SI2704-A10 SILABS [Silicon Laboratories], SI2704-A10 Datasheet - Page 30

• Manufacturer Part Number: SI2704-A10
• Description: EMI MITIGATING 2.1X 5 W CLASS D AUDIO AMPLIFIER
• Manufacturer: SILABS [Silicon Laboratories]

Si2704/05/06/07-A10
Figure 24. Time Domain Characteristics of the Audio Dynamic Range Controller
4.6.7. Hard Signal Limiter
The device implements a hard limiter to avoid exceeding the maximum modulation rate of the amplifier. The hard
limiter is always enabled.
4.6.8. DC Notch Filter
A dc notch filter with a 5 Hz corner frequency is implemented as the final function in the signal processing chain to
remove any dc component from the output signal. Each channel has a separate dc notch filter.
4.6.9. Tone and Alert Generation
The Si270x includes two independent tone generators with programmable frequencies and on/off times.
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The output of both tone generators is fed to a mixer which combines the tones with the I
S inputs. The tones’
amplitudes can be adjusted by programming the mixer coefficients using the SET_AUDIO_INPUT_MIXER
command.
This feature allows customization of audible alarms and alerts. Programmable frequencies range from 100 Hz to
20 kHz in 100 Hz steps and on/off times range from 0 to 65 seconds in 1 ms steps and are set via the 2-Wire
interface using the properties TONE_ONE_FREQ, TONE_ONE_ON_TIME, TONE_ONE_OFF_TIME, and
TONE_ONE_AMPLITUDE
for
the
first
tone
and
TONE_TWO_FREQ,
TONE_TWO_ON_TIME,
TONE_TWO_OFF_TIME, and TONE_TWO_AMPLITUDE for the second tone.
4.7. Fault Detection and Response
To help protect the H-bridge driver and external loads, the output stage has fault detection circuitry that allows the
device to respond to over-current and over-temperature events.
The over-temperature circuitry monitors the temperature of the device and if the temperature exceeds 135 ºC a
thermal error is issued, and the output stage is shut down by transitioning the device to Standby Mode.
The over-current protection circuit constantly monitors the current of the output stage and triggers a fault alarm if
an over-current condition is detected from three different events: a short circuit across the speaker terminals, a
short circuit of any of the outputs to ground and a short circuit of any of the outputs to the supply voltage. In each
case, the detector issues a fault if the 2.5 A current threshold is exceeded. In response to this fault the device
power stage is shut down by transitioning the device to Standby Mode.
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Rev. 0.6