TI Information – Selective Disclosure

Prescalar – PostscalarOpen-loop and Closed-loop

Settings

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WHY PRES-SCALAR – POST-SCALAR

• What is it?– Pre-scalar has digital headroom of +24dB without clipping– Post-scalar can be adjusted to the desire distortion for

increased power over the full scale input.

• What is it for?– By increasing the input signal over the full scale (clipped

signal) in the pre-scalar block and then adjusting the output the desired distortion in the post-scalar block:

• The distortion level is independent of PVCC• The distortion level is also maintained in post-scalar block, i.e. in a

certain range the post-scalar block can be adjusted so that the output amplitude changes but the distortion level stays constant

TI Information – Selective Disclosure

Closed-loop TAS5710

Prescalar: 0x57 00AB AAAAPostscalar: 0x56 0002 3333Input: 13 VDC, full scale digitalLoad: 8 OhmOutput: 8W, 10% THD+N

1kHz – 8W – 10% THD+N 15kHz – 8W – 10% THD+N

TI Information – Selective Disclosure

Open-loop TAS5709

Prescalar: 0x57 002B 0000Postscalar: 0x56 0006 B000Input: 13 VDC, full scale digitalLoad: 8 OhmOutput: 8W, 10% THD+N

1kHz – 8W – 10% THD+N 15kHz – 8W – 10% THD+N

TI Information – Selective Disclosure