AN763: Latch-Up Protection for MOSFET Drivers:  Microchip Application Note - Published 5-Feb-03   (Circuit / schematic design added 6/06)

AN-932: SEU and Latch Up Tolerant Advanced CMOS Technology:  National Semiconductor - Application Note   (added 2/06)

AN-989: AN-989 Single Event Upset and Latchup Considerations for CMOS Devices Operated at 3.3 V:  National Semiconductor - Application Note   (added 2/06)

Asynchronous Circuit Latches Safely:  04/28/94 EDN-Design Ideas / (Electronic Circuit diagram added 03/03) The circuit in Fig 1 is a digital latch that is resettable only after the condition that set the latch clears. A set input (active low) permanently latches the output (active low). A reset input (active high) resets the output to a logic high.Unlike the 74279 set-reset latch, you can drive the set and reset lines low simultaneously. A 74279's output is unpredictable and unstable when you drive both its set and reset lines low simultaneously. In contrast, this circuit's output remains in its present state. The circuit operates asynchronously and can handle both .... 

Bipolars Provide Safe Latch Off Against Opto Failures:  12/07/00 EDN Design Ideas /  (added 2/06)

Circuit Adds Latch Off Current Limit to Regulator:  03/30/00 EDN-Design Ideas / (added 2/06)

Circuit Drives Latching Relays:  02/01/96 EDN-Design Ideas / (Circuit / schematic design added 6/06)

Circuit Latches Solenoids at a Distance:  10/14/00 EDN Design Ideas  / (added 5/05) 

Circuit Prevents Processor Latch Up:  03/04/99 EDN-Design Ideas / (added 6/03) The circuit in Figure 1 uses a Dallas Semiconductor DS1820 one-wire digital thermometer in a multipoint temperature-measurement system. The DS1820 sensor allows distributed temperature measurement and uses only one wire for both data communication and the power supply. You can easily connect the one-wire interface to a µC (in this example, a PIC16C63). The application accommodates as many as 16 DS1820 sensors in a 100m-long network, dubbed MicroLAN by Dallas. Unfortunately, with such long wires near high-current power cables, inductively coupled high-voltage peaks can cause µC latch-up, because the transient-voltage suppressor, D1, cannot limit the line voltage below 9.8V. The interface circuit in Figure 1 prevents such faults....

Continuity Tester Latching:  Awesome tester! (Electronic circuit added 5/02)

Fault Latch Circuit Protects Switchers:  02/19/04 EDN Design Ideas  /  (added 1/05)  Many power-supply designers like to have a regulator latch off in the event of an overcurrent situation or other fault condition. Yet, many PWM controllers do not internally support this latch-off function. Most do, however, have a power-good output and an enable function. The circuit in Figure 1 adds that latch-off capability at low cost in little additional space....

Inverting Latches Make Simple VCO:  06/19/97 EDN-Design Ideas / (Circuit / schematic design added 6/06)  

Latching Continuity Tester :  A continuity tester is a must on every service bench for testing cables, pcboards, switches, motors, plugs, jacks, relays, and many other kinds of components. But there are times when a simple continuity test (or your multi-meter) doesn't tell the whole story. For example, vibration-induced problems in automobile wiring can be extremely difficult to detect because a short or open is not maintained long enough for a non-latching tester to respond. And an analog meter is too slow to react. This latching continuity tester detects intermittent (and steady state) opens and shorts. The tester will detect and latch on an intermittent condition with a duration of less than a millisecond. In addition, it provides both visual and (defeatable) audio indicators, uses only one inexpensive and easy-to-find IC, and can be built from all new parts for about $35, or less if you have a well-stocked junk box.... (added 2/06)

Latching Light Detector is Frugal with Power and Parts:  09/26/02 EDN Design Ideas  /  (added 1/05)  This idea demonstrates three uses for the humble LED. The circuit in Figure 1a forms a simple light detector that latches and turns on an LED when the ambient light exceeds a preset limit determined by potentiometer P1. LED D1 is both the indicator and the light detector. All junction diodes exhibit some degree of photosensitivity....

Latching Power Switch uses Momentary Action Pushbutton:  10/28/04 EDN Design Ideas  / (added 11/05)  Most inexpensive pushbutton switches, particularly pc-board-mounting and membrane types, have momentary action. Latching types are often larger and relatively expensive, and they frequently are unavailable in the style you'd like to use. You can thus have a problem if you need a small, inexpensive on/off switch for latching power to a load.

Latching Regulator Prevents Deep Discharge:  03/16/95 EDN-Design Ideas / (added 07/03)

Power supply interrupter fights ESD induced Devicelatch up:  02/05/2004  EDN-Design Ideas  In low-noise analog circuits, a high-gain amplifier serves at the input to increase the SNR. The input signal level determines the input-stage gain; low-level signals require the highest gain. It is also standard practice in low-noise analog-signal processing to make the circuit's bandwidth as narrow as possible to pass only the useful input-signal spectrum. (Circuit / schematic design added 6/06)

Preventing Latch-Up in the COMBO II CODEC/Filter:  National Semiconductor - Application Note   (added 2/06)

Relays: Self Latching:  (Circuit added 9/04)

Scalable Latch Requires No Capacitors or Clock:  08/19/04 EDN Design Ideas  /  (added 1/06)  Circuits that latch one-of-N switches usually use a digital approach. Such circuits are often useful in human-interface situations, such as audio-mixing consoles, video-feed selection, or current-loop-control redundancy systems. In high-precision analog systems, such as high-fidelity audio or video, elimination of clocking circuits, whenever possible, reduces the chances of coupling noise back ......

SEU and Latch Up Tolerant Advanced CMOS Technology:  National Semiconductor - Application Note   (added 2/06)

Simple Circuit Prevents Processor Latch Up:  03/04/99 EDN-Design Ideas / (added 6/03) The circuit in Figure 1 uses a Dallas Semiconductor DS1820 one-wire digital thermometer in a multipoint temperature-measurement system. The DS1820 sensor allows distributed temperature measurement and uses only one wire for both data communication and the power supply. You can easily connect the one-wire interface to a µC (in this example, a PIC16C63). The application accommodates as many as 16 DS1820 sensors in a 100m-long network, dubbed MicroLAN by Dallas. Unfortunately, with such long wires near high-current power cables, inductively coupled high-voltage peaks can cause µC latch-up, because the transient-voltage suppressor, D1, cannot limit the line voltage below 9.8V. The interface circuit in Figure 1 prevents such faults....

Single Event Upset and Latchup Considerations for CMOS Devices Operated at 3.3 V:  National Semiconductor - Application Note   (added 2/06)

Solid State Relay Saves Battery's Life:  09/01/94 EDN-Design Ideas / (Electronic circuit added 5/02)  The circuit in Fig 1 uses a low-resistance p-channel FET, Q4, to disconnect a load from the battery when the battery's voltage drops below a certain value. After you disconnect the circuit, it remains off until you remove and replace the battery....

TB-01: Preventing Latch-Up in the COMBO II CODEC/Filter:  National Semiconductor - Application Note   (added 2/06)

Transistor Latch Improves On/Off Circuitry:  11/23/00 EDN-Design Ideas / (added 6/03)

Transistors Offer Thermal Protection for Controller:  07/19/01 EDN - Design Ideas / (added 11/03)  When a switch-mode power-supply controller, such as On Semiconductor's NCP1200, operates at a high ambient temperature, you should protect the entire power supply against lethal thermal runaway. The NCP1200 operates directly from the power mains without an auxiliary winding; therefore, the die in the IC dissipates power (Figure 1)..