High-voltage NMOS switch

• US 6,188,265 B1
• Filed: 12/12/1997
• Issued: 02/13/2001
• Est. Priority Date: 12/12/1997
• Status: Expired due to Fees

• Current Assignee: JatoTech Affiliates LP (JatoTech Ventures Inc), JatoTech Ventures LP (JatoTech Ventures Inc), Mayfield Associates Fund VI, Mayfield Ix, Mayfield Principals Fund II, Mayfield Xi, Mayfield XI Qualified, Qualcomm, Inc., The Chip Trust III, Unger-Luchsinger Family Trust
• Original Assignee: UBICOM Incorporated (Qualcomm, Inc.)
• Inventors: Cheng-Wing Cheng, Chuck, Liu, Kwo-Jen
• Primary Examiner(s): Cunningham, Terry D.
• Application Number:
  US08/989,846
• Time in Patent Office: 1,159 Days
• Field of Search: 327/390, 327/536, 327/537, 327/589, 307/110, 307/126, 307/130
• US Class Current: 327/390
• CPC Class Codes: G11C 16/12 Programming voltage switching circuits
• CPC Class Codes: G11C 5/145 Applications of charge pumps; Boosted voltage circuits; Clamp circuits therefor G11C5/141 takes precedence
• CPC Class Codes: H03K 17/063 in field-effect transistor switches

Abstract

A high voltage NMOS switch is adjustable in order to optimize the switch for proper operation with different circuit configurations. A high voltage booster, included within the high voltage NMOS switch, enables the switch to reclaim the previously unused second half-cycle of a power source waveform signal, which thereby increases the speed of the NMOS switch by a factor of two. In addition, the high voltage NMOS switch provides added ramp rate flexibility by enabling a user to optimize the ramp rate of the high voltage NMOS switch for different circuit configurations.

Claims

1. A high voltage switch system, electrically coupled to a power source transmitting a first signal and a second signal, the system comprising:

a high voltage pump, electrically coupled to the power source, adapted to receive the first signal from the power source and to transmit a pump signal;

a high voltage booster, electrically coupled to the power source and the high voltage pump, receiving the second signal from the power source, to receive the pump signal from the high voltage pump and to transmit a booster signal when said booster signal has a voltage level higher than the pump signal; and

a switch, electrically coupled to the high voltage booster, responding to receipt of an input signal having a first logic state by receiving the booster signal and transmitting an ouput signal with a high voltage level and adapted to respond to receipt of the input signal having a second logic state by transmitting the output signal with a low voltage level.

2. The high voltage switch system of claim 1 wherein the high voltage pump includes:

a capacitor having an input and an output, the input of the capacitor, electrically coupled to the power source and receives the first signal;

a transistor diode having an input and an output, the input of the transistor diode, electrically coupled to the output of the capacitor, the output of the transistor diode to transmit the pump signal; and

a transistor, having a first electrode, a second electrode and a gate electrode, the second electrode of the transistor electrically coupled to a voltage source, the first electrode of the transistor-electrically coupled to the input of the transistor diode and the gate electrode of the transistor electrically coupled to the high voltage booster, wherein the transistor assists in the ramping up of the pump signal.

3. The high voltage switch system of claim 1 wherein the high voltage booster includes:

a capacitor having an input and an output, the input of the capacitor, electrically coupled to the power source, adapted to receive the second signal; and

a transistor diode, having an input and an output, the input of the transistor diode, electrically coupled to the high voltage pump and the output of the capacitor, adapted to receive the pump signal from the high voltage pump, the output of the transistor diode adapted to transmit the booster signal.

4. The high voltage switch system of claim 1 wherein the switch is electrically coupled to a voltage source having a first voltage level, wherein the high voltage level equals the first voltage level.

5. The high voltage switch system of claim 1 wherein the switch is electrically coupled to electrical ground, wherein the low voltage level equals electrical ground.

6. The high voltage switch system of claim 1 wherein the switch includes:

a first transistor, having a gate electrode, a first electrode and a second electrode, the gate electrode adapted to receive the input signal, the first electrode electrically coupled to the high voltage booster and the second electrode electrical coupled to electrical ground, wherein the first transistor responds to the input signal having the second logic state by halting a ramping up of the booster signal by the high voltage booster and the pump signal by the high voltage pump.

7. The high voltage switch system of claim 1 wherein the switch includes:

a first transistor having a gate electrode, a first electrode and a second electrode, the gate electrode of the first transistor, electrically coupled to the high voltage booster, adapted to receive the booster signal, the first electrode of the first transistor electrically coupled to a voltage source, the first transistor responding to receiving at the gate electrode the booster signal at a first voltage level by transmitting at the second electrode of the first transistor the output signal at a second voltage level.

8. The high voltage switch system of claim 7 wherein the switch further includes:

a second transistor having a gate electrode, a first electrode and a second electrode, the gate electrode of the second transistor adapted to receive the input signal, the first electrode of the second transistor electrically coupled to the second electrode of the first transistor and the second electrode of the second transistor electrically coupled to electrical ground, the second transistor responding to receiving the input signal in the second logic state by electrically coupling the second electrode of the first transistor to electrical ground, wherein the output signal transmitted by the second electrode of the first transistor is equal to electrical ground.

9. The high voltage switch system of claim 1 wherein the high voltage pump comprises a claiming diode transistor, electrically coupled to the output of the high voltage booster, adapted to prevent the booster signal from ramping up to above a first voltage level.

10. The high voltage switch system of claim 1 further comprising a storage device, electrically coupled to the switch, adapted to receive and store the output signal.

11. The high voltage switch system of claim 1 wherein the switch is electrically coupled to a first voltage source having a first voltage level, wherein the low voltage level equals the first voltage level.

12. The high voltage switch system of claim 11 wherein the first voltage source includes a transistor having a gate electrode, a first electrode and a second electrode, the gate electrode and the first electrode electrically coupled to a second voltage source having a second voltage level, the second electrode of the first voltage source electrically coupled to the high voltage booster.

13. The high voltage switch system of claim 1 wherein the switch includes:

a first transistor, having a gate electrode, a first electrode and a second electrode, the gate electrode of the first transistor adapted to receive the input signal, the second electrode of the first transistor electrically coupled to electrical ground, wherein the first transistor responds to the input signal having the second logic state by halting the ramping up of the booster signal by the high voltage booster and the pump signal by the high voltage pump; and

a second transistor having a gate electrode, a first electrode and a second electrode, the gate electrode of the second transistor, electrically coupled to the high voltage booster, adapted to receive the booster signal, the first electrode of the second transistor electrically coupled to a first voltage source having a first voltage level, the second electrode of the second transistor electrically coupled to the first electrode of the first transistor, the second transistor responding to receiving at the gate electrode the booster signal at a second voltage level by transmitting at the second electrode of the second transistor the output signal at the first voltage level.

14. The high voltage switch system of claim 1 wherein the first signal is a first square waveform signal and the second signal is a second square waveform signal, wherein said first square waveform signal is the inverse of said second square waveform signal.