| US 7,498,869 B2 | ||
| Voltage reference circuit for low voltage applications in an integrated circuit | ||
| Wagdi W. Abadeer, Jericho, Vt. (US); and John A. Fifield, Underhill, Vt. (US) | ||
| Assigned to International Business Machines Corporation, Armonk, N.Y. (US) | ||
| Filed on Jan. 15, 2007, as Appl. No. 11/623,114. | ||
| Prior Publication US 2008/0169869 A1, Jul. 17, 2008 | ||
| Int. Cl. G05F 1/56 (2006.01) | ||
| U.S. Cl. 327—541 [327/543; 323/316] | 12 Claims |
| 1. An integrated circuit chip, comprising:
a voltage reference circuit that includes:
a first voltage divider stack comprising:
a first input for receiving a regulated voltage; and
a first internal node for providing a first divided output voltage;
a second voltage divider stack electrically coupled in parallel with said first voltage divider stack and having a nonlinear
relationship to said regulated voltage, said second voltage divider stack comprising:
a second input for receiving said regulated voltage; and
a second internal node for providing a second divided output voltage; and
a voltage regulator operatively configured to generate said regulated voltage as a function of said first divided output voltage
and said second divided output voltage;
wherein:
said second voltage divider stack comprises a first leaky capacitor and a second leaky capacitor coupled in series with one
another so as to define said second internal node;
said first leaky capacitor has a first leakage current and comprises a first transistor having a first gate oxide and said
first leakage current is provided by current tunneling across said first gate oxide;
said second leaky capacitor has a second leakage current and comprises a second transistor having a second gate oxide and
said second leakage current is provided by current tunneling across said second gate oxide; and
said first transistor is a low-voltage-threshold device and said second transistor is a regular-voltage-threshold device.
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