参数资料
型号: SI3220DC0-EVB
厂商: Silicon Laboratories Inc
文件页数: 79/112页
文件大小: 0K
描述: DAUGHTER CARD W/SI3200 INTERFACE
标准包装: 1
系列: ProSLIC®
主要目的: 接口,模拟前端(AFE)
已用 IC / 零件: Si3220
已供物品: 板,CD
Si3220/25 Si3200/02
Rev. 1.3
69
Not
Recommended
fo
r N
ew
D
esi
gn
s
Figure 38. Pulse Metering Generation Block Diagram
3.23. DTMF Detection
On-chip DTMF detection, also known as touch tone, is
available in the Si3220 and Si3225.
It is an in-band signaling system that replaces the pulse-
dial signaling standard. In DTMF, two tones generate a
DTMF digit. One tone is chosen from the four possible
row tones, and one tone is chosen from the four
possible column tones. The sum of these tones
constitutes one of 16 possible DTMF digits. The row
and column tones and corresponding digits are shown
DTMF detection is performed using a modified Goertzel
algorithm to compute the DFT for each of the eight
DTMF frequencies and their second harmonics. At the
end of the DFT computation, the squared magnitudes of
the DFT results for the 8 DTMF fundamental tones are
computed. The row results are sorted to determine the
strongest row frequency, and the column frequencies
are sorted as well. Upon completion of this process,
checks are made to determine if the strongest row and
column tones constitute a DTMF digit.
The detection process occurs twice within the 45 ms
minimum tone time. A digit must be detected on two
consecutive tests after a pause to be recognized as a
new digit. If all tests pass, an interrupt is generated, and
the DTMF digit value is loaded into the DTMF register
according to Table 39. If tones occur at the maximum
rate of 100 ms per digit, the interrupt must be serviced
within 85 ms so that the current digit is not overwritten
by a new one. There is no buffering of the digit
information.
Decimation
Filter
ADC
DAC
Pulse
Metering
DAC
Pulse
Metering
Oscillator
Volume
PMRAMP
Peak Detector
PMAMPTH
Z
A
I
BUF
8 kHz
7FFF
or 0
Clip
Logic
+
12/16 kHz
Bandpass
+
+
+
x
+
±
Table 39. DTMF Row/Column Tones
697 Hz
1
2
3
A
770 Hz
4
5
6
B
852 Hz
7
8
9
C
941 Hz
*
0
#
D
1209 Hz
1336 Hz
1477 Hz
1633 Hz
相关PDF资料
PDF描述
H1KXH-6436M IDC CABLE - HPK64H/AE64M/X
A3BRB-2418M IDC CABLE - ASR24B/AE24M/APR24B
SI3232PPTX-EVB BOARD EVAL W/DISCRETE INTERFACE
SI3216MDCQX-EVB DAUGHTER CARD W/DISCRETE INTRFC
M3TTK-3418J IDC CABLE - MSD34K/MC34G/MSD34K
相关代理商/技术参数
参数描述
SI3220DCX-EVB 功能描述:子卡和OEM板 Si3220 Daughter Card RoHS:否 制造商:BeagleBoard by CircuitCo 产品:BeagleBone LCD4 Boards 用于:BeagleBone - BB-Bone - Open Source Development Kit
SI3220-F-GQ 制造商:Silicon Laboratories Inc 功能描述:DUAL-CHANNEL SLIC/CODEC WITH INTERNAL 65 VRMS BALANCED RINGI - Trays
SI3220-F-GQR 制造商:Silicon Laboratories Inc 功能描述:DUAL-CHANNEL SLIC/CODEC WITH INTERNAL 65 VRMS BALANCED RINGI - Tape and Reel
Si3220-FQ 功能描述:电信线路管理 IC Dual-Channel SLIC/ codec RoHS:否 制造商:STMicroelectronics 产品:PHY 接口类型:UART 电源电压-最大:18 V 电源电压-最小:8 V 电源电流:30 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:VFQFPN-48 封装:Tray
SI3220-FQR 制造商:Silicon Laboratories Inc 功能描述: 制造商:Silicon Laboratories Inc 功能描述:SLIC 2CH 63DB 45MA 3.3V/5V 64TQFP - Tape and Reel