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AD7177-2 incorrect data rate

Question asked by AnalogGuru on Mar 5, 2018
Latest reply on Mar 9, 2018 by JellenieR

Hello,

 

I am using AD7177-2 at a maximum 10,000 sps data rate in continuous conversion mode, single channel, using external 16MHz clock. Conversion end is checked with RDY output. With the Sinc3 filter enabled each conversion takes 1600 clock ticks resulting in exactly 10,000 sps data rate. But with the Sinc5+Sinc1 filter and no enhanced filter each conversion takes 1602 clock ticks resulting in about 9,988 sps data rate.

 

I need exactly 10,000 sps data rate with Sinc5+Sinc1 filter enabled. Is this possible?

 

The AD7177-2 part is properly reset after power-up.

The rest of settings are:

REF_EN - 0

HIDE_DELAY - I tried both - no effect on data rate

SING_CYC - 0

DELAY - 0

MODE - 000

CLOCKSEL -10

ALT_SYNC - 0

IOSTRENGTH - 0

DOUT_RESET - 0

CONTREAD - 0

DATA_STAT - 0

REG_CHECK - 0

CRC_EN - 00

WL32 - 0

MUX_IO - 0

SYNC_EN - 0

ERR_EN - 00

IP_EN0, IP_EN1,  OP_EN0,  OP_EN1 -0

CH_EN0 - 1

SETUP_SEL0 - 00

BI_UNIPOLAR0 - 1

REFBUF0+, REFBUF0-, AINBUF0+, AINBUF0- - 1

REF_SEL0 - 00

CH_EN1, CH_EN2, CH_EN3 - 0

SINC3_MAP0 - 0

ENHFILTEN0 - 0

ENHFILT0 - 101

ORDER0 - 00

ODR0 - 00111

 

Please help,

Vadim.

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