TCM320AC56

` Single 5-V Operation
` Low Power Consumption: Operating Mode . . . 40 mW Typ Standby Mode . . . 5 mW Typ Power-Down Mode . . . 3 mW Typ
` Combined A/D, D/A, and Filters
` Extended Variable-Frequency Operation Sample Rates up to 16 kHz Passband up to 7.2 kHz
` Electret Microphone Bias Reference Voltage Available
` Drive a Piezo Speaker Directly
` Compatible With All Digital Signal Processors (DSPs)
` Selectable Between 8-Bit Companded and 13-Bit (Dynamic Range) Linear Conversion: TCM320AC56 . . .  m-Law and Linear Modes TCM320AC57 . . . A-Law and Linear Modes
` Programmable Volume Control in Linear Mode
` 300-Hz to 3.6-kHz Passband with Specified Master Clock
` Designed for Standard 2.048-MHz Master Clock for U.S. Analog, U.S. Digital, and CT2, DECT, GSM, and PCS Standards for Hand-Held Battery-Powered Telephones

Supply voltage range, VCC (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 7 V
Output voltage range at DOUT, VO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 7 V
Input voltage range at DIN, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 7 V
Continuous total power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Dissipation Rating Table
Operating free-air temperature range: C suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C
I suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40°C to 85°C
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65°C to 150°C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C


† Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

NOTE 1: Voltage value is with respect to GND.

The TCM320AC56 and TCM320AC57 voice-band audio processor (VBAP) integrated circuits perform the transmit encoding (A/D conversion) and receive decoding (D/A conversion) together with transmit and receive filtering for voice-band communications systems. Cellular telephone systems are targeted in particular; however, these integrated circuits can function in other systems including digital audio, telecommunications, and data acquisition.

These devices TCM320AC56 are pin-selectable for either of two modes - companded and linear - providing data in two formats. In the companded mode, data is transmitted and received in 8-bit words. In the linear mode, 13 bits of data, and either three bits of gain-setting control data, or three 0 bits of padding (to create a 16-bit word), are sent and received.

The transmit section TCM320AC56 is designed to interface directly with an electret microphone element. 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 bandpass filters. The filtered signal is then applied to the input of a compressing analog-to-digital converter (COADC) when companded mode is selected. Otherwise, the analog-to-digital converter performs a linear conversion. The resulting data is then clocked out of DOUT as a serial data stream.

The receive section TCM320AC56 converts a frame of serial data on DIN to analog through an expanding digital-to-analog converter (EXDAC) when the companded mode is selected; otherwise, a linear conversion is performed. The analog signal then passes through switched capacitor filters, which provide out-of-band rejection, (sin x)/x correction functions, and smoothing. The filtered signal is sent to the earphone amplifier. The earphone amplifier TCM320AC56 has a differential output with adjustable gain and is designed to minimize static power dissipation. A single on-chip high-precision band-gap circuit generates all voltage references, eliminating the need for external reference voltages. An internal reference voltage, VMID, equal to VCC/2 is used to develop the midlevel virtual ground for all the amplifier circuits and the microphone bias circuit. Another reference voltage, MICBIAS, can supply bias current for the microphone.

The TCM320AC56 devices are characterized for operation from 0°C to 70°C. The TCM320AC5xI devices are characterized for operation from 40°C to 85°C.