REV. B
–2–
AD7724–SPECIFICATIONS
1
(AVDD = 5 V ⴞ 5%; DVDD = 5 V ⴞ 5%, DVDD1 = 3 V ⴞ 5%; AGND = DGND = 0 V,
f
MCLK
= 13 MHz ac-coupled sine wave, REF2A = REF2B = 2.5 V; T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
Parameter A Version Unit Test Conditions/Comments
STATIC PERFORMANCE When Tested with Ideal FIR Filter as in Figure 1
Integral Nonlinearity ±0.003 % FSR typ
Offset Error ±0.24 % FSR typ
Gain Error
2
±0.6 % FSR typ
Offset Error Drift ±37.69 µV/°C typ
Gain Error Drift REF2 Is an Ideal Reference, REF1 = AGND
Unipolar Mode ±37.69 µV/°C typ
Bipolar Mode ±18.85 µV/°C typ
ANALOG INPUTS
Signal Input Span (VIN(+) – VIN(–))
Bipolar Mode ±V
REF2
/2 V max BIP = V
IH
Unipolar Mode 0 to V
REF2
V max BIP = V
IL
Maximum Input Voltage AVDD V
Minimum Input Voltage 0 V
Input Sampling Capacitance 2 pF typ
Input Sampling Rate 2 f
MCLK
MHz
Differential Input Impedance 10
9
/(8 f
MCLK
)kΩ typ
REFERENCE INPUTS
REF1 Output Voltage 2.32 to 2.68 V min/max
REF1 Output Voltage Drift 60 ppm/°C typ
REF1 Output Impedance 4 kΩ typ
Reference Buffer Offset Voltage ±12 mV max Offset Between REF1 and REF2
Using Internal Reference
REF2 Output Voltage 2.32 to 2.68 V min/max
REF2 Output Voltage Drift 60 ppm/°C typ
Using External Reference REF1 = AGND
REF2 Input Impedance 10
9
/(16 f
MCLK
)kΩ typ
External Reference Voltage Range 2.32 to 2.68 V min/max Applied to REF1 or REF2
DYNAMIC SPECIFICATIONS
3
When Tested with Ideal FIR Filter as in Figure 1
Bipolar Mode BIP = V
IH
, V
CM
= 2.5 V, VIN(+) = VIN(–) = 1.25 V p-p
or VIN(–) = 1.25 V, VIN(+) = 0 V to 2.5 V
Signal-to-(Noise + Distortion) 90 dB typ Input BW = 0 kHz–94.25 kHz
86 dB min
Total Harmonic Distortion –90 dB max Input BW = 0 kHz–94.25 kHz
Spurious Free Dynamic Range –90 dB max Input BW = 0 kHz–94.25 kHz
Unipolar Mode BIP = V
IL
, VIN(–) = 0 V, VIN(+) = 0 V to 2.5 V
Signal-to-(Noise + Distortion) 88 dB typ Input BW = 0 kHz–94.25 kHz
Total Harmonic Distortion –90 dB typ Input BW = 0 kHz–101.556 kHz
Spurious Free Dynamic Range –90 dB typ Input BW = 0 kHz–101.556 kHz
Intermodulation Distortion –93 dB typ
AC CMRR 96 dB typ VIN(+) = VIN(–) = 2.5 V p-p, V
CM
= 1.25 V to
3.75 V, 20 kHz
CLOCK
Square Wave
4
MCLK Duty Ratio 45 to 55 % max For Specified Operation
V
MCLKH
, MCLK High Voltage 4 V min MCLK Uses CMOS Logic
V
MCLKL
, MCLK Low Voltage 0.4 V max
Sine Wave
XTAL1 Voltage Swing 0.4 V p-p min XTAL_OFF Tied Low
4 V p-p max
LOGIC INPUTS
V
IH
, Input High Voltage 2.4 V min
V
IL
, Input Low Voltage 0.8 V max
I
INH
, Input Current 10 µA max
C
IN
, Input Capacitance 10 pF max
