ADA4941-1YRZ Analog Devices Inc, ADA4941-1YRZ Datasheet - Page 21

• Manufacturer Part Number: ADA4941-1YRZ
• Description: IC DIFF ADC DVR 18BIT 8-SOIC
• Manufacturer: Analog Devices Inc
• Type: ADC Driverr

Specifications of ADA4941-1YRZ

• Design Resources: Converting a Single-Ended Signal with AD7982 Differential PulSAR ADC (CN0032) Converting a Single-Ended Signal with AD7984 Differential PulSAR ADC (CN0033)
• Applications: Data Acquisition
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Number Of Channels: 1
• Number Of Elements: 2
• Power Supply Requirement: Single
• Common Mode Rejection Ratio: 84dB
• Voltage Gain Db: 6.06dB
• Unity Gain Bandwidth Product (typ): 31MHz
• Input Resistance: 24@5VMohm
• Input Offset Voltage: 0.4@5VmV
• Input Bias Current: 4.5@5VnA
• Single Supply Voltage (typ): 3/5/9V
• Dual Supply Voltage (typ): Not RequiredV
• Power Supply Rejection Ratio: 87dB
• Rail/rail I/o Type: Rail to Rail Output
• Single Supply Voltage (min): 2.7V
• Single Supply Voltage (max): 12V
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Operating Temp Range: -40C to 125C
• Operating Temperature Classification: Automotive
• Mounting: Surface Mount
• Pin Count: 8
• Package Type: SOIC N
• No. Of Amplifiers: 1
• Bandwidth: 31MHz
• Slew Rate: 22V/µs
• Supply Voltage Range: 2.7V To 12V
• Supply Current: 2.2mA
• Amplifier Case Style: SOIC
• No. Of Pins: 8
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ADDING A 3-POLE, SALLEN-KEY FILTER
The noninverting amplifier in the ADA4941-1 can be used as
the buffer amplifier of a Sallen-Key filter. A 3-pole, low-pass
filter can be designed to limit the signal bandwidth in front of
an ADC. The input signal first passes through the noninverting
stage where it is filtered. The filtered signal is then passed through
the inverting stage to obtain the complementary output.
562Ω
VIN
3.9nF
562Ω
Figure 54. Sallen-Key, Low-Pass Filter with 100 kHz Cutoff Frequency
10nF
Figure 55. Frequency Response of the Circuit Shown in Figure 54
–100
–10
–20
–30
–40
–50
–60
–70
–80
–90
562Ω
0
10
1.69kΩ
560pF
100
1
8
FB
IN
6
–5V
1k
Rev. B | Page 21 of 24
3
A1
V
V
+5V
S+
S–
FREQUENCY (Hz)
2
10k
REF
500Ω
1kΩ
100k
Figure 54 illustrates a 3-pole, Sallen-Key, low-pass filter with a
−3 dB cutoff frequency of 100 kHz. The 1.69 kΩ resistor is
included to minimize dc errors due to the input offset current
in A1. The passive RC filters on the outputs are generally
required by the ADC converter that is being driven. The
frequency response of the filter is shown in Figure 55.
1kΩ
A2
1M
V
O, dm
0.1µF
0.1µF
10M
= 3V p-p
OUT+
OUT–
100M
4
5
33Ω
33Ω
2.7nF
2.7nF
V
O, dm
+
–
ADA4941-1