TAS5717 no sound

Andreas Koch

Other Parts Discussed in Thread: TAS5717

Hello,

I'm using the TAS5717 audio amplifier controlled by an ARM-Cortex-M3 microcontroller on a custom board. I followed exactly the instruction list for getting the device running (like described here: http://e2e.ti.com/support/amplifiers/audio_amplifiers/f/6/t/105299.aspx). Further I proofed the communication on the I²C and I²S interfaces via oszilloscope, and measured a pwm-signal on the analog outputs of the amplifier (50% duty cycle). The problem is, that no audio signal consversion takes place. For test purposes I supply the IC with a simple continous ramp signal on both (l+r) channels. Error status register returns 0.

I²S-configuration:

I²S-32-fs-Format (Phillips) (fig. 28 datasheet), SCLK = 44100 * 2 * 16 Hz = 1411200 Hz, SCLK continues

MCLK is absent (logical undefined). According to the datasheet the IC should be able to generate this main clock by itself?

Do you have any idea solving this problem.

Thanks in advance!

Andreas

over 10 years ago

0 Damian Lewis over 10 years ago

TI__Mastermind 34675 points

Hello Andreas,

Thanks for the interest in our TAS5717. You misunderstood what the datasheet is say. In the absence of MCLK the internal clock will run the digital core and the class D PWM output will be 50% duty cycle and frequency will be based on the internal clock. There isn't any audio in the absence of MCLK. MCLK is needed for audio and it needs to follow the specs in the datasheet for MCLK.

0 Damian Lewis over 10 years ago in reply to Damian Lewis

TI__Mastermind 34675 points

Andreas,

If you use 44.1kHz x 64 = 2.8224MHz for SCLK (64fs) then you can share SCLK with MCLK to play audio.

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TAS5717 no sound