Power regulation scheme for a high voltage output in integrated circuit devices
A power regulation scheme for high voltage output in integrated circuits is realized in a regulated high voltage generator, a voltage clamp, and a power regulator connected between the voltage clamp and the voltage generator. The voltage clamp produces a clamp current during a voltage limiting operation. A regulating clamp current corresponds to an initial limit voltage of the clamp. The power regulator senses the clamp current and suspends voltage generation as the limit magnitude of clamp current is attained. The clamp current is mirrored in a current comparator circuit that triggers a stop signal to the regulated high voltage generator, thus saving power.
1. A high voltage generator comprising:
a voltage generator configured to produce a regulated high voltage supply in response to a control signal;
a voltage clamp comprising a plurality of reverse biased zener diodes connected in series with a plurality of forward biased zener diodes configured to limit a magnitude of said regulated high voltage supply and produce a clamp current that is determined only by the regulated high voltage supply applied to the voltage clamp; and
a power regulator, comprising:
a mirror voltage transistor configured to produce a mirror voltage reflecting a magnitude of said clamp current;
a current limit transistor configured to produce a limit current; and
a current mirror transistor configured to receive said mirror voltage, to generate a mirror current in response to said clamp current, said mirror current being constrained by said limit current, and to produce a control voltage;
said power regulator configured to produce said control signal to change when the mirror current equals the limit current and the clamp current is increasing to terminate the production of the regulated high voltage supply.
2. The high voltage generator of claim 1 , wherein said regulated high voltage supply upon attaining a given magnitude of voltage is configured to produce said clamp current through said voltage clamp.
3. The high voltage generator of claim 1 , wherein said power regulator further comprises:
a buffer configured to receive the control voltage and produce the control signal.
4. The high voltage generator of claim 1 , wherein said voltage generator is configured to suspend said production of said regulated high voltage supply when said control signal indicates that said control voltage is less than said one threshold voltage and resume said production of said regulated high voltage supply when said control signal indicates that said control voltage is greater than said one threshold voltage.
5. A regulated high voltage system comprising:
an oscillator configured to produce an oscillating signal in response to a control signal;
a charge pump configured to produce a regulated high voltage supply utilizing the oscillating signal;
a voltage clamp comprising a plurality of reverse biased zener diodes connected in series with a plurality of forward biased zener diodes configured to limit a magnitude of said regulated high voltage supply and to produce a clamp current, the clamp current being determined only by the regulated high voltage supply applied to the voltage clamp;
a memory array configured to receive said regulated high voltage supply; and
a power regulator comprising:
a mirror voltage transistor configured to produce a mirror voltage reflecting a magnitude of said clamp current;
a current limit transistor configured to produce a limit current; and
a current mirror transistor configured to receive said mirror voltage, to generate a mirror current in response to said clamp current, said mirror current being constrained by said limit current, and to produce a control voltage based on said mirror current;
a buffer configured to receive the control voltage and produce said control signal to change when the mirror current equals the limit current and the clamp current is increasing to terminate the production of the oscillating signal to suspend said production of said regulated high voltage supply.
6. The regulated high voltage system of claim 5 , wherein said
a buffer is an inverter.
7. A regulated high voltage system comprising:
an oscillator configured to produce an oscillating signal in response to a control signal;
a charge pump configured to produce a regulated high voltage supply utilizing the oscillating signal;
a voltage clamp comprising a plurality of reverse biased zener diodes connected in series with a plurality of forward biased zener diodes configured to limit a magnitude of said regulated high voltage supply and produce a clamp current that is generated solely in response to the regulated high voltage supply applied to the voltage clamp;
a memory array configured to receive said regulated high voltage supply; and
a power regulator comprising:
a mirror voltage transistor configured to produce a mirror voltage reflecting a magnitude of said clamp current;
a current limit transistor configured to produce a limit current; and
a current mirror transistor configured to receive said mirror voltage, to generate a mirror current in response to said clamp current, said mirror current being constrained by said limit current, and to produce a control voltage;
said power regulator configured to produce said control signal to change when the mirror current equals the limit current and the clamp current is increasing to terminate the production of the oscillating signal.
8. The regulated high voltage system of claim 7 , wherein said regulated high voltage supply upon attaining a given magnitude of voltage is configured to produce said clamp current through said voltage clamp.
9. The regulated high voltage system of claim 7 , wherein said power regulator comprises:
a buffer configured to receive the control voltage and produce the control signal.
10. The regulated high voltage system of claim 9 , wherein said oscillator is configured to suspend production of said oscillating signal when said control signal indicates that said control voltage is less than said one threshold voltage and resume said production of said oscillating signal when said control signal indicates that said control voltage is greater than said one threshold voltage.
11. A high voltage generator comprising:
a voltage generator configured to produce a regulated high voltage supply in response to a control signal;
a voltage clamp comprising a plurality of reverse biased zener diodes connected in series with a plurality of forward biased zener diodes configured to limit a magnitude of said regulated high voltage supply and produce a clamp current, wherein the clamp current is generated solely in response to the regulated high voltage supply applied to the voltage clamp; and
a power regulator comprising:
means for producing a control voltage from a magnitude of said clamp current and a limit current; and
means for producing said control signal to change when the clamp current equals the limit current and the clamp current is increasing to terminate the production of the regulated high voltage supply.
12. The high voltage generator of claim 11 , wherein said regulated high voltage supply upon attaining a given magnitude of voltage is configured to produce said clamp current through said voltage clamp.
13. The high voltage generator of claim 11 , wherein said voltage generator comprises a means for suspending said production of said regulated high voltage supply when said control signal indicates that said control voltage is less than said one threshold voltage and resume said production of said regulated high voltage supply when said control signal indicates that said control voltage is greater than said one threshold voltage.
14. A high voltage generator comprising:
a voltage generator configured to produce a regulated high voltage supply in response to a control signal;
a voltage clamp comprising a plurality of reverse biased zener diodes connected in series with a plurality of forward biased zener diodes configured to limit a magnitude of said regulated high voltage supply and produce a clamp current, wherein the clamp current is generated solely in response to the regulated high voltage supply applied to the voltage clamp; and
a power regulator configured to:
receive said clamp current;
produce a limit current;
generate a mirror current in response to said clamp current, said mirror current being constrained by said limit current;
produce a control voltage based on said mirror current; and
produce said control signal to change when the mirror current equals the limit current and the clamp current is increasing to terminate the production of the regulated high voltage supply.
15. The high voltage generator of claim 14 , wherein said regulated high voltage supply upon attaining a given magnitude of voltage is configured to produce said clamp current through said voltage clamp.
16. The high voltage generator of claim 14 , wherein said voltage generator is further configured to suspend said production of said regulated high voltage supply when said control signal indicates that said control voltage is less than said one threshold voltage and resume said production of said regulated high voltage supply when said control signal indicates that said control voltage is greater than said one threshold voltage.
17. The high voltage generator of claim 1 , wherein said voltage generator comprises:
an oscillator; and
a charge pump coupled to said oscillator.
18. The high voltage generator of claim 1 further comprising:
a load device configured to receive said regulated high voltage supply.
19. A high voltage generator comprising:
a voltage generator configured to produce a high voltage in response to a control signal;
a voltage clamp comprising a plurality of reverse biased zener diodes connected in series with a plurality of forward biased zener diodes configured to limit a magnitude of said high voltage to a clamp voltage and to generate a clamp current from the high voltage; and
a power regulator configured to produce the control signal from a comparison of said clamp current with a limit current produced by the power regulator, the power regulator configured to change the control signal when the clamp current equals the limit current and the clamp current is increasing to terminate the production of the high voltage.
20. The regulated high voltage system of claim 7 , wherein said oscillator is to suspend production of said oscillating signal when said control signal indicates that said control voltage is less than said one threshold voltage and resume said production of said oscillating signal when said control signal indicates that said control voltage is greater than said one threshold voltage.
21. The regulated high voltage system of claim 8 , wherein said oscillator is to suspend production of said oscillating signal when said control signal indicates that said control voltage is less than said one threshold voltage and resume said production of said oscillating signal when said control signal indicates that said control voltage is greater than said one threshold voltage.
22. The high voltage generator of claim 1 , wherein an upper bound magnitude of said limit current is configured to be less than or equal to an expected magnitude of said clamp current.
23. The regulated high voltage system of claim 5 , wherein an upper bound magnitude of said limit current is configured to be less than or equal to an expected magnitude of said clamp current.