Multiplier improved voltage

• US 5,831,469 A
• Filed: 12/21/1995
• Issued: 11/03/1998
• Est. Priority Date: 12/28/1994
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Menichelli, Stefano
• Primary Examiner(s): Callahan, Timothy P.
• Assistant Examiner(s): Wells, Kenneth B.
• Application Number:
  US08/576,281
• Time in Patent Office: 1,048 Days
• Field of Search: 327/536, 327/148, 327/157, 363/59, 363/60, 307/110
• US Class Current: 327/536
• CPC Class Codes: G11C 5/145 Applications of charge pumps; Boosted voltage circuits; Clamp circuits therefor G11C5/141 takes precedence

Abstract

An on-chip voitage multiplier circuit, comprising N serially arranged stages wherein each stage includes a switch Tj (j=1 . . . N), having an upper pin and a lower pin, to the upper pin of which the lower pin of a capacitor Ci (i=1 . . . N) is serially connected, said capacitor also having a lower pin and an upper pin; the intermediate node between each switch Tj (j=1 . . . N) and each capacitor Ci (i=1 . . . N) is connected to the ground voltage Vss through a respective switch Si (i=1 . . . N) and the upper pin of each capacitor Ci (i=1 . . . N) is connected to the supply voltage Vdd through a switch Di (i=1 . . . N); and the lower pin of the switch (T11) of the first stage is directly connected to the supply voltage Vdd and the upper pin of the capacitor (CN) of the last stage is connected to the output pin through an additional switch (T(N+1)).

Claims

1. A voltage multiplier circuit, comprising:

a chain of capacitors Ci (i=1 . . . N) connected in series through a chain of transistors Tj (j=1 . . . N),

a transistor Si (i=1 . . . N) for coupling every connection between each capacitor Ci (i=1 . . . N) and each transistor Tj (j=1 . . . N) to a ground voltage Vss;

a transistor Di (i=1 . . . N) for coupling every connection between each capacitor Ci and each transistor Tj+1 to a supply voltage Vdd;

wherein the first transistor T1 in the chain of transistors Tj has a source/drain connection connected to said supply voltage Vdd; and

wherein the last capacitor CN in the chain of capacitors Ci (i=1 . . . N) is connected to an output terminal of the voltage multiplier circuit through an additional transistor T (N+1).

2. The voltage multiplier circuit of claim 1 wherein during a charge phase, transistors Tj (j=1 . . . N) are open and transistors Si and Di (i=1 . . . n) are closed such that capacitors Ci (i=1 . . . N) are charged up to the supply voltage Vdd;

and

wherein during a discharge phase, transistors Tj (j=1 . . . N) are closed and transistors Si and Di (i=1 . . . N) are open such that capacitors Ci (i=1 . . . N) are serially connected and discharged to the output terminal.

3. The voltage multiplier circuit of claim 2 wherein the transistors Tj (j=1 . . . N) are P-channel MOS transistors and the transistors Si and Di (i=1 . . . N) are N-channel MOS transistors.

4. The voltage multiplier circuit of claim 3 wherein a clock signal is connected to the commonly connected gates of each transistor Tj (j=1 . . . N) and each transistor Si (i=1 . . . N) and the clock signal is connected to the gate of each transistor Di (i=1 . . . N) through a voltage doubler circuit, comprising:

a diode having one terminal connected to the supply voltage Vdd;

a capacitor having one plate connected to the clock signal; and

wherein the other terminal of the diode is connected to the other plate of the capacitor and to the gate of each transistor Di (i=1 . . . N).