Oscillators – Solid state active element oscillator – Transistors
Reexamination Certificate
2005-11-15
2008-03-11
Lee, Benny (Department: 2817)
Oscillators
Solid state active element oscillator
Transistors
C331S143000, C327S182000
Reexamination Certificate
active
07342463
ABSTRACT:
A timing circuit operates by applying an arbitrary voltage across a resistance, and using the resulting current to generate a charging current which charges and/or discharges a capacitance to an endpoint voltage. Additional circuitry is arranged such that the capacitance is charged and/or discharged until its voltage crosses a threshold which is proportional to one of the resistance's endpoint voltages, such that the capacitance's endpoint voltage tracks the resistance's endpoint voltage. Thus, the resistor voltage can vary with supply voltage or temperature, or the resistance value itself can vary, without materially affecting the timing relationships. The arbitrary voltage is preferably provided with a pair of diode-connected transistors connected in series with the resistance, so that a single transistor operated at the same current density as one of the diode-connected transistors establishes the threshold voltage and detects when the capacitor voltage reaches the threshold.
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patent: 5592128 (1997-01-01), Hwang
patent: 5668508 (1997-09-01), Pulvirenti et al.
patent: 6326859 (2001-12-01), Goldman et al.
patent: 6924709 (2005-08-01), Bashar
patent: WO 2004055968 (2004-07-01), None
Analog Devices 1.2 MHz DC-DC Step-Up Switching Converter, ADP1610, Oct. 2004, pp. 1, 4-16.
Brokaw A. Paul
Li Yuxin
Analog Devices Inc.
Gannon Levi
Koppel, Patrick, Heybl & Dawson
Lee Benny
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