公开(公告)号：HK26792A

公开(公告)日：1992-04-16

申请号：HK26792

申请日：1992-04-09

Applicant: MOTOROLA INC

Inventor： PACE WILSON DAVID ,  WELTY DENNIS LEE

IPC: H04M9/10 ,  H03G3/20

Abstract: A DC control loop is disclosed which is used in conjunction with a control circuit to precisely set the maximum control voltage produced by the control circuit for maximizing the gain of an attenuator controlled thereby. The attenuator includes a current mirror having an output for sourcing a DC current the magnitude of which is proportional to the gain of the attenuator and the control circuit includes a capacitor that is charged or discharged accordingly to vary the magnitude of the control voltage. The DC control loop includes a circuit for sinking the current supplied from the current mirror and a current of a predetermined magnitude, the circuit being coupled to the output of the current mirror and a transistor which is turned on when the magnitude of the current from the current mirror equals the magnitude of the current sank by the circuit to inhibit further charge or discharge of the capacitor whereby the gain of the attenuator is held at a predetermined maximum value.

公开(公告)号：FR2603397A1

公开(公告)日：1988-03-04

申请号：FR8712168

申请日：1987-09-01

Applicant: MOTOROLA INC

Inventor： PACE WILSON DAVID ,  WELTY DENNIS LEE

IPC: H04M9/10 ,  G05F3/26 ,  H03G3/30

Abstract: A DC control loop is disclosed which is used in conjunction with a control circuit to precisely set the maximum control voltage produced by the control circuit for maximizing the gain of an attenuator controlled thereby. The attenuator includes a current mirror having an output for sourcing a DC current the magnitude of which is proportional to the gain of the attenuator and the control circuit includes a capacitor that is charged or discharged accordingly to vary the magnitude of the control voltage. The DC control loop includes a circuit for sinking the current supplied from the current mirror and a current of a predetermined magnitude, the circuit being coupled to the output of the current mirror and a transistor which is turned on when the magnitude of the current from the current mirror equals the magnitude of the current sank by the circuit to inhibit further charge or discharge of the capacitor whereby the gain of the attenuator is held at a predetermined maximum value.

公开(公告)号：DE2757292A1

公开(公告)日：1978-07-06

申请号：DE2757292

申请日：1977-12-22

Applicant: MOTOROLA INC

Inventor： PACE WILSON DAVID

IPC: H03K17/90 ,  F02P7/07 ,  H01L27/22 ,  H01L23/56 ,  F02P1/08

公开(公告)号：HK37793A

公开(公告)日：1993-04-30

申请号：HK37793

申请日：1993-04-22

Applicant: MOTOROLA INC

Inventor： PACE WILSON DAVID ,  WELTY DENNIS LEE

IPC: H04M1/60 ,  H04M9/10 ,  H04M9/08

Abstract: A speakerphone circuit having fast sensitive switching between the receive mode and the transmit mode is disclosed which includes circuitry for providing four point sensing at the input and output of both the transmit and receive attenuators located in the transmit and receive signal paths thereof for controlling the gains of the attenuators in a complementary manner. A logic control circuit comprising a controller circuit provides an attenuator algorithm that first detects that voice signals are present in both signal paths then quickly causes the attenuators to be set to equal gains during a fast idle mode to then allow the stronger of the two signals to set the operating mode of the speakerphone.

公开(公告)号：DE3683105D1

公开(公告)日：1992-02-06

申请号：DE3683105

申请日：1986-08-07

Applicant: MOTOROLA INC

Inventor： PACE WILSON DAVID ,  WELTY DENNIS L

IPC: H03G3/02 ,  H03G3/00 ,  H03G3/30 ,  H03G3/32 ,  H04B1/44 ,  H04M1/60 ,  H04M9/08

Abstract: A control circuit (l2) for developing a modulated voltage which is proportional to absolute temperature includes a thermal current source (70) for producing current having a predetermined temperature coefficient and current steering circuitry (74, 80) for proportionally steering the current between first and second outputs in response to a direct current bias voltage applied thereto wherein the current at the first output of the current steering circuitry flows through a resistor (76). The resistor is connected between a source of direct current operating potential and the first output of the current steering circuitry whereby the voltage developed thereacross due to the current steered therethrough is proportional to absolute temperature.

公开(公告)号：GB2194694B

公开(公告)日：1991-01-02

申请号：GB8717706

申请日：1987-07-27

Applicant: MOTOROLA INC

Inventor： PACE WILSON DAVID ,  WELTY DENNIS LEE

IPC: H04M9/10

Abstract: A DC control loop is disclosed which is used in conjunction with a control circuit to precisely set the maximum control voltage produced by the control circuit for maximizing the gain of an attenuator controlled thereby. The attenuator includes a current mirror having an output for sourcing a DC current the magnitude of which is proportional to the gain of the attenuator and the control circuit includes a capacitor that is charged or discharged accordingly to vary the magnitude of the control voltage. The DC control loop includes a circuit for sinking the current supplied from the current mirror and a current of a predetermined magnitude, the circuit being coupled to the output of the current mirror and a transistor which is turned on when the magnitude of the current from the current mirror equals the magnitude of the current sank by the circuit to inhibit further charge or discharge of the capacitor whereby the gain of the attenuator is held at a predetermined maximum value.

公开(公告)号：HK51283A

公开(公告)日：1983-11-11

申请号：HK51283

申请日：1983-11-03

Applicant: MOTOROLA INC

Inventor： PACE WILSON DAVID

IPC: H03K17/90 ,  F02P7/07 ,  H01L27/22 ,  G01R33/06

公开(公告)号：HK5194A

公开(公告)日：1994-01-28

申请号：HK5194

申请日：1994-01-20

Applicant: MOTOROLA INC

Inventor： PACE WILSON DAVID ,  WEITY DENNIS L

IPC: H03G3/02 ,  H03G3/00 ,  H03G3/30 ,  H03G3/32 ,  H04B1/44 ,  H04M1/60 ,  H04M9/08

Abstract: A control circuit (l2) for developing a modulated voltage which is proportional to absolute temperature includes a thermal current source (70) for producing current having a predetermined temperature coefficient and current steering circuitry (74, 80) for proportionally steering the current between first and second outputs in response to a direct current bias voltage applied thereto wherein the current at the first output of the current steering circuitry flows through a resistor (76). The resistor is connected between a source of direct current operating potential and the first output of the current steering circuitry whereby the voltage developed thereacross due to the current steered therethrough is proportional to absolute temperature.

公开(公告)号：FR2619980B1

公开(公告)日：1992-05-29

申请号：FR8712169

申请日：1987-09-01

Applicant: MOTOROLA INC

Inventor： PACE WILSON DAVID ,  WELTY DENNIS LEE

IPC: H04M9/08 ,  H04B1/46

公开(公告)号：FR2619980A1

公开(公告)日：1989-03-03

申请号：FR8712169

申请日：1987-09-01

Applicant: MOTOROLA INC

Inventor： PACE WILSON DAVID ,  WELTY DENNIS LEE

IPC: H04M9/08

Abstract: The invention relates to a circuit for a microphone loudspeaker unit which effects a rapid and responsive switching between the reception mode and transmission mode, this circuit offering a detection at four points in the region of the input and of the output of the transmission attentuator 12 and of the reception attenuator 14 for the purpose of controlling the gains of the attenuators, in a complementary manner. A control logic circuit 36 produces an algorithm which, firstly, detects whether voice signals are present on the two lines, then rapidly places the attenuators at equal gain levels during a rapid idle-time mode, so as to allow the stronger of the two signals to fix the mode of operation of the microphone loudspeaker unit.