Datasheet

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SLAS370C − APRIL 2002 − REVISED OCTOBER 2004
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5
ELECTRICAL CHARACTERISTICS
For Internal Functions
(1)
, −40°C ≤ T
A
≤ 85°C, V
DD
= 5 V, BUFIN = 2.5 V (using external reference), 2.5-MHz CCLK and 2.5-MHz SCLK (unless
otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Multiplexer
On resistance 100 Ω
Off resistance 1 GΩ
Off channel leakage
On channel = 5.2 V,
Off channel = 0 V
V
LNx
= 5.2 V 100 pA
Off channel leakage
current
On channel = 0 V,
Off channel = 5.2 V
100 pA
On channel leakage
On channel = 5.2 V,
Off channel = 0 V
100 pA
On channel leakage
current
On channel = 0 V,
Off channel = 5.2 V
100 pA
PGA Amplifier
Offset voltage 100 µV
Small signal bandwidth 5/Gain MHz
Settling time
G = 1 0.3 µs
Settling time
G = 20 6.4 µs
Analog-To-Digital Converter DC Characteristics
Resolution 14 Bits
Integral linearity error ±2 LSB
Differential linearity error ±0.5 LSB
No missing codes 14 Bits
Offset error REFIN = 2.5 V ±2 LSB
Full-scale (gain) error ±0.02 %
Common mode rejection, RTI of A/D 60 dB
Power supply rejection, RTI of ADS7871 External reference, V
DD
= 5 V ±10% 60 dB
PGA Plus A/D Converter Sampling Dynamics f
CCLK
= 2.5 MHz, DF = 1
Throughput rate 50 CCLK cycles 50 kHz
Conversion time 14 CCLK cycles 5.6 µs
Acquisition time 28 CCLK cycles 9.6 µs
Auto zero time 8 CCLK cycles 3.2 µs
Aperture delay 36 CCLK cycles 12.8 µs
Small signal bandwidth 5 MHz
Step response 1 Complete Conversion Cycle
(1)
The specifications for the total system are overall analog input to digital output specifications. The specifications for internal functions indicate
the performance of the individual functions in the ADS7871.