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DA6116.010

5 October, 2017

GENERAL DESCRIPTION

Operating modes

When power is first applied, the Power-On Reset circuit (POR) initializes the control registers and sets MAS6116

into mute state, ignoring the state of the XMUTE pin. The activation of the device requires that XMUTE pin is high

pin low will mute both channels. Setting the XMUTE pin back high will return the channels to previously written

gain values. The zero cross detector function is used when entering and returning from the mute state to prevent

large transients in the output signal (see chapter Changing the gain of the channels).

The device has a special test mode register, which is used only for internal testing of the device. It is strongly

testing the XMUTE pin is bi-directional. When the test register bit 1 is set to high, XMUTE pin is in output mode. In

the test mode internal signals can be directed to the XMUTE pin. Note: In the test mode both analog outputs are

in mute state and the device will not allow new gain values to be written in the gain registers. An exception to this

is the force latch command specified in table Test Register CR5 Description, which can be used to instantly change

the gain of both channels. This function is intended to be used in the test mode only, and it is recommended to use

the commands specified in Register Description to instantly change the channel gains.

Changing the gain of the channels

When a new gain value is written to the gain register the device will activate the zero crossing detection and delay

generator for the selected channel. MAS6116 will wait until a rising edge of the input signal is detected to change

the gain value. This is done to ensure that no audible clicks are produced to the output signal during the gain

change operation. The zero cross detection circuit has also a timeout delay generator that will force the gain

change. The delay generator generates a typical delay of 22 ms.

If a new gain value is written before the previous write operation has finished, the previously written value will be

overwritten and will not be set to the output. If it is desired that each gain value is set to the output, it is

recommended to read the status bit from the write operation status register (CR6) or wait for at least 30 ms before

the next gain change instruction.

Both channels can be programmed independently with separate commands. In this case the gain values will be

set to the output in the order of writing. Both channels can also be programmed to the same value by writing only

one instruction (see the Register Description on page 8).

Note: Due to the input signal dependency of the zero cross detection circuits the order of the gain changes may

differ from the order of writing to the registers if the input signals to the channels are different. This applies to all

instructions that use the zero cross detection and timeout functions, i.e. instructio

ns that are not labeled as “instant”

in the register description.

The new gain value can be set instantly to the output by using the instant gain change function. By using this

command function the gain is set to the output instantly after the write operation has finished, without waiting for a

zero cross to occur in the input signal or a delay to pass. The gains can be set independently to both channels

using different commands, or both channels can be set to the same gain value by using a single command. Using

the instant gain change function to change the gain value in larger than 0.5 dB steps may produce audible clicks

to the output signal.