AD9864BCPZRL Analog Devices Inc, AD9864BCPZRL Datasheet - Page 9

• Manufacturer Part Number: AD9864BCPZRL
• Description: IC,RF/Baseband Circuit,LLCC,48PIN,PLASTIC
• Manufacturer: Analog Devices Inc

Specifications of AD9864BCPZRL

• Rf Type: UHF, Cellular, GSM, EDGE, TETRA
• Frequency: 10MHz ~ 300MHz
• Features: General Purpose IF Subsystem
• Package / Case: 48-LFCSP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DEFINITION OF SPECIFICATIONS/TEST METHODS
Single Sideband Noise Figure (SSB NF)
Noise figure (NF) is defined as the degradation in SNR per-
formance (in dB) of an IF input signal after it passes through a
component or system. It can be expressed with the equation
The term SSB is applicable for heterodyne systems containing a
mixer. It indicates that the desired signal spectrum resides on
only one side of the LO frequency (i.e., single sideband); thus a
“noiseless” mixer has a noise figure of 3 dB.
The SSB noise figure of the AD9864 is determined by the equation
where P
the noise measurement bandwidth, –174 dBm/Hz is the ther-
mal noise floor at 293K, and SNR is the measured signal-to-
noise ratio in dB of the AD9864.
Note that P
measured SNR due to phase noise from the RF and LO signal
generators. The IF frequency, CLK frequency, and decimation
factors are selected to minimize any spurious components
falling within the measurement bandwidth. Note also that a
bandwidth of 10 kHz is used for the data sheet specification. All
references to noise figures within this data sheet imply single
sideband noise figure.
Input Third Order Intercept (IIP3)
IIP3 is a figure of merit used to determine a component’s or
system’s susceptibility to intermodulation distortion (IMD)
from its third order nonlinearities. Two unmodulated carriers
at a specified frequency relationship (f1 and f2) are injected into
a nonlinear system exhibiting third order nonlinearities pro-
ducing IMD components at 2f1 – f2 and 2f2 – f1. IIP3 graphi-
cally represents the extrapolated intersection of the carrier’s
input power with the third order IMD component when plot-
ted in dB. The difference in power (D in dBc) between the two
carriers and the resulting third order IMD components can be
determined from the equation
SSB
Noise
D
=
IN
NF
2 ×
is the input power of an unmodulated carrier, BW is
Figure
IN
=
(
IIP
P
is set to –85 dBm to minimize any degradation in
IN
3
–
–
=
[
10
10 ×
P
IN
×
log
)
log
(
BW
(
SNR
)
]
( –
IN
−
174
/
SNR
dBm/Hz
OUT
)
)
–
SNR
Rev. 0 | Page 9 of 44
Dynamic Range (DR)
Dynamic range is the measure of a small target input signal
(P
(P
characteristic of the component or system to degrade, thus mak-
ing it unable to detect the smaller target signal correctly. In the
case of the AD9864, it is often a degradation in noise figure at
increased VGA attenuation settings that limits its dynamic range.
The test method for the AD9864 is as follows. The small target
signal (an unmodulated carrier) is input at the center of the IF
frequency, and its power level (P
SNR
3 dB prior to injecting the interferer signal. The offset frequency
of the interferer signal is selected so that aliases produced by the
decimation filter’s response as well as phase noise from the LO
(due to reciprocal mixing) do not fall back within the measure-
ment bandwidth. For this reason, an offset of 110 kHz was
selected. The interferer signal (also an unmodulated carrier) is
then injected into the input and its power level is increased to the
point (P
dynamic range is determined with the equation
Note that the AD9864’s AGC is enabled for this test.
IF Input Clip Point
The IF input clip point is defined as the input power that
results in a digital output level 2 dB below full-scale. Unlike
other linear components that typically exhibit a soft compres-
sion (characterized by its 1 dB compression point), an ADC
exhibits a hard compression once its input signal exceeds its
rated maximum input signal range. In the case of the AD9864,
which contains a Σ-∆ ADC, hard compression should be
avoided because it causes severe SNR degradation.
TARGET
INTER
TARGET
DR
). Typically, the large signal will cause some unwanted
) in the presence of a large unwanted interferer signal
INTER
=
of 6 dB. The power of the signal is then increased by
P
) where the target signal SNR is reduced to 6 dB. The
INTER
–
P
TARGET
+
SNR
TARGET
TARGET
) is adjusted to achieve an
AD9864