Datasheet AD743 (Analog Devices)

Ultralow Noise BiFET Op Amp AD743 FEATURES CONNECTION DIAGRAMS Ultralow Noise Performance 8-Lead PDIP (N) 16-Lead SOIC (R) 2.9 nV/
√
Hz at 10 kHz 0.38
␮
V p-p, 0.1 Hz to 10 Hz 6.9 fA/
√
Hz Current Noise at 1 kHz NULL 1 AD743 8 NC NC 1 8 16 NC OFFSET AD743 –IN +V 2 Excellent DC Performance 2 7 S 15 NC NULL 0.5 mV Max Offset Voltage +IN 3 6 OUT –IN 3 14 NC 250 pA Max Input Bias Current –VS 4 5 NULL NC 4 +V 13 S 1000 V/mV Min Open-Loop Gain TOP VIEW +IN 5 12 OUTPUT AC Performance NC = NO CONNECT OFFSET –VS 6 11 2.8 V/
␮
s Slew Rate NULL 4.5 MHz Unity-Gain Bandwidth NC 7 10 NC THD = 0.0003% @ 1 kHz TOP VIEW NC 8 9 NC Available in Tape and Reel in Accordance with EIA-481A Standard NC = NO CONNECT APPLICATIONS Sonar Preamplifiers High Dynamic Range Filters (>140 dB) Photodiode and IR Detector Amplifiers
2. The combination of low voltage and low current noise make
Accelerometers
the AD743 ideal for charge sensitive applications such as accelerometers and hydrophones. 3. The low input offset voltage and low noise level of the AD743
GENERAL DESCRIPTION
provide >140 dB dynamic range. The AD743 is an ultralow noise, precision, FET input, monolithic 4. The typical 10 kHz noise level of 2.9 nV/√Hz permits a three operational amplifier. It offers a combination of the ultralow volt- op amp instrumentation amplifier, using three AD743s, to be age noise generally associated with bipolar input op amps and built which exhibits less than 4.2 nV/√Hz noise at 10 kHz the very low input current of a FET input device. Furthermore, and which has low input bias currents. the AD743 does not exhibit an output phase reversal when the negative common-mode voltage limit is exceeded.
1000
The AD743’s guaranteed, maximum input voltage noise of
R OP27 AND SOURCE RESISTOR
4.0 nV/√Hz at 10 kHz is unsurpassed for a FET input mono-
E ( — ) O
lithic op amp, as is the maximum 1.0 µV p-p, 0.1 Hz to 10 Hz
z) H
noise. The AD743 also has excellent dc performance with 250 pA
/ R 100 SOURCE
maximum input bias current and 0.5 mV maximum offset voltage.
(nV E IS
The AD743 is specifically designed for use as a preamp in capaci-
O AD743 AND RESISTOR N AD743 AND OR
tive sensors, such as ceramic hydrophones. The AD743J is rated
E RESISTOR G OP27 AND RESISTOR ( )
over the commercial temperature range of 0°C to 70°C.
LTA O 10
The AD743 is available in a 16-lead SOIC and 8-lead PDIP.
T V U P IN PRODUCT HIGHLIGHTS RESISTOR NOISE ONLY
1. The low offset voltage and low input offset voltage drift of the
(– – –)
AD743 coupled with its ultralow noise performance mean
1
that the AD743 can be used for upgrading many applications
100 1k 10k 100k 1M 10M
now using bipolar amplifiers.
SOURCE RESISTANCE (
⍀
)
Figure 1. Input Voltage Noise vs. Source Resistance REV. E Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. No license is granted by implication or otherwise
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Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION PRODUCT HIGHLIGHTS CONNECTION DIAGRAMS SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD SUSCEPTIBILITY ORDERING GUIDE Typical Performance Characteristics OP AMP PERFORMANCE: JFET VS. BIPOLAR DESIGNING CIRCUITS FOR LOW NOISE LOW NOISE CHARGE AMPLIFIERS HOW CHIP PACKAGE TYPE AND POWER DISSIPATION AFFECT INPUT BIAS CURRENT REDUCED POWER SUPPLY OPERATION FOR LOWER IB AN INPUT IMPEDANCE COMPENSATED, SALLEN-KEY FILTER TWO HIGH PERFORMANCE ACCELEROMETER AMPLIFIERS LOW NOISE HYDROPHONE AMPLIFIER BALANCING SOURCE IMPEDANCES OUTLINE DIMENSIONS Revision History