Sharp LC-32SV21L, Service Manual

Page: 48 / 101

LC-32SV21L&LC-42SV31L
48
The STA339BW is part of the Sound Terminal™ family that provides full digital audio streaming to the speaker, offering cost effectiveness, low power
dissipation and sound enrichment.
The STA339BW power section consists of four independent half-bridges. These can be configured via digital control to operate in different modes. 2.1
channels can be provided by two half-bridges and a single full-bridge, providing up to 2 x 9 W + 1 x 20 W of power output. Two channels can be provided
by two full-bridges, providing up to 2 x 20 W of power. The IC can also be configured as 2.1 channels with 2 x 20 W provided by the device and external
power for FFX power drive.
Also provided in the STA339BW are a full assortment of digital processing features. This includes up to 8 programmable 28-bit biquads (EQ) per channel
and bass/treble tone control. Available presets enable a time-to-market advantage by substantially reducing the amount of software development needed
for certain functions. This includes 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 speaker linear frequency response regardless output power
level. This feature independently processes the two bands, controlling, dynamically, the output power level in each band and so providing a better sound
quality.
The serial audio data input interface accepts all possible formats, including the popular I2S format. Three channels of FFX processing are provided. This
high-quality conversion from PCM audio to FFX PWM switching waveform provides over 100 dB SNR and dynamic range.
Features
■ Wide voltage supply range
– 5 V to 26 V (operating range)
– 30 V (absolute maximum rating)
■ 3 power output configurations
– 2 channels of ternary PWM (stereo mode) (2 x 20 W into 8 Ω at 18 V)
– 3 channels - left, right using binary and LFE using ternary PWM (2.1 mode) (2 x 9 W + 1 x 20W into 2 x 4 Ω , 1 x 8 Ω at 18 V)
– 2 channels of ternary PWM (2 x 20 W) + stereo lineout ternary
■ 2.1 channels of 24-bit FFX®100 dB SNR and dynamic range
■ Selectable 32 to 192 kHz input sample rates
■ I2C control with selectable device address
■ Digital gain/atten48 dB to -80 dB with 0.5 dB/step resolution
■ Soft volume update with programmable ratio
■ Individual channel and master gain/attenuation
■ Two independent DRC configurable as a dualband anti-clipper (B2DRC) or independent limiters/compressors
■ EQ-DRC for DRC based on filtered signals
■ Dedicated LFE processing for bass boosting with 0.5 dB/step resolution
■ Audio presets:
– 15 preset crossover filters
– 5 preset anti-clipping modes
– Preset night-time listening mode
■ Individual channel and master soft/hard mute.
■ Independent channel volume and DSP bypass
■ Automatic zero-detect mute
■ Automatic invalid input-detect mute
■ 2-channel I2S input data interface
■ Input and output channel mapping
■ Up to 8 user-programmable biquads per channel with 28-bit resolution
■ 3 coefficients banks for EQ presets storing with fast recall via I2C interface
■ Bass/treble tones and de-emphasis control
■ Selectable high-pass filter for DC blocking
■ Advanced AM interference frequency switching and noise suppression modes
■ Selectable high- or low-bandwidth noise-shaping topologies
■ Variable max power correction for lower full-power THD
■ Selectable clock input ratio
■ 96 kHz internal processing sample rate, 24 to 28-bit precision