Datasheet

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ELECTRICAL CHARACTERISTICS
ADS7864
SBAS141A – SEPTEMBER 2000 – REVISED MARCH 2005
All specifications T
MIN
to T
MAX
, +V
A
= +V
D
= +5V, V
REF
= internal +2.5V and f
CLK
= 8MHz, f
SAMPLE
= 500kHz (unless otherwise
noted).
ADS7864Y ADS7864YB
PARAMETER TEST CONDITIONS UNIT
MIN TYP MAX MIN TYP MAX
Resolution 12 12 Bits
Analog Input
Input Voltage Range-Bipolar V
CENTER
= +2.5V –V
REF
+V
REF
–V
REF
+V
REF
V
Absolute Input Range +IN –0.3 +V
A
+ 0.3 V
–IN –0.3 +V
A
+ 0.3 V
Input Capacitance 15 15 pF
Input Leakage Current CLK = GND ±1 ±1 µA
System Performance
No Missing Codes 12 12 Bits
Integral Linearity ±0.75 2 ±0.5 ±1 LSB
Integral Linearity Match 0.5 0.5 LSB
Differential Linearity –0.9 ±0.6 –0.9 ±0.4 LSB
Bipolar Offset Error Referenced to REF
IN
±0.75 ±4 ±0.5 ±3 LSB
Bipolar Offset Error Match 3 3 LSB
Positive Gain Error Referenced to REF
IN
±0.15 ±0.75 ±0.1 ±0.5 % of FSR
Positive Gain Error Match 3 3 LSB
Negative Gain Error Referenced to REF
IN
±0.15 ±0.75 ±0.1 ±0.5 % of FSR
Negative Gain Error Match 3 3 LSB
Common-Mode Rejection Ratio At DC 84 84 dB
V
IN
= ±1.25V
PP
at 50kHz 80 80 dB
Noise 120 120 µV
RMS
Power Supply Rejection Ratio 0.3 2 0.3 2 LSB
Sampling Dynamics
Conversion Time per A/D 1.75 1.75 µs
Acquisition Time 0.25 0.25 µs
Throughput Rate 500 500 kHz
Aperture Delay 3.5 3.5 ns
Aperture Delay Matching 100 100 ps
Aperture Jitter 50 50 ps
Small-Signal Bandwidth 40 40 MHz
Dynamic Characteristics
Total Harmonic Distortion V
IN
= ±2.5V
PP
at 100kHz –75 –75 dB
SINAD V
IN
= ±2.5V
PP
at 100kHz 71 71 dB
Spurious Free Dynamic Range V
IN
= ±2.5V
PP
at 100kHz 78 78 dB
Channel-to-Channel Isolation V
IN
= ±2.5V
PP
at 50kHz –76 –76 dB
Voltage Reference
Internal Reference Voltage 2.475 2.5 2.525 2.475 2.5 2.525 V
Internal Drift 10 10 ppm/°C
Internal Noise 50 50 µV
PP
Internal Source Current 2 2 mA
Internal Load Rejection 0.005 0.005 mV/µA
Internal PSRR 80 80 dB
External Reference Voltage Range 1.2 2.5 2.6 1.2 2.5 2.6 V
Input Current 100 100 µA
Input Capacitance 5 5 pF
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