and transmit paths to be attenuated linearly. When these registers are set to
all 0s, the receive and transmit paths are muted. These registers affect the call progress output only and do not
affect transmit and receive operations on the telephone line.
The PWMM[1:0] bits (Register 1, bits 5:4) select one of the three different PWM output modes for the AOUT signal,
including a delta-sigma data stream, a conventional 32 kHz return to zero PWM output, and balanced 32 kHz PWM
output.
20
Rev. 1.05
SILICON [ SILICON ]
