Dual RF-Power Detector Delivers 80dB Dynamic Range at 900MHz
SUNNYVALE, CA-November 24, 2004-Maxim Integrated Products
(NASDAQ: MXIM) introduces the MAX2016, the industry's most precise monolithic solution for low-frequency-to-2.5GHz VSWR, gain, and power measurements. Designers can configure the MAX2016 as a simple RF-power detector and comparator, or as a complete closed-loop gain and power controller. The outstanding combination of precision, channel-to-channel isolation, and dynamic range makes this SiGe IC particularly useful in a variety of wireless applications, including dual-channel RF-power measurements, gain/loss detection, VSWR monitoring, load integrity detection, and automatic gain control (AGC). (See Addendum for detailed description of each application).
The MAX2016 uses a pair of temperature-tracking logarithmic amplifiers to detect and compare the power levels of two RF input signals. The device internally subtracts one power level from the other to provide a DC-output voltage that is proportional to the power difference (i.e. gain). The MAX2016 can also measure the return loss/VSWR of an RF signal by monitoring the incident and reflected power levels associated with any given load. A window detector is easily implemented by using the on-chip comparators, OR gate, and 2V reference. This combination of circuitry provides an automatic indication of when the measured gain is outside a programmable range. Alarm monitoring can thus be implemented for detecting high-VSWR states, such as open or shorted loads.
As an added feature, the MAX2016 can also be employed as a fully integrated AGC loop controller. Built-in circuitry allows the device to detect and maintain either gain or power within a closed-loop system. Comparable functionality in discrete form would require twice the component count and over three times more board space.
While maintaining log conformance of ±3dB over temperature, each detector on the MAX2016 can provide dynamic ranges of 80dB, 67dB, 64dB, and 52dB at 900MHz, 1900MHz, 2170MHz, and 2500MHz, respectively. The cornerstone, however, to the MAX2016's outstanding performance is the superior performance of its on-chip, RF comparator circuitry. At 900MHz, the comparator output delivers 70dB of dynamic range with ±1dB of precision over -20°C to +85°C. Measurements at 1900MHz, 2170MHz, and 2500MHz are equally impressive with dynamic ranges of 55dB, 50dB, and 45dB, respectively, over the same precision and temperature constraints. This is due, in part, to the MAX2016's excellent channel-to-channel isolation. Typical isolation values range from 90dB for the cellular band, 65dB for the PCS band, and 55dB for WLAN applications. The resulting performance greatly enhances the accuracy and range of any RF-power measurement.
The MAX2016 comes in a compact 5mm x 5mm, 28-pin thin QFN. Lead-free packaging is also available. Prices start at $9.85 (1000-up, FOB USA).
|
