Linear Technology has released the LT5538, a monolithic broadband, logarithmic RF power detector that covers the 800-900MHz and 1.7-2.2GHz cellular bands, as well as the 2.6GHz and 3.5GHz WiMAX bands. The LT5538 RF power detector provides a DC output voltage that is log-linearly proportional to its input power level. Within its measurement dynamic range, the detector exhibits accuracy and linearity of ±0.8dB over its rated operating temperature range of -40 to +85°C. Optimized for sensitivity, the LT5538 can detect signals from -75dBm to +10dBm at 2.14GHz. The device operates with a single-ended RF input and requires no external RF transformer.
The LT5538 is well suited for RF power amplifier power control and monitoring for a wide range of wireless systems, as well as receiver AGC (Automatic Gain Control), and RSSI (Receive Signal Strength Indicator) functions.
The LT5538 features output response of 100ns rise time and 200ns fall time. It operates over a voltage range of 3V to 5.25V, drawing a quiescent supply current of 29mA. A shutdown feature is provided. When the chip is disabled with a logic LOW applied to its ENABLE input pin, the chip draws a typical shutdown current of 1μA, and a maximum of 100μA. The device comes in an 8-lead, 3mm x 3mm DFN surface mount package. Pricing starts at $4.50 each in 1,000-piece quantities. The LT5538 is available immediately from stock.