L9966 datasheet(32/122 Pages) STMICROELECTRONICS

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Multiplexing switches

The FlexInput has different type of integrated switches to connect the input channels to the desired functionality.

These functionalities are:

•

Integrated ADC for voltage measurement (with 4 different full-scale voltage ranges)

•

Integrated ADC for resistance measurement (with 3 different resistance ranges, according to the 3 external

pull-up reference resistances)

•

AOX output to provide an analog output signal of the input line

•

SENTx_GTMx output pins to provide the SENT signals to an external SENT decoder

•

SENTx_GTMx outputs to provide a digital output signal of the input line

•

Ratiometric analog comparator

The switches are controlled by register SWITCH_ROUTE, CURR_SRC_CTRL_X and SC_CONF/SQNCR_CMD

registers.

The sequencer, if used, can anyhow take control of the switches settings connecting the input lines to the 2

integrated ADCs for voltage and resistance measurements.

7.1

Channels routing to SENTx_GTMx output buffers

Channel comparator output can be read with a SPI on DIG_IN_STAT register or routing the channel state to

SENTx_GTMx buffers.

By default at power-up, IO15 is routed on SENT4_GTM4 while the others SENTx_GTMx outputs are kept in

HiZ. Once an IOx is configured as SENT through SWITCH_ROUTE register, the corresponding SENTx_GTMx

buffer is automatically programmed to output the SENT signal. An eventual previous configuration of the same

SENTx_GTMx as GTM is overwritten.

Routing input channel comparators to SENTx_GTMx (x=1:4) requires:

•

Disabling SENT_x functionality by writing RSENT_x = ‘0’ in SWITCH_ROUTE register (in case the SENT

functionality was enabled)

•

Configure the routed channel by writing SENTx_GTM_ROUTE[4:1] in GTM_TO_SENT_ROUTE_1_2 (for

SENT 1/2) or in GTM_TO_SENT_ROUTE_3_4 (for SENT 3/4)

It is possible to put the SENTx_GTMx output buffers in high impedance configuring SENTx_GTM_ROUTE[4:1] =

"0000" in GTM_TO_SENT_ROUTE_1_2/3_4 register.

L9966

Multiplexing switches

DS12459 - Rev 10

page 32/122

L9966 датащи(PDF) 32 Page - STMicroelectronics