Circuit yields accurate absolute values: 07/05/2001 EDN -
Design Ideas / The circuit in Figure 1 delivers the absolute
value of the input signal with an accuracy better than 10 ppm of
the full-scale range. The circuit has low zero-crossing error.
You can use it as an asynchronous demodulator, as a source for
logarithmic amplifiers, or simply as a demonstration of the
wonders of feedback.. |
Clock recovery scheme suits low SNR systems: 06/05/00 EDN-Design
Ideas / A clock-recovery architecture can operate with NRZ
digital signals, even at low SNRs. A clock-recovery subsystem is
based on a PLL comprising a phase comparator, a loop filter, and
a voltage-controlled oscillator (VCO).... |
Demodulator Schematic/Design: |
Inverted bipolar transistor doubles as a signal clamp:
06/07/01EDN-Design Ideas / A number of circuits, such as level
detectors and AM demodulators, benefit from a rectifier with a
low offset voltage. Silicon diodes have an offset of
approximately 0.6V and do not work well in low-level circuitry.
A Schottky diode is a bit better... |
Inverted bipolar transistor doubles as a signal clamp:
11/09/00 EDN-Design Ideas / A number of circuits, such as level
detectors and AM demodulators, benefit from a rectifier with a
low offset voltage.... |
Novel method detects lock in Costas loops: 06/22/00 EDN-Design
Ideas / In the well-established lock-detection scheme for
conventional PLLs, the VCO or VCXO local oscillator splits the
output into 0 and 90 signals ( Figure 1 ). The incoming IF
signal mixes with the 0 and 90 signals to perform phase locking
and lock detection,... |
QPSK Demodulator Is Good Match For Low Cost Modulator:
04/14/03 Electronic Design - Ideas for Design / This demodulator
is suitable for the quadrature phase-shift keying (QPSK)
modulator previously published by the same author, "Novel
Low-Cost QPSK Modulator Needs No Adjustments" (electronic
design, Sept. 16, 2002, p. 92). Also based on...
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Self modifying code extends addressing mode: 12/17/98 EDN-Design
Ideas / Self-modifying code extends addressing mode. VHDL
procedure dynamically opens a file . Configure buck converter
for boost operation. Circuit eases three-phase monitoring. PLL
forms simple MSK demodulator. C makes inexpensive sine-wave
generator. 74...
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Simple BER meter is easy to build: 03/02/00 EDN-Design Ideas
/ A bit-error-rate (BER) tester is a basic tool for
digital-communications measurements. Although many commercial
BER testers are available, you can easily design and build an
inexpensive version. The scheme in Figure 1 has performance
similar to that of a... |
Single sideband demodulator covers the HF band: 07/20/00 EDN-Design
Ideas / The circuit in Figure 1 complements a previous Design
Idea ( Reference 1 ). The modulator used a phasing network to
split a low-frequency (audio) signal into in-phase and
quadrature (orthogonal) components. The phasing network has an
advantage over... |
Single sideband demodulator covers the HF band: 10/26/00 EDN-Design
Ideas / The circuit in Figure 1 complements a previous Design
Idea (" SSB modulator covers HF band ," EDN , Sept 30, 1999, pg
122). The modulator employs a phasing network to split a
low-frequency audio signal into in-phase and quadrature
(orthogonal) compo... |
Spread spectrum method identifies audio path: 04/13/00 EDN-Design
Ideas / An unusual method of audio spread spectrum can identify
the audio path that's currently in use through a
consumer-electronic device. The design in Figure 1a uses an
injected audio spread-spectrum tag signal because a listener
does not notice the low... |