LT5537_15 Datasheet, PDF (1/16 Pages) Linear Technology – Wide Dynamic Range RF/IF Log Detector

FEATURES
■ _{Low Frequency to 1000MHz Operation}
■ _{83dB Dynamic Range with ±1dB Nonlinearity}
at 200MHz
■ _{Sensitivity –76dBm or Better at 200MHz}
■ _{Log-Linear Transfer Slope of 20mV/dB}
■ _{Supply Voltage Range: 2.7V to 5.25V}
■ _{Supply Current: 13.5mA at 3V}
■ _{Tiny 8-Lead (3mm × 2mm) DFN Package}
U
APPLICATIO S
■ _{Linear-to-Log Signal Level Conversion}
■ _{Received Signal Strength Indication (RSSI)}
■ _{RF Power Control}
■ _{RF/IF Power Detection}
■ _{Receiver RF/IF Gain Control}
■ _{Envelope Detection}
■ _{ASK Receiver}
TYPICAL APPLICATIO
7k
7k
RF IN
15nF
IN⁺
2
15nF
IN^–
3
OPTIONAL
4
CAP⁺
5
CAP^–
OFFSET
CANCELLATION
DETECTOR CELLS
ENBL
1
BANDGAP REFERENCE
AND BIASING
EXPOSED PAD
9
LT5537
Wide Dynamic Range
RF/IF Log Detector
DESCRIPTIO
The LT^®5537 is a wide dynamic range RF/IF detector,
operational from below 10MHz to 1000MHz. The lower
limit of the operating frequency range can be extended to
near DC by the use of an external capacitor. The input
dynamic range at 200MHz with ±3dB nonlinearity is 90dB
(from –76dBm to 14dBm, single-ended 50Ω input). The
detector output voltage slope is nominally 20mV/dB, and
the typical temperature coefficient is 0.01dB/°C at 200MHz.
, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
V_CC
6
OUTPUT
BUFFER
OUT
8
7.2k
V_EE
7
5537 TA01a
Output Voltage, Linearity Error
vs Input Power at 200MHz
2.4
3
2.0
2
1nF
1µF
85°C
25°C
1.6
1
1.2 ^{–40°C}
0
0.8
–1
0.4
–2
V_CC = ENBL = 3V
0
–80 –60 –40 –20
0
INPUT POWER (dBm)
–3
20
5537 TA01b
5537fa
1