Buffer Amplifier and LED Improve PWM Power Controller's Low Load Operation:  09/15/05  EDN -Design Ideas  /  (added 6/06)   PWM IC is enhanced with discrete components for wider-range operation.

Cheap PWM IC Makes Synchronous Gate Driver:  02/04/99 EDN-Design Ideas  / (added 6/03)  A system with a µP, memory, and peripherals usually requires several power-supply voltages. Designers typically use local switching regulators to produce the desired voltage rails. One of the most common topologies, the synchronous buck regulator, converts a 5 or 12V bus to some other, lower voltage. ....

Circuit Converts Pulse Width to Voltage:  10/25/01 EDN Design Ideas  /  (added 1/05)  The circuit in Figure 1 converts pulse information to a clean dc voltage by the end of a single incoming pulse. In another technique, an RC filter can convert a PWM signal to an averaged dc voltage, but this method is slow in responding. Converting low-duty-cycle pulse information is slower yet. ...

Circuit Converts Pulse Width to Voltage #2:  10/28/99 EDN-Design Ideas / (added 6/06) -The circuit is optimized for a positive-going pulse width of1 to2 msec, repeating at intervals of approximately17 msec. The output produces a voltage of0.95V for a1-msec pulse to2.25V for a2-msec pulse.

Circuit for Driving Microcontroller Friendly PWM Generators:  Microchip Application Note Published 27-Jun-05   (app note added 2/06)

Circuit Provides Efficient PWM:  02/18/99 EDN-Design Ideas / (added 6/03) You often need to control the duty cycle of a square wave. The circuit in Figure 1 works from a single 5V supply at a frequency of 100 kHz. With minor component changes, you can configure it for a range of frequencies. The circuit consists of a ramp (sawtooth) oscillator and a comparator. The circuit compares the ramp to an externally applied voltage, VCNTRL. When VCNTRL is greater than the ramp voltage, the PWM output is 5V. The sawtooth oscillator consists of a current source (R1, R2, R3, and Q1), a timing capacitor (C1), and the oscillator-control circuitry (R4, R5, R6, and IC1A). The oscillator-control circuitry sets the upper and lower voltages of the timing capacitor at 3 and 1V....

Circuit sequences supplies for FPGAs:  01/23/03 EDN Design Ideas  /  (added 1/05)  System designers must consider the timing and voltage differences between core and I/O power supplies (in other words, power-supply sequencing) during power-up and power-down. The possibility of a latch-up failure or excessive current draw exists when power-supply sequencing does not occur properly. The trigger for latch-up may occur if power supplies apply different potentials to the core and ......

Circuits provide 4-to 20-mA PWM control :  09/01/98 EDN-Design Ideas  / (added 2/06)

DDS circuit generates precise PWM Waveforms:  10/02/03 EDN Design Ideas  /  (added 1/05)  Pulse-width modulation is a simple way to modulate, or change, a square wave. In its basic form, the duty cycle of the square wave changes according to some input. The duty cycle is the ratio of high and low times in the square wave. A waveform with a 50% duty cycle would be high for 50% of the time and low for 50% of the time, and a waveform with a 10% duty cycle would be high for 10% and low ......

Eight Channel Eight Bit PWM Controller:  National Semiconductor Application Note 05-Aug-1995 (app note added 8/02)

Embedding Temperature Information in the ADXL202's PWM Outputs:  AN-600 Analog Devices Application Notes  (app note added 6/06)

Frequency and Resolution Options for PWM Outputs:  Microchip Application Note Published 26-Aug-97   (app note added 2/06)

Fuel Injector Pulse Width Monitor:  (circuit / schematic design added 6/06)

Generate stabilized PWM signals:  08/17/00 EDN-Design Ideas  / (added 2/06)   

Green Current Mode PWM Controller FAN7601 / AN-4129:  Fairchild Application Notes / (app note added 6/06)

Li-ION Charge Termination IC Interfaces with PWM Switchers:  DN242  Design Notes (Linear Technology) (app note added 6/06)

Low power PWM circuit is simple inexpensive:  01/06/00 EDN-Design Ideas / (added 2/06)

Make a DAC with a Microcontroller's PWM Timer:  09/05/02  EDN Design Ideas / (added 2/05)    Many embedded-microcontroller applications require generation of analog signals. An integrated or stand-alone DAC fills the role. However, you can often use PWM signals for generating the required analog signals. You can use PWM signals to create both dc and ac analog signals. This Design Idea shows how to use a PWM timer to simultaneously create a sinusoid, a ramp, and a dc voltage..

Modulator's Design Cuts FPGA's Gate Count:  01/06/94 EDN-Design Ideas / (added 3/03) The pulse-width modulator (PWM) macro in Fig 1 requires only half as much logic as a conventional 2-counter design. With the help of extra logic, a synchronous, loadable up/down counter can encode information in the duty cycle of a constant-frequency, constant-amplitude signal....

Multiple PWM Output Soft-Start Controller:  Microchip Application Note Published 29-Nov-05   (app note added 2/06)

Nanosecond Width Pulse Generator Provides High Performance:  11/11/04 EDN Design Ideas  / (added 5/05)  If you need to produce extremely fast pulses in response to an input and trigger, such as for sampling applications, the predictably programmable short-time-interval generator has broad uses. The circuit of Figure 1, built around a quad high-speed comparator and a high-speed gate, has settable 0to 10-nsec output width with 520-psec, 5V transitions.

One Shot Remembers Input Pulse Width:  07/18/96  EDN-Design Ideas  / (added6/03)    The circuit in Figure 1a remembers the width of an input pulse at the in terminal. After the input pulse returns to zero, a trigger input causes an output pulse to occur at the out terminal. This output pulse is proportional to the width of the input pulse. R2 and R3 set this pulse-width ratio. For the values shown, the output pulse is half the width of the input pulse, but you can set the output-pulse width to any fraction or multiple by selecting the ratio of R2/R3. The circuit's operation depends on this resistor ratio but is independent of power-supply variation, temperature drift, and the tolerances of R1 and C1.  The waveforms in Figure 1b help explain the circuit's operation. The switches....