Datasheet
MAX9985
Dual, SiGe, High-Linearity, 700MHz to 1000MHz
Downconversion Mixer with LO Buffer/Switch
4
Maxim Integrated
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
LO1-to-LO2 Port Isolation
P
LO1
= +3dBm, P
LO2
= +3dBm,
f
LO1
-f
LO2
= 1MHz, P
RF
= -5dBm,
f
IF
= 100MHz (Notes 7, 10)
39 43 dB
Maximum LO Leakage at RF Port -40 -30 dBm
M axi m um 2LO Leakag e at RF P or t -45 -20 dBm
-30 -20
Maximum LO Leakage at IF Port
T
C
= +100°C -30.3
dBm
30 45
Minimum RF-to-IF Isolation
T
C
= +100°C 49.5
dB
40 47
Minimum Channel-to-Channel
Isolation
P
RF
= -10dBm, RFMAIN (RFDIV)
power measured at IFDIV
(IFMAIN), relative to IFMAIN
(IFDIV), all unused ports
terminated to 50Ω
T
C
=
+100°C
47.5
dB
LO Switching Time
50% of LOSEL to IF settled within 2 degrees
(Note 7)
0.05 1 µs
RF Input Impedance 50 Ω
LO Input Impedance 50 Ω
IF Output Impedance Differential 200 Ω
RF Input Return Loss LO on and IF terminated 24 dB
LO port selected 35
LO Input Return Loss
LO port unselected 36
dB
IF Return Loss RF terminated in 50Ω 20 dB
Note 5: All limits reflect losses of external components. Output measurements taken at IF outputs of the
Typical Application Circuit
.
Note 6: Performance is guaranteed for f
RF
= 820MHz to 920MHz, f
LO
= 670MHz to 865MHz, and f
IF
= 100MHz. Operation outside
this range is possible, but with degraded performance of some parameters. See the
Typical Operating Characteristics
.
Note 7: Guaranteed by design and characterization.
Note 8: Performance at T
C
= -40°C is guaranteed by design.
Note 9: Measured with external LO source noise filtered so the noise floor is -174dBm/Hz. This specification reflects the effects of
all SNR degradations in the mixer including the LO noise, as defined in Maxim Application Note 2021.
Note 10: Measured at IF port at IF frequency. LOSEL may be in any logic state.
AC ELECTRICAL CHARACTERISTICS (continued)
(Using the
Typical Application Circuit
, V
CC
= 4.75V to 5.25V, RF and LO ports are driven from 50Ω sources, P
LO
= -3dBm to +3dBm,
P
RF
= -5dBm, f
RF
= 820MHz to 920MHz, f
LO
= 670MHz to 865MHz, f
IF
= 100MHz, f
RF
> f
LO
, T
C
= -40°C to +85°C. Typical values are at
V
CC
= 5.0V, P
RF
= -5dBm, P
LO
= 0dBm, f
RF
= 870MHz, f
LO
= 770MHz, f
IF
= 100MHz, T
C
= +25°C, unless otherwise noted.) (Note 5)