Datasheet

ADS1299

www.ti.com

SBAS499A –JULY 2012–REVISED AUGUST 2012

LOFF: Lead-Off Control Register

Address = 04h

BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0

COMP_TH2 COMP_TH1 COMP_TH0 0 ILEAD_OFF1 ILEAD_OFF0 FLEAD_OFF1 FLEAD_OFF0

This register configures the lead-off detection operation.

Bits[7:5] COMP_TH[2:0]: Lead-off comparator threshold

These bits determine the lead-off comparator threshold level setting. See the Lead-Off Detection subsection of the EEG-

Specific Functions section for a detailed description.

Comparator positive side

000 = 95% (default)

001 = 92.5%

010 = 90%

011 = 87.5%

100 = 85%

101 = 80%

110 = 75%

111 = 70%

Comparator negative side

000 = 5% (default)

001 = 7.5%

010 = 10%

011 = 12.5%

100 = 15%

101 = 20%

110 = 25%

111 = 30%

Bit 4 Must always be set to '0'

Bits[3:2] ILEAD_OFF[1:0]: Lead-off current magnitude

These bits determine the magnitude of current for the current lead-off mode.

00 = 6 nA (default)

01 = 24 nA

10 = 6 µA

11 = 24 µA

Bits[1:0] FLEAD_OFF[1:0]: Lead-off frequency

These bits determine the frequency of lead-off detect for each channel.

00 = DC lead-off detection (default)

01 = AC lead-off detection at 7.8 Hz (SYS_CLK / 2

)

10 = AC lead-off detection at 31.2 Hz (SYS_CLK / 2

)

11 = AC lead-off detection at f

/ 4

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