Features

• Frequency Range: 40MHz to 6GHz
• Linear Dynamic Range: Up to 60dB
• ±0.5dB (Typ) Accuracy Over Temperature
• 40dB Channel-to-Channel Isolation at 2GHz Even with Single-Ended RF Inputs
• Matched Dual-Channel Outputs: <1.25dB (Typ)
• Single-Ended RF Inputs—No Transformer Required
• Accurate RMS Power Measurement of High Crest Factor Modulated Waveforms
• Difference Output Provides VSWR Measurement
• Fast Envelope Detector Outputs
• Fast Response Time: 140ns Rise Time
• Small 4mm × 4mm QFN24 Package

Typical Application

Description

The LTC5583 is a dual-channel RMS power detector, capable of measuring two AC signals with wide dynamic range, from –59dBm to 4dBm, depending on frequency. Each AC signal’s power in decibel-scaled value is precisely converted to a DC voltage on a linear scale, independent of the crest factor of the input signal waveforms. The LTC5583 is suitable for precision power measurement and level control for a variety of RF standards, including LTE, EDGE, W-CDMA, CDMA2000, TD-SCDMA, and WiMAX.

Good channel-to-channel isolation is necessary for operating the dual channels simultaneously. For applications where the two input signals are at the same frequency (e.g. measuring VSWR), the LTC5583 provides 40dB isolation at 2.14GHz even with single-ended inputs. No baluns are needed. When the two input signals are at different frequencies, the isolation can be as high as 50dB. The isolation can be improved to >55dB with differential inputs.

The power difference of the two input signals is provided at a difference output pin. Each channel also has a fast envelope detector, which tracks the RF input signal’s envelope and outputs a voltage directly proportional to the signal’s instantaneous power. The envelope detectors can be disabled to reduce power consumption.