SI3018FS Silicon Laboratories Inc, SI3018FS Datasheet - Page 20

• Manufacturer Part Number: SI3018FS
• Description: DAA - MODEM FA19 TELECOM/DATACO
• Manufacturer: Silicon Laboratories Inc

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.
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
Component
AOUT
LS1
C41
R41
Q6
+5 VA
Figure 18. AOUT PWM Circuit for Call Progress
Table 13. Component Values—AOUT PWM
Speaker BRT1209PF-06
0.1 µF, 16 V, X7R, ±20%
150 Ω, 1/16 W, ±5%
NPN KSP13
Value
R41
Rev. 1.05
C41
Venkel, SMEC, Panasonic
Venkel, SMEC
Supplier
Fairchild
Intervox
NPN
Q6
LS1