Charge pump system dynamically reconfigurable for read and program
A charge pump system can provide multiple regulated output levels, including several concurrently, in an arrangement that can reduce the area and power consumption of such a high voltage generation system. The charge pump system can be dynamically reconfigurable based on output requirements. When output level is low, but required for a large AC, DC load, the system is configured in parallel to share the load. When a higher output is required, such as for a programming in a non-volatile memory, the system is configured in serial to generate the desired high output level. The exemplary embodiment uses all of the pump units in each operation and, hence, is able to be optimized for smaller pump area and less power consumption, while still delivering the same pump ability as larger, more power consuming arrangements.
1. A charge pump system connected to receive an input voltage and generate therefrom first and second regulated output voltages respectively at first and second output nodes, comprising:
a first charge pump connected to receive the input voltage and provide at the first output node an output voltage generated therefrom;
a second charge pump connected to provide at a second output voltage at the second output node and connectable to receive the input voltage;
a third charge pump connectable to receive the input voltage;
a first switch, whereby the output of the third charge pump is connectable to the first output node;
a set of second switches, whereby the output of the first charge pump can be supplied to the third charge pump and the output of the third charge pump can be supplied to the second charge pump;
a first regulation circuit connected to receive the voltage at the first output node;
a second regulation circuit connected to receive the voltage at the second output node; and
control circuitry connected to the first and second switches whereby the charge pump system can be operated in one of a first or a second mode,
where, in the first mode, the first switch is on and the second switches are off so that the first and third charge pumps are connected in parallel to generate the output voltage at the first output node from the input voltage and be regulated by the first regulation circuit at the first regulated output voltage and the second charge pump generates the output voltage at the second output node from the input voltage and is regulated by the second regulation circuit at the second regulated output voltage, and
where, in second mode, the first switch is off and the second switches are on so that the first charge pump generates the output voltage at the first output node from the input and is regulated by the first regulation circuit at the first regulated output voltage and the third and second charge pumps are connected in series to generate the output voltage at the second output node from the first output voltage and be regulated by the second regulation circuit at the second regulated output voltage,
wherein the second regulated output voltage is higher than the first regulated output voltage, and the second regulated output voltage is higher in the second mode than in the first mode.
2. The charge pump system of claim 1 , further comprising:
a fourth charge pump connectable to receive the input voltage;
an additional first switch connected to the control circuitry, whereby the output of the fourth charge pump is connectable to the first output node; and
whereby the second set switches can provide the output of the first charge pump to the third charge pump through the fourth charge pump,
wherein, in the first mode, the additional first switch is on so that the fourth charge pump is connected in parallel with the first and third charge pumps to generate the output voltage at the first output node from the input voltage, and where, in the second mode, the additional first switch is off and fourth charge pump is connected in series between the third and second charge pumps to generate the output voltage at the second output node from the first output voltage.
3. The charge pump system claim 1 , wherein said charge pump system is formed as peripheral circuitry on a non-volatile memory circuit.
4. The charge pump system of claim 1 , wherein the first and third charge pumps are responsive to a first independent enable signal, the second and third charge pumps are responsive to a second enable signal, and the second charge pump is response to a third enable signal, wherein the first, second and third enable signals can be independently asserted.
5. The charge pump system of claim 1 , wherein can operate the charge pump system in a sequence of alternating first and second modes.
6. The charge pump system of claim 5 , wherein level of the second regulated output voltage is increased for each second mode of alternating sequence.
7. The charge pump system of claim 1 , wherein the input voltage is high supply level of the circuit upon which the charge pump system is formed.
8. A method of operating a charge pump system to provide a first and a second regulated voltage at respective first and second output nodes, comprising:
selectively operating the charge pump system in a first mode or in a second mode, wherein the first mode concurrently includes:
operating a first charge pump and a second charge pump in parallel to generate from an input voltage a first output voltage at the first output node;
operating a third charge pump to generate from the input voltage a second output voltage at the second output node;
regulating the first output voltage at a first regulated level; and
regulating the second output voltage a second regulated level, wherein the second regulated level is higher that the first regulated level, and wherein the second mode concurrently includes:
operating the first charge pump to generate from the input voltage a first output voltage at the first output node;
operating the first charge pump, the second charge pump, and the third charge pump in series to generate from the input voltage a second output voltage at the second output node;
regulating the first output voltage at a first regulated level; and
regulating the second output voltage a second regulated level, wherein the second regulated level is higher that the first regulated level, and wherein the second regulated voltage of the second mode is higher than the second regulated voltage of the first mode.
9. The method of claim 8 , wherein the method includes operating the charge pump system in a sequence of alternating first and second modes.
10. The method of claim 9 , wherein the second regulated level is increased for each second mode in the sequence.
11. The method of claim 8 , wherein the first mode further comprises operating a fourth charge pump in parallel with the first and second charge pumps to generate from the input voltage the first output voltage at the first output node, and
wherein, in the second mode, the fourth charge pump is operated in series with the second charge pump between first and third charge pumps to generate from the input voltage the second output voltage at the second output node.