Datasheet

ELECTRICAL CHARACTERISTICS
ADS1174
ADS1178
www.ti.com ........................................................................................................................................ SBAS373B – OCTOBER 2007 – REVISED SEPTEMBER 2008
Limit specifications at T
A
= – 40 ° C to +105 ° C. Typical specifications at T
A
= +25 ° C, AVDD = +5V, DVDD = +1.8V, IOVDD =
+3.3V, f
CLK
= 27MHz, VREFP = 2.5V, VREFN = 0V, and all channels active, unless otherwise noted.
ADS1174, ADS1178
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
ANALOG INPUTS
Full-scale input voltage (FSR
(1)
) V
IN
= (AINP – AINN) ± V
REF
V
Absolute input voltage AINP or AINN to AGND AGND – 0.1 AVDD + 0.1 V
Common-mode input voltage V
CM
= (AINP + AINN)/2 2.5 V
High-Speed mode 28 k Ω
Differential input impedance
Low-Power mode 140 k Ω
DC PERFORMANCE
Resolution No missing codes 16 Bits
High-Speed mode 52,734 SPS
Data rate (f
DATA
)
Low-Power mode 10,547 SPS
Integral nonlinearity (INL)
(2)
Differential input ± 0.3 ± 1 LSB
Offset error 0.3 2 mV
Offset drift 2 µ V/ ° C
Gain error 0.1 0.5 %
Gain drift 2 ppm/ ° C
Noise Shorted input 1 LSB
PP
Common-mode rejection f
CM
= 60Hz
(3)
100 dB
AVDD f
PS
= 60Hz
(3)
75 dB
Power-supply rejection DVDD f
PS
= 60Hz
(3)
85 dB
IOVDD f
PS
= 60Hz
(3)
90 dB
V
COM
output voltage No load AVDD/2 V
AC PERFORMANCE
Crosstalk V
IN
= 1kHz, – 0.5dBFS – 107 dB
Signal-to-noise ratio (SNR) (unweighted) V
IN
= 1kHz, – 0.5dBFS 92 97 dB
Total harmonic distortion (THD)
(4)
High-Speed mode V
IN
= 1kHz, – 0.5dBFS – 105 – 96 dB
Spurious-free dynamic range 106 dB
Passband ripple ± 0.005 dB
Passband 0.453 f
DATA
Hz
– 3dB Bandwidth 0.49 f
DATA
Hz
Stop band attenuation 100 dB
Stop band 0.547 f
DATA
63.453 f
DATA
Hz
Group delay 38/f
DATA
s
Settling time (latency) Complete settling 76/f
DATA
s
(1) FSR = full-scale range = 2V
REF
(2) Best-fit method.
(3) f
CM
is the input common-mode frequency. f
PS
is the power-supply frequency.
(4) THD includes the first nine harmonics of the input signal.
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