Sandisk Technologies Inc.

Western Digital Technologies, Inc.

Sai Gautham Thoppa

Parth Amin

Anubhav Khandelwal

Jiahui Yuan

Long C Pham

Abu Naser Zainuddin

Anantharaj Thalaimalai Vanaraj

Dharmaraju Marenahally Krishna

A non-volatile memory comprises a non-volatile memory structure that includes non-volatile memory cells. The non-volatile memory adjusts a ramp rate of a voltage signal applied to the non-volatile memory structure as part of a memory operation for the non-volatile memory cells. The adjusting the ramp rate is performed during the ramping up of the voltage signal and is based on voltage magnitude of the voltage signal at a particular time during the ramping up of the voltage signal.

Non-volatile memory with adjustable ramp rate

A memory system implemented on one or more die includes a power input line for the one or more die, a current detection circuit connected to the power input line such that the current detection circuit is configured to indicate whether current at the power input is greater than a reference current, and a control circuit connected to the power input line and the current detection circuit. The control circuit is also connected to a non-volatile memory structure comprising a plurality of non-volatile memory cells. The control circuit is configured to sense data from the non-volatile memory structure including lowering a voltage used during the sensing in response to the current detection circuit indicating that current at the power input line is greater than the reference current.

Non-volatile memory with current detection circuit

Non-volatile memory cells are programmed by raising a voltage applied to a selected word line to a program voltage during a first time period of a programming process for selected non-volatile memory cells connected to the selected word line; programming the selected non-volatile memory cells using the program voltage during a second time period after the first time period; testing, during the first time period, whether the voltage applied to the selected word line is greater than one or more intermediate voltages; and elongating the first time period during the first time period if the voltage applied to the selected word line is not greater than one or more of the intermediate voltages.

Non-volatile memory with slow voltage ramp compensation

As part of the erase operation for a memory block, one or more post-erase tests can be incorporated into the erase operation to see whether the block has grown any defects. After erasing a block and verifying the erase, the post-erase tests can be performed on the block. As these test involve biasing the block and performing a sensing operation, these post erase tests come with a time penalty. To reduce the associated time penalty and improve memory performance while incorporating the defect tests into the erase process, when biasing the memory array for the post-erase defect tests different ramp rates can be used. In particular, faster ramp rates for bias levels, such those applied to the word lines of the block, are used for the post-erase tests than are used for the same bias level when performing the standard read, program verify, or read verify operations.

Non-volatile memory with faster post-erase defect testing

Embodiments described herein aim to optimize the Erratic Program Detection (EPD) process by eliminating unnecessary operations and adjusting operations that are not optimized for the EPD process. For example, one optimization includes the EPD read operations being performed based on a read mode optimized for faster data retrieval. Further, another optimization includes a first read voltage ramping up at a rate that is faster than a ramp rate used to ramp up a read voltage during performance of a normal read operation. Another optimization also includes a read voltage kick operation between the EPD read operations being eliminated. Finally, another optimization includes parallelizing the scan operation with other ongoing operations.

Optimized erratic program detection process

To reduce Icc spikes during the operation of a non-volatile memory device, a distributed temperature sensing system individually monitors each plane of a memory die during memory operations. Icc levels during a memory operation are temperature dependent. By monitoring the temperature of the individual memory planes during an operation, the bias levels for performing the operation can be changed during the course of that operation in order to reduce Icc spikes during the operation. For example, during a write operation if the temperature increase of a plane exceeds a threshold during earlier programming loops, the bias conditions, such as word line or bit line bias voltages, can be altered for later programming loops of the write operation.

Distributed temperature sensing scheme to suppress peak Icc in non-volatile memories

Embodiments of the present technology provide non-volatile memory devices comprising memory dies that natively generate 'exclusive OR (XOR) data pages' that can be used to recover data pages corrupted by UECC errors. Through memory die native-XOR data page generation, embodiments can recover data pages corrupted by UECC errors more efficiently, more rapidly, and with fewer resources than potential alternative technologies.

Automatic XOR data programming by memory die for uncorrectable page failure recovery

Technology is disclosed herein for quickly determining which erase block is bad if there is a failure in parallel erasing a set of erase blocks. The erase blocks may be tested individually in response to a fail of the parallel multi-block erase. A voltage generator ramps up the erase voltage from a steady state magnitude towards a target magnitude. The magnitude of the erase voltage is measured at a pre-determined time. If there is a defect then the erase voltage may fail to be above a threshold voltage after the ramp-up period. If the erase voltage is below the threshold voltage after the ramp-up period then the erase block may be marked as defective. If the erase voltage is above the threshold voltage after the ramp-up period then the erase block may be marked as good.

Vera detection method to catch erase fail

Adaptive and dynamic control of the duration of a pre-program pulse based on a number of planes selected for the pre-program operation is disclosed. A value for a pre-program time increment parameter may be selected based on the number of planes for which the pre-program operation will be performed or determined based on a predefined association with the number of planes. A pre-program voltage pulse may then be applied for a duration that is equal to a default duration for a single-plane pre-program operation incremented by the time increment parameter value. This approach solves the technical problem of Vt downshift for multi-plane pre-program operations, and thus, ensures that the success rate of secure erase operations does not diminish as the number of planes increases. This, in turn, allows for pre-program operations to be consistently performed on a multi-plane basis, which produces the technical effect of improved system performance.

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San Jose, CA, United States of America

Sai Gautham Thoppa