AD8313ARMZ

Product Summary

The AD8313ARMZ is a complete multistage demodulating logarithmic amplifier that can accurately convert an RF signal at its differ-ential input to an equivalent decibel-scaled value at its dc output. The AD8313ARMZ maintains a high degree of log conformance for signal frequencies from 0.1 GHz to 2.5 GHz and is useful over the range of 10 MHz to 3.5 GHz. The nominal input dynamic range is -65 dBm to 0 dBm (re: 50 Ω), and the sensitivity can be increased by 6 dB or more with a narrow-band input impedance matching network or a balun. Application is straightforward, requiring only a single supply of 2.7 V to 5.5 V and the addition of a suitable input and supply decoupling. The AD8313ARMZ uses a cascade of eight amplifier/limiter cells, each having a nominal gain of 8 dB and a -3 dB bandwidth of 3.5 GHz. This produces a total midband gain of 64 dB. At each amplifier output, a detector (rectifier) cell is used to convert the RF signal to baseband form; a ninth detector cell is placed directly at the input of the AD8313ARMZ. The current-mode outputs of these cells are summed to generate a piecewise linear approxi-mation to the logarithmic function. They are converted to a low impedance voltage-mode output by a transresistance stage, which also acts as a low-pass filter.

Parametrics

AD8313ARMZ absolute maximum ratings: (1)Supply Voltage VS: 5.5 V; (2)VOUT, VSET, PWDN: 0 V, VPOS; (3)Input Power Differential (re: 50 Ω, 5.5 V): 25 dBm ; (4)Input Power Single-Ended (re: 50 Ω, 5.5 V): 19 dBm; (5)Internal Power Dissipation: 200 mW ; (6)Maximum Junction Temperature: 125℃; (7)Operating Temperature Range: -40℃ to +85℃; (8)Storage Temperature Range: -65℃ to +150℃.

Features

AD8313ARMZ features: (1)Wide bandwidth: 0.1 GHz to 2.5 GHz min; (2)High dynamic range: 70 dB to ±3.0 dB; (3)High accuracy: ±1.0 dB over 65 dB range (@ 1.9 GHz); (4)Fast response: 40 ns full-scale typical; (5)Controller mode with error output; (6)Scaling stable over supply and temperature; (7)Wide supply range: 2.7 V to 5.5 V; (8)Low power: 40 mW at 3 V; (9)Power-down feature: 60 mW at 3 V; (10)Complete and easy to use.

Diagrams