Flexible word line boosting across VCC supply
View Patent ↗Systems and methods for producing a boosted voltage which can be used as a boosted word line voltage for read mode operations of memory cells are disclosed. The system contains a VCC comparator, a look up table, and a boosting circuit including a set of boosting capacitors. The look up table has a list of trim codes that indicates desired boosting ratios. The boosting ratio can vary depending on a level of a supply voltage to provide a sufficient word line voltage, thereby preventing and/or mitigating delay in reading operations. The number of the capacitors in the boosting circuit can be predetermined to be turned on or off according to the trim code. Accordingly, the voltage boost circuit provides a sufficient boosted word line voltage to a core cell gate with flexibility despite fluctuation of the supply voltage level.
1. A method for producing a boosted voltage for read operations of a memory cell, comprising:
providing a digital code by a VCC comparator according to a level of a supply voltage;
sending the digital code to a look up table;
matching the digital code to a trim code in the look up table; and
commanding a boosting circuit to boost or not to boost the supply voltage according to the trim code.
2. The method of claim 1 , wherein the VCC comparator measures the supply voltage.
3. The method of claim 1 , wherein the VCC comparator encodes the supply voltage.
4. The method of claim 1 , wherein the VCC comparator translates the supply voltage to the digital code.
5. The method of claim 1 , wherein the digital code from the VCC comparator comprises n bits and the digital code is determined by the level of the supply voltage.
6. The method of claim 1 , wherein the digital code is used as a pointer to access a set of trim codes stored in the look up table.
7. The method of claim 1 , wherein the digital code is matched to the one of the trim codes in the look up table.
8. The method of claim 1 , wherein the trim code indicates a boosting ratio which varies depending on the level of the supply voltage.
9. The method of claim 1 , wherein the boosting ratios determine boosting capacitors settings in a boosting circuit.
10. The method claim 1 , wherein commanding the boosting circuit comprises turning on a predetermined set of boosting capacitors according to the trim code.
11. The method of claim 1 , wherein the boosting circuit receives a command whether boost or not to boost the supply voltage based on the trim code.
12. The method of claim 8 , wherein the boosting circuit produces a boosted voltage according to the desired boosting ratio.
13. The method of claim 1 , further comprising using the boosted voltage as a boosted word line voltage for read mode operations of memory cells.
14. The method of claim 1 , further comprising the boosted voltage to the core cell gate.
15. A system for producing a boosted voltage in a memory device, comprising:
a VCC comparator that translates a supply voltage to a digital code;
a look up table that matches the digital code to a trim code; and
a boosting circuit that boosts the supply voltage according to the trim code.
16. The system of claim 15 , wherein the digital code of the VCC comparator is a binary signal.
17. The system of claim 15 , wherein the digital code comprises a set of digital number of 1 or 0.
18. The system of claim 15 , wherein the look up table comprises a list of trim codes.
19. The system of claim 15 , wherein the boosting circuit comprises a set of boosting capacitors.
20. A system that produces a boosted voltage, comprising:
means for translating a level of a supply voltage to a digital code;
means for sending the digital code to a look up table;
means for matching the digital code to a trim code; and
means for commanding a boosting circuit to boost or not to boost the supply voltage based on the trim code.