AD8629 Analog Devices, AD8629 Datasheet - Page 17

• Manufacturer Part Number: AD8629
• Description: Zero Drift, Single-Supply, R/R, Input/Output Operational Amplifier
• Manufacturer: Analog Devices

Specifications of AD8629

• -3db Bandwidth: 2.5MHz
• Slew Rate: 1V/µs
• Vos: 1µV
• Ib: 30pA
• # Opamps Per Pkg: 2
• Input Noise (nv/rthz): 22nV/rtHz
• Vcc-vee: 2.7V to 6V
• Isy Per Amplifier: 1.1mA
• Packages: SOIC,SOP

V
V
V
Figure 60. Negative Input Overload Recovery for Competitor A
Figure 61. Negative Input Overload Recovery for Competitor B
Figure 59. Negative Input Overload Recovery for the AD8628
OUT
OUT
OUT
V
V
V
0V
0V
0V
0V
0V
0V
IN
IN
IN
TIME (500µs/DIV)
TIME (500µs/DIV)
TIME (500µs/DIV)
CH1 = 50mV/DIV
CH2 = 1V/DIV
A
CH1 = 50mV/DIV
CH2 = 1V/DIV
A
CH1 = 50mV/DIV
CH2 = 1V/DIV
A
V
V
V
= –50
= –50
= –50
Rev. I | Page 17 of 24
The results shown in Figure 56 to Figure 61 are summarized in
Table 5.
Table 5. Overload Recovery Time
Model
AD8628
Competitor A
Competitor B
INFRARED SENSORS
Infrared (IR) sensors, particularly thermopiles, are increasingly
being used in temperature measurement for applications as wide
ranging as automotive climate control, human ear thermometers,
home insulation analysis, and automotive repair diagnostics.
The relatively small output signal of the sensor demands high
gain with very low offset voltage and drift to avoid dc errors.
If interstage ac coupling is used, as in Figure 62, low offset and
drift prevent the output of the input amplifier from drifting close to
saturation. The low input bias currents generate minimal errors
from the output impedance of the sensor. As with pressure sensors,
the very low amplifier drift with time and temperature eliminate
additional errors once the temperature measurement is calibrated.
The low 1/f noise improves SNR for dc measurements taken
over periods often exceeding one-fifth of a second.
Figure 62 shows a circuit that can amplify ac signals from 100 μV to
300 μV up to the 1 V to 3 V levels, with a gain of 10,000 for
accurate analog-to-digital conversion.
DETECTOR
100µV TO 300µV
Figure 62. AD8629 Used as Preamplifier for Thermopile
IR
100Ω
Positive Overload
Recovery (μs)
6
650
40,000
AD8628/AD8629/AD8630
100kΩ
5V
1/2 AD8629
f
C
≈ 1.6Hz
10µF
10kΩ
VOLTAGE
10kΩ
TO BIAS
Negative Overload
Recovery (μs)
9
25,000
35,000
100kΩ
5V
1/2 AD8629