Pulse generator including slew rate controller without complementary transistors

• US 5,587,679 A
• Filed: 05/08/1995
• Issued: 12/24/1996
• Est. Priority Date: 05/08/1995
• Status: Expired due to Fees

• Current Assignee: Yokogawa Electric Corporation
• Original Assignee: Yokogawa Electric Corporation
• Inventors: Imamura, Makoto
• Primary Examiner(s): Callahan, Timothy P.
• Assistant Examiner(s): Wells, Kenneth B.
• Application Number:
  US08/436,693
• Time in Patent Office: 596 Days
• Field of Search: 327/172, 327/170, 327/374, 327/375, 327/376, 327/377, 327/108, 327/65, 327/66, 327/67, 327/333, 327/563, 326/17, 326/18, 326/29, 330/252
• US Class Current: 327/170
• CPC Class Codes: H03G 1/0023 in emitter-coupled or cascode amplifiers H03G1/0029 takes precedence
• CPC Class Codes: H03K 4/94 having trapezoidal shape
• CPC Class Codes: H03K 5/02 by amplifying H03K5/04 takes precedence

Abstract

A pulse generator using a buffer for receiving a differential signal and for generating an output signal in response thereto; a first differential amplifier for receiving the output signal from the buffer; and a pair of capacitors connected to the first differential amplifier and being caused to be charged by the buffer for selectively controlling the first differential amplifier; and means for receiving another differential signal from the first differential amplifier to produce a pulse, whereby a slew rate controller is used without requirement of complementary transistors to produce the pulse.

Claims

1. A pulse generator for generating a pulse, comprising:

buffer means for receiving a differential signal and for producing an output signal, said buffer means comprising a pair of selectively controllable current sources;

a first differential amplifier for receiving said output signal from said buffer means and for producing another differential signal, said first differential amplifier comprising a positive input terminal, a negative input terminal, a positive output terminal, and a negative output terminal;

a first capacitor connected between said positive input terminal and said negative output terminal of said first differential amplifier, and being caused to be charged by said buffer means and selectively controlling said first differential amplifier;

a second capacitor connected between said negative input terminal and said positive output terminal of said first differential amplifier, and being caused to be charged by said buffer means and selectively controlling said first differential amplifier;

wherein said another differential signal is obtained at connections of said first and second capacitors and said positive and negative input terminals of said first differential amplifier; and

means for receiving said another differential signal and in response thereto for producing said pulse, whereby a rising slew rate of said pulse is selectively controlled by one of said pair of current sources of said buffer means and a falling slew rate of said pulse is selectively controlled by the other of said pair of current sources of said buffer means without the use of complementary transistors.

2. The generator of claim 1, wherein said buffer means comprises a transistor, and wherein said first differential amplifier comprises an NPN transistor.

3. The generator of claim 1, wherein said buffer means comprises a transistor, and wherein said first differential amplifier comprises a field effect transistor.

4. The generator of claim 3, wherein said field effect transistor comprises GaAs.

5. The generator of claim 1, wherein said means for receiving comprises a second differential amplifier, and wherein said another differential signal produced by said first differential amplifier is supplied to said second differential amplifier, and wherein said second differential amplifier produces said pulse.

6. The generator of claim 1, further comprising:

a rate generating unit for generating a rate signal; and

a pulse width generating unit for receiving said rate signal and for producing a pulse width signal, whereby said pulse width signal is supplied to said means for receiving.

7. The generator of claim 1, further comprising a plurality of pulse generators, and means for controlling the slew rates of pulses produced by said plurality of pulse generators so that said pulses are synchronized with each other.

8. A pulse generator for generating a pulse upon receipt of a pair of differential signals wherein one of said pair of differential signals is at a first level, and the other of said pair of differential signals is at a second and lower level, said pulse generator comprising:

buffer means comprising a first NPN transistor and a second NPN transistor, having emitters thereof connected to a first current source and a second current source, respectively, and having collectors thereof commonly connected;

a first differential amplifier comprising a third NPN transistor and a fourth NPN transistor, having emitters thereof connected to a third current source, and having bases thereof connected to said emitters of said first and second NPN transistors, respectively;

a first capacitor connected between a collector of said third NPN transistor and said base thereof;

a second capacitor connected between a collector of said fourth NPN transistor and said base thereof; and

a second differential amplifier comprising a fifth NPN transistor and a sixth NPN transistor, having emitters thereof connected to a fourth current source, and having bases thereof connected to said bases of said third and fourth NPN transistors, respectively, whereby

said pulse is generated at one of said collectors of said fifth and sixth NPN transistors.

9. The generator of claim 8, further comprising means for controlling current from at least one of said first and second current sources thereby to control a slew rate of said pulse.

10. The generator of claim 8, further comprising means for controlling said second differential amplifier thereby to control the voltage level of said pulse.

11. The generator of claim 8, further comprising

a rate generating unit for generating a rate signal;

a pulse width generating unit for receiving said rate signal and for producing a pulse width signal; and

means for applying said pulse width signal to said second differential amplifier to thereby produce said pulse.

12. The generator of claim 8, further comprising a plurality of pulse generators, and means for controlling slew rates of pulses outputted by said plurality of pulse generators to be synchronized with each other.