Description

STA370BWS

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Doc ID 16884 Rev 1

1

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.

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.

Two channels can be provided by two full-bridges, supplying up to 2 x 20 W of output

power.

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.

format. The high-quality conversion from PCM audio to FFX PWM switching provides over

100 dB of SNR and of dynamic range.

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.