ADSP-21990 View Datasheet(PDF) - Analog Devices
Part Name
Description
MFG CO.
'ADSP-21990' PDF : 50 Pages View PDF
ADSP-21990
PERIPHERALS ELECTRICAL CHARACTERISTICS—ADSP-21990BST
Parameter
Description
Min
Typ
Max
Unit
ANALOG-TO-DIGITAL CONVERTER
SNR
SNRD
THD
CTLK
CMRR
PSRR
Signal-to-Noise Ratio1
Signal-to-Noise and Distortion1
Total Harmonic Distortion1
Channel-Channel Crosstalk1
Common-Mode Rejection Ratio1
Power Supply Rejection Ratio1
68
72
68
71
–80
–68
–78
–66
–74
–66
0.05
0.2
dB
dB
dB
dB
dB
%FSR
Accuracy
INL
DNL
Integral Nonlinearity1
Differential Nonlinearity1
±0.6
±2.0
LSB
±0.5
±1.25
LSB
No Missing Codes
Zero Error1
Gain Error1
12
1.25
2.5
0.5
1.5
Bits
%FSR
%FSR
Input Voltage
VIN
CIN
Conversion Time
Input Voltage Span
Input Capacitance2
2.0
V
10
pF
FCLK
ADC Clock Rate
20
MHz
tCONV
Total Conversion Time All 8 Channels
725
ns
VOLTAGE REFERENCE
Internal Voltage Reference3
0.94
0.98
1.02
V
Output Voltage Tolerance
40
mV
Output Current
Load Regulation4
100
μA
–2
+0.5
+2
mV
Power Supply Rejection Ratio
–2
+0.5
+2
mV
Reference Input Resistance
8
kΩ
POWER-ON-RESET
VRST
Reset Threshold Voltage
1.4
2.1
V
VHYST
Hysteresis Voltage
50
mV
1 In all cases, the input frequency to the ADC system is assumed to be <100 kHz.
2 Analog input pins VIN0 to VIN7.
3 These specifications are for operation of the internal voltage reference so that SENSE = REFCOM, with the default 1.0 V operating mode.
4 Operation with full 0.1 mA load current. For optimal operation, it is recommended to buffer the VREF output voltage before using it in other parts of the system.
Rev. A | Page 23 of 50 | August 2007
Share Link: 
