MAX2620
10MHz to 1050MHz Integrated
RF Oscillator with Buffered Outputs
6 _______________________________________________________________________________________
_______________________________________________________________Pin Description
NAME FUNCTIONPIN
3 FDBK
Oscillator Feedback Circuit Connection. Connecting capacitors of the appropriate value between FDBK and
TANK and between FDBK and GND tunes the oscillator’s reflection gain (negative resistance) to peak at the
desired oscillation frequency. Refer to the Applications Information section.
2 TANK Oscillator Tank Circuit Connection. Refer to the Applications Information section.
1 V
CC
1
Oscillator DC Supply Voltage. Decouple VCC1 with 1000pF capacitor to ground. Use a capacitor with low
series inductance (size 0805 or smaller). Further power-supply decoupling can be achieved by adding a
10Ω resistor in series from VCC1 to the supply. Proper power-supply decoupling is critical to the low noise
and spurious performance of any oscillator.
8 OUT
Open-Collector Output Buffer. Requires external pull-up to the voltage supply. Pull-up can be resistor,
choke, or inductor (which is part of a matching network). The matching-circuit approach provides the high-
est-power output and greatest efficiency. Refer to Table 1 and the Applications Information section. OUT
can be used with OUT in a differential output configuration.
7 V
CC
2
Output Buffer DC Supply Voltage. Decouple VCC2 with a 1000pF capacitor to ground. Use a capacitor with
low series inductance (size 0805 or smaller).
6 GND Ground Connection. Provide a low-inductance connection to the circuit ground plane.
5
OUT
Open-Collector Output Buffer (complement). Requires external pull-up to the voltage supply. Pull-up can be
resistor, choke, or inductor (which is part of a matching network). The matching-circuit approach provides
the highest-power output and greatest efficiency. Refer to Table 1 and the Applications Information section.
OUT can be used with OUT in a differential output configuration.
4
SHDN
Logic-Controlled Input. A low level turns off the entire circuitry such that the IC will draw only leakage current
at its supply pins. This is a high-impedance input.
_____________________________Typical Operating Characteristics (continued)
(Typical Operating Circuit, V
CC
= +3.0V, V
TUNE
= 1.5V, SHDN = V
CC,
load at OUT = 50Ω, load at OUT = 50Ω, L1 = coaxial ceramic
resonator: Trans-Tech SR8800LPQ1357BY, C6 = 1pF, T
A
= +25°C, unless otherwise noted.)
