Abstract: A method for erasing a non-volatile memory includes: performing a first pre-erase program step on the non-volatile memory; determining that the non-volatile memory failed to program correctly during the first pre-erase program step; performing a first soft program step on the non-volatile memory in response to determining that the non-volatile memory failed to program correctly; determining that the non-volatile memory soft programmed correctly; performing a second pre-erase program step on the non-volatile memory in response to determining that the non-volatile memory soft programmed correctly during the first soft program step; and performing an erase step on the non-volatile memory. The method may be performed using a non-volatile memory controller.

Abstract: A current injector circuit comprises a clock modulating circuit, a first current injector, a feedback circuit, a first input modulating circuit and a second current injector. The clock modulating circuit receives a clock, a control signal, and an output. The first current injector has an input coupled to the clock modulating circuit, and an output coupled to a power supply terminal for providing a first current. The feedback circuit is coupled between the power supply terminal and another input of the clock modulating circuit. The feedback circuit is for providing the control signal for controlling the clock modulating circuit. The first current injector provides the first current in response to the clock modulating circuit. The first input modulating circuit receives an input signal, the control signal, and an output. The second current injector has an input coupled to the first input modulating circuit, and an output for providing a second current.

Abstract: A compare cycle of a comparator includes a precharge phase and a compare phase. During the precharge phase, a node of the comparator is precharged to a defined voltage. In addition, during the precharge phase an input transistor of the comparator is decoupled from the node. During the compare phase, an input voltage is coupled to the node via the input transistor. The input transistor is maintained in saturation during both the precharge phase and the compare phase, reducing switching noise.

Abstract: A method includes erasing bits and identifying bits that have been over-erased by the erasing. A first subset of the bits that have been over-erased are soft programmed. The results of soft programming the first subset of bits is measured. An initial voltage condition from a plurality of possible voltage conditions based on the results from soft programming the first subset of bits is selected. A second subset of bits that have been over-erased are soft programmed. The soft programming applies the initial voltage condition to the bits in the second subset of bits. The second subset comprises bits that are still over-erased when the step of selecting occurs. The result is that the soft programming for the second subset may begin at a more optimum point for quickly achieving the needed soft programming to bring all of the bits within the desired erase condition.

Abstract: A current injector circuit comprises a clock modulating circuit, a first current injector, a feedback circuit, a first input modulating circuit and a second current injector. The clock modulating circuit receives a clock, a control signal, and an output. The first current injector has an input coupled to the clock modulating circuit, and an output coupled to a power supply terminal for providing a first current. The feedback circuit is coupled between the power supply terminal and another input of the clock modulating circuit. The feedback circuit is for providing the control signal for controlling the clock modulating circuit. The first current injector provides the first current in response to the clock modulating circuit. The first input modulating circuit receives an input signal, the control signal, and an output. The second current injector has an input coupled to the first input modulating circuit, and an output for providing a second current.

Abstract: A charge pump system (100) includes a charge pump (102), and a regulator (101) that includes a clock generator (120) for providing a clock signal, a control logic (130) coupled to the clock generator, and a comparator (140) coupled to an output of the charge pump. The comparator includes a plurality of interleaved latches (211, 212, 213 and 214) driven by a single differential (203) stage that compares the output voltage and a reference voltage. The control logic provides timing signals to cause each latch to perform a latch action at different points in time within each period of the clock signal, each point in time equally spaced apart. An output from each latch is coupled to an output stage (205). An output signal from the output stage regulates an output voltage from the charge pump. In one embodiment, the charge pump is coupled to a flash memory (190).

Abstract: A charge pump system (100) includes a charge pump (102), and a regulator (101) that includes a clock generator (120) for providing a clock signal, a control logic (130) coupled to the clock generator, and a comparator (140) coupled to an output of the charge pump. The comparator includes a plurality of interleaved latches (211, 212, 213 and 214) driven by a single differential (203) stage that compares the output voltage and a reference voltage. The control logic provides timing signals to cause each latch to perform a latch action at different points in time within each period of the clock signal, each point in time equally spaced apart. An output from each latch is coupled to an output stage (205). An output signal from the output stage regulates an output voltage from the charge pump. In one embodiment, the charge pump is coupled to a flash memory (190).

Abstract: A compare cycle of a comparator includes a precharge phase and a compare phase. During the precharge phase, a node of the comparator is precharged to a defined voltage. In addition, during the precharge phase an input transistor of the comparator is decoupled from the node. During the compare phase, an input voltage is coupled to the node via the input transistor. The input transistor is maintained in saturation during both the precharge phase and the compare phase, reducing switching noise.

Abstract: A voltage multiplier (10) including a first clocked multiplier stage (12) having an input and an output and a second clocked multiplier stage (14, 16) having an input and an output is provided. The voltage multiplier further includes an input level regulator (18) coupled to the input of the first multiplier stage. The voltage multiplier further includes a feedback bias control circuit (32) coupled to the input level regulator, wherein the feedback bias control circuit is further coupled to receive the output (50) of the second multiplier stage, and wherein the feedback bias control circuit generates a feedback signal (58) affecting an output of the input level regulator based on a comparison between a voltage proportional to a voltage at the output of the second clocked multiplier stage and a reference voltage.

Abstract: A circuit and method reduces disturb in a memory array resulting from one of two supply voltages dropping below a predetermined value. Memory control logic is operated using a logic power domain. Higher voltages than that of the logic power domain are generated in response to an oscillator oscillating. The higher voltages are used to operate the memory array. Operation of the oscillator is controlled with the memory control logic when the logic power domain is at least at a first level or value. The oscillator is disabled when the logic power domain is below the first level. The disabling of the oscillator has the effect of preventing generation of the higher voltages. This facilitates preventing the higher voltages from reaching the memory array when they may not be properly controlled.

Abstract: An erase operation in a non-volatile memory includes selecting a block on which to perform an erase operation, erasing the selected block, receiving test data corresponding to the selected block, determining a soft program verify voltage level based on the test data, and soft programming the erased selected block using the soft program verify voltage level. A non-volatile memory includes a plurality of blocks, a test block which stores test data corresponding to each of the plurality of blocks, and a flash control coupled to the plurality of blocks and the test block, the flash control determining a soft program verify voltage level for a particular block of the plurality of blocks based on the test data for the particular block when the particular block is being soft programmed.

Abstract: A non-volatile memory can have multiple blocks erased in parallel for a relatively few number of erase operations. This saves time for the user in the set-up of the memory because the erase operation is relatively slow. Problems with parallel erase relate to different blocks having different program/erase histories with the result that the blocks with different histories erase differently. Thus, after a predetermined number of erase cycles are performed, the ability to parallel erase is prevented. This is achieved by allowing parallel erasing operations until the predetermined number of erase operations have been counted. After that predetermined number has been reached, a parallel erase mode disable signal is generated to prevent further parallel erase cycles. The count and the predetermined number are maintained in a small block of the non-volatile memory that is inaccessible to the user.

Abstract: An electronic data storage system uses current comparison to generate a voltage bias. In at least one embodiment, a voltage bias generator, that includes a current differential amplifier, generates a current that charges a load to a predetermined voltage bias level. The current comparison results in the comparison between two currents, Iref and Isaref. The current Isaref can be generated using components that match components in the load and memory circuits in the system. In one embodiment, multiple sense amplifiers represent the load. By using matched components, as physical characteristics of the load and memory circuits change, the current Isaref also changes. Thus, the voltage bias changes to match the changing characteristics of the load and memory circuits. The voltage bias generator can include a current booster that decreases the initial charging time of a reactive load.

Abstract: A voltage regulator for a charge pump includes a capacitor divider and a reset circuit. The capacitor divider produces, based on an input voltage (VPP), a sample voltage at a sampling node. The sampling node and a reference voltage VREF are connected to respective inputs of a comparator that generates an enable signal for the charge pump. The reset circuit connects to the divider and includes a first transistor connected between the sampling node and a biasing node. During a sampling mode, the reset circuit biases VDS of the first transistor to approximately zero at the regulation point to minimize sub-threshold IDS. During reset intervals, the reset circuit applies VREF to the biasing node. The reset circuit may include a second transistor connected between the biasing node and a known level (e.g., ground) and a biasing transistor connected between the biasing node and VREF.

Abstract: An adjustable voltage supply (310) may have a plurality of levels of adjustment, such as a coarse select circuit (471) and a fine select circuit (473), to generate an adjustable voltage (e.g. Vout 364 of FIGS. 3 and 4) with fine resolution across a wide voltage range. In one embodiment, the adjustable voltage may be used as an adjustable read voltage to measure the threshold voltages of bitcells in a memory array (300). From the distribution of these threshold voltages, it is possible to determine the marginality of the bitcells with regard to the voltage which is required to read the bitcells. In one embodiment, the adjustable voltage supply (310) may also be used to provide an adjustable voltage to one or more integrated circuit pwells and/or nwells in order to apply electrical stress. An adjustable voltage supply (310) may be used in any desired context, not just memories.

Abstract: A voltage multiplier (10) including a first clocked multiplier stage (12) having an input and an output and a second clocked multiplier stage (14, 16) having an input and an output is provided. The voltage multiplier further includes an input level regulator (18) coupled to the input of the first multiplier stage. The voltage multiplier further includes a feedback bias control circuit (32) coupled to the input level regulator, wherein the feedback bias control circuit is further coupled to receive the output (50) of the second multiplier stage, and wherein the feedback bias control circuit generates a feedback signal (58) affecting an output of the input level regulator based on a comparison between a voltage proportional to a voltage at the output of the second clocked multiplier stage and a reference voltage.

Abstract: An integrated circuit (10) comprises a plurality of non-volatile memory cells (14) and a charge distribution ramp rate control circuit (11). Each memory cell of the array (12) includes a charge storage region and a plurality of terminals. The charge distribution ramp rate control circuit includes a capacitor (62,116,144) having a first plate electrode coupled to at least one terminal of the plurality of terminals, and a second plate electrode. The charge distribution ramp rate control circuit further includes a bandgap generated current source (58,106,136) for providing a reference current to determine a ramp rate of a voltage at the at least one terminal.

Abstract: A voltage regulator for a charge pump includes a capacitor divider and a reset circuit. The capacitor divider produces, based on an input voltage (VPP), a sample voltage at a sampling node. The sampling node and a reference voltage VREF are connected to respective inputs of a comparator that generates an enable signal for the charge pump. The reset circuit connects to the divider and includes a first transistor connected between the sampling node and a biasing node. During a sampling mode, the reset circuit biases VDS of the first transistor to approximately zero at the regulation point to minimize subthreshold IDS. During reset intervals, the reset circuit applies VREF to the biasing node. The reset circuit may include a second transistor connected between the biasing node and a known level (e.g., ground) and a biasing transistor connected between the biasing node and VREF.

Abstract: An erase operation in a non-volatile memory includes selecting a block on which to perform an erase operation, erasing the selected block, receiving test data corresponding to the selected block, determining a soft program verify voltage level based on the test data, and soft programming the erased selected block using the soft program verify voltage level. A non-volatile memory includes a plurality of blocks, a test block which stores test data corresponding to each of the plurality of blocks, and a flash control coupled to the plurality of blocks and the test block, the flash control determining a soft program verify voltage level for a particular block of the plurality of blocks based on the test data for the particular block when the particular block is being soft programmed.

Abstract: A circuit and method reduces disturb in a memory array resulting from one of two supply voltages dropping below a predetermined value. Memory control logic is operated using a logic power domain. Higher voltages than that of the logic power domain are generated in response to an oscillator oscillating. The higher voltages are used to operate the memory array. Operation of the oscillator is controlled with the memory control logic when the logic power domain is at least at a first level or value. The oscillator is disabled when the logic power domain is below the first level. The disabling of the oscillator has the effect of preventing generation of the higher voltages. This facilitates preventing the higher voltages from reaching the memory array when they may not be properly controlled.