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Analog input circuit serves any microcontroller:
12/20/2001 EDN - Design Ideas / The simple ADC in Figure 1 is
perfect for getting analog signals into a purely digital
microcontroller. Using just five surface-mount parts, you can
assemble it for less than 50 cents (1000), which is
approximately half the cost of a single-chip-ADC approach in the
same volume. Moreover, this design takes only one pin from the
microcontroller to operate. . |
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Circuit performs high-speed voltage-to-current,
current-to-current conversion:
07/25/02 EDN Design Ideas - The circuit in Figure 1performs
active voltage-to-current conversion or acts as a variable-gain
current mirror with high precision and bandwidth. A typical
application is testing high-speed ICs or other devices that have
inputs designed to be driven from current-steering DACs to
enable a modulated voltage source to control the devices.... |
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LED driver delivers constant luminosity:
06/12/03 EDN Design Ideas The circuit in Figure 1 is similar in
principle to that of a previous Design Idea (Reference 1) but
offers improved, more reproducible performance. The output
current is almost constant over an input-voltage range of 1.2 to
1.5V and is insensitive to variations of transistor gain.
Transistors Q1 and Q2 form an astable flip-flop.... |
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Network imitates thermocouples:
11/08/01 EDN Design Ideas Thermocouples find widespread use for
temperature measurement in systems. During system design or
testing, you must observe the system's response at different
temperatures. However, it's inconvenient to heat a thermocouple
every time you need to check a system's performance. You can use
the simple trick of touching the thermocouple with a hot
soldering iron, but this method provides only ... ... |
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Positive feedback yields fast amplifier with
precision dc offset: 04/01/04 EDN
Design Ideas Some signal-processing applications require a
high-speed, low-noise, dc-coupled amplifier that incorporates a
precision dc-offset adjustment. Examples include oscilloscopes,
in which the offset adjustment typically acts as a "position"
control), ADC-input gain blocks, and
scanning-ion-beam-microscopy deflection circuitry.... |
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Transmitter accurately transfers voltage input:
05/15/03 EDN Design Ideas - When you connect remote sensors to a
central process Controller, a simple, robust, and commonly used
interface is the 4- to 20-mA loop. The advantages of this
current loop include the simplicity of just two twisted wires
that share both power and signal, the loop's high noise immunity
in harsh environments, and the de facto loop standard within the
process-control industry.... |
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Voltage-to-current converter drives white LEDs:
06/27/02 EDN Design Ideas - You sometimes need to drive a white
LED from one 1.5V battery. Unfortunately, the forward voltage of
a white LED is 3 to 4V. So, you would need a dc/dc converter to
drive the LED from one battery. Using the simple circuit in
Figure 1, you can drive one white LED or two series-connected
green LEDs, using only a few components.... |
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Voltage-to-current converter makes a flexible
current reference: 09/18/03 EDN
Design Ideas -The voltage-to-current converter in Figure 1 can
both source and sink current. The circuit is more flexible than
some traditional current references that require different
topologies for current sourcing and sinking. Also, you can
easily adjust the value of the current reference by simply
adjusting the circuit's input voltage.... |
