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DA6116.001

27 February, 2009

GENERAL DESCRIPTION

Peak level detection

MAS6116 has a 8-bit digital-to-analog converter (DAC) used to monitor the peak level of the output signal. The

reference value is programmed using the serial interface and the same reference value is used for both channels.

The reference value V REF can be calculated using the following formula.

VREF = (0.0036 + 0.0145 · CODE) · AVCC

where CODE is the decimal value of the control byte (0...255) and AVCC is the analog supply voltage of the

MAS6116 device. With nominal analog supply voltage of 5V the reference value is

VREF = 18mV + 72.5mV · CODE

When a positive peak signal level at the output exceeds the V REF value, bits 0 and 1 of the status register are

set (see register description). When set, the register contents will remain high until the value of the status register

has been read.

Write operation status register

MAS6116 features a status register that can be used to determine if the channel registers are ready to accept

new gain values. The status register bits 0 and 1 are set high at the start of a gain write operation, and are set

back low when the new gain value has been set to the output. This happens when a positive zero crossing is

detected in the input signal or the timeout delay has passed.

It is allowed to write a new gain value to a channel that is busy (i.e. waiting for a zero cross in the input signal).

The new value will overwrite the previous one and the timeout delay will be reset. This means that the previously

written gain value will not be set to the channel gain registers. To prevent this from happening it is recommended

to read the write operation status register prior to setting a new gain value to determine if the write operation can

be safely executed.