Voltage up-conversion circuit using low voltage transistors

• US 7,408,330 B2
• Filed: 06/06/2006
• Issued: 08/05/2008
• Est. Priority Date: 06/06/2006
• Status: Active Grant

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Skyworks Solutions Incorporated
• Inventors: Zhao, Bin
• Primary Examiner(s): Riley; Shawn
• Application Number:
  US11/448,651
• Publication Number:
  US 20070279023A1
• Time in Patent Office: 791 Days
• Field of Search: 327/306, 327/536, 327/537, 327/589, 307/109, 307/110, 363/59, 363/60, 323/266, 323/288
• US Class Current: 323/266
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

According to one exemplary embodiment, a voltage up-conversion circuit includes a modulated voltage generator circuit, where the modulated voltage generator circuit is configured to receive an input voltage and generate a modulated voltage, and where the modulated voltage generator circuit includes at least one transistor. The voltage up-conversion circuit further includes a switching circuit coupled to the modulated voltage generator circuit, where the switching circuit is configured to couple the modulated voltage to a load capacitor when the modulated voltage is at a high level and decouple the modulated voltage to the load capacitor when the modulated voltage is at a low level. In the voltage up-conversion circuit, the load capacitor reaches a voltage greater a breakdown voltage of the at least one transistor in the modulated voltage generator circuit. The breakdown voltage can be a reliability breakdown voltage.

Claims

1. A modulated voltage generator circuit comprising:

an input node for receiving an input voltage;

an output node for providing a modulated voltage, said modulated voltage alternating between a low level and a high level, said high level being substantially greater than said input voltage;

a first FET configured to isolate said output node from said input node when said modulated voltage is at said high level;

wherein said high level of said modulated voltage is greater than a breakdown voltage of said first FET;

said modulated voltage generator circuit further comprising a first capacitor having a first terminal and a second terminal, said first terminal being coupled to said output node and said second terminal being coupled to a ground when said modulated voltage is at said low level and said second terminal being coupled to said input node when said modulated voltage is at said high level;

said modulated voltage generator circuit further comprising a second FET having a source terminal, a drain terminal, and a gate terminal, wherein said source terminal of said second FET is coupled to said output node, said drain terminal of said second FET is coupled to a gate terminal of said first FET, and said drain terminal of said second FET is coupled to said input node, wherein said high level of said modulated voltage is greater than a breakdown voltage of said second FET.

2. The modulated voltage generator circuit of claim 1 wherein said breakdown voltage of said second FET comprises a reliability breakdown voltage.

3. The modulated voltage generator circuit of claim 1 further comprising a second capacitor having a first terminal and a second terminal, wherein said first terminal of said second capacitor is switchably coupled to said input node and said second terminal of said second capacitor is coupled to said gate terminal of said first FET and said drain terminal of said second FET.

4. The modulated voltage generator circuit of claim 1 wherein said first FET comprises a PFET.

5. The modulated voltage generator circuit of claim 1 wherein said first FET and said second FET each comprise a PFET.

6. The modulated voltage generator circuit of claim 1 wherein said breakdown voltage of said first FET is a reliability breakdown voltage.

7. The modulated voltage generator circuit of claim 1 wherein said first FET is turned off and said second FET is turned on when said modulated voltage is at said high level.

8. The modulated voltage generator circuit of claim 1 wherein said input voltage is approximately equal to said modulated voltage when said modulated voltage is at said low level.

9. The modulated voltage generator circuit of claim 3 wherein said first terminal of said second capacitor is switchably coupled to said input node by a PFET, wherein a source terminal and a body terminal of said PFET are connected to said input node.

10. The modulated voltage generator circuit of claim 1 wherein said second terminal of said first capacitor is coupled to said ground by an NFET, wherein a source terminal and a body terminal of said NFET are coupled to said ground.