Monolithic Voltage-Controlled Oscillators
Pin Description
PIN
NAME
FUNCTION
N.C.
No Connection. Not internally connected.
1
Oscillator Frequency Tuning Voltage Input. High-impedance input with a voltage input range of 0.4V
(low frequency) to 2.4V (high frequency) adjustment.
2
3
4
5
TUNE
GND
Ground Connection for Oscillator and Biasing. Requires a low-inductance connection to the circuit board
ground plane.
Shutdown Logic Input. A high-impedance input logic level low disables the device and reduces supply current
to 0.1µA. A logic level high enables the device.
SHDN
Output Buffer DC Supply Voltage Connection. Bypass with a 220pF capacitor to GND for best high-
frequency performance.
V
CC
CC
Bias and Oscillator DC Supply Voltage Connection. Bypass with a 220pF capacitor to GND for low noise
and low spurious content performance from the oscillator.
6
7
8
V
OUT
GND
Buffered Oscillator Output
Ground Connection for Output Buffer. Requires a low-inductance connection to the circuit board
ground plane.
Detailed Description
Applications Information
Oscillator
Tune Input
The tuning input is typically connected to the output of
the PLL loop filter. The loop filter is presumed to pro-
vide an appropriately low-impedance source. It may
incorporate an extra RC filter stage to reduce high-fre-
quency noise and spurious signals. Any excess noise
on the tuning input is directly translated into FM noise,
which can degrade the phase-noise performance of the
oscillator. Therefore, it is important to minimize the
noise introduced on the tuning input. A simple RC filter
with low corner frequency is needed during testing in
order to filter the noise present on the voltage source
driving the tuning line.
The MAX2622/MAX2623/MAX2624 VCOs are imple-
mented as an LC oscillator topology, integrating all of
the tank components on-chip. This fully monolithic
approach provides an extremely easy-to-use VCO,
equivalent to a VCO module. The frequency is con-
trolled by a voltage applied to the TUNE pin, which is
internally connected to the varactor. The VCO core
uses a differential topology to provide a stable frequen-
cy versus supply voltage and improve the immunity to
load variations. In addition, there is a buffer amplifier
following the oscillator core to provide added isolation
from load variations and to boost the output power.
Output Buffer
The oscillator signal from the core drives an output
buffer amplifier. The amplifier is constructed as a com-
mon-emitter stage with an integrated on-chip reactive
output match. No external DC blocking capacitor is
required, eliminating the need for any external compo-
Layout Issues
Always use controlled impedance lines (microstrip,
coplanar waveguide, etc.) for high-frequency signals.
Always place decoupling capacitors as close to the
V
pins as possible; for long V
lines, it may be nec-
CC
CC
essary to add additional decoupling capacitors located
further from the device. Always provide a low-induc-
tance path to ground, and keep GND vias as close to
the device as possible. Thermal reliefs on GND pads
are not recommended.
nents. The output amplifier has its own V
and GND
CC
pins to minimize load-pulling effects. The amplifier
boosts the oscillator signal to a level suitable for driving
most RF mixers.
4
_______________________________________________________________________________________
5秒后页面跳转
一文带你解读74HC244资料手册：特性、应用场景、封装方式、引脚配置说明、电气参数、推荐替代型号
AD623资料手册解读：特性、应用、封装、引脚功能及电气参数
RT9193资料手册解读：RT9193引脚功能、电气参数、替换型号推荐
VIPER22A的资料手册解读、引脚参数说明、代换型号推荐
微信公众号
抖音公众号
浙公网安备 33010502006866号 浙ICP备10014259号-119
营业执照ICP证
数据手册
如果您发现信息不准确，
