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0.02% V/F converter consumes only 26 µA: 07/04/96 EDN-Design Ideas / (added
11/05) |
|
10 kHz VFC uses Charge Pump Variation: 04/09/98 EDN-Design Ideas /
(Electronic Circuit diagram added 03/03) In telemetry or security applications
in which a modem connection automatically establishes itself between two systems, a
failure in one of the systems can interrupt the data exchange while the connection
remains established until someone physically breaks the line or restarts the failed
system. This situation can also happen if your PC crashes during a long-lasting
Internet download. To prevent this problem, the circuit in Figure 1 continuously
supervises the RS-232C data lines (TxD and RxD) and automatically hangs up the
connection when the circuit detects a long period without transmitted or received
data.... |
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8 pin µC forms one-chip Programmable VCO : 09/24/98 EDN-Design Ideas /
(Circuit / schematic design added 6/06) The circuit in Figure 1 uses a
Microchip 8-pin µC (PIC12C671) as a voltage-controlled oscillator (VCO). Because the
PIC12C671 has an internal 4-MHz oscillator, four-channel 8-bit A/D converters, and
built-in power-reset circuitry, you need no external components to configure the VCO.
The µC reads two analog inputs through AN0 and AN1. The reference voltage for the A/D
conversion is the µC's power supply VDD. The converted 8-bit data determines the
duration of output high and output low. Assume, for example, the digitized outputs
from AN0 and AN1 are 43 and 87, respectively. Timer 0 loads the 43 after the µC sets
output GP2 to logic one. Timer 0 receives its timing from the internal clock.... |
|
AC and Op Amp Provide Variable
Control Voltage: 12/06/01 EDN - Design Ideas / (Circuit / schematic design
added 4/08) Early DACs contained standard R-2R ladder networks, and produced a
negative output voltage. These early DACs, such as the MAX7837/7847 and the MAX523,
require both positive and negative supply rails to accommodate their negative output.
With the transition to single-supply ICs, however, many modern DACs operate with a
single supply rail and an inverted R-2R ladder network. . |
|
Acolpitts VCO for Wideband (0.95-2.15 GHz) Set-Top TV Tuner Applications:
Alpha Industries Application Note 1006 (Circuit / schematic design added 6/06) |
|
AN-1174: Startup Time[comma] Profile Measurement of PLL VCOs and Crystal Oscillators:
National Semiconductor - Application Note (Circuit / schematic design
added 6/06) |
|
AN-213: Low Cost, Two-Chip, Voltage-Controlled Amplifier and Video Switch:
AN-213 - Analog Devices Application Notes (Circuit / schematic design added
6/06) |
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AN-45-001 Automated load measurement of VCO's: Application Note -
MiniCircuits.com (Circuit / schematic design added 6/06) |
|
AN-45-002 Line Stretchers Ease VCO Load-Pull Testing: Application Note -
MiniCircuits.com (Circuit / schematic design added 6/06) |
|
AN-95-003 Glossary of VCO terms: Application Note - MiniCircuits.com
(Circuit / schematic design added 6/06) |
|
AN-95-004 Wide Modulation Bandwidth Measurements: Application Note -
MiniCircuits.com (Circuit / schematic design added 6/06) |
|
AN-95-005 How VCO Parameters Affect Each Other: Application Note -
MiniCircuits.com (Circuit / schematic design added 6/06) |
|
AN-95-006 Optimizing VCO/PLL Evaluations and PLL Synthesizer Designs:
Application Note - MiniCircuits.com (Circuit / schematic design added 6/06) |
|
Automated load measurement of VCO's AN-45-001: Application Note -
MiniCircuits.com (Circuit / schematic design added 6/06) |
|
Characterizing and minimizing VCO phase noise: Application Note -
MiniCircuits.com (Circuit / schematic design added 6/06) |
|
Circuit Tests VCOM Drivers: 11/11/04 EDN Design Ideas / (Circuit /
schematic design added 6/06) Flat-panel LCD monitors offer excellent image
quality and more compact form factor than CRTs—hence, their steadily increasing
popularity. Unfortunately, the complexity of their manufacturing process makes LCD
monitors considerably more expensive than CRTs. The amplifier that drives VCOM, the
voltage on the backplane of the LCD panel, must be able to drive large capacitive
loads, deliver h... |
|
CMOS Inverter VCO tunes octave to UHF: 11/19/98 EDN-Design Ideas /
(Electronic Circuit diagram added 03/03) |
|
Design features of a synthesizer using Mini-Circuits VCOs: Application Note
- MiniCircuits.com (Circuit / schematic design added 6/06) |
|
Designing VCOs and Buffers Using the UPA family of Dual Transistors (3/99) :
Application Note - California Eastern Laboratories - Doc #927 (Circuit /
schematic design added 6/06) |
|
DPP adds versatility to VFC: 11/14/02 EDN Design Ideas (added 12/04)
The basic VFC (voltage-to-frequency converter) in Figure 1 comprises an integrator
(IC1) and a Schmitt-trigger circuit (IC2). The integrator converts the dc input
voltage, VIN , to a linear voltage ramp, and the Schmitt trigger sets the limits of
the integrator's output voltage. Feedback around both circuits provides the condition
for oscillation.... |
|
Enhancing CLC031 Jitter Performance with Easy-To-Use VCXOs: National
Semiconductor - Application Note (added 2/06) |
|
GBSE: Gate Boost Solar Engine: Voltage-Controlled Solar Engine: The "Gate
Boost Solar Engine" is a new (6/2002) Wilf Rigter 1381-based design. This uses an
internal voltage doubler to turn on a FET more efficiently. (added 11/05) |
|
Glossary of VCO terms AN-95-003: Application Note - MiniCircuits.com
(Circuit / schematic design added 6/06) |
|
How VCO Parameters Affect Each Other AN-95-005: Application Note -
MiniCircuits.com (Circuit / schematic design added 6/06) |
|
Inverters form three phase VCO: 08/02/01 EDN Design Ideas (added 12/04)
You sometimes need an inexpensive VCO that can produce evenly spaced three-phase
outputs over a wide frequency range. You could use tracking all-phase filters with
only one oscillator, but this technique is difficult to implement and offers limited
range. Other methods, such as using a DSP, are feasible, but they're complex and
expensive.... |
|
Inverting Latches Make Simple VCO: 06/19/97 EDN-Design Ideas / (Electronic
Circuit diagram added 03/03) The output frequency of the simple VCO in Figure 1, which
is synthesized from inverting latch stages, is tunable to an integer multiple of the
input frequency by selecting which output phases feed back to the input multiplexer.
The circuit has worked successfully in on-chip clock multiplication in ASICs. The
number of latch stages that you can cascade in a real-world design limits the
multiplication factor. However, this circuit is practical for applications that
require low size, cost, and power consumption but that don't require output
frequencies in the hundreds of megahertz. You can also use this circuit to implement a
fixed delay, such as a 90° delay of a master clock (Figure 3c).... |
|
Line Stretchers Ease VCO Load-Pull Testing AN-45-002: Application Note -
MiniCircuits.com (Circuit / schematic design added 6/06) |
|
Low Cost Circuit Biases VCOs for Cable and TV: 11/20/97 EDN-Design Ideas /
(Circuit / schematic design added 6/06) -- PLLs are useful in a variety of
applications, most notably cable and TV tuners |
|
Multilayer capacitor doubles as varactor: 03/20/03 EDN Design Ideas (added
12/04) The main purpose for building the circuit in Figure 1 is to study the
idiosyncrasies of X5R, Z5U, and Y5V multilayer ceramic capacitors. The circuit is also
an inexpensive VCO (voltage-controlled oscillator) with only five components. Many
types of ceramic capacitors for surface-mount placement are on the market.... |
|
Optimizing VCO/PLL Evaluations and PLL Synthesizer Designs AN-95-006:
Application Note - MiniCircuits.com (Circuit / schematic design added 6/06) |
|
PIC controlled DDS VFO 0 to 6 MHz: (circuit added 7/02) |
|
Programmable Clock Oscillator: voltage controller oscillator that was
designed as a wide range oscillator to generate clock pulses for a stepper motor drive
system, frequency could be varied over1,000,000:1 (Electronic circuit added 5/02) |
|
Reducing power supply noise in VCO's: Application Note - MiniCircuits.com
(Circuit / schematic design added 6/06) |
|
Simple VCOM adjustment uses any logIC Supply Voltage: 09/30/04 EDN Design
Ideas / (Circuit / schematic design added 6/06) All TFT
(thin-film-transistor) LCD panels require at least one appropriately tuned VCOM signal
to provide a reference point for the panel's backplane. The exact value of VCOM varies
from panel to panel, so the manufacturer must program the voltage at the factory to
match the characteristics of each screen. |
|
Startup Time[comma] Profile Measurement of PLL VCOs and Crystal Oscillators:
National Semiconductor - Application Note (Circuit / schematic design
added 6/06) |
|
Testing Dual-Chip Transistor Arrays for VCO/Buffer Amp Combinations and Two-Stage
Amplifier Applications (11/28/97) : Application Note - California Eastern
Laboratories - Doc #907 (Circuit / schematic design added 6/06) |
|
Trimless IF VCO part 2: Maxim Application Note 688, February 5, 2001 (added
02/06) |
|
Trimless IF VCO: Part 1: Design Considerations: This application note
explores the design fundamentals needed to implement a trimless, fixed-frequency, IF
voltage-controlled oscillator (VCO) and points out the challenges in guaranteeing
proper circuit operation. VCOs are essential components in the architecture of most
wireless systems. In dual-conversion approaches, a fixed-frequency IF VCO is required
to control the frequency translation from IF to baseband and/or baseband to IF.
APP 711: Feb 05, 2001 (added 02/06) |
|
Universal Watchdog Fully Controls µ Preset: 05/25/95 EDN-Design Ideas /
(Electronic Circuit diagram added 03/03) |
|
Use PSPICE for Behavioral modeling of VCOs: 12/12/02 EDN Design Ideas
/ (Circuit / schematic design added 6/06) PSpice, a member of the Spice
family for PC users, is becoming a standard tool for analog and mixed analog-digital
simulation. Many analog designers are familiar with the software of Design Center,
Design Lab, and OrCad (www.orcad.com) PSpice and use the software in their everyday
lives. This Design Idea should be helpful to those who design and simulate PLL systems
at a behavioral level.... |
|
Using the LTC6900 Low Power SOT-23 Oscillator as a VCO: DN293 - Design
Notes (Linear Technology) (added 1/06) |
|
VCO footprints and layout considerations to improve Performance: Application
Note - MiniCircuits.com (Circuit / schematic design added 6/06) |
|
VCO fundamentals and concepts: Application Note - MiniCircuits.com
(Circuit / schematic design added 6/06) |
|
VCO has Digitally Programmable Center Frequency: 04/25/96 EDN-Design Ideas /
(Electronic Circuit diagram added 03/03) The circuits in Figure 1 illustrates a
narrowband VCO, which has a digitally programmable center-frequency ratio of greater
than 2-to-1. With a VCO having center-frequency ratio (F HIGH/FLOW) of greater than
2-to-1, you can derive any output frequency by simple binary division. The VCO has
extremely high spectral purity, and typically operates at frequencies greater than 230
MHz by using high-performance ECL. Also, you can enable and disable the VCO almost
instantaneously... |
|
VCO produces positive and negative output frequencies: 12/25/03 EDN Design
Ideas (added 12/04) The circuit in Figure 1 is a quadrature-output VCO that
provides both positive and negative output frequencies, depending on the polarity of
the control-voltage input. The circuit provides a function that designers
traditionally implement in analog music-effects units, such as Bode/Moog frequency
shifters.... |
|
VCO test methods: Application Note - MiniCircuits.com (Circuit /
schematic design added 6/06) |
|
VCO uses Programmable logic: 11/14/02 EDN Design Ideas (added 12/04) A
VCO (voltage-controlled oscillator) is an analog circuit, so you cannot find it in the
libraries for the design of digital programmable chips. When you need such a circuit
for synchronization or clock multiplication, you need to find a circuit that works
with the standard digital functions, such as AND and NAND.... |
|
VCOM Adjustment uses Any Logic Supply Voltage: 09/30/04 EDN Design Ideas
/ (Circuit / schematic design added 6/06) All TFT (thin-film-transistor)
LCD panels require at least one appropriately tuned VCOM signal to provide a reference
point for the panel's backplane. The exact value of VCOM varies from panel to panel,
so the manufacturer must program the voltage at the factory to match the
characteristics of each screen. |
|
Versatile Monolithic Volt/Fs can Compute as Well as Convert with High Accuracy:
National Semiconductor Application Note 04-Nov-1995 (Electronic Schematic / circuit
added 4/02) |
|
Volt/F Converter Draws Flea Power: 04/24/97 EDN-Design Ideas / (Electronic
Circuit diagram added 03/03) The V/F converter in Figure 1 is unique because it draws
less than 30 µA from one unregulated supply while converting bipolar input voltages.
It produces three CMOS-compatible, 0- to 10-kHz outputs: one (F+) that becomes active
when the input voltage is positive, another (F) that takes over for negative inputs,
and a third (FABS) that produces a frequency proportional to the absolute value of the
input. Linearity is better than 0.1%, and the full-scale span and offset drift are
typically less than 100 ppm/ºC and 2 µV/ºC, respectively.... |
|
Voltage Controlled Amplifier: (Circuit / schematic design added 6/06) |
|
Voltage Controlled Oscillator ( VCO ): The oscillation frequency of the
voltage controlled oscillator is controlled by the output of the PLL synthesizer and
does the stable oscillation of 119.3 MHz. (added 02/06) |
|
Voltage controlled Panner: (Electronic circuit added 7/03) |
|
Voltage Controlled Resistor: Circuit Ideas for Designers - Application Notes
- Advanced Linear Devices, Inc. (Circuit / schematic design added 6/06) |
|
Voltage Controls Sine Wave Frequency: 08/17/95 EDN-Design Ideas /
(Electronic Circuit diagram added 03/03) The circuit in Fig 1 generates a 50-Hz to
1-kHz sinusoidal waveform that exhibits lower than 60-dB THD. The input voltage
controls the output frequency with the relationship 1 kHz/V. The output amplitude is
invariant with frequency over the entire operating range. IC1 is a V/F converter with
an input control range of 0 to 1V. You adjust R5 so that the output frequency equals 1
kHz with a 1V input.... |
|
Wide Modulation Bandwidth Measurements AN-95-004: Application Note -
MiniCircuits.com (Circuit / schematic design added 6/06) |
