Datasheet

ADS8556
ADS8557
ADS8558
www.ti.com SBAS404B –OCTOBER 2006– REVISED JANUARY 2012
ELECTRICAL CHARACTERISTICS: ADS8557
Over recommended operating free-air temperature range of –40°C to +125°C, AVDD = 4.5V to 5.5V, BVDD = 2.7V to 5.5V,
HVDD = 10V to 15V, HVSS = –15V to –10V, V
REF
= 2.5V (internal), and f
DATA
= 670kSPS in parallel mode or 470kSPS in
serial mode, unless otherwise noted.
ADS8557
PARAMETER CONDITIONS MIN TYP
(1)
MAX UNIT
DC ACCURACY
Resolution 14 Bits
No missing codes 14 Bits
Integral linearity error INL –1 ±0.4 1 LSB
Differential linearity error DNL –1 ±0.25 1 LSB
Offset error –4 ±0.8 4 mV
Offset error drift ±3.5 μV/°C
Gain error Referenced to voltage at REFIO –0.75 ±0.25 0.75 %FSR
Gain error drift Referenced to voltage at REFIO ±6 ppm/°C
Power-supply rejection ratio PSRR At output code FFFFh, related to AVDD 60 dB
SAMPLING DYNAMICS
Acquisition time t
ACQ
280 ns
Conversion time per ADC t
CONV
1.19 μs
18.5 t
CCLK
Internal conversion clock period t
CCLK
64.1 ns
Parallel interface,
670 kSPS
internal clock and reference
Throughput rate f
DATA
Serial interface,
470 kSPS
internal clock and reference
AC ACCURACY
Signal-to-noise ratio SNR At f
IN
= 10kHz 84 85 dB
Signal-to-noise ratio + distortion SINAD At f
IN
= 10kHz 83 84 dB
Total harmonic distortion
(2)
THD At f
IN
= 10kHz –91 –86 dB
Spurious-free dynamic range SFDR At f
IN
= 10kHz 86 92 dB
Channel-to-channel isolation At f
IN
= 10kHz 100 dB
In 4 × V
REF
mode 48 MHz
–3dB small-signal bandwidth
In 2 × V
REF
mode 24 MHz
(1) All values are at T
A
= +25°C.
(2) Calculated on the first nine harmonics of the input frequency.
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