Features: 13-Bit Linear Sigma Delta Codec with Filters Exceeding ETSI prETS30085 and G712 .
Single Rail 3.0 V ~5.5 V Power Supply.
Typical Power Dissipation of 30 mW at 3 V.
Two Low Noise Microphone Inputs with Internal Gain Adjust (+16 / +46 dB).
150 Push/Pull Earpiece Driver with Internal Gain Adjust (-12 / +6 dB).
50 Loudspeaker Amplifier with up to 50 mW Output Power.
Push/ Pull Output Driver for Tone Ringer.
On Chip Electret Microphone Voltage Source.
Digital Transmit Gain Setting (-38 / +10 dB).
Digital Receive Gain Setting ( -42 / +6 dB).
Digital Sidetone Control Function ( 0 / -48 dB).
Programmable Call Progress Tone/ DTMF /Ring Tone Generator.
Analogue and Digital Loopback Modes.
16-Bit Linear / 8-Bit A-Law Switchable Serial PCM Interface with Non Delayed and Delayed Timing Modes.
4-Wire Serial Control Interface.
Packaged in SOIC-28, TQFP-64.Pinout
SpecificationsSupply Voltage............................................................................................................-0.3VDD7 V
Voltage applied on Any Input ...................................................................... -0.3 VVINVDD+0.3 V
Voltage applied on Digital Outputs............................................................ -0.3 VVOUTVDD+0.3 V
Input Current (all pins)................................................................................................ IIN ± 50 mA
Output Current .......................................................................................................... IOUT ±10 mA
Storage Temperature Range....................................................................................... -65 to +150°CDescriptionThe AS3501/2 combine a high quality (0.1% THD, >100dB SNR), true ground, audio headphone amplifier with all the necessary circuitry to enable superior performance Active Noise Cancellation, all at very low power consumption.
The AS3501 is ideally suited for feed-forward topology, whereas AS3502 is better suited for feedback topology
The speakers of AS3502 can be configured in single ended mode (2x 34mW @1.5V, 16 Ohm) or Bridge Tied Load (1x 109mW @1.5V, 16 Ohm) and the line-in gain is adjustable to allow for locally controlled volume setting.
AS3502 contains an OTP-ROM to store calibration settings for the noise cancelling microphones, removing the need for the manually trimmed pots typically used. The OTP can also be used to store device configuration settings, allowing flexibility and differentiation for a broad end-product portfolio.
AS3502 is designed to operate in both stand-alone mode, ideal for accessories, and embedded mode targeting MP3 players and other portable multimedia equipment.
The AS3501/2 also contains a monitor mode, allowing the user to attenuate Line-in, while amplifying the ambient noise. This is typically used to hear announcements in airports, without the need to remove the headset.
Typically powered directly off a AAA battery, the AS3501/2 tolerates 1.0V to 1.8V supply, and contains the necessary charge pumps to enable true ground operation, as well as providing a supply voltage for the microphones.
AS3502 is a high performance 13-bit linear feature Codec/Filter with 8 kHz sampling rate specifically tailored to implement all analogue frontend functions of battery powered digital terminals. It includes a programmable analogue interfaces for handset and handsfree operation with a minimum amount of external components.
The Codec function of AS3502 uses Sigma-Delta ()modulation conversion techniques with 2nd order modulators and an over sampling rate of 128 for excellent signal to noise performance. The AS3502 exceeds all CCITT G712 recommendations and the European ETSI prETS 300085 recommendations.
Digital gain setting stages for transmit and receive allow to compensate for transducer tolerances and to set up a handsfree function under software control. A programmable tone generator AS3502 allows to generate DTMF/Call-Progress Tones and alert sounds required in digital terminals. All programmable functions of AS3502 are controlled by a 4-wire serial control port that easily interfaces to any popular micro controller.The interface to the digital world is accomplished by a serial PCM interface that supports 16-bit linear format or 8-bit A-Law format for both non-delayed and delayed frame synchronzation modes.
AS3502 Data Sheet
