Datasheet

ADS1299
www.ti.com SBAS499A –JULY 2012–REVISED AUGUST 2012
ELECTRICAL CHARACTERISTICS
Minimum and maximum specifications apply from –40°C to +85°C. Typical specifications are at +25°C. All specifications are
at DVDD = 3.3 V, AVDD – AVSS = 5 V, V
REF
= 4.5 V, external f
CLK
= 2.048 MHz, data rate = 250 SPS, and gain = 12, unless
otherwise noted.
ADS1299
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
ANALOG INPUTS
Full-scale differential input voltage
±V
REF
/ gain V
(AINP – AINN)
See the Input Common-Mode Range
Input common-mode range subsection of the PGA Settings and Input
Range section
C
i
Input capacitance 20 pF
T
A
= +25°C, input = 2.5 V ±300 pA
I
IB
Input bias current
T
A
= –40°C to +85°C, input = 2.5 V ±300 pA
No lead-off 1000 MΩ
DC input impedance
Current source lead-off detection
500 MΩ
(I
LEADOFF
= 6 nA)
PGA PERFORMANCE
Gain settings 1, 2, 4, 6, 8, 12, 24
BW Bandwidth See Table 5
ADC PERFORMANCE
Resolution 24 Bits
DR Data rate f
CLK
= 2.048 MHz 250 16000 SPS
CHANNEL PERFORMANCE (DC Performance)
10 seconds of data, gain = 24
(1)
1.0 μV
PP
250 points, 1 second of data, gain = 24,
1.0 1.35 μV
PP
T
A
= +25°C
Input-referred noise (0.01 Hz to 70 Hz)
250 points, 1 second of data, gain = 24,
1.0 1.6 μV
PP
T
A
= –40°C to +85°C
All other sample rates and gain settings See Noise Measurements section
INL Integral nonlinearity Full-scale with gain = 12, best fit 8 ppm
E
O
Offset error 60 μV
Offset error drift 80 nV/°C
E
G
Gain error Excluding voltage reference error 0.1 ±0.5 % of FS
Gain drift Excluding voltage reference drift 3 ppm/°C
Gain match between channels 0.2 % of FS
CHANNEL PERFORMANCE (AC Performance)
CMRR Common-mode rejection ratio f
CM
= 50 Hz and 60 Hz
(2)
–110 –120 dB
PSRR Power-supply rejection ratio f
PS
= 50 Hz and 60 Hz 96 dB
Crosstalk f
IN
= 50 Hz and 60 Hz –110 dB
SNR Signal-to-noise ratio V
IN
= –2 dBFs, f
IN
= 10-Hz input, gain = 12 121 dB
THD Total harmonic distortion V
IN
= –0.5 dBFs, f
IN
= 10 Hz –99 dB
(1) Noise data measured in a 10-second interval. Test not performed in production. Input-referred noise is calculated with the input shorted
(without electrode resistance) over a 10-second interval.
(2) CMRR is measured with a common-mode signal of AVSS + 0.3 V to AVDD – 0.3 V. The values indicated are the minimum of the eight
channels.
Copyright © 2012, Texas Instruments Incorporated 3