Data Sheet

AD8313

0.1 GHz to 2.5 GHz 70 dB Logarithmic Detector/Controller

Rev. F

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FEATURES

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Wide bandwidth: 0.1 GHz to 2.5 GHz min

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High dynamic range: 70 dB to ±3.0 dB

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High accuracy: ±1.0 dB over 65 dB range (@ 1.9 GHz)

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Fast response: 40 ns full-scale typical

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Controller mode with error output

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Scaling stable over supply and temperature

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Wide supply range: 2.7 V to 5.5 V

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Low power: 40 mW at 3 V

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Power-down feature: 60 mW at 3 V

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Complete and easy to use

APPLICATIONS

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RF transmitter power amplifier setpoint control and level monitor-

ing

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Logarithmic amplifier for RSSI measurement cellular base sta-

tions, radio link, radar

FUNCTIONAL BLOCK DIAGRAM

Figure 1.

GENERAL DESCRIPTION

The AD8313 is a complete multistage demodulating logarithmic

amplifier that can accurately convert an RF signal at its input to

an equivalent decibel-scaled value at its dc output. The AD8313

maintains a high degree of log conformance for signal frequencies

from 0.1 GHz to 2.5 GHz. 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. Operating on a 3 V supply, its 13.7 mA

consumption (for TA = 25°C) is only 41 mW. A power-down feature

is provided; the input is taken high to initiate a low current (20 µA)

sleep mode, with a threshold at half the supply voltage.

The AD8313 is fabricated on Analog Devices, Inc., advanced 25

GHz silicon bipolar IC process and is available in an 8-lead MSOP

package. The operating temperature range is −40°C to +85°C.

Table 1. Next Generation Upgrades for AD8313

Part Number

Comments

ADL5513

Improved range and temperature stability, operation up to 4 GHz

AD8318

Improved temperature stability, operation up to 8 GHz

AD8317

Lower input range, improved temperature stability, operation up

to 10 GHz

AD8319

Lower input range, improved temperature stability, operation up

to 10 GHz

Figure 2. Typical Logarithmic Response and Error vs. Input Amplitude