ADL5519ACPZ-R2 AD [Analog Devices], ADL5519ACPZ-R2 Datasheet - Page 19

• Manufacturer Part Number: ADL5519ACPZ-R2
• Description: 1 MHz to 10 GHz, 50 dB Dual Log Detector/Controller
• Manufacturer: AD [Analog Devices]

Preliminary Technical Data
increase until the power on the two input channels is equal,
resulting in a signal chain gain of unity.
If a gain other than 0 dB is required, an attenuator can be used
in one of the RF paths, as shown in Figure 21. Alternatively,
power splitters or directional couplers of different coupling
factors can be used. Another convenient option is to apply a
voltage on VLVL other than OUTA. Refer to Equation 11 and
the Controller Mode section for more detail.
POWER SPLITTER
DIRECTIONAL
OR
50Ω
50Ω
0.1μF
0.1μF
0.1μF
0.1μF
INHA
INHB
INLA
INLB
Figure 21. Operation in Controller Mode for Automatic Gain Control
ADL5519
Log Detector
Log Detector
CHANNEL B
CHANNEL A
Rev. PrB | Page 19 of 27
VLVL
If the VGA/VVA has a positive gain control sense, the OUTN
output of the difference amplifier can be used with the
integrating capacitor tied back to FBKB.
The choice of the integrating capacitor affects the response time
of the AGC loop. Small values give a faster response time but
can result in instability, whereas larger values reduce the response
time. Note that in this mode, the capacitors on CLPA and CLPB,
which perform the rms averaging function, must still be used
and also affect the loop response time.
CLPB
CLPA
VSTA
OUTA
FBKA
OUTP
OUTN
FBKB
OUTB
VSTB
VGA/VVA
C
DIFF OUT +
INT
POWER SPLITTER
DIRECTIONAL
OR
ATTENUATOR
ADL5519