MAX2472EUT-T Maxim Integrated Products, MAX2472EUT-T Datasheet - Page 10

• Manufacturer Part Number: MAX2472EUT-T
• Description: RF Amplifier 500MHz to 2500Mhz VC O Buffer Amplifier w
• Manufacturer: Maxim Integrated Products
• Type: Buffer Amplifierr

Specifications of MAX2472EUT-T

• Operating Frequency: 2500 MHz
• Noise Figure: 10.2 dB at 1900 MHz
• Operating Supply Voltage: 3 V, 5 V
• Supply Current: 5.2 mA
• Maximum Power Dissipation: 696 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-23
• Minimum Operating Temperature: - 40 C
• Number Of Channels: 1 Channel

500MHz to 2500MHz
VCO Buffer Amplifiers
Figure 1. Input Structure
Figure 2. Output Structure
The MAX2472/MAX2473 offer high-impedance inputs
ideal for low-distortion buffering of a VCO. For applica-
tions with discrete transistor-based oscillator designs,
simply AC-couple the oscillator directly to the input; the
buffer’s high input impedance results in minimal load-
ing on the oscillator. For use with 50Ω VCO modules,
determine the approximate input impedance (S11) of
10
______________________________________________________________________________________
(PIN 4)
IN
(PIN 5)
GND
Applications Information
(PIN 6)
(PIN 2)
1.3pF
GND
V
CC
2k
10
Input Considerations
1k
(PIN 6)
V
CC
250
33
OUT
the MAX2472/MAX2473 from the S parameter tables in
the Typical Operating Characteristics . Terminate the
buffer input with a shunt resistor “R
R
capacitor between the shunt resistor and the device
input. This provides a very stable 50Ω termination and
increases reverse isolation. For those applications
needing both high gain and good input match, reac-
tively match the buffer inputs to 50Ω with simple two-
element matching circuits. Figure 1 shows an equivalent
input circuit of the MAX2472/MAX2473 IN pin.
The MAX2472/MAX2473 outputs are configured as
open-collector output stages, allowing maximum flexi-
bility. To achieve maximum gain and output drive, reac-
tively match these outputs with a shunt inductor/choke
to V
applications not requiring high gain and output drive
(PLL prescaler), use a simple resistor to V
by a DC blocking capacitor. Figure 2 shows an equiva-
lent circuit of the MAX2472/MAX2473 OUT pin(s).
Figure 3 shows an equivalent circuit of the MAX2473
BIAS pin.
Table 1 lists recommended values for lumped-element
output matching circuits at certain frequencies. For fre-
quencies other than those specified, use the parame-
ters given in the Typical Operating Characteristics .
A properly designed PC board is essential to any
RF/microwave circuit. Be sure to use controlled imped-
ance lines on all high-frequency inputs and outputs.
Bypass the power supply with decoupling capacitors
Figure 3. BIAS Structure (MAX2473 only)
TERM
CC
followed by a series capacitor (DC block). For
||
Layout and Power-Supply Bypassing
RE[S
REFERENCE
INTERNAL
1.2V
11
] = 50Ω, and use a series blocking
1k
Output Matching Circuit
Output Considerations
(PIN 2)
GND
(PIN 6)
V
CC
TERM
BIAS
(PIN 3)
CC
” such that
followed