The AD637 is a complete high accuracy monolithic rms-to-dc converter that computes the true rms value of any complex waveform. It offers performance that is unprecedented in integrated circuit rms-to-dc converters and comparable to discrete and modular techniques in accuracy, bandwidth and dynamic range. A crest factor compensation scheme in the AD637 permits measurements of signals with crest factors of up to 10 with less than 1% additional error. The circuit's wide bandwidth permits the measurement of signals up to 600 kHz with inputs of 200 mV rms and up to 8 MHz when the input levels are above 1 V rms.
As with previous monolithic rms converters from Analog Devices, the AD637 has an auxiliary dB output available to the user. The logarithm of the rms output signal is brought out to a separate pin allowing direct dB measurement with a useful range of 60 dB. An externally programmed reference current allows the
user to select the 0 dB reference voltage to correspond to any level between 0.1 V and 2.0 V rms.
A chip select connection on the AD637 permits the user to decrease the supply current from 2.2 mA to 350 µA during periods when the rms function is not in use. This feature facilitates the addition of precision rms measurement to remote or hand-held applications where minimum power consumption is
critical. In addition when the AD637 is powered down the out-put goes to a high impedance state. This allows several AD637s to be tied together to form a wide-band true rms multiplexer.
|
|
High Accuracy 0.02% Max Nonlinearity, 0 V to 2 V RMS Input 0.10% Additional Error to Crest Factor of 3Wide Bandwidth 8MHz at 2 V RMS Input 600 kHz at 100 mV RMSComputes: True RMSSquare Mean Square Absolute ValuedB Output (60 dB Range)Chip Select-Power Down Feature Allows: Analog "3-State" Operation Quiescent Current Reduction from 2.2mA to 350 mASide-Brazed DIP, Low Cost Cerdip and SOIC
|
ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500 V
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±18 V dc
Internal Quiescent Power Dissipation . . . . . . . . . . . . 108 mW
Output Short-Circuit Duration . . . . . . . . . . . . . . . . . Indefinite
Storage Temperature Range . . . . . . . . . . . . 65°C to +150°C
Lead Temperature Range (Soldering 10 secs) . . . . . . . +300°C
Rated Operating Temperature Range
AD637J, K . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C
AD637A, B . . . . . . . . . . . . . . . . . . . . . . . . 40°C to +85°C
AD637S, 5962-8963701CA . . . . . . . . . . . 55°C to +125°C
Post a Buying Lead
Required Field 
