TCM320AC46 Datasheet, PDF (1/19 Pages) Texas Instruments – GEBERAL-PURPOSE AUDIO INTERFACE FOR DSP

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TCM320AC46
GENERALĆPURPOSE AUDIO INTERFACE FOR DSP
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SLWS001 − D4091, JUNE 1993
• Single 5-V Operation
• Low Power Consumption:
Operating Mode . . . 55 mW Typ
Standby Mode . . . 8 mW Typ
Power-Down Mode . . . 3 mW Typ
• Combined ADC, DAC, and Filters
• Extended Variable-Frequency Operation
Pass-Band up to 10 kHz
• Electret Microphone Bias Reference
Voltage Available
• Directly Drives a Piezo Speaker
• Compatible With All DSPs
• Selectable Between 8-Bit, µ-Law
Companded and 13-Bit Linear Conversion
• Programmable Volume Control in Linear
Mode
• Designed for Standard 2.048-MHz Master
Clock for U.S. Analog, U.S. Digital, CT2,
Battery-Powered Telephones
DW OR N PACKAGE
(TOP VIEW)
PDN ₁
EARA 2
EARB 3
EARGS 4
V_CC 5
MICMUTE 6
DCLKR 7
DIN 8
FSR 9
EARMUTE ¹⁰
20 ^MICBIAS
19 MICGS
18 MICIN
17 VMID
16 GND
15 LINSEL
14 TSX/DCLKX
13 DOUT
12 FSX
11 _CLK
description
The general-purpose audio interface for digital signal processors (DSPs) is designed to perform the transmit
encoding (A/D conversion) and receive decoding (D/A conversion) together with transmit and receive filtering
for voice-band audio systems. In particular, cellular telephone systems are targeted; however, this integrated
circuit can function in several systems, including digital audio, multimedia telecommunications, noise
cancellation, and other data acquisition.
The converted data is available in two formats. The formats are pin selectable between companded and linear.
When the device is in the companded mode, data is transmitted and received in eight-bit words. When the linear
mode is selected, 13 bits of data are sent and received, padded with trailing zeros or volume control bits to
provide a 16-bit word.
The transmit section is designed to directly interface with an electret microphone element. A reference voltage
equal to V_CC /2, called VMID, is used to develop the midlevel virtual ground for all the amplifier circuits and the
microphone bias circuit. A reference voltage called MICBIAS can be used to supply bias current for the
microphone. The microphone input signal (MICIN) is buffered and amplified with provision for setting the
amplifier gain to accommodate a range of signal input levels. The amplified signal is passed through antialiasing
and band-pass filters. The filtered signal is then input to a compressing analog-to-digital converter (COADC)
if companded mode is selected; otherwise, the analog-to-digital converter performs a linear conversion.
Caution. These devices have limited built-in protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
• POST OFFICE BOX 1443 HOUSTON, TEXAS 77001
Copyright  1993, Texas Instruments Incorporated
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