L6460 datasheet(93/139 Pages) STMICROELECTRONICS

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L6460

Digital comparator

Doc ID 17713 Rev 1

93/139

Digital comparator

L6460 includes one digital comparator that can be used to signal, through serial interface,

that a channel converted by the ADC is greater, greater-equal, lesser, lesser equal, or equal

than a fixed value set by serial interface or than the value converted by the other ADC

channel.

This circuit can be used to monitor the temperature of the IC advising the firmware when it

reaches a certain value decided by the firmware by setting one ADC channel to do

continuous conversions of the temperature sensor.

The circuit operation can be enabled or disabled changing the EnDigCmp bit in the

configuration register DigCmpCfg. By setting the DigCmpUpdate[1:0] bits in the

configuration register, the comparator can be programmed to update its output in one of the

following ways:

●

DigCmpUpdate[1:0]=00

–

Continuously (each clock).

●

DigCmpUpdate[1:0]=01

–

Each time a conversion is performed on ADC channel 0.

●

DigCmpUpdate[1:0]=10

–

Each time a conversion is performed on ADC channel 1.

●

DigCmpUpdate[1:0]=11

–

ADC state machine driven.

When the last option is selected, the digital comparator will update its output in two different

ways depending on the configuration of the ADC converter. If ADC converter is configured to

do continuous conversions on both channels, the output of the comparator will be updated

when the double conversion is completed. If ADC converter is not configured to do

continuous conversions on both channels, the output of the comparator will be updated each

time a conversion is completed.

The comparator output can be digitally filtered so that the programmed condition has to be

found for three consecutive checks before to be signaled.

The Figure 29 shows the block diagram of digital comparator.

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