Dual Echo Canceler & Noise Canceler with Dual Codec for Hands-Free
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Description

The ML7037-003 is an IC device developed for portable, handsfree communication with built-in line echo canceler, acoustic echo canceler, and transmission signal noise canceler. Built-in to the voice signal interface is a PCM linear CODEC for the analog interface on the acoustic-side, and a PCM linear CODEC for the analog interface on the line-side. On the line-side, in addition to the analog interface, there is also a µ-law PCM/16-bit linear digital interface. Equipped with gain and mute controls for data transmission and reception, a µ-law PCM/16-bit linear digital interface for memo recording and message output, and transfer clock and sync clock generators for digital communication, this device is ideally suited for a handsfree system.
Block Diagrams
Features
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Single 3 V Power Supply Operation (3.0 to 3.6 V) [with built-in regulator to generate internal power supply] |
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Built-in 2-channel (line and acoustic) echo canceler
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Echo attenuation: 35 dB (typ.) for white noise
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Cancelable echo delay time:
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Single echo canceler mode (only an acoustic echo canceler is enabled) Tacoud = 100 ms (max.)
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Dual echo canceler mode (both of an acoustic and line echo cancelers are enabled) Tacoud = 100 ms; Tlined = 20 ms | | |
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Built-in transmission signal noise canceler
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Noise attenuation : 17 dB (typ.) for white noise 40 dB (typ.) for single tone | |
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Built-in 2-channel CODEC
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Synchronous transmission and reception enables full duplex operation | |
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Built-in analog input gain amp stage (max. gain = 30 dB) |
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Analog output configuration: Push-pull drive (can drive a 2.0 k load) |
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Receive-side ALC’s (Auto Level Controlers) |
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Programmable Gain/Mute |
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A slope filter on transmit side |
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16 GPI’s and 5 GPO’s |
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Speech digital interface coding formats: µ-law PCM (G.711 [64kbps]), 16-bit linear (2's complement) |
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Speech digital interface sync formats : Long-frame-sync, short-frame-sync |
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PCM shift clocks (BCLK)
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Clock slave mode : 64kHz to 2.048MHz (µ-law PCM) / 128kHz to 2.048MHz (16bit Linear PCM) | |
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Digital transmission rate
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External input: 64 kbps to 2048 kbps |
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Internal generation: 64 kbps (µ-law PCM)/128 kbps (16-bit linear) | |
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Fixed digital interface sync clock (SYNC) enables automatic power-down |
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Master clock frequency: 19.2 MHz Compatible with crystal oscillator and crystal |
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Low power consumption
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Operating mode: typ. 35 mW (when VDD = 3.0 V in a silent mode) |
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Power-down mode: typ. 0.02 mW (when VDD = 3.0 V in a silent mode) | |
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Control by both the serial microcomputer interface and parallel port is possible |
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Transmit / receive mute function, transmit/receive programmable gain setting |
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Package: 64-pin plastic QFP (QFP64-P-1414-0.80-BK) (Product name: ML7037-003) |