DC to 6 GHz

Envelope and TruPwr RMS Detector

Data Sheet

ADL5511

Rev. C

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FEATURES

Envelope tracking RF detector with output proportional to

input voltage

Separate TruPwr rms output

No balun or external tuning required

Excellent temperature stability

Input power dynamic range of 47 dB

Input frequency range from dc to 6 GHz

130 MHz envelope bandwidth

Envelope delay: 2 ns

Single-supply operation: 4.75 V to 5.25 V

Supply current: 21.5 mA

Power-down mode: 130 µW

APPLICATIONS

RMS power and envelope detection of W-CDMA, CDMA2000,

LTE, and other complex waveforms

Drain modulation based power amplifier linearization

Power amplifier linearization employing envelope-tracking

methods

FUNCTIONAL BLOCK DIAGRAM

Figure 1.

Figure 2. RMS and Envelope Response to a 20 MHz QPSK-Based LTE Carrier

(Test Model E-TM1_1_20MHz)

GENERAL DESCRIPTION

The ADL5511 is an RF envelope and TruPwr™ rms detector.

The envelope output voltage is presented as a voltage that is

proportional to the envelope of the input signal. The rms

output voltage is independent of the peak-to-average ratio

of the input signal.

The rms output is a linear-in-V/V voltage with a conversion

gain of 1.9 V/V rms at 900 MHz. The envelope output has a

conversion gain of 1.46 V/V at 900 MHz and is referenced to

an internal 1.1 V reference voltage, which is available on the

EREF pin.

The ADL5511 can operate from dc to 6 GHz on signals with

envelope bandwidths up to 130 MHz.

The extracted envelope can be used for RF power amplifier

(PA) linearization and efficiency enhancements and the rms

output can be used for rms power measurement. The high rms

accuracy and fast envelope response are particularly useful for

envelope detection and power measurement of broadband, high

peak-to-average signals that are used in CDMA2000, W-CDMA,

and LTE systems.

The ADL5511 operates from −40°C to +85°C and is available in

a 16-lead, 3 mm × 3 mm LFCSP package.

RFIN

ENBL

RMS

400Ω

20pF

ENVELOPE

VRMS

VENV

EREF

VPOS

VPOS

VPOS

400Ω

FLT1

FLT2

FLT3

COMM

FLT4

0.8pF

0.4pF

10kΩ

5pF

250Ω

250Ω

100

Ω

ADL5511

BIAS AND POWER-

DOWN CONTROL

G = 1.7

G = 1.5

NC

15

14

4

2

3

11

10

9

13

6

7

8

12

16

1

5

T

–68ns

CH1 200mV Ω CH2 30.8mV Ω M 100ns

A CH4

1.60V

CH3 200mV

CH4

234mV Ω

CH1 HIGH

20mV

VRMS

VENV

RF INPUT