公开(公告)号：JPH0542179B2

公开(公告)日：1993-06-25

申请号：JP50172582

申请日：1982-04-21

Applicant: MOTOROLA INC

Inventor： KELLEY STEPHEN HARLOW ,  ULMER RICHARD WALTER

IPC: H03H19/00 ,  H03M1/00 ,  H03M1/80

公开(公告)号：JPS58500684A

公开(公告)日：1983-04-28

申请号：JP50172582

申请日：1982-04-21

Applicant: MOTOROLA INC

Inventor： KELLEY STEPHEN HARLOW ,  ULMER RICHARD WALTER

IPC: H03H19/00 ,  H03M1/00 ,  H03M1/80

公开(公告)号：DE3278065D1

公开(公告)日：1988-03-03

申请号：DE3278065

申请日：1982-10-04

Applicant: MOTOROLA INC

Inventor： WURZBURG HENRY ,  KELLEY STEPHEN HARLOW

IPC: H04Q3/58 ,  H04M9/00 ,  H04Q3/60 ,  H04Q5/20 ,  H04Q11/04

Abstract: In a digital telephone system, a digital private automatic branch exchange (PABX) has a plurality of digital line cards for coupling the PABX to respective digital subscriber sets via subscriber lines. In each digital line card, a digital loop transceiver operates in a master mode to couple the digital data bus of the PABX to the subscriber line via a subscriber line interface circuit in response to control signals provided by the PABX on the control bus thereof. In each digital subscriber set, a digital loop transceiver operates in a slave mode to couple the subscriber set to the subscriber line via a subscriber line interface circuit and to provide the several control signals required by the other components thereof. The digital loop transceivers provide communication on each of two communication channels, with the digital data words of the first channel being treated the same as the digital data words of the second channel.

公开(公告)号：IT8247698D0

公开(公告)日：1982-02-01

申请号：IT4769882

申请日：1982-02-01

Applicant: MOTOROLA INC

Inventor： KELLEY STEPHEN HARLOW ,  ULMER RICHARD WALTER ,  WHATLEY ROGER ALAN

IPC: H03F3/34 ,  H03F1/30 ,  H03F

Abstract: A temperature stable bandgap voltage reference source utilizing bipolar transistors biased at different emitter current densities is provided. Switched capacitors are used to input the Vbe and the DELTA Vbe of the transistors (PTC and NTC voltages, respectively,) into an operational amplifier to provide a reference voltage proportional to the sum of the PTC and NTC voltages. Proper selection of the ratio of the switched capacitors renders the reference voltage substantially independent of temperature. In a modified form of the reference, the reference amplifier is implemented by an auto-zeroed operational amplifier which uses switched capacitor techniques and an integrated capacitor to achieve the auto-zeroing function.

公开(公告)号：CA1182924A

公开(公告)日：1985-02-19

申请号：CA401210

申请日：1982-04-19

Applicant: MOTOROLA INC

Inventor： KELLEY STEPHEN HARLOW ,  ULMER RICHARD WALTER

IPC: H03H19/00 ,  H03M1/00 ,  H03M1/80 ,  H03M1/66

Abstract: A CAPACITIVE DAC TO FILTER INTERFACE CIRCUIT An operational amplifier capable of selectively performing a variety of circuit functions is provided. A single operational amplifier utilizes switched capacitors for sampling and holding an input signal, for establishing a low frequency pole, for applying the sample to an output capacitance to charge the capacitance and for comparing the input signal with a reference. The multi-function circuit provides a large savings in circuit area and permits versatility of circuit applications. One embodiment of the invention is to utilize a companding DAC having a capacitor array which may be used as the output capacitance of the operational amplifier circuit. The DAC provided utilizes an R ladder DAC coupled directly to a C DAC and has a switching structure that is simpler than comparable prior art circuits. The DAC is asynchronous and has programmable A- and Mu-225 law PCM conversion capability. Coupled directly to the C DAC is an operational amplifier receive filter circuit which utilizes the C DAC as an input capacitor thereby eliminating the need for a buffer amplifier and allowing the DAC to be used for both analog to digital and digital to analog conversion.

公开(公告)号：DE3279500D1

公开(公告)日：1989-04-06

申请号：DE3279500

申请日：1982-04-21

Applicant: MOTOROLA INC

Inventor： KELLEY STEPHEN HARLOW ,  ULMER RICHARD WALTER ,  ALLGOOD ROBERT NOBLE ,  WURZBURG HENRY

IPC: H03F1/34 ,  H03F1/30 ,  H03H19/00 ,  H03M1/12

Abstract: An operational amplifier capable of selectively performing a variety of circuit functions is provided. A single operational amplifier utilizes switched capacitors for sampling and holding an input signal, for establishing a low frequency pole, for applying the sample to an output capacitance to charge the capacitance and for comparing the input signal with a reference. The multi-function circuit provides a large savings in circuit area and permits versatility of circuit applications. One embodiment of the invention is to utilize a companding DAC having a capacitor array which may be used as the output capacitance of the operational amplifier circuit. The DAC provided utilizes an R ladder DAC coupled directly to a C DAC and has a switching structure that is simpler than comparable prior art circuits. The DAC is asynchronous and has programmable A-and Mu-255 law PCM conversion capability. Coupled directly to the C DAC is an operational amplifier receive filter circuit which utilizes the C DAC as an input capacitor thereby eliminating the need for a buffer amplifier and allowing the DAC to be used for both analog to digital and digital to analog conversion.

公开(公告)号：IT1186660B

公开(公告)日：1987-12-04

申请号：IT4769882

申请日：1982-02-01

Applicant: MOTOROLA INC

Inventor： KELLEY STEPHEN HARLOW ,  ULMER RICHARD WALTER ,  WHATLEY ROGER ALAN

IPC: H03F3/34 ,  H03F1/30 ,  H03F

Abstract: A temperature stable bandgap voltage reference source utilizing bipolar transistors biased at different emitter current densities is provided. Switched capacitors are used to input the Vbe and the DELTA Vbe of the transistors (PTC and NTC voltages, respectively,) into an operational amplifier to provide a reference voltage proportional to the sum of the PTC and NTC voltages. Proper selection of the ratio of the switched capacitors renders the reference voltage substantially independent of temperature. In a modified form of the reference, the reference amplifier is implemented by an auto-zeroed operational amplifier which uses switched capacitor techniques and an integrated capacitor to achieve the auto-zeroing function.

公开(公告)号：HK65290A

公开(公告)日：1990-08-31

申请号：HK65290

申请日：1990-08-23

Applicant: MOTOROLA INC

Inventor： WURZBURG HENRY ,  KELLEY STEPHEN HARLOW

IPC: H04Q3/58 ,  H04M9/00 ,  H04Q3/60 ,  H04Q5/20 ,  H04Q11/04

Abstract: In a digital telephone system, a digital private automatic branch exchange (PABX) has a plurality of digital line cards for coupling the PABX to respective digital subscriber sets via subscriber lines. In each digital line card, a digital loop transceiver operates in a master mode to couple the digital data bus of the PABX to the subscriber line via a subscriber line interface circuit in response to control signals provided by the PABX on the control bus thereof. In each digital subscriber set, a digital loop transceiver operates in a slave mode to couple the subscriber set to the subscriber line via a subscriber line interface circuit and to provide the several control signals required by the other components thereof. The digital loop transceivers provide communication on each of two communication channels, with the digital data words of the first channel being treated the same as the digital data words of the second channel.

公开(公告)号：HK103188A

公开(公告)日：1988-12-30

申请号：HK103188

申请日：1988-12-22

Applicant: MOTOROLA INC

Inventor： KELLEY STEPHEN HARLOW ,  ULMER RICHARD WALTER ,  WHATLEY ROGER A

IPC: H03F1/02

公开(公告)号：DE3270199D1

公开(公告)日：1986-05-07

申请号：DE3270199

申请日：1982-01-25

Applicant: MOTOROLA INC

Inventor： KELLEY STEPHEN HARLOW ,  ULMER RICHARD WALTER ,  WHATLEY ROGER A

IPC: H03F3/34 ,  H03F1/30 ,  H03F1/02

Abstract: A temperature stable bandgap voltage reference source utilizing bipolar transistors biased at different emitter current densities is provided. Switched capacitors are used to input the Vbe and the DELTA Vbe of the transistors (PTC and NTC voltages, respectively,) into an operational amplifier to provide a reference voltage proportional to the sum of the PTC and NTC voltages. Proper selection of the ratio of the switched capacitors renders the reference voltage substantially independent of temperature. In a modified form of the reference, the reference amplifier is implemented by an auto-zeroed operational amplifier which uses switched capacitor techniques and an integrated capacitor to achieve the auto-zeroing function.