Datasheet

AD7870/AD7875/AD7876
Rev. C | Page 3 of 28
SPECIFICATIONS
V
DD
= +5 V ± 5%, V
SS
= −5 V ± 5%, AGND = DGND = 0 V, f
CLK
= 2.5 MHz external, unless otherwise stated. All Specifications T
min
to
T
max
, unless otherwise noted.
AD7870 SPECIFICATIONS
Table 1.
ADN7870
1
Parameter J, A K, B L, C T Units Test Conditions/Comments
DYNAMIC PERFORMANCE
2
Signal-to-Noise Ratio
3
(SNR)
@ +25°C 70 70 72 69 dB min V
IN
= 10 kHz sine wave, f
SAMPLE
= 100 kHz
T
MIN
to T
MAX
70 70 71 69 dB min Typically 71.5 dB for 0 < V
IN
< 50 kHz
Total Harmonic Distortion (THD) −80 −80 −80 −78 dB max
V
IN
= 10 kHz sine wave, f
SAMPLE
= 100 kHz
Typically −86 dB for 0 < V
IN
< 50 kHz
Peak Harmonic or Spurious Noise −80 −80 −80 −78 dB max
V
IN
= 10 kHz, f
SAMPLE
= 100 kHz
Typically −86 dB for 0 < V
IN
< 50 kHz
Intermodulation Distortion (IMD)
Second Order Terms −80 −80 −80 −78 dB max fa = 9 kHz, fb = 9.5 kHz, f
SAMPLE
= 50 kHz
Third Order Terms −80 −80 −80 −78 dB max fa = 9 kHz, fb = 9.5 kHz, f
SAMPLE
= 50 kHz
Track-and-Hold Acquisition Time 2 2 2 2 μs max
DC ACCURACY
Resolution 12 12 12 12 Bits
Minimum Resolution for which No Missing Codes
are Guaranteed
12 12 12 12 Bits
Integral Nonlinearity ±1/2 ±1/2 ±1/4 ±1/2 LSB typ
Integral Nonlinearity ±1 ±1/2 ±1 LSB max
Differential Nonlinearity ±1 ±1 ±1 LSB max
Bipolar Zero Error ±5 ±5 ±5 ±5 LSB max
Positive Full-Scale Error
4
±5 ±5 ±5 ±5 LSB max
Negative Full-Scale Error
4
±5 ±5 ±5 ±5 LSB max
ANALOG INPUT
Input Voltage Range ±3 ±3 ±3 ±3 V
Input Current ±500 ±500 ±500 ±500 μA max
REFERENCE OUTPUT
REF OUT @ +25°C 2.99 2.99 2.99 2.99 V min
3.01 3.01 3.01 3.01 V max
REF OUT Tempco ±60 ±60 ±35 ±35
ppm/°C
max
Reference Load Sensitivity
(ΔREF OUT/ΔI)
±1 ±1 ±1 ±1 mV max
Reference load current change (0 μA to
500 μA). Reference load should not be
changed during conversion.
LOGIC INPUTS
Input High Voltage, V
INH
2.4 2.4 2.4 2.4 V min V
DD
= 5 V ± 5%
Input Low Voltage, V
INL
0.8 0.8 0.8 0.8 V max V
DD
= 5 V ± 5%
Input Current, I
IN
±10 ±10 ±10 ±10 μA max V
IN
= 0 V to V
DD
Input Current (12/8/CLK Input Only)
±10 ±10 ±10 ±10 μA max V
IN
= V
SS
to V
DD
Input Capacitance, C
IN
5
10 10 10 10 pF max
LOGIC OUTPUTS
Output High Voltage, V
OH
4.0 4.0 4.0 4.0 V min I
SOURCE
= 40 μA
Output Low Voltage, V
OL
0.4 0.4 0.4 0.4 V max I
SINK
= 1.6 mA
DB11 to DB0
Floating-State Leakage Current ±10 ±10 ±10 ±10 μA max
Floating-State Output Capacitance
5
15 15 15 15 pF max