MAX2055EVKIT Maxim Integrated Products, MAX2055EVKIT Datasheet - Page 3

• Manufacturer Part Number: MAX2055EVKIT
• Description: EVAL KIT FOR MAX2055
• Manufacturer: Maxim Integrated Products
• Type: Amplifierr

Specifications of MAX2055EVKIT

• Frequency: 30MHz ~ 300MHz
• For Use With/related Products: MAX2055
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

6) (Optional) Gain can be determined with a network
Figure 1 shows the schematic for the MAX2055 EV kit.
The EV kit is matched for operation up to 300MHz.
Capacitors C1, C4, C5, C8, and C9 are DC-blocking
capacitors for the RF_IN, ATTN
To reduce the possibility of noise pickup, capacitors
C2, C3, C10, C11, and C12 form the V
network. Inductors L1–L5 provide a method of biasing.
Inductor L2 needs to handle the total IC current and
have a DC resistance that is less than 0.2Ω. If the DC
resistance is higher than 0.2Ω, the value of R1 may
need to be adjusted down to maintain the nominal
operating current. Inductors L4 and L5 are nonmagnet-
ic coils that provide the output supply bias for the
amplifier. Transformer T1 is used to convert the single-
ended attenuator output to a differential signal. This
technique results in an improved 2nd harmonic perfor-
mance for the device. The amplifier can be driven single
ended if the improved 2nd harmonic is not required
(see Modifying the EV Kit section). Output transformer
T2 enables single-ended measurements, in addition to
providing common-mode rejection for the 2nd harmon-
ic. Resistor R7 helps reduce video leakage during
switching. Replace R7 with a 0Ω resistor if video leak-
age is not a concern.
trum analyzer display should indicate a magnitude
of approximately 5dBm. Be sure to account for
external cable losses.
analyzer. This has the advantage of displaying gain
over a swept frequency band, in addition to display-
ing input and output return loss. Refer to the network
analyzer manufacturer’s user manual for setup
details.
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Detailed Description
OUT
, and RF_OUT ports.
CC
decoupling
MAX2055 Evaluation Kit
The EV kit is easily configured for other topologies.
For a single-ended amplifier input:
1) Remove T1 and place a low-inductance short circuit
2) Add a 1000pF 0603 case style capacitor for C7.
3) Change L2 to the same style and value inductor as
4) Change R1 to 909Ω (to adjust the DC current to
Note: In this configuration, C6 is not required.
The EV kit also provides the ability for additional methods
of testing by adding in the option for an interstage RF
connection along with differential RF output connections.
The MAX2055 evaluation boards can be used as a guide
for your board layout. Give close attention to thermal
design and close placement of parts to the IC. The
MAX2055 package exposed paddle (EP) conducts heat
out of the part and provides a low-impedance electrical
connection. The EP must be attached to the PC board
ground plane with a low thermal and electrical-imped-
ance contact. Ideally, this is provided by soldering the
backside package contact directly to a top metal ground
plane on the PC board. Alternatively, the EP can be con-
nected to a ground plane using an array of plated vias
directly below the EP. The MAX2055 EV kit uses eight
evenly spaced, 0.016in-diameter, plated through holes to
connect the EP to the lower ground planes.
Depending on the RF ground plane spacing, large sur-
face-mount pads in the RF path may need to have the
ground plane relieved under them to reduce shunt
capacitance.
between the T1 surface-mount pads that connect
capacitors C4 to C5.
L1 (330nH) noted in the Component List.
compensate for the higher L2 resistance).
Layout Considerations
Modifying the EV Kit
3