Rapid turn-on voltage regulator

• US 4,574,232 A
• Filed: 10/21/1983
• Issued: 03/04/1986
• Est. Priority Date: 10/21/1983
• Status: Expired due to Term

• Current Assignee: Alliant Techsystems Incorporated (Northrop Grumman Corporation)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Petty, Thomas J.
• Primary Examiner(s): BEHA JR, WILLIAM
• Application Number:
  US06/544,931
• Time in Patent Office: 865 Days
• Field of Search: 323/268, 323/273, 323/280, 323/281, 323/901, 330/257
• US Class Current: 323/268
• CPC Class Codes: G05F 1/468 characterised by reference voltage circuitry, e.g. soft start, remote shutdown
• CPC Class Codes: Y10S 323/901 Starting circuits

Abstract

An operational amplifier having negative feedback to provide voltage regulation and having a current pulse generator connected thereto for supplying a relatively large pulse of current to the amplifier upon initial application of power thereto for charging capacitances in the amplifier to quickly bring the circuit to an operating condition.

Claims

1. A rapid turn-on voltage regulator comprising:

amplifier means, including negative feedback, for providing a regulated voltage source at an output thereof,

a power source coupled to said amplifier means;

a current source coupled to said amplifier means and said power source for providing a relatively small bias current to said amplifier means; and

current pulse generating means coupled to said amplifier means and said power source for providing a pulse of current which is large relative to the bias current, to said amplifier means to rapidly bring said amplifier means to an operating level.

2. A rapid turn-on voltage regulator as claimed in claim 1 wherein the current source includes a microampere current source and a current mirror in an output thereof coupled to said amplifier means for adjusting current flowing in said amplifier means to equal that of said microampere current source and said current pulse generating means provides a pulse of current substantially larger than the bias current.

3. A rapid turn-on voltage regulator as claimed in claim 2 wherein the microampere current source includes a junction field effect transistor having source, drain and gate terminals and a known pinch-off voltage, and a resistor having one terminal connected to the source terminal of said transistor and an opposite terminal connected to the gate terminal of said transistor, said resistance means having a resistance value which in conjunction with the pinch-off voltage of said transistor limits the current flowing through the source/drain terminals of said transistor to a predetermined microampere current source.

4. A rapid turn-on voltage regulator as claimed in claim 3 wherein the current mirror is coupled to one of the opposite terminal of said resistor and the drain terminal of said transistor for mirroring the microampere current flowing through said transistor into said amplifier means.

5. A rapid turn-on voltage regulator as claimed in claim 4 wherein said amplifier means, portions of said power source, said current source and said current pulse generating means are formed in a single integrated circuit.

6. A rapid turn-on voltage regulator as claimed in claim 1 wherein the power source includes initial turn-on circuitry and an operating power source.

7. A rapid turn-on voltage regulator as claimed in claim 6 wherein said current source is coupled to said operating power source and said current pulse generating means is coupled to said initial turn-on circuitry.

8. A rapid turn-on voltage regulator as claimed in claim 7 wherein said current pulse generating means includes circuitry coupled to apply a surge of current approximately 20 times the bias current to said amplifier means upon initial application of input power to the rapid turn-on voltage regulator and circuitry for turning the surge of current off when the input power reaches a predetermined value.

9. A rapid turn-on voltage regulator as claimed in claim 6 wherein said operating power source includes a storge capacitor and said initial turn-on circuitry includes an input terminal adapted to receive input power and a semiconductor diode coupling said input terminal to said storage capacitor.