1 MHz to 4 GHz, 80 dB
Logarithmic Detector/Controller
ADL5513
FEATURES
Wide bandwidth: 1 MHz to 4 GHz
80 dB dynamic range (±3 dB)
Constant dynamic range over frequency
Stability over −40
o
C to +85
o
C temperature range: ±0.5 dB
Operating temperature range: −40
o
C to +125
o
C
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
FUNCTIONAL BLOCK DIAGRAM
NC
16
NC
15
CLPF
14
NC
13
DET
VPOS
1
INHI
2
DET
DET
DET
DET
I
V
12
VOUT
I
INLO
3
V
11
VSET
ADL5513
VPOS
4
SLOPE
CONTROL
5
6
10
COMM
BAND GAP
REFERENCE
7
GAIN
BIAS
8
9
TADJ
07514-001
NC
NC
NC
NC
Figure 1.
APPLICATIONS
RF transmitter power amplifier linearization and gain/power
control
Power monitoring in radio link transmitters
RSSI measurement in base stations, WLAN, WiMAX, RADAR
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.
The feedback loop through an RF amplifier is closed via VOUT,
the output of which regulates the amplifier output to a magni-
tude corresponding to VSET. The ADL5513 provides 0 V to
(V
POS
− 0.1 V) output capability at the VOUT pin, suitable
for controller applications. As a measurement device, VOUT
is externally connected to VSET to produce an output voltage,
V
OUT
, that increases linear-in-dB with RF input signal amplitude.
The logarithmic slope is 21 mV/dB, determined by the VSET
interface. The intercept is −88 dBm (referred to 50 Ω, conti-
nuous 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.
Rev. 0
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