Gary G Fang, 57San Francisco, CA

6380877, Apr 30, 2002

Apr 23, 2001

09/840661

David Castaneda - Sunnyvale CA
Gary G. Fang - San Jose CA
Chowdhury F. Rahim - Saratoga CA

Maxim Integrated Products, Inc. - Sunnyvale CA

H03M 178

341154, 341144

Operating range of R-2R ladders for digital to analog converters (DACs) is improved by increasing resistance in series with a termination switch in a termination leg to avoid transistor saturation for increasing DAC resolution, increasing reference voltage range, or other application. The switched R-2R ladder circuit is modified to compensate for increasing resistance to maintain proper resistor matching for generation of the appropriate range of analog output voltages for a digital input signal.

6266001, Jul 24, 2001

May 5, 1999

9/305908

Gary G. Fang - San Jose CA
David Castaneda - Sunnyvale CA
Chowdhury F. Rahim - Saratoga CA

Maxim Integrated Products, Inc. - Sunnyvale CA

H03M 166

341144

A varying power supply range, that can exceed the breakdown voltage of switches within a DAC, is used to generate positive and negative generated OFF voltages substantially fixed and less than the breakdown voltage to accommodate a wide range of analog reference voltages and power supply voltages. The digital input signal having digital input levels is received by a TTL/CMOS input receiver and level shifted to logic levels having the positive and negative generate voltage levels. A circuit matches switch resistance and forms positive and negative switch ON voltage levels from the voltage levels of the input positive and negative analog reference levels. Switch drivers properly drive control terminals of the switches with appropriate voltage levels avoiding switch breakdown in response to the digital input signal.

6154063, Nov 28, 2000

Apr 26, 1999

9/299359

Gary G. Fang - San Jose CA
David Castaneda - Sunnyvale CA
Chowdhury F. Rahim - Saratoga CA

Maxim Integrated Products, Inc. - Sunnyvale CA

H03K 19018

326126

Buffers having an output pull-up transistor controlled by the input signal, an output pull-down transistor and a pull-down transistor control circuit. A current source provides a current that is divided between the pull-up transistor and the pull-down transistor control circuit to maintain the desired output voltage. A boost capacitor is coupled between the output and the pull-down transistor control circuit to provide good dynamic response to the circuit even in the presence of substantial capacitive loads on the output. In addition a second capacitor is coupled between the pull-down transistor control circuit and a fixed voltage to provide a low frequency pole internal to the circuit. The connection of the boost capacitor to the pull-down transistor control circuit and the connection of the second capacitor to the pull-down transistor control circuit are separated by a substantial resistance, allowing the effect of each capacitor to be substantially independent of each other. Exemplary circuits are disclosed incorporating these and other features.

6304199, Oct 16, 2001

May 5, 1999

9/305909

Gary G. Fang - San Jose CA
David Castaneda - Sunnyvale CA
Chowdhury F. Rahim - Saratoga CA

Maxim Integrated Products, Inc. - Sunnyvale CA

H03M 106

341118

Asynchronous and synchronous deglitch controllers controlling switches of sample and hold circuits for deglitching digital to analog converters. Asynchronous and synchronous deglitch controllers detect transitions in the state of the digital input code to trigger or allow a one shot pulse to cause sample and hold circuits to go into hold mode for the period of the one shot pulse. Secondary glitch cancellation circuitry models the environment of the sample and hold circuit to emulate secondary glitch impulse generation. A differential amplifier substantially cancels secondary glitches related to the parasitic charges generated by the switching of the sample and hold circuit.

6222473, Apr 24, 2001

Apr 26, 1999

9/299691

David Castaneda - Sunnyvale CA
Gary G. Fang - San Jose CA
Chowdhury F. Rahim - Saratoga CA

Maxim Integrated Products, Inc. - Sunnyvale CA

H03M 178

341154

Operating range of R-2R ladders for digital to analog converters (DACs) is improved by increasing resistance in series with a termination switch in a termination leg to avoid transistor saturation for increasing DAC resolution, increasing reference voltage range, or other application. The switched R-2R ladder circuit is modified to compensate for increasing resistance to maintain proper resistor matching for generation of the appropriate range of analog output voltages for a digital input signal.