AD7890ARZ-10 Analog Devices Inc, AD7890ARZ-10 Datasheet - Page 19

• Manufacturer Part Number: AD7890ARZ-10
• Description: IC DAS 12BIT 8CH 24-SOIC
• Manufacturer: Analog Devices Inc
• Type: Data Acquisition System (DAS)r

Specifications of AD7890ARZ-10

• Resolution (bits): 12 b
• Data Interface: Serial
• Sampling Rate (per Second): 117k
• Voltage Supply Source: Single Supply
• Voltage - Supply: ±10V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (7.5mm Width)
• Input Channel Type: Single Ended
• Supply Voltage Range - Analogue: 4.75V To 5.25V
• Supply Current: 10mA
• Digital Ic Case Style: MSOP
• No. Of Pins: 24
• Sampling Rate: 117kSPS
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Effective Number of Bits
The formula for Signal to (Noise + Distortion) Ratio (See Ter-
minology section) is related to the resolution or number of bits
in the converter. Rewriting the formula, below, gives a measure
of performance expressed in effective number of bits (N):
where SNR is Signal to (Noise + Distortion) Ratio
The effective number of bits for a device can be calculated
from its measured Signal to (Noise + Distortion) Ratio. Fig-
ure 21 shows a typical plot of effective number of bits versus
frequency for the AD7890-2 from dc to 40 kHz. The sampling
frequency is 102.4 kHz. The plot shows that the AD7890 con-
verts an input sine wave of 40 kHz to an effective numbers of
bits of 11 which equates to a Signal to (Noise + Distortion)
level of 68 dB.
N = (SNR — 1.76)/6.02
12.0
11.5
11.0
10.5
10.0
0
INPUT FREQUENCY – kHz
20
AD7890
40