Features: Single 3-V Operation
Low Power Consumption:
Operating Mode ... 20 mW Typ
Standby Mode ... 5 mW Typ
Power-Down Mode ... 2 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:
TLV320AC56 . . . µ-Law and Linear Modes
TLV320AC57 ... 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 Stan-dards for Hand-Held Battery-Powered Telephones
Pinout
SpecificationsSupply voltage range, VCC (see Note 1) . . . .. . . . . . . . . .0.3 V to 5.5 V
Output voltage range at DOUT, VO . . . . . . . . .. . . . . . .. 0.3 V to 5.5 V
Input voltage range at DIN, VI . . . . . .. . . . . . . . . . . . . . 0.3 V to 5.5 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
Description The TLV320AC56 and TLV320AC57 voice-band audio processor (VBAP) integrated circuits perform the transmit enco-ding (A/D conversion) and receive decoding (D/A conversion) together with transmit and receive filtering for voiceband 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 TLV320AC56 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 ei-ther three bits of gain-setting control data, or three 0 bits of padding (to create a16-bit word), are sent and received.
The transmit section of TLV320AC56 is designed to interface directly with an electret microphone element. The microphone inputsignal (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 TLV320AC56 performs a linear conversion. The resulting data is then clocked out of DOUT as a serial data stream.
The receive section of TLV320AC56 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 has a differential output with adjustable gain and is designed to minimize static power dissipation.
A single on-chip high-precision band-gap circuit of TLV320AC56 generates all voltage references, eliminating the need forexternal 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 TLV320AC5xC devices are characterized for operation from 0°C to 70°C. The TLV320AC5xI devices are chara-cterized for operation from 40°C to 85°C.
TLV320AC56 Data Sheet
