Ultrafast 15 GHz RF Detector with Fast Comparator Withstands 125°C Environments

LTC5564HLinear Technology has introduced a high temperature grade RF Schottky peak power detector that operates from 600MHz to 15GHz, and has ultrafast detection response time of 7ns from a pulsed RF signal.

The LTC5564H, has an on-chip fast latchable comparator with a total detection and propagation delay of 9ns. Its fast response times enable many new RF and microwave applications that other slower devices are not capable of supporting. For example, the device can detect desired signals such as a fast radar pulse, accurately regulate RF power amplifier power levels, and support envelope tracking and spectrum analysis. Also, the device can detect undesired signals such as RF PA overdrive, fault conditions and radio signals used to activate jammers. The device’s high temperature capability extends its usability and survivability in applications required for operation in harsh environments such as in high power PA amplifiers that typically run inefficiently and hot in cellular towers, automobile engines, aircraft and wireless infrastructure equipment exposed to extreme temperatures.

The detector accurately measures RF input signal levels from -24dBm to 16dBm. The device has a programmable gain output amplifier with four gain settings that are digitally controlled with two binary-weighed logic input pins. This ensures improved sensitivity when measuring low level signals. Also, the output amplifier has bandwidth capable of demodulating the envelope of an RF modulated signal up to 75MHz.

The fast on-chip comparator threshold voltage is user-settable, enabling a flexible trip point to detect specific RF power levels. Its output can be latched by asserting a latch-enable input, permitting fast capture of a short-duration, single-event signal or a fault condition. Best-in-class performance enables unprecedented speed in timing measurements, rapid response to fault detection and RF power measurements in RF/PA and microwave systems in harsh operating environments.

The LTC5564H can be powered from a single 3.3V or 5V supply. Normal operation draws a current of 44mA. The H-grade device is rated for case operating temperature from -40°C to 125°C and is 100% tested over temperature. It is available in a small3mm x 3mm 16-pin QFN package. The detector is now available in production quantities at $3.44 each in 1000-pieces quantities.