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Maxim > Design Support > Technical Documents > Application Notes > Amplifier and Comparator Circuits > APP 4626
Maxim > Design Support > Technical Documents > Application Notes > Microprocessor Supervisor Circuits > APP 4626
Keywords: IC testing, quad op amps, switch debouncers, pulse generators, serial programming
APPLICATION NOTE 4626
Multiple-Pulse Generator Aids IC Testing
By: Kevin Frick
Oct 21, 2009
Abstract:
Comprising a
quad op amp, logic gate, pushbutton switch, debounce circuit, and D flip-flop, this
circuit substitutes for a microcontroller or arbitrary-waveform generator in producing the serial digital codes
needed to program a single IC input.
This design idea appeared in the September 1, 2009 issue of Test & Measurement World magazine.
Because ICs continue to shrink in size, even as their complexity increases, the IC packages have grown
smaller even as their pin count drops or remains constant. The resulting burden on pin functionality has
created a need for pin-saving measures like serial programming. For example, multiple pins might have been
available in the past for programming an IC's current or voltage limit, but today's IC may have to encode that
limit as a set number of pulses on a serial line.
A circuit like that of Figure 1 is therefore useful when a microcontroller or arbitrary-waveform generator is not
available. Comprising a quad op amp, logic gate, pushbutton switch, debounce circuit, and D flip-flop, it
generates 500Hz bursts of one, two, or three pulses.
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