PRELIMINARY DATA SHEET MICRONAS Edition Nov. 9, 1999 6251-487-1PD UAC 3552A Universal Serial Bus DAC MICRONAS UAC 3552A PRELIMINARY DATA SHEET Contents Page Section Title 4 5 1. 1.1. Introduction Features 6 6 6 6 6 6 6 6 6 6 7 8 8 8 9 9 9 10 10 10 10 10 10 10 10 10 10 11 11 11 11 12 12 13 13 13 13 13 2. 2.1. 2.1.1. 2.1.1.1. 2.1.1.2. 2.1.1.3. 2.1.2. 2.1.3. 2.1.4. 2.1.5. 2.1.5.1. 2.1.5.2. 2.1.5.3. 2.1.5.4. 2.1.5.5. 2.1.5.6. 2.1.6. 2.1.7. 2.1.7.1. 2.1.7.2. 2.1.7.3. 2.1.8. 2.2. 2.2.1. 2.2.1.1. 2.2.1.2. 2.2.1.3. 2.2.1.4. 2.2.2. 2.2.2.1. 2.2.2.2. 2.2.2.3. 2.2.2.4. 2.2.2.5. 2.2.2.6. 2.2.2.7. 2.2.3. 2.2.3.1. Functional Description Hardware USB Interface Transceiver Interface Engine Microcontroller Audio Control Interface Audio Streaming Interface Audio Processing Unit Analog Back-end DAC Analog Low-pass Postfilter Op Amps Input Mixer Analog Volume Control Line-out/Headphone Amplifier General Purpose I/O Special I/O SOF (Start of Frame) AUXEN SUSPEND Clock System Software USB Microcontroller Software Chapter 9 Functions Device Descriptor String Descriptor HID Report Descriptor Audio Processing Software Sample Rate Converter Automatic Gain Control Bass Control Treble Control Bass Boost Control Parametric Equalizer Volume and Balance Control Mute Control Oversampling 2 Micronas PRELIMINARY DATA SHEET UAC 3552A Contents, continued Page Section Title 14 14 14 16 16 16 17 17 18 19 19 20 22 3. 3.1. 3.2. 3.3. 3.3.1. 3.3.2. 3.3.3. 3.4. 3.5. 3.6. 3.6.1. 3.6.2. 3.6.3. Specifications Outline Dimensions Pin Connections and Short Descriptions Pin Descriptions Power Supply Pins Analog Audio Pins Other Pins Pin Configuration Pin Circuits Electrical Characteristics Absolute Maximum Ratings Recommended Operating Conditions Characteristics 26 26 27 4. 4.1. 4.2. Applications Recommended Low-Pass Filters for Analog Outputs Typical Application 28 5. Data Sheet History Micronas 3 UAC 3552A PRELIMINARY DATA SHEET Universal Serial Bus DAC 1. Introduction The UAC 3552A is the first member of Micronas’ USB audio controller family of ICs targeting a wide variety of audio applications on the USB. The UAC 3552A is a single-chip, high-precision digital-to-analog audio converter. It includes a high-quality audio sample rate converter and is able to support a wide range of sample rates, as well as different audio formats. The IC contains a complete USB transceiver that allows direct connection to the USB. An on-chip EEPROM allows storing of manufacturer-specific data or product identification. The EEPROM can be programmed directly via the USB. The audio DAC uses Micronas’ proprietary multibit sigma-delta technique. It features very low sensitivity to clock jitter, high linearity, and a superior S/N ratio. The UAC 3552A provides an on-chip headphone/ speaker amplifier. Moreover, mixing additional analog audio sources to the D/A-converted signal is supported. The IC is designed for all kinds of USB audio applications, such as USB active speakers, USB headphones, and USB interfaces to home stereo equipment, etc. Any existing analog speaker set can easily be upgraded to USB by just including the UAC 3552A according to the application circuit on page 27. No software development is required, because all drivers are already part of the operating system which supports USB (e. g. Windows™ 98). Baseband audio processing is handled by an internal, powerful DSP. Apart from basic audio features, like tone and volume control, there is enough processing power left to realize customer-specific applications. HID IO Analog Input External Loop-through Filter EEPROM D+ D− USB Interface DSP ROM ROM DAC Input Select and Mixing Volume and Headphone Amplifier OUTL OUTR +5 V GND Fig. 1–1: Block diagram of the UAC 3552A 4 Micronas UAC 3552A PRELIMINARY DATA SHEET 1.1. Features – single-chip, USB specification 1.0/1.1 compliant, stereo audio D/A converter – 12-Mbit/s USB transceiver – adaptive isochronous endpoint for USB Audio – USB-programmable vendor IDs (1024-bit EEPROM on chip) – four general purpose input pins and four output pins (human interface pins) – customizable I/O functionality by download-software – supports 16-bit mono/stereo and 24-bit stereo audio data – adaptive sample rate converter for 5 to 50 kHz input sampling rate – audio baseband control: bass, treble, volume, and balance, additional analog volume, mute – bass boost – automatic gain control (AGC) – “PerfectSpeaker” digital speaker equalizer – THD better than 0.01 %, SNR of 96 dB – integrated low-power stereo headphone amplifier – on-chip op amps for external analog filter – analog stereo input (AUX) with source selection and mixing – single 5-V power supply Active Stereo Speakers USB UAC Headphones Stereo Equipment Fig. 1–2: System application diagram Micronas 5 UAC 3552A 2. Functional Description 2.1. Hardware A detailed block diagram of the UAC 3552A is depicted in Fig. 2–1. The functions of the blocks are explained in the following sections. 2.1.1. USB Interface 2.1.1.1. Transceiver The differential input receiver is used to accept the USB data signal according to the full-speed (12 MB/s) USB driver characteristics (USB SPEC 1.1 - 7.1.4). 2.1.1.2. Interface Engine The interface engine comprises two major sections: the transceiver logic and the receiver logic. The transceiver logic transmits data packets built in memory by the microcontroller. These packets are converted from a serial to a parallel data stream. This includes NRZI encoding, bit stuffing, CRC-computation, and addition of SYNC field and EOP. The receiver logic will receive USB data and stores these packets in its memory for processing by the microcontroller. Serial USB data is converted to a byte-wide parallel data stream and stored in system memory. In addition to USB basic data decoding, the Rx logic performs a PID check and protocol layer checks. PRELIMINARY DATA SHEET The ROM contains the USB drivers for the microcontroller as well as the complete descriptor table including the report descriptor for the HID-class. Some parts of the descriptor which are subjected to be changed by the customer, however, reside in the EEPROM. The EEPROM is built to keep static customer-related data that will customize the UAC 3552A-based USB device during production. The 128×8 bit EEPROM contains the customer specific information of the USB device descriptor, like vendor ID, product ID, as well as strings for manufacturer, product and serial number. Apart from this USBrelated information, the EEPROM holds customer-specific parameters for the PerfectSpeaker equalizer. The UAC 3552A is shipped with a preprogrammed EEPROM that allows normal USB functionality even if no reprogramming is performed on the customer’s side. The EEPROM can be programmed via USB by means of UAC 3552A application tools. 2.1.2. Audio Control Interface The audio control interface links the microcontroller to the DSP and is used to initialize the DSP and to transmit audio-related USB control data, like volume setting, tone control etc. 2.1.3. Audio Streaming Interface 2.1.1.3. Microcontroller The microcontroller manages buffers for all enabled endpoints and interacts with the interface engine. The buffers are built and decoded in memory. This way, the microcontroller realizes the USB protocol handling, like USB reset, enumeration, and all chapter 9 processing, error handling, as well as class-specific endpoint handling, like audio class and HID class. The audio-class processing consists of interpreting the USB audio commands and accordingly controlling the DSP-audio function through a dedicated audio-control-interface to the DSP. HID class processing means polling keys providing the corresponding key-codes to the host-computer’s requests. These keys are connected to the GPIO-pins. The RAM can be accessed by the microcontroller and by the interface-engine’s DMA-controller. All endpoint communication is realized with intelligent buffer management built up in the RAM. A part of the RAM is reserved for download software. This allows adding extra functionality to the GPIO pins, like I2C-handling or any other control of external components via USB. Downloading is handled by an extra driver which allows direct RAM/ROM access via USB. 6 The audio streaming interface directly connects the serial interface engine to the DSP in order to transmit the digital audio data. The interface collects and buffers the burst audio data for further processing by the audio processing unit. 2.1.4. Audio Processing Unit The audio processing unit is a powerful DSP core which allows high-quality sample conversion, baseband audio processing, and interpolation filtering used for oversampling DAC, as well as customized algorithms. For more details on the software see Section 2.2.2. “Audio Processing Software” on page 11. 2.1.5. Analog Back-end The analog back-end comprises the audio DAC, analog filters, input mixer, op amps for optimal external postfiltering, analog volume and mute, and the output amplifier. Micronas UAC 3552A PRELIMINARY DATA SHEET 2.1.5.1. DAC The DAC uses oversampling technique with 3rd-order multibit noise-shaping. This technique results in extremely low quantization noise in the audio band. DMINUS 24 DPLUS 25 Transceiver 26 VREG 14 15 16 17 19 20 21 22 GPIO0 GPIO1 GPIO2 GPIO3 GPIO4 GPIO5 GPIO6 GPIO7 29 30 31 32 33 TEST RESQ SUSPEND SOF AUXEN 27 VDD 28 VSS Interface Engine µC RAM ROM XTI 8 XTO 9 Oscillator GP I/O EEPROM Control I/O Audio Streaming Interface Audio Control Interface Audio Processing Unit DAC Digital Supply AUXL 36 AUXR 37 Analog Input Input Mixer Volume Analog Supply Headphone Amplifier 4 OUTL 6 AVDD0 7 AVDD1 3 AVSS0 2 AVSS1 44 VREF 1 AGNDC 5 OUTR Fig. 2–1: Detailed block diagram of the UAC 3552A Micronas 7 UAC 3552A PRELIMINARY DATA SHEET 2.1.5.2. Analog Low-pass Table 2–1: AUXEN pin The output of the DAC is filterted by an analog lowpass filter with a cut-off frequency of approximately 1.4 MHz. This filter removes the high-frequency components of the noise-shaping signal. AUXEN 0 AUX not selected 1 AUX selected 2.1.5.3. Postfilter Op Amps This block contains the active components for the optional analog postfilters. It is recommended to use a second-order filter (see Section 4. “Applications” on page 26) in order to attenuate the out-of-band noise caused by the noise shaper The op amps and all I/Opins for this block are shown in Fig. 2–2. This allows to use a jack that switches the AUXEN to low when an analog source is plugged in, according to the application note Section 4. “Applications” on page 26. The DAC-signal is permanently connected to the mixer because the DAC is extremely quiet if no USB audio is applied. The AUXEN pin also keeps the UAC 3552A from entering the low-power mode when an analog source is connected. Please note that in this mode, the UAC 3552A is not USB-compliant. If the USB is not connected the GPIO pins work as an USB-independent volume control (see Table 2–2). BassBoost is not supported in this mode. 2.1.5.4. Input Mixer This block is used to mix the auxiliary inputs and the signals coming from the DAC. This allows to use an UAC 3552A-based USB speaker in a non-USB environment, like WIN 3.11 or other operating systems. On the other hand, it allows to connect additional analog sources, like CD-player or Walkman even while the speaker is connected to the USB. The input mixer is hardware-controlled by the AUXEN pin. For external components, see section “Applications” FOUTL FOPL FINL Analog Vol. L UAC 3552A (Back-end) OUTL − − from switch matrix − OUTR − Analog Vol. R AVSS VREF AGNDC FOUTR FOPR FINR For external components, see section “Applications” Fig. 2–2: Postfilter op amps and analog volume 8 Micronas UAC 3552A PRELIMINARY DATA SHEET 2.1.5.5. Analog Volume Control 2.1.6. General Purpose I/O The analog volume control covers a range from 0 dB to −75 dB plus an additional mute position. The GPIO pins are used to connect keys which are related to the USB HID class or for vendor-specific control functions and LEDs in order to indicate on/off states for example. The standard configuration defines the GPIOs as four input pins (GPIO0...GPIO3) and four output pins (GPIO4...GPIO7). The function of the input pins is shown in Table 2–2. The analog step size is split into a 3-dB and a 1.5-dB range: −75 dB...−54 dB: −54 dB...0 dB: 3 dB step size 1.5 dB step size The overall volume system, however, consists not only of the analog volume. An additional digital volume control allows a step size of 0.5 dB over the complete range. See Section 2.2.2.7. “Volume and Balance Control” on page 13. Please note that analog input signals (AUXL, AUXR) do not have the additional digital volume control. 2.1.5.6. Line-out/Headphone Amplifier The line-out/headphone amplifier output is provided at the OUTL and OUTR pins connected either to stereo headphones or to the power amplifier within an USB speaker. The stereo headphones require external 47-Ω serial resistors in both channels. See Section 4. “Applications” on page 26. Table 2–2: Standard Key Configuration Pin Function Key Code Usage ID GPIO0 Volume Up 1 E9 GPIO1 Volume Down 2 EA GPIO2 MuteToggle 4 E2 GPIO3 BassBoost Toggle 8 E5 The keys are polled by the microcontroller and the corresponding key codes are transmitted to the host on request. The relation between key code and usage ID (see Universal Bus HID Usage Tables, Version 1.0, Chapter 14 – Consumer Page) is defined in the HID report descriptor (see Section 2.2.1.4. “HID Report Descriptor” on page 11) which is transmitted to the host along with the configuration descriptor during the bus enumeration. When the device is not connected to USB, the functionality of the volume-control and mute pins are preserved. In this case, however, the parameters are directly transferred to the DSP-core. This allows using the device in stand-alone mode providing volume and mute control for analog sources. The output pins are not predefined and therefore not related to any USB functions. They can be set or reset by vendor-specific software. The standard configuration can be changed also by vendor-specific USB software, but in this case, Table 2–2 is no longer valid. Micronas 9 UAC 3552A PRELIMINARY DATA SHEET 2.1.7. Special I/O 2.2. Software 2.1.7.1. SOF (Start of Frame) The functionality of the UAC 3552A is mainly defined by software. The internal µ-controller handles the USB requests whereas the Audio Processing Unit processes the sound features. The SOF-pin provides a 1-ms signal which is synchronous to the USB 1-ms frame rate. It can be used for test purpose or as an USB-synchronous reference for vendor-specific external circuitry. 2.2.1. USB Microcontroller Software 2.1.7.2. AUXEN 2.2.1.1. Chapter 9 Functions This is a digital input that has to be used if an analog signal is connected to the AUX R/L pins. It triggers the microcontroller to switch the input mixer to the analog input (the DAC signal always remains active!) and it keeps the device from entering the low-power mode which can be requested by the host PC or by disconnecting the device from the USB. The chapter 9 of the USB Spec 1.1 defines the USB device framework which is the middle layer of the USB protocol hierarchy (see USB Spec 1.1 page 175). It handles routing data between the bus interface and various endpoints. The endpoint is a source or sink for data within the device. 2.2.1.2. Device Descriptor 2.1.7.3. SUSPEND The SUSPEND pin indicates the low-power mode. It can be used to power down external circuitry, like power amplifiers in an USB speaker. Unlike the configuration descriptor, which is located in ROM, the device descriptor is more flexible. The manufacturer-related data are stored in the on-chip EEPROM, and can be adapted individually. In detail these data are Table 2–3: SUSPEND pin – vendor ID – product ID SUSPEND – device release number low normal power – manufacturer string high low power – product string – serial number string 2.1.8. Clock System The UAC 3552A requires a 12-MHz clock source, which is realized as an on-chip oscillator with external crystal. Also an external oscillator can be used. In this case, the clock has to be connected to XTI. The 12 MHz is the input clock for a PLL circuit which generates all clocks needed within the IC. A comfortable programming tool allows this data to be defined and writes it into the corresponding EEPROM location. The UAC 3552A is shipped with the Micronas device descriptor and allows USB functionality without any EEPROM reprogramming. 2.2.1.3. String Descriptor The string descriptor is located in the EEPROM. The UAC 3552A holds three strings. The programming tool handles the programming of strings and will take care of string length control also. The UAC 3552A is shipped with the Micronas string descriptor and allows USB functionality without any EEPROM reprogramming. 10 Micronas UAC 3552A PRELIMINARY DATA SHEET 2.2.1.4. HID Report Descriptor 2.2.2.1. Sample Rate Converter The HID report descriptor defines the functionality of the GPIO Pins. The basic information here are the usage IDs for the key inputs. These IDs are stored in the EEPROM and can therefore be modified if the default configuration does not fit the application. The UAC 3552A, however, only supports the default functions: volume up/down, mute on/off and BassBoost on/ off. This means, that all nonstandard usage IDs will be transmitted to the host on request and can be used with vendor specific software, but only the default IDs will work together with the operating system. The purpose of the sample rate converter is first to transform the block transferred audio data into a continuous data stream and second to convert all incoming sample rates to a fixed 50-kHz sample rate. This technique eliminates input data jitter. Furthermore, all audio algorithms and the DAC run on a single sample rate and no parameter switching is required on change of audio sampling rate. Furthermore, all audio clocks, such as sampling clock, noise-shaping clock, and DAC-clock can be derived from a single free-running 12-MHz oscillator. This mechanism allows continuous input sampling rates from 5 kHz up to 50 kHz. 2.2.2. Audio Processing Software 2.2.2.2. Automatic Gain Control All audio processing is realized by DSP-software, apart from volume control which is located in the analog back-end. The audio building blocks split into USBindependent features, like sample rate conversion and oversampling filters and blocks which belong to the so called USB feature unit, defined in the USB Device Class Definition for Audio Devices. The feature unit provides basic manipulation of the incoming logical channels. The UAC 3552A supports two logical channels (i.e. left & right). Multichannel or surround systems, however, can also be realized using more than one UAC 3552A, because phase or delay distortion is eliminated by locking the audio processing to the USB frame rate. An overview of the architecture is given in Fig. 2–3. The Automatic Gain Control (AGC) is one of the building blocks of the feature unit (USB Device Class Definition for Audio Devices 1.0, page 39). Different sound sources fairly often do not have the same volume level. The Automatic Gain Control solves this problem by equalizing the volume levels within a defined range. Below a theshold level the signals are not affected. The level-adjustment is performed with time constants in order to avoid short-time adjustments due to signal peaks. Feature Unit Sample Rate Converter AGC Bass/Treble Bass Boost Equalizer Volume/ Balance OverSampling Fig. 2–3: Audio processing Micronas 11 UAC 3552A PRELIMINARY DATA SHEET 2.2.2.3. Bass Control 2.2.2.4. Treble Control The bass control provides gain or attenuation to frequency components below a corner frequency of 120 Hz. The characteristic is shown in Fig. 2–4. The treble control provides gain or attenuation to frequency components above a corner frequency of 6 kHz. The characteristic is shown in Fig. 2–5. dB dB 15 15 10 10 5 5 0 0 -5 -5 -10 -10 -15 -15 10. 50. 100. 500. 1000. 5000. 10000. 10. 50. 100. 500. 1000. 5000. Hz 10000. Hz Fig. 2–4: Bass control Fig. 2–5: Treble control The bass control works identically on both channels. The treble control works identically on both channels. Table 2–4: Bass Control Characteristics Table 2–5: Treble Control Characteristics Min Max Step Min Max Step −12 dB +12 dB 0.5 dB −12 dB +12 dB 0.5 dB 12 Micronas UAC 3552A PRELIMINARY DATA SHEET 2.2.2.5. Bass Boost Control 2.2.2.7. Volume and Balance Control The bass boost algorithm provides an additional 12-dB gain for the low-frequency components. The characteristic is shown in Fig. 2–6. The volume and balance control operate separately on the left and right channel. Table 2–7: Volume and Balance Control dB 14 12 Min Max Step −75 dB 0 dB 0.5 dB 10 8 6 4 2 0 10. 20. 50. 100. 200. 500. 1000. Hz The volume control is realized in the analog back-end. This preserves high audio quality (SNR) at low volume settings because signal and noise are attenuated in the same way, which is not the case for pure digital volume control. The UAC 3552A uses digital volume control only for the fine tuning of the 0.5 dB step size. The volume setting is smoothed by an internal ramping algorithm in order to avoid audible clicks during volume change. Fig. 2–6: Bass boost The splitting between analog and digital volume is handled by the UAC 3552A automatically. The bass boost works on both channels and can be switched on and off under USB control. 2.2.3. Mute Control 2.2.2.6. Parametric Equalizer The parametric equalizer is a non-USB audio feature. It allows the compensation of unwanted frequency responses of a speaker. Alternatively, frequency responses can be set to suit individual tastes. The equalizer consists of 5 individually adjustable bands. The control parameters and the parameter range for each band is shown in Table 2–6. Table 2–6: Equalizer Parameters Parameter Min Max center frequency 50 Hz 15 kHz The mute control is part of the volume system in the UAC 3552A. It functions simultaneously on both channels and can be switched on and off under USB control. As with the volume control, clicks are avoided by a ramping algorithm. 2.2.3.1. Oversampling The oversampling filter increases the audio sampling rate by a factor of 4. The final upsampling to the noiseshaping rate is handled by a sample and hold circuit. The pass-band characteristic of the oversampling filter is shown in Fig. 2–7. dB gain/attenuation −6 dB +6 dB filter quality (Q) 0.5 3 0 -0.1 -0.2 The adjustment of the equalizer is supported by an application program that allows to set up frequency responses and to download the corresponding filter coefficients into the UAC 3552A. When the frequency response fits the target, it can be programmed into the on-chip EEPROM. The UAC 3552A is shipped with a flat frequency response. -0.3 -0.4 -0.5 0 5000 10000 15000 20000 kHz Fig. 2–7: 1 to 4 Oversampling filter, pass-band Micronas 13 UAC 3552A PRELIMINARY DATA SHEET 3. Specifications 3.1. Outline Dimensions 10 x 0.8 = 8 ± 0.1 0.17 ± 0.06 12 44 1 11 1.75 10 ± 0.1 0.375 ± 0.075 13.2 ± 0.2 1.3 0.8 22 34 1.75 0.8 23 10 x 0.8 = 8 ± 0.1 33 2.0 ± 0.1 13.2 ± 0.2 2.15 ± 0.2 10 ± 0.1 0.1 SPGS0006-3(P44)/1E Fig. 3–1: 44-Pin Plastic Metric Quad Flat Pack (PMQFP44) Weight approximately 0.4 g Dimensions in mm 3.2. Pin Connections and Short Descriptions NC = not connected, leave vacant LV = if not used, leave vacant VSS = if not used, connect to VSS = obligatory; connect as described in circuit diagram VDD = connect to VDD Pin No. Pin Name 1 AGNDC IN/OUT X Analog reference voltage 2 AVSS1 IN X VSS 1 for audio back-end 3 AVSS0 IN X VSS 0 for audio output amplifiers 4 OUTL OUT LV Audio Output: Headphone left or Speaker + 5 OUTR OUT LV Audio Output: Headphone right or Speaker − 6 AVDD0 IN X VDD 0 for audio output amplifiers 7 AVDD1 IN X VDD 1 for audio back-end 8 XTI IN X quartz oscillator pin 1 9 XTO OUT X quartz oscillator pin 2 10 NC LV Not connected 11 NC LV Not connected 12 NC LV Not connected 13 NC LV Not connected 14 GPIO 0 IN VSS HID IO 0 15 GPIO 1 IN VSS HID IO 1 14 Type X Connection Short Description (If not used) Micronas UAC 3552A PRELIMINARY DATA SHEET Pin No. Pin Name 16 GPIO 2 IN VSS HID IO 2 17 GPIO 3 IN VSS HID IO 3 18 NC LV Not connected 19 GPIO 4 OUT LV HID IO 4 20 GPIO 5 OUT LV HID IO 5 21 GPIO 6 OUT LV HID IO 6 22 GPIO 7 OUT LV HID IO 7 23 TRDY OUT LV Test Output Pin 24 DMINUS IN/OUT X USB DATA MINUS 25 DPLUS IN/OUT X USB DATA PLUS 26 VREG OUT X Capacitor for internal supply 27 VDD IN X digital VDD 28 VSS IN X digital VSS 29 TEST IN X Test Enable 30 RESQ IN VDD Power On Reset, active low 31 SUSPEND OUT LV Low-Power Mode Indicator 32 SOF OUT LV 1-ms Start-Of-Frame Signal 33 AUXEN IN VSS Enable AUX Input 34 NC LV Not connected 35 NC LV Not connected 36 AUXL IN VSS AUX Input Left 37 AUXR IN VSS AUX Input Right 38 FOUTL OUT X Output to left external filter 39 FOPL IN/OUT X Filter op amp inverting input, left 40 FINL IN/OUT X Input for FiltoutL or filter op amp output (line out) 41 FOUTR OUT X Output to right filter op amp 42 FOPR IN/OUT X Right Filter op amp inverting input 43 FINR IN/OUT X Input for FILTOUTR or Filter op amp output (line out) 44 VREF IN X Analog reference Ground Micronas Type Connection Short Description (If not used) 15 UAC 3552A 3.3. Pin Descriptions 3.3.1. Power Supply Pins The UAC 3552A combines various analog and digital functions which may be used in different modes. For optimized performance, major parts have their own power supply pins. All VSS power supply pins must be connected. VDD (27) VSS (28) The VDD and VSS power supply pair are connected internally with all digital parts of the UAC 3552A. AVDD0 (6) AVSS0 (3) AVDD0 and AVSS0 are separate power supply pins that are exclusively used for the on-chip headphone/ loudspeaker amplifiers. AVDD1 (7) AVSS1 (2) The AVDD1 and AVSS1 pins supply the analog audio processing parts, except the headphone/loudspeaker amplifiers. 3.3.2. Analog Audio Pins AGNDC (1) Reference for analog audio signals. This pin is used as reference for the internal op amps. This pin must be blocked against VREF with a 3.3-µF capacitor. Note: The pin has a typical DC-level of 2.25 V. It can be used as reference input for external op amps when no current load is applied. VREF (44) Reference ground for the internal band-gap and biasing circuits. This pin should be connected to a clean ground potential. Any external distortions on this pin will affect the analog performance of the UAC 3552A. PRELIMINARY DATA SHEET AUXL (36) AUXR (37) The AUX pins provide two analog stereo inputs. Auxiliary input signals, e.g. the output of a conventional receiver circuit or the output of a tape recorder can be connected with these inputs. The input signals have to be connected by capacitive coupling. FOUTL (38) FOPL (39) FINL (40) FOUTR (41) FOPR (42) FINR (43) Filter op amps are provided in the analog baseband signal paths. These inverting op amps are freely accessible for external use by these pins. The FOUTL/R pins are connected with the buffered output of the internal switch matrix. The FOPL/R-pins are directly connected with the inputs of the inverting filter op amps. The FINL/R pins are connected with the outputs of the op amps. OUTL (4) OUTR (5) The OUTL/R pins are connected to the internal output amplifiers. They can be used for either line-out or stereo headphones. Caution: A short circuit at these pins for more than a momentary period may result in destruction of the internal circuits. XTI (8) XTO (9) The XTI pin is connected to the input of the internal crystal oscillator; the XTO pin to its output. Both pins should be directly connected to the crystal and two ground-connected capacitors (see application diagram). DMINUS (24) DPLUS (25) Differential USB port pins. 16 Micronas UAC 3552A PRELIMINARY DATA SHEET 3.3.3. Other Pins 3.4. Pin Configuration TEST (29) Test enable. This pin is for test purposes only and must always be connected to VSS. VSS TEST VDD RESQ VREG (26) This pin is used to connect an external buffer capacitor to stabilize the internal supply for the USB transceiver. RESQ (30) This pin may be used to reset the chip. GPIO 0 ... GPIO 7 (14,15,16,17,19,20,21,22) These pins are configurable to be either input or output and can be used to connect audio function keys or signalling LEDs. SUSPEND (31) This pin indicates that the host PC sets the USB bus to the suspend-mode state. DPLUS SOF DMINUS AUXEN TRDY 33 32 31 30 29 28 27 26 25 24 23 NC 34 22 GPIO 7 NC 35 21 GPIO 6 AUXL 36 20 GPIO 5 AUXR 37 19 GPIO 4 FOUTL 38 18 NC FOPL 39 17 GPIO 3 FINL 40 16 GPIO 2 FOUTR 41 15 GPIO 1 FOPR 42 14 GPIO 0 FINR 43 13 NC VREF 44 12 NC UAC 3552A 1 SOF(32) Start of Frame Signal. 1-ms signal that can be used for external application circuits. VREG SUSPEND 2 3 4 5 6 7 8 9 AGNDC NC AVSS1 NC AVSS0 AUXEN (33) Aux enable. This pin must be connected to VSS if an analog source is connected to the AUX input. Otherwise connect to VDD. 10 11 XTO OUTL XTI OUTR AVDD1 AVDD0 Fig. 3–2: 44-pin PMQFP package TRDY (23) Test Output Pin. This pin is intended for test purposes only and must not be connected. Micronas 17 UAC 3552A PRELIMINARY DATA SHEET 3.5. Pin Circuits ext. filter network FOPn FOUTn AUXL/R FINn AGNDC Fig. 3–8: Input Pins AUXL/R AGNDC Fig. 3–3: Pins FINR, FOPR, FINL, FOPL OUTn AGNDC AGNDC Fig. 3–9: Output Pins OUTL, OUTR 125 kΩ VREF DVSUP AVSS0/1 P Fig. 3–4: Pins AGNDC, VREF N GND Fig. 3–10: Digital Output Pins SOF, SUSPEND FOUTn DPLUS AGNDC DMINUS Fig. 3–5: Output Pins FOUTL, FOUTR XTO 500 kΩ XTI Fig. 3–11: Digital Input/Output Pins DMINUS, DPLUS Fig. 3–6: Output/Input Pins XTI, XTO DVSUP P Fig. 3–7: Input Pins RESQ, TEST, AUXEN N GND Fig. 3–12: Input/Output Pins GPIO0...GPIO7 18 Micronas UAC 3552A PRELIMINARY DATA SHEET 3.6. Electrical Characteristics 3.6.1. Absolute Maximum Ratings Symbol Parameter TA Min. Max. Unit Ambient Operating Temperature 0 70 °C TS Storage Temperature −40 125 °C PPmax Power Dissipation − 900 mW VSUPA Analog Supply Voltage1) −0.3 6 V VSUPD Digital Supply Voltage −0.3 6 V VIdig Input Voltage, all digital inputs −0.3 VSUPD + 0.3 V IIdig Input Current, all digital inputs −5 +0.5 mA IIdig Input Current, all digital outputs −8 8 mA IOdig Output Current, all digital outputs −14.8 14.8 mA VIana Input Voltage, all analog inputs −0.3 VSUPA + 0.3 V IIana Input Current, all analog inputs −5 −5 mA IOaudio Output Current, audio output2) 0.2 A 1) 2) Pin Name AVDD0/1 OUTL/R Both have to be connected together! These pins are NOT short-circuit proof! Stresses beyond those listed in the “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only. Functional operation of the device at these or any other conditions beyond those indicated in the “Recommended Operating Conditions/Characteristics” of this specification is not implied. Exposure to absolute maximum ratings conditions for extended periods may affect device reliability. Micronas 19 UAC 3552A PRELIMINARY DATA SHEET 3.6.2. Recommended Operating Conditions Symbol Parameter Pin Name Min. Typ. Max. Unit 70 °C Temperature Ranges and Supply Voltages TA Ambient Temperature Range VSUPA1 Analog Audio Supply Voltage AVDD0/1 4.5 5.0 5.5 V VSUPD Digital Supply Voltage VDD 4.5 5.0 5.5 V VSUPD −0.25 V 0 Relative Supply Voltages VSUPA Analog Audio Supply Voltage in relation to the Digital Supply Voltage AVDD0/1 VIL Input Voltage Low GPI[7:0], AUXEN, VIH Input Voltage high GPI[7:0], AUXEN VRIL Reset Input high-low transition voltage RESQ VRIH Reset Input low-high transition voltage RESQ 0.8 VSUPD TRL Reset low time after VDD stable and oscillator start-up RESQ 5 µs 1.0 5.5 V 0.25 0.75 VSUPD VSUPD 0.45 VSUPD Analog Reference 3.3 µF AGNDC 10 nF AUXL/R 0.525 CAGNDC1 Analog Reference Capacitor AGNDC CAGNDC2 Analog Reference Capacitor Analog Audio Inputs VAI Analog Input Voltage AC 1.05 Vrms 6 kΩ pF 7.5 kΩ pF Analog Filter Input and Output ZAFLO ZAFLI Analog Filter Load Output1) Analog Filter Load Input1) FOUTL/R FINL/R 7.5 5.0 Analog Audio Output ZAOL_HP 20 Analog Output Load HP (47 Ω Series Resistor required) OUTL/R 32 400 Ω pF Micronas UAC 3552A PRELIMINARY DATA SHEET Symbol Parameter Pin Name Min. Typ. Max. Unit 70 °C Quartz Characteristics TAC Ambient Temperature Range FP Load Resonance Frequency at Cl = 20 pF ∆F/Fs Accuracy of Adjustment −20 20 ppm ∆F/Fs Frequency Variation versus Temperature −20 20 ppm REQ Equivalent Series Resistance 12 30 Ω C0 Shunt (parallel) Capacitance 3 5 pF 0 12 MHz Voltage Regulator 3.3 µF 10 nF CVREG1 Voltage Regulator Capacitor VREG CVREG2 Voltage Regulator Capacitor VREG RUSB Input Serial Resistance DPLUS/ DMINUS 24 (±0.5 %) Ω CUSB Shunt Capacitor DPLUS/ DMINUS 22 pF 1.0 Transceiver 1) Please refer to Section 4.1. “Recommended Low-Pass Filters for Analog Outputs” on page 26. Micronas 21 UAC 3552A PRELIMINARY DATA SHEET 3.6.3. Characteristics At TA = 0 to 70 °C, VSUPD = 4.75 V to 5.25 V, VSUPA = 4.75 V to 5.25 V; typical values at TJ = 27 °C, VSUPD = VSUPA = 5.0 V, quartz frequency = 12 MHz, duty cycle = 50 %, positive current flows into the IC bass/treble: 0 dB, bass boost: off, AGC: off, equalizer: off Symbol Parameter Pin Name Min. Typ. Max. Unit Test Conditions 100 125.5 mA VSUPD =5 V ±1 µA VGND ≤ VI ≤ VSUP V Iout =8 mA Digital Supply IVDD Current Consumption1) VDD Digital Input Pin – Leakage Input Leakage Current II GPIO[7:0], AUXEN, RESQ Digital Output Pin VOH Output High Voltage VOL Output Low Voltage GPIO[7:0], SUSPEND, SOF VSUPD − 0.4 0.4 V 15 mA mA SUSPD = 0, Mute SUSPD = 1, Mute 50 dB 1 kHz sine at 100 mVrms 20 dB ≤ 100 kHz sine at 100 mVrms Analog Supply IAVDD Current Consumption Analog Audio PSRRAA Power Supply Rejection Ratio for Analog Audio Output 11 2 AVDD0/1, OUTL/R Reference Frequency Generation VDCXTI DC Voltage at Oscillator Pins XTI/O 0.5 * VSUPA V CLI Input Capacitance at Oscillator Pin XTI 3 pF CLO Input Capacitance at Oscillator Pin XTO 3 pF VXTALOUT Voltage Swing at Oscillator Pins (peak-peak) XTI/O 0.6 * VSUPA Oscillator Start-Up Time 1.0 * VSUPA V 10 ms EEPROM 1) 22 EEPROM unpowered data retention 10 Number of write cycles 100 year no load attached to GPIO’s Micronas UAC 3552A PRELIMINARY DATA SHEET Symbol Parameter Pin Name Min. Typ. Max. Unit Test Conditions 3.4 3.55 V CL=1µF USB Transceiver VREG Regulator Voltage VREG 3.25 RO Driver Output Resistance including the 24-Ω external serial resistor DPLUS/ DMINUS 28 43 Ω static, LOW or HIGH tr / tf Rise and Fall Times DPLUS/ DMINUS 4 20 ns CL=50 pF, driver mode MA_TRTF Rise/Fall Time Matching DPLUS/ DMINUS 90 111.1 % CL=50 pF, driver mode VXOVER Crossover Voltage DPLUS/ DMINUS 1.3 2.0 V CL=50 pF, driver mode VCM_DREC Differential Receiver Common-Mode Range DPLUS/ DMINUS 0.8 2.5 V VT_SREC Single-ended Receiver Threshold Voltage DPLUS/ DMINUS 0.8 2.0 V Analog Audio VAGNDC Analog Reference Voltage AGNDC RIAUX Input Resistance at Input Pins AUXL/R 2.25 V RL >> 10 MΩ, referred to VREF 12.1 11.6 15 17.9 19.0 kΩ kΩ TJ = 27 °C TA = 0 to 70 °C Input selected, SUSPD = 0 i = ± 10 µA, referred to VREF 24.2 23.3 30 35.8 37.9 kΩ kΩ TJ = 27 °C TA = 0 to 70 °C Input not selected SUSPD = 1 i = ± 10 µA, referred to VREF ROOUT Output Resistance at Output Pins OUTL/R 700 Ω TJ = 27 °C SUSPD = 1 i = ± 200 µA, referred to VREF ROFILT Output Resistance of Filter Pins FINL 15 kΩ FINR 11.25 kΩ SUSPD = 1, Mute i = ± 10 µA, referred to VREF VOffI Offset Voltage at Input Pins AUXL/R −20 20 mV SUSPD = 0, referred to AGNDC VOffO Offset Voltage at Output Pins OUTL/R −10 10 mV SUSPD = 0, Mute referred to AGNDC VOffFI Offset Voltage at Filter Output Pins FOUTL/R −20 20 mV SUSPD = 0, referred to AGNDC VOffFO Offset Voltage at Filter Input Pins FINL/R −20 20 mV SUSPD = 0, referred to AGNDC dVDCPD Difference of DC Voltage at Output Pins after Back-end Low Power Sequence OUTL/R −10 10 mV Analog Gain = Mute, SUSPD switched from 0 to 1 Micronas 23 UAC 3552A PRELIMINARY DATA SHEET Symbol Parameter Pin Name RD/A D/A Pass Band Ripple OUTL/R, FOUTL/R AD/A D/A Stop Band Attenuation BWAUX Bandwidth for Auxiliary Inputs AUXL/R, FINL/R THDHP Total Harmonic Distortion OUTL/R SNRAUX Signal-to-Noise Ratio from Analog Input to Outputs AUXn, OUTL/R SNR1 Signal-to-Noise Ratio OUTL/R SNR2 Signal-to-Noise Ratio OUTL/R LevMute Mute Level OUTL/R VAO Analog Output Voltage AC OUTL/R 1.0 1.05 GAUX Gain from Auxiliary Inputs to Outputs AUXL/R, OUTL/R −0.5 0 PHP Output Power (Headphone) OUTL/R 24 Min. Typ. Max. Unit Test Conditions 0.01 dB 0...22 kHz (no external filters used) 60 dB 31 kHz...164 kHz (no external filters used) 760 kHz 0.05 % BW = 20 Hz...0.5 fs, unweighted, RL ≥ 32 Ω (47 Ω series resistor required), Analog Gain = 0 dB, Input 1 kHz at −3 dBFS 96 dB input −40 dB below 1.05 Vrms 89 91 dB RL ≥ 32 Ω (external 47 Ω series resistor required) BW =20 Hz...0.5 fs unweighted, Analog Gain = 0 dB, Input = −20 dBFS 58 62 dB RL ≥ 32 Ω (external 47 Ω series resistor required) BW = 20 Hz..0.5 fs unweighted Analog Gain= −40.5 dB, Input = −3 dBFS −110 dBV BW = 20 Hz...22 kHz unweighted, no digital input signal, Analog Gain = Mute 1.1 Vrms RL > 5 kΩ, Analog Gain = 0 dB Input = 0 dBFS digital 0.5 dB f = 1 kHz, sine wave, RL > 5 kΩ 0.5 Vrms to AUXL/R mW RL = 32 Ω, Analog Gain = +2 dB, distortion < 1%, external 47 Ω series resistor required 12 Micronas UAC 3552A PRELIMINARY DATA SHEET Symbol Parameter Pin Name Min. GAO Analog Output Gain Setting Range OUTL/R −75 dGAO1 Analog Output Gain Step Size OUTL/R 3.0 dB dGAO2 Analog Output Gain Step Size OUTL/R 1.5 dB EGA1 Analog Output Gain Error OUTL/R −2 2 dB Analog Gain = −54 dB EGA2 Analog Output Gain Error OUTL/R −1 1 dB Analog Gain = −45 dB EGA3 Analog Output Gain Error OUTL/R −0.5 0.5 dB Analog Gain = −39 dB EdGA Analog Output Gain Step Size Error OUTL/R −0.5 0.5 dB Analog Gain = −48 dB XTALKHP Crosstalk Left/Right Channel (Headphone) OUTL/R −70 −80 dB f = 1 kHz, sine wave, OUTL/R: RL ≥ 32 Ω (47 Ω series resistor required) Analog Gain = 0 dB, Input = −3 dBFS or 0.7 Vrms to AUXL/R XTALK2 Crosstalk between Input Signal Pairs AUXnL/R −70 −80 dB f = 1 kHz, sine wave, FOUTL/R: RL > 7.5 kΩ OUTL/R: RL ≥ 32 Ω (47-Ω series resistor required) Analog Gain = 0 dB, Input = −3 dBFS and 0.7 Vrms to AUXL/R Micronas Typ. Max. Unit 18 dB Test Conditions Analog Gain: −75 dB...-54 dB Analog Gain: −54 dB...+18 dB 25 UAC 3552A PRELIMINARY DATA SHEET 4. Applications 3rd-order 4.1. Recommended Low-Pass Filters for Analog Outputs 1) 1st-order 7.5 kΩ 330 pF 15 kΩ 15 kΩ 7.5 kΩ 1.8 nF 15 kΩ 7.5 kΩ 120 pF 1.8 nF AVSS FOUTL(R) FOPL(R) FINL(R) − FOUTL(R) FOPL(R) FINL(R) − Fig. 4–3: 3rd-order low-pass filter Fig. 4–1: 1st-order low-pass filter Table 4–3: Attenuation of 3rd-order low-pass filter Table 4–1: Attenuation of 1st-order low-pass filter Frequency Gain 24 kHz −2.2 dB 30 kHz −3.0 dB Gain 18 kHz 0.17 dB 24 kHz −0.23 dB 30 kHz −3.00 dB 11 kΩ 2nd-order 11 kΩ Frequency 11 kΩ 220 pF 1.0 nF AVSS FOUTL(R) FOPL(R) FINL(R) − Fig. 4–2: 2nd-order low-pass filter Table 4–2: Attenuation of 2nd-order low-pass filter 1) Frequency Gain 24 kHz −1.5 dB 30 kHz −3.0 dB without deemphasis circuit 26 Micronas 1 2 3 4 J15 USB ser ies B 8VDC P1 1 5 4 3 2 D5 1n4001 DD+ 22p 100n C22 22p R18 11k resq + VIN 470n 2 L1 Ferrite bead C20 100n 100n 5Vana C19 5Vdig 11k C4 220p R5 R9 11k C1 12MHz C17 22p Y1 47u/16V C16 C18 22p 470n 5 4 32 31 23 C10 10n 100n C16 3.3u/16V C14 5Vdig UAC 3 5 5 2 A OUTR OUTL SOF Suspend T R DY GPIO7 GPIO6 GPIO5 GPIO4 22 21 20 19 C3 R14 11k C5 220p 11k R 1 0 11k R7 1n UAC 3552A + C21 d m i nu s dplus AU X L AU X R TEST RES# AU X E N GPIO0 GPIO1 GPIO2 GPIO3 U1 5Vdig 5Vana 100n 24 25 36 37 29 30 33 14 15 16 17 Bass Boost S4 C11 R 2 9 single connection point VO U T J14 D- C7 470n S3 Mute GPIO0 GPIO1 GPIO2 GPIO3 test resq S2 Volume down J16 D+ auxen R 1 7 1k R 1 1 11k R 6 11k R21 11k C6 5Vdig R16 150k 24 0.5% R25 1.5k U2 LM7805 47u/16V C23 1 R27 R 2 6 24 0.5% P H O N E J AC K S T E R E O S W J11 470n C2 220k R2 5Vdig R 3 11k S1 35 34 18 13 12 11 10 NC6 NC5 NC4 NC3 NC2 NC1 NC0 VREG Volume up 1 VREG GND 43 42 41 40 39 38 FinR Fo p R FoutR FinL FopL FoutL AV S S 1 AV S S 0 AV D D 0 AV D D 1 XTI XTO VREG VDD VSS VREF AGNDC 2 3 6 7 8 9 26 27 28 44 1 1n + C8 11k R12 C9 160u/16V 160u/16V + R 1 11k 1 R23 1k GPIO7 GPIO6 GPIO5 GPIO4 R 2 8 680 R 2 4 680 D4 D3 D2 D1 2 3 4 5 1 J7 LED LED LED LED J12 left J17 right J18 RCA right J13 RCA left P H O N E J AC K S T E R E O S W R 1 5 1k R 2 2 47 R 2 0 47 R19 1k 1k 1k R 1 3 1k R8 R4 1 1 Micronas + 3 PRELIMINARY DATA SHEET UAC 3552A 4.2. Typical Application Fig. 4–4: Application circuit 27 UAC 3552A PRELIMINARY DATA SHEET 5. Data Sheet History 1. Preliminary data sheet: “UAC 3552A Universal Serial Bus DAC, Nov. 9, 1999, 6251-487-1PD. First release of the preliminary data sheet. Micronas GmbH Hans-Bunte-Strasse 19 D-79108 Freiburg (Germany) P.O. Box 840 D-79008 Freiburg (Germany) Tel. +49-761-517-0 Fax +49-761-517-2174 E-mail: [email protected] Internet: www.micronas.com Printed in Germany Order No. 6251-487-1PD 28 All information and data contained in this data sheet are without any commitment, are not to be considered as an offer for conclusion of a contract, nor shall they be construed as to create any liability. Any new issue of this data sheet invalidates previous issues. Product availability and delivery are exclusively subject to our respective order confirmation form; the same applies to orders based on development samples delivered. By this publication, Micronas GmbH does not assume responsibility for patent infringements or other rights of third parties which may result from its use. Further, Micronas GmbH reserves the right to revise this publication and to make changes to its content, at any time, without obligation to notify any person or entity of such revisions or changes. No part of this publication may be reproduced, photocopied, stored on a retrieval system, or transmitted without the express written consent of Micronas GmbH. Micronas