MAX2681EUT-T Maxim Integrated Products, MAX2681EUT-T Datasheet - Page 10

• Manufacturer Part Number: MAX2681EUT-T
• Description: Up-Down Converters SiGe Downconverter M Mixer with Shutdown
• Manufacturer: Maxim Integrated Products

Specifications of MAX2681EUT-T

• Maximum Input Frequency: 2500 MHz
• Maximum Power Dissipation: 696 mW
• Mounting Style: SMD/SMT
• Maximum Operating Frequency: 500 MHz
• Maximum Power Gain: 14.2 dB
• Operating Supply Voltage: 3.3 V, 5 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Package / Case: SOT-23-6

400MHz to 2.5GHz, Low-Noise,
SiGe Downconverter Mixers
Table 3. IFOUT Port Impedance
Table 4. IF Output Impedance-Matching
Components
10
MAX2680
MAX2681
MAX2682
COMPONENT
MATCHING
PART
______________________________________________________________________________________
C2
L1
R1
THE VALUES OF MATCHING COMPONENTS C2, L1, R1, Z1, Z2, AND Z3 DEPEND ON THE IF AND RF FREQUENCY AND DOWNCONVERTER. SEE TABLES 2 AND 4.
INPUT
RF
960-j372
934-j373
670-j216
45MHz
45MHz
390nH
250Ω
39pF
Z
1
INPUT
LO
FREQUENCY
803-j785
746-j526
578-j299
FREQUENCY
Z
70MHz
3
70MHz
C1
330nH
Open
15pF
Z
2
1
2
3
LO
GND
RFIN
186-j397
161-j375
175-j296
240MHz
240MHz
Open
MAX2680
MAX2681
MAX2682
82nH
3pF
IFOUT
SHDN
V
CC
6
5
4
To minimize coupling between different sections of the
IC, the ideal power-supply layout is a star configuration
with a large decoupling capacitor at a central V
node. The V
node, each going to a separate V
board. At the end of each trace is a bypass capacitor
that has low ESR at the RF frequency of operation. This
arrangement provides local decoupling at the V
At high frequencies, any signal leaking out of one sup-
ply pin sees a relatively high impedance (formed by the
V
even higher impedance to any other supply pin, as well
as a low impedance to ground through the bypass
capacitor.
The RFIN and IFOUT impedance-matching networks are
very sensitive to layout-related parasitics. To minimize
parasitic inductance, keep all traces short and place
components as close as possible to the chip. To mini-
mize parasitic capacitance, use cutouts in the ground
plane (and any other plane) below the matching network
components. However, avoid cutouts that are larger
than necessary since they act as aperture antennas.
CC
trace inductance) to the central V
Impedance-Matching Network Layout
L1
C3
SHUTDOWN
CONTROL
R1
CC
Typical Operating Circuit
traces branch out from this central
C2
C4
1000pF
IF
OUTPUT
Power-Supply Layout
C5
10µF
+2.7V TO +5.5V
CC
V
CC
node on the PC
CC
node, and an
CC
pin.
CC