|
Watchdog reset catcher
aids embedded system debugging - 11/19/98 EDN Design
Idea A simple "junk-box" circuit uses a 4013CMOS flip-flop and a handful of passive components to determine
whether random resets are the result of a blown stack or the result of the watchdog-reset circuit tripping
(Figure 1). You ca. . . [by Scott Newell, PCSI, Fort Smith, AR]
Watchdog Time-Out Is Independent of Reset - 09/01/95 EDN Design Idea Many embedded systems use µP supervisors with on-chip watchdog
timers. Some supervisors, such as the MAX691, allow you to select different watchdog and reset time-out periods,
depending on how you connect pin 7 (Osc In] and pin 8 (. . . [by Larry Buyan, Criticare Systems Inc, Waukesha,
WI]
Watchdog timer allows entry to test mode - 07/19/01 EDN Design Idea Manuals for microprocessor-based devices often include
instructions for entering a "secret mode" in which you can test or reset the device. These instructions typically
ask you to depress and hold one or two switches for a minimum . . . [by Greg Sutterlin and Larry Barnes, Maxim
Integrated Products, Sunnyvale, CA, and Craig Gestler, Mining Safety Appliances Co, Mars, PA]
Watchdog timer assumes varied roles - 02/01/01 EDN Design Idea The MAX6369-74 series of pin-selectable watchdog timers are
designed to superviseµP activity and indicate when a system is working improperly. During normal operation, aµP
should repeatedly toggle the WDI (watchdog input) before the selected watchdog-time. . . [by Terry Millward,
Maxim Integrated Products, Lambourn Hungerford, UK ]
Watchdog Timer Assumes Varied Roles - The following application note demonstrates alternative uses for the MAX6369-MAX6374 family
of pinselectable watchdog timers. Alternative uses include a power saving power-on LED indicator circuit, load
connect/disconnect circuit and push-button reset circuit. (APPLICATION NOTE 582) . . .
Watchdog Timer Reboots PC's - 06/05/97 EDN Design Idea
When you use a PC to control a process or collect data, it's often desirable to have a watchdog timer reboot the
computer if it runs astray. The circuit in Figure 1 uses a PIC16C84. . . . [by Charles Hamilton, Burr-Brown
Corp, Tucson, AZ]
Watchdog
Timer set for 36 Hrs - A watchdog timer is often used
in computer systems to detect when a computer is hung up and is no longer running properly. If it does become
locked up and is not able to supply a reset pulse to the circuit within a defined time frame the timer times out
a . . . [Hobby Circuit designed by David Johnson P.E., 04/11/10]
Watchdog-reset catcher aids embedded-system debugging -
11/19/98 EDN Design Idea (File has serval designs) Power op amps have a real need for active output-current
limiting. Most power-amplifier designs rely on the voltage drop across a user-supplied sense resistor to turn on
an internal transistor. This method has several drawbacks, notably, an inability to change the current-limit
point under program control. The current-limit circuit in Figure 1 allows you to establish the setpoint by
applying a voltage to one of the amplifier's pins. With this design, it is possible to set the current-limit
point with the output of a DAC, possibly under the control of an embedded µC. . . . [by Joe Engle, Burr-Brown
Corp, Tucson, AZ]
Waveform generator demodulates FM signal - 10/10/96 EDN Design Idea The circuit in Figure 1 uses the phase-detector signals of a
precision waveform-generator IC to perform FM demodulation. In a standard application, the IC's phase-detector
input and output synchronize the chip's output frequency . . . [by Doug Vargha, Maxim Integrated Products,
Sunnyvale, CA]
Weekly
Reminder - This circuit reminds you of all the important
tasks that are due on a specific day every week. It can flash an LED on a particular day of week. It also has a
buzzer that can be turned on manually through a switch, if beeping is required along with flashing for reminder.
. . . [© EFY Enterprises Pvt. Ltd. All rights reserved.]
Weston Voltmeter Clock - This was the first clock I built, but I've since built a couple others, a single-digit NIXIE
and a CRT clock, so the whole count-60-cycles seems like old hat at this point. The PIC sits there interrupting
on RA4/T0CKI and dutifully keeping count of those oh-so-accurate (at least, over long periods of time) cycles
coming out of the wall. . . . [© 2007 by Riad S. Wah[by]
Wide Frequency
Range 555 VCO - The 555 frequency can be varied via
adjusting the voltage at pin 5. However, the range and linearity of frequency adjustment is very limited. This is
a way to greatly improve performance using the inverted 555 timer circuit that was previously posted. 555 VCO
Schematic Current source Q2 is connected in the common base. . . [Circuit posted by Jim Keith]
Wide Range Timer - App Note, 28 Jun1996 /. . . [National Semiconductor]
Wideband Receiver - The LTC5551 is a 2. 5V to 3. 6V mixer optimized for RF downconverting mixer applications
that require very high dynamic range. The LTC5551 covers the 300MHz to 3. 5GHz RF Frequency range with LO
frequency range of 200MHz to 3. 5GHz. The LTC5551 provides very high IIP3 and P1dB with low power consumption. A
typical application is. . . [Linear Technology App Note, Sep 19th 2013]
xTimer V1.0 - Easy build 4-channel timer, suitable for energy saving, simple hardware and nice firmware
with c coding. Automatic power down mode, simple settings, optional buzzer for sound alarm. . . . [Wichit
Sirichote, designer]
Zero-Delay Clock Buffer Layout &
Schematic Guidelines - Application Note # 050. . . [Pericom
Semiconductor]
<<<<Previous
PAGE |
