Safe Operating Areas for Peripheral Drivers:  National Semiconductor Application Note   (app note added 2/06)

Safely swap SCSI disk drives:  09/30/99 EDN-Design Ideas / (added 6/06)

Saving and Restoring Status on Interrupt:  Microchip Application Note Published 26-Aug-97   (app note added 2/06)

SB-101: Digital PBX Linecard and Terminal:  National Semiconductor Application Note   (app note added 2/06)

SB-102: ISDN Terminals and Terminal Adapters:  National Semiconductor Application Note   (app note added 2/06)

SB-103: ISDN Network Terminators and Repeaters:  National Semiconductor Application Note   (app note added 2/06)

SB-108: Apple Macintosh Ethernet Add-In Card:  National Semiconductor Application Note   (app note added 2/06)

SB-110: IBM 3270/5250 Connectivity:  National Semiconductor Application Note   (app note added 2/06)

SB-111: Mass Storage: Hard Disk:  National Semiconductor Application Note   (app note added 2/06)

SB-113: Laser Beam Printer (LBP) Controller Solution Card:  National Semiconductor Application Note   (app note added 2/06)

SB-114: Monitor: VGA:  National Semiconductor Application Note   (app note added 2/06)

SB-115: A FDDI: Ethernet Router:  National Semiconductor Application Note   (app note added 2/06)

SB-116: FDDI: Adapter Card:  National Semiconductor Application Note   (app note added 2/06)

SB-117: PC87310 Super I/O:  National Semiconductor Application Note   (app note added 2/06)

SB-119: 10Base-T Solutions: Network Interface Adapter:  National Semiconductor Application Note   (app note added 2/06)

Scalable Latch Requires No Capacitors or Clock:  08/19/04 EDN Design Ideas  /  (added 10/05)  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 ......

Scenix (And Pic) Programmer:  (electronic circuit added 4/05)

Schematic and Board Layout Recommendations for PI7C7300:  Pericom Semiconductor App Note # 044 (app note added 02/05)

Schematic and Layout Guidelines for PI7AT04:  Pericom Semiconductor App Note # 057 (app note added 02/05)

Schematic of a Standard PC Joystick:  (design circuit added 8/02)

Scheme Autodetects Baud Rate:  07)/20/00 EDN-Design Ideas / (added11/05)

Scheme implements multiple output ports :  02/16/98 EDN-Design Ideas  / (added 2/06)    

Scheme Improves on Low Cost Keyboard:  10/30/03 EDN Design Ideas  /  (added 1/05)  You can easily improve on a previous Design Idea to produce a slightly simpler resistor arrangement with better timing balance between switches, using a single resistor value (Reference 1, Figure 1). The use of a single resistor value, RS, in a series chain for the switch resistors gives the timing parameters a simpler format and should reduce bill-of-materials cost....

SCSI Printer Controller using either the DP8490 Easi or Dp5380 Asi and Users Guide:  National Semiconductor Application Note   (app note added 2/06)

Sega 3D Glass Interfacing Circuits #2:  (design circuit added 8/02)

Sega 3D Glass Interfacing Circuits:  (electronic circuit added 11/05)

Selection of MOSFETs in Switch Mode DC-DC Converters / AB-8:  Fairchild Application Notes / (app note added 6/06)

Serial Controlled Postage Stamp Computer Governs Process:  10/13/94 EDN Design Ideas /  (added 11/05)

Serial Controller IC Interfaces with ADSP2100A:  03/28/96 EDN-Design Ideas / (added 11/05) 

Serial Digital Video and Interface Rapidesigner Operation and Applications Guide:  National Semiconductor Application Note   (app note added 2/06)

Serial Infrared Remote Controller:  a simple, cheap device that can be connected to any serial port to control most components that have infrared remote controls, includes schematics for receiver and transmitter   (added 4/02)

Serial MIDI Interface:  (electronic circuit added 4/05)

Serial Port A/D Converter:  (design circuit added 8/02)

Serial Port A/D :  12bits, no power, cheap! (added 7/03)

Serial Port Controller Infrared Transmitter (PIC16f628):  (electronic circuit added 7/03)

Serial Port Drives 12 BitADC:  10/12/95 EDN-Design Ideas / (added 11/05) 

Serial Port Provides Interrupts for 8031µC:  12/09/99 EDN Design Ideas /  (added 11/05)

Serial Port Routines Without using the Rtcc:  Microchip Application Note Published 26-Aug-97   (app note added 2/06)

Serial Port to MIDI Synthesizer Interface Cable:  (circuit / schematic design added 1/07)

Serial Port Utilities Implementing Table Read and Table Write:  Microchip Application Note Published 26-Aug-97   (app note added 2/06)

Shared-Memory Interface Eliminates Arbitration:  08/01/96 EDN-Design Ideas  /  (added 2/06) 

Simple Analog-to-Digital Converter:  Normally analogue-to-digital con-verter (ADC) needs interfacing through a microprocessor to convert analogue data into digital format. This requires hardware and necessary software, resulting in increased complexity and hence the total cost. The circuit of A-to-D converter shown here is configured around ADC 0808, avoiding the use of a microprocessor…. (added 10/05)

Simple AVR Programmers:  These are four different AVR programmers that can be controlled via standard ports of a PC.  (added 10/05)

Simple can Node using the MCP2510 and PIC12C67x:  Microchip Application Note Published 16-Sep-02   (app note added 2/06)

Simple Efficient All-In-One USB Power Management IC Solution:  DN1008  Design Notes (Linear Technology)  (app note added 1/06)

Simple MIDI Switcher:  (electronic circuit added 4/05)

Simple MIDI Tester #2:  Sometimes when experimenting with different soundcards and MIDI interfaces it is useful to see if there is some data going in MIDI interface. This can be easily tested with this adapter, which converts the midi signals to visible light pulses. Just the circuit and plug it to the MIDI output of your computer. When computer sends any midi data out, you see the LED flashing. I found this tester very useful in testing homebuilt soundcard MIDI interface.... (added 4/05)

Simple MIDI Tester:  (electronic circuit added 11/05)

Simple module gives voice to PC :  05/26/94 EDN Design Ideas /  (added 11/05)

Simple Monovibrator uses Three PLD Pins:  09/28/95 EDN-Design Ideas / (added 11/05) 

Simple PC Smartcard Reader:  (electronic circuit added 4/05)

Simple Printer Emulator Adapter:  (electronic circuit added 11/05)

Simple RS-232 Serial Port Buffer Circuit:  (electronic circuit added 4/05)

Simple RS-232c Level Converter using Transistors:  (electronic circuit added 4/05)

Simple Software I2C Routine for the COP8:  National Semiconductor Application Note   (app note added 6/06)

Simple Technique Makes Low Cost PC Board Shields:  02/19/04 EDN Design Ideas  /  (added 1/05)  Many pc-board assemblies require shields to reduce susceptibility to interference from electromagnetic fields. A classic example is a radio receiver, in which the front end usually needs high isolation from the tuning synthesizer. Historically, shields for low-volume or low-cost applications involve trade-offs....

Simple Wireless Radio Data Link:  This is a description of a very simple unit designed and constructed for use as a wireless data connection between two nearby computers. The error rate is excellent over short runs, and the transmission speed means that a useful PPP link can be established between the machines. Which are, of course, running Linux..... (added 4/05)

Simplified PC Connections for Gpib Instruments:  Aligent Application Note (app note added4/08)

Simulate Input Offset Current for Current Mirrors:  06/24/2004  EDN-Design Ideas  Simulating the output-offset current of a current mirror is straightforward. You simply have to apply an input current, measure the output current, and calculate the difference. This output-offset current, however, is not equal to the input-offset current, especially when the circuit is not a 1-to-1 mirror.  (added 10/05)

Single µC pin makes half duplex RS 232C:  08/05/99 EDN-Design Ideas / (added 5/03) In many µC designs, nearly all the I/O pins are occupied. If only one I/O pin is available, the circuit in Figure 1 can help you implement a serial RS-232C interface. For many purposes, half-duplex operation using a software-driven RS-232C interface provides a good communications link. Many µCs have open-drain I/O pins,....

Single Interface Chip Controls Two Smart Cards:  DN289  Design Notes (Linear Technology) (app note added 1/06)

Single Supply RS-232 Interface for Bipolar to D Converters:  DN29  Design Notes (Linear Technology) (app note added 6/06)

Single wire connects microcontrollers :  10/22/98 EDN-Design Ideas  / (added 11/05)   

Single Wire Keypad Interface Frees Microcontroller I/O Pins:  03/31/05 EDN Design Ideas  / (added 5/05)  Using this interface topology, you can reduce the number of keypad interface wires to just one and thus save critical microcontroller I/O ports.

Sio Input/Output Register Description:  National Semiconductor Application Note   (app note added 2/06)

Small Mezzanine-Board Format Offers More I/O:  04/10/99 EDN-Design Ideas / (added 6/06)  [Note:  File contains multiple circuits.  Scroll to find this one.]  You can now get both modules and carrier boards for the PC-MIP mezzanine format. MEN and SBS-Greenspring (now called SBS Technologies) developed the format as a smaller alternative to PMC modules and lets you put six PCI-based modules on any CompactPCI, PCI, or VME motherboards. Motorola sponsors the format, and about 20 companies now support it. PC-MIP uses an unaltered PCI bus and the same connectors as PMC but in a layout measuring 47X90 mm....

Smart Sensor can Node using the MCP2510 and PIC16F876:  Microchip Application Note Published 16-Aug-00   (app note added 2/06)

Smbus Accelerator Improves Data Integrity:  DN193  Design Notes (Linear Technology) (app note added 1/06)

Software Code EE-162 :  EE-162 SoftwareCode-Analog Device Application Notes  (app note added 6/06) 

Software Code EE-236 :  EE-236 Analog Devices Application Notes  (app note added 2/06)

Software Code EE-247 :  EE-247 Analog Devices Application Notes  (app note added 2/06)

Software Code EE-248 :  EE-248 Analog Devices Application Notes  (app note added 2/06)

Software Driver for the HPC Universal Peripheral Interface Port:  National Semiconductor Application Note   (app note added 2/06)

Software I2C Routine for the COP8:  National Semiconductor Application Note   (app note added 6/06)

Software Implements Digital Potentiometer:  06/08/95 EDN-Design Ideas / (added 11/05)

Software Makes Full Use of 8051's Interrupt System:  12/06/01 EDN Design Ideas  /  (added 1/05)  The program in Listing 1 uses a pseudo-RETI instruction to provide a five-priority-level interrupt system for the 8051P microcontroller. The interrupt-priority order, from high to low, is INT0 IT0 INT1 IT1 INTP. Before the pseudo-RETI instruction arrives in the IT0 or IT1 interrupt-service routine, the address of the first instruction, which is after the pseudo-RETI instruction, goes ba... ...

Software PLL locks VCXO to reference :  08/03/98 EDN-Design Ideas  / (added 2/06)

Software Provides Three-Priority-Level Interrupt for 8051:  09/14/00 EDN-Design Ideas / (added 11/05) 

Software Reset uses I˛C I/O Port:  05/16/02 EDN Design Ideas  /  (added 1/05)  You can use the circuit in Figure 1 to allow the I2C or SMBus to control device resets in a system by using the PCA9554 I2 C I/O-port IC. Normally, a reset function takes an active-low signal. On power-up of the PCA9554, the IC sets all the I/O pins as inputs. The 4.7-kΩ pull-down resistor on each I/O ensures that all the active-low reset pins are initially in a low state during power-up....

Software Routine Minimizes Large Logic Tables:  07)/03/97 EDN-Design Ideas / (added 11/05)  

Software routine stabilizes hardware register :  07)/18/96 EDN-Design Ideas / (added 11/05) 

Software Snippet Provides Improved Subset Sum Algorithm:  09/25/03 EDN Design Ideas  /  (added 1/05)  The subset-sum problem is one of the most frequently occurring NP (nondeterministic, polynomial-time)-complete) problems. It asks whether a subset of numbers in a set of positive integers adds up exactly to a given value. A relaxed version of the problem tries to identify a subset of numbers that adds up to a maximum value no greater than a given value....

Software speeds 8051 RS-232C receiver :  12/04/97 EDN-Design Ideas / (added 11/05)  

Sonic Distortion:  (electronic circuit added 10/06)

Sound Blaster Microphone PreAmplifier:  (electronic circuit added 11/05)

Sound Blaster Preamp: Fixes that Well known problem and needs no Batteries :  The Sound Blaster 16 PCI and Sound Blaster 16 ISA do not have a very sensitive microphone input. This little one transistor amplifier is powered directly from the microphone jack on the sound card and has LOTS of gain. Just put a 100uF bypass capacitor in parallel with the diode to increase gain even more. Note that sound cards other than those mentioned above might not supply the correct power to run this amplifier.  (added 2/05)

Sound Card Interface with Tone Keyer:  This is an improved version of the audio interface commonly used to connect a computer soundcard to a transceiver's receive and transmit audio circuits. This kind of interface is used by computer programs that send and receive SSTV, RTTY, CW, PSK31 and various other digital modes entirely in software. Soundcard interfaces are not data controllers, TNCs, decoders or signal processors. (added 4/05)

Soundcard Joystick Port Problem Solver:  (schematic / circuit (added (6/03)

Stepping Motor Driver: Minimalist circuit uses one CMOS gate and is reversible :  Many floppy drives and some subminiature printers contain bipolar stepping motors that draw very little current. The first circuit will drive small 5 volt steppers directly but you can switch to a 407)0 chip and add output transistors to drive heaftier loads at higher voltages. The circuit is not particularly susceptible to motor transients and supports FULL STEPS FORWARD, FULL STEPS REVERSE, ACTIVE HOLD, and POWER OFF aka RELEASED. If the motor does not turn then swap around the leads of ONE of the two coils. To reverse the sense of the EN signal simply rework the circuit around an XNOR gate. (added 2/05)

Storage Area Network (SAN):  Intersil Application Block Diagram  (app note added 2/06)

Summary of Well Known Interface Standards:  National Semiconductor Application Note   (app note added 2/06)

Super I/O Demo Board Design Guide:  National Semiconductor Application Note   (app note added 2/06)

Supervisory circuit monitors modem connection :  04/09/98 EDN-Design Ideas  / (added 11/05)   

S-Video to Composite Video Adapter:  This simple adapter can be used to convert Y/C video (S-video) to a composite video. This adapter is useful in cases where your video output device has only S-video output but your signal source accepts only composite video input. This circuit works with both PAL and NTSC video standards. (added 4/05)

Switching RGB Video between Monitor and TV using Pi5V330:  Pericom Semiconductor Application Brief # 010 (app note added 02/05)

SWTP PR-40 Printer Interface Schematics:  (diagram added 2/07)

Synchronizing Controller Detects Baud Rate:  03/03/98 EDN-Design Ideas  / (added 03/03)  -A simple and inexpensive implementation using an eight-pin12C508 controller (Microchip Technology, Chandler, AZ) provides both bit-rate detection and a synchronous, appended-clock output from an asynchronous input-data stream -A simple and inexpensive implementation using an eight-pin 12C508 controller (Microchip Technology, Chandler, AZ) provides both bit-rate detection and a synchronous, appended-clock output from an asynchronous input-data stream (Figure 1a). This implementation relies on two code sequences (Figure 1b). A training sequence first identifies the bit rate. This sequence begins with register and counter initialization followed by a gap detection. Following the detected, 0.325-sec, high-true gap, the controller monitors eight transitions. Between each....