STA370BWS 2.1-channel 40-W high-efficiency digital audio system Sound Terminal™ Data brief Features Wide-range supply voltage, 7.0 V to 21.5 V Three power output configurations: – 2 channels of ternary PWM (2 x 20 W into 8 Ω at 18 V) + PWM output – 2 channels of ternary PWM (2 x 20 W into 8 Ω at 18 V) + ternary stereo line-out – 2.1 channels of binary PWM (left, right, LFE) (2 x 9 W into 4 Ω + 1 x 20 W into 8 Ω at 18 V) Load-driving capabilities: – 11 W into 6 Ω at 14 V, ternary – 20 W into 4 Ω at 14 V, ternary FFX with 100-dB SNR and dynamic range Scalable FFX modulation index (up to 100%) Selectable 32- to 192-kHz input sample rates I2C control with selectable device address Digital gain/attenuation +48 dB to -80 dB with step resolution: – 0.125 dB/step from -60 dB to +48 dB – 0.25 dB/step from -80 dB to -60 dB PowerSSO-36 with exposed pad down (EPD) Input and output channel mapping Programmable zero-detect mute Automatic invalid input-detect mute Up to 8 user-programmable biquads/channel Three coefficients banks for EQ presets storing with fast recall via I2C interface Extended filter dynamics +4/-4 for better sound shaping and easier filter implementation Bass/treble tones and de-emphasis control Selectable high-pass filter for DC blocking Advanced AM interference frequency switching and noise suppression modes F3X™ advanced PWM modulation scheme for carrier suppression (headphone or line output) Selectable high- or low-bandwidth noise-shaping topologies Soft volume update with programmable ratio Individual channel and master gain/attenuation and soft/hard mute. Two independent DRCs configurable as a dual-band anti-clipper (B2DRC) or as independent limiters/compressors with optional global DRC capability 96-kHz internal processing sample rate with quantization error noise shaping for very low cut-off frequency filters Full short-circuit protection at device power-up Coefficient checksum with software reset capabilities EQ-DRC for DRC based on filtered signals Dedicated LFE processing for bass boosting with 0.125-dB/step resolution Audio presets: – 15 preset crossover filters – 5 preset anti-clipping modes – Preset night-time listening mode Table 1. Device summary Order code STA370BWS Package PowerSSO-36 EPD STA370BWSTR PowerSSO-36 EPD Packing Tube Tape and reel I2S input data interface December 2009 Doc ID 16884 Rev 1 For further information contact your local STMicroelectronics sales office. 1/5 www.st.com 5 Description 1 STA370BWS Description The STA370BWS is an integrated solution of digital audio processing, digital amplifier controls and power output stage to create a high-power single-chip FFX digital amplifier with high-quality and high-efficiency. Three channels of FFX processing are provided. The FFX processor implements the ternary, binary and binary differential processing capabilities of the full FFX processor. The STA370BWS is part of the Sound Terminal™ family that provides full digital audio streaming to the speakers and offers cost effectiveness, low power dissipation and sound enrichment. The power section consists of four independent half-bridges. These can be configured via digital control to operate in different modes. z 2.1 channels can be provided by two half-bridges and a single full-bridge, supplying up to 2 x 9 W + 1 x 20 W of output power. z Two channels can be provided by two full-bridges, supplying up to 2 x 20 W of output power. z The IC can also be configured as 2.1 channels with 2 x 20 W supplied by the device plus a drive for an external FFX power amplifier, such as STA533WF or STA515W. The STA370BWS flexibility is shown by the load driving capability of 11 W into 6 Ω and 20 W into 4 Ω with ternary modulation with a supply of 14 V. Also provided in the STA370BWS are a full assortment of digital processing features. This includes up to 8 programmable biquads (EQ) per channel. Special digital signal processing techniques are available to manage low-frequency quantization noise in filters with very low cut-off frequencies. The coefficient range -4 to +4 allows easy high-shelf filter usage and better sound shaping. Available presets enable a time-to-market advantage by substantially reducing the amount of software development needed for functions such as audio preset volume loudness, preset volume curves and preset EQ settings. There are also new advanced AM radio interference reduction modes. Dual-band DRC dynamically equalizes the system to provide linear frequency speaker response regardless of output power level. This feature separates the audio frequency band into two sub-bands independently processed to provide better sound clarity and to avoid speaker saturation. The serial audio data input interface accepts all possible formats, including the popular I2S format. The high-quality conversion from PCM audio to FFX PWM switching provides over 100 dB of SNR and of dynamic range. Full short-circuit protection is also embedded protecting output to GND, output to VCC and output to output connections. The short-circuit (fault) condition is checked at device turn-on, so if a short circuit is detected the IC does not power up. This avoids dangerous conditions, component break down and minimizes the return from the field. The new F3X™ modulation, already offered within STA369BWS, is capable of digitally filtering the PWM carrier to simplify external filtering requirements, AM interference and EMI. F3X™ is implemented in the auxiliary output of STA370BWS and it is specifically designed for application where a simple op-amp can be used to drive an auxiliary headphone line. 2/5 Doc ID 16884 Rev 1 STA370BWS 2 Applications Applications Figure 1. Applications circuit 3V3 U1 1 C2 2 + 3 100uF 4 C3 5 100nF C4 1uF 6 OUT2B 7 8 C6 100nF OUT2A C7 100nF Vcc OUT1B 9 10 11 12 C9 1uF 13 OUT1A 14 C11 15 100nF 16 OUT3B 17 OUT3A 18 GND_SUB Vdd_DIG SA GND_DIG TEST_MODE SCL Vss SDA Vcc_REG INT_LINE OUT2B RESET GND2 SDI Vcc2 LRCKI OUT2A BICKI OUT1B XTI Vcc1 PLL_GND GND1 PLL_DC OUT1A N.C. GND_REG PWRDN Vdd GND_DIG CONFIG Vdd_DIG OUT3B TWARN/OUT4B OUT3A EAPD/OUT4A 36 C1 35 100nF 34 SCL 33 R1 SDA 10K INTL1 32 31 RESET 30 C5 DATA 29 1nF LRCKI 28 SW1 RESET BICKI 27 XTI 26 C8 25 2.2uF 24 23 PWDN C10 22 21 100nF 20 OUT4B 19 OUT4A 3V3 STA370BWS Figure 2. Output low-pass filtering L1 22uH OUTxA C1 100nF R2 6R2 R1 22 C2 100nF LS1 C3 470nF R3 6R2 C4 330pF 8ohm C5 100nF C6 100nF OUTxB L2 L1 22uH 22uH OUTxA C1 220nF R2 R1 3R3 22 C2 220nF LS1 C3 1uF R3 3R3 C4 330pF C5 4ohm 220nF C6 220nF OUTxB L2 22uH Doc ID 16884 Rev 1 3/5 Revision history 3 STA370BWS Revision history Table 2. 4/5 Document revision history Date Revision 10-Dec-2009 1 Changes Initial release. Doc ID 16884 Rev 1 STA370BWS Please Read Carefully: Information in this document is provided solely in connection with ST products. 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The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners. © 2009 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com Doc ID 16884 Rev 1 5/5