ANALOG DEVICES ADL5513 Service Manual

ADL5513

I V

DET

DET DETDETDET

SLOPE

CONTROL

GAIN BIAS

BAND GAP

REFERENCE

13141516

8765

ADL5513

VOUT

VSET

COMM

TADJ

INHI

INLO

VPOS

NC NC CLPF NC

NC NC NC NC

07514-001

1 MHz to 4 GHz, 80 dB

FEATURES

Wide bandwidth: 1 MHz to 4 GHz 80 dB dynamic range (±3 dB) Constant dynamic range over frequency Stability over −40 Operating temperature range: −40 Sensitivity: −70 dBm Low noise measurement/controller output (VOUT) Pulse response time: 21 ns/20 ns (fall/rise) Single-supply operation: 2.7 V to 5.5 V @ 31 mA Power-down feature: 1 mW @ 5 V Small footprint LFCSP Fabricated using high speed SiGe process

APPLICATIONS

RF transmitter power amplifier linearization and gain/power

control Power monitoring in radio link transmitters RSSI measurement in base stations, WLAN, WiMAX, RADAR

C to +85oC temperature range: ±0.5 dB

C to +125oC

Logarithmic Detector/Controller

FUNCTIONAL BLOCK DIAGRAM

Figure 1.

GENERAL DESCRIPTION

The ADL5513 is a demodulating logarithmic amplifier, capable of accurately converting an RF input signal to a corresponding decibel-scaled output. It employs the progressive compression technique over a cascaded amplifier chain, each stage of which is equipped with a detector cell. The device can be used in either measurement or controller modes. The ADL5513 maintains accurate log conformance for signals up to 4 GHz. The input dynamic range is typically 80 dB (referred to 50 Ω) with error less than ±3 dB and 74 dB with error less than ±1 dB. The ADL5513 has 20 ns response time that enables RF burst detection to a pulse rate of beyond 50 MHz. The device provides unprecedented logarithmic intercept stability vs. ambient temperature conditions. A supply of 2.7 V to 5.5 V is required to power the device. Current consumption is 31 mA, and it decreases to 200 μA when the device is disabled.

The ADL5513 can be configured to provide a control voltage to a power amplifier or a measurement output from the VOUT pin. Because the output can be used for controller applications, special attention has been paid to minimize wideband noise. In this mode, the setpoint control voltage is applied to the VSET pin.

Rev. 0

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners.

The feedback loop through an RF amplifier is closed via VOUT, the output of which regulates the amplifier output to a magnitude corresponding to VSET. The ADL5513 provides 0 V to (V

− 0.1 V) output capability at the VOUT pin, suitable

POS

for controller applications. As a measurement device, VOUT is externally connected to VSET to produce an output voltage, V

, that increases linear-in-dB with RF input signal amplitude.

OUT

The logarithmic slope is 21 mV/dB, determined by the VSET interface. The intercept is −88 dBm (referred to 50 Ω, continuous wave input, 900 MHz) using the INHI input. These parameters are very stable against supply and temperature variations.

The ADL5513 is fabricated on a SiGe bipolar IC process and is available in a 3 mm × 3 mm, 16-lead LFCSP package for the

−40°C to +125°C operating temperature range. A fully populated evaluation board is available.

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