Features: •Echo canceler has two channels, which can be used for acoustic and line echoes. Set as a single cross-connected channel, it can be used for both acoustic and line echoes.
•ITU-T G164/G165 standard tone disabler.
•PCM line level adjustment possible with SIN level attenuator (SA pin) and SOUT level amplifier (SG pin). Can also be used for ERL amplification with the SIN level attenuator (SA pin).
•RGC pin provides input/output adjustment mode (±6LR mode) that can prevent malfunction due to excessive inputs without changing the RIN-ROUT input/output levels.
•Cancelable echo delay time: 55 ms (max.)
•Echo attenuation: 30 dB (typ.)
•Clock frequency: 18 to 20 MHz 19.2 MHz if using internal clock signal
•Power supply voltage: 4.5 to 5.5 V
•Package: 64-pin plastic QFP (QFP64-P-1414-0.80-BK)
•Product name: MSM7617-001GS-BK (-law)
Pinout
Specifications
|
Symbol |
Parameter |
Conditions |
Limits |
Unit |
|
VDD |
Power Supply Voltage |
Ta = 25°C
|
_0.3 to +7 |
V |
|
VIN |
Input Voltage |
0.3 to VDD + 0.3 |
V |
|
PD |
Power Dissipation |
1 |
W |
|
TSTG |
Storage Temperature |
- |
55 to +150 |
°C |
DescriptionThe MSM7617 cancels echoes (acoustic or line echoes) generated in voice channels. It is a lowpower CMOS LSI device with two channels.
MSM7617 echo canceling is performed by digital signal processing. It negates echoes by estimating the echo channel and then generating a pseudo-echo signal.
When used as an acoustic echo canceler, the MSM7617 can cancel acoustic echoes between speaker and microphone that occur during hands-free speaking with car phones, conferencing system phones, etc. When used as a line echo canceler, the MSM7617 can cancel line echoes returned by hybrid impedance mismatches.
By setting its mode for use as a single cross-connected channel, the MSM7617 can cancel both acoustic and line echoes.
Also, the MSM7617 can improve voice communication by using its howling detection, doubletalk detection, attenuation, and gain control functions to prevent and suppress howling levels,and by using its center clipping function to suppress low level noise.
Furthermore, the MSM7617 can disable echo canceling during data communication with its 2100 Hz tone detector and 2100 Hz phase reversal detector. It also provides the ability to attenuate SIN levels, to amplify SOUT levels, and to adjust input/output levels.
An economical and highly efficient echo canceler unit can be constructed by using a 2-channel single-chip CODEC like the MSM7533 together with the MSM7617.
MSM7617 Data Sheet
