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公开(公告)号:US11829281B2
公开(公告)日:2023-11-28
申请号:US17348910
申请日:2021-06-16
Applicant: SanDisk Technologies LLC
Inventor: Jang Woo Lee , Srinivas Rajendra , Anil Pai , Venkatesh Ramachandra
IPC: G06F11/36 , G11C7/10 , G06F18/214 , G06F13/16 , G06F3/06
CPC classification number: G06F11/368 , G06F13/1689 , G06F18/214 , G11C7/1096 , G06F3/061 , G11C2207/2254
Abstract: Technology is disclosed herein for semi receiver side write training in a non-volatile memory system. The transmitting device has delay taps that control the delay between a data strobe signal and data signals sent on the communication bus. The delay taps on the transmitting device are more precise that can typically be fabricated on the receiving device (e.g., NAND memory die). However, the receiving device performs the comparisons between test data and expected data, which alleviates the need to read back the test data. After the different delays have been tested, the receiving device informs the transmitting device of the shortest and longest delays for which data was validly received. The transmitting device then sets the delay taps based on this information. Moreover, the write training can be performed in parallel on many receiving devices, which is very efficient.
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公开(公告)号:US10587247B2
公开(公告)日:2020-03-10
申请号:US15875519
申请日:2018-01-19
Applicant: SanDisk Technologies LLC
Inventor: Tianyu Tang , Venkatesh Ramachandra , Srinivas Rajendra
IPC: H03K3/017 , H03K17/687 , H03M1/66
Abstract: A correction system is configured to correct for duty cycle distortion and/or cross-point distortion in a pair of sample signals. A slope adjustment circuit is configured to generate a plurality of pairs of intermediate signals according to a plurality of drive strengths. A measurement circuit is configured to measure for duty cycle distortion and/or cross-point distortion, and the slope adjustment circuit is configured to set the plurality of drive strengths based on the measurement. The setting of the drive strengths may reduce certain rising and falling slopes of certain transitions of the plurality of intermediate signals, which in turn may reduce duty cycle distortion and/or cross-point distortion in the sample signals.
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公开(公告)号:US11482262B1
公开(公告)日:2022-10-25
申请号:US17348904
申请日:2021-06-16
Applicant: SanDisk Technologies LLC
Inventor: Jang Woo Lee , Srinivas Rajendra , Anil Pai , Venkatesh Ramachandra
Abstract: Technology is disclosed herein for per pin internal reference voltage generation for data receivers in non-volatile memory systems. A receiving circuit may have an on-die voltage generator that has inputs to receive a separate voltage magnitude select signal for each data receiver on the receiving circuit. The on-die voltage generator provides a separate reference voltage for each data receiver. This allows the reference voltage for each data receiver to be calibrated separately. A separate reference voltage for each data receiver compensates for variations between data paths, and provides for a wider data valid window than if the same reference voltage were used for all data receivers. Generating the different reference voltages on-die can potentially require a large area, as well as consume considerable power and/or current. A voltage divider and multiplexers may provide the different reference voltages, which saves space and is power and current efficient.
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公开(公告)号:US20190109585A1
公开(公告)日:2019-04-11
申请号:US15875519
申请日:2018-01-19
Applicant: SanDisk Technologies LLC
Inventor: Tianyu Tang , Venkatesh Ramachandra , Srinivas Rajendra
IPC: H03K3/017 , H03K17/687 , H03M1/66
Abstract: A correction system is configured to correct for duty cycle distortion and/or cross-point distortion in a pair of sample signals. A slope adjustment circuit is configured to generate a plurality of pairs of intermediate signals according to a plurality of drive strengths. A measurement circuit is configured to measure for duty cycle distortion and/or cross-point distortion, and the slope adjustment circuit is configured to set the plurality of drive strengths based on the measurement. The setting of the drive strengths may reduce certain rising and falling slopes of certain transitions of the plurality of intermediate signals, which in turn may reduce duty cycle distortion and/or cross-point distortion in the sample signals.
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公开(公告)号:US09792994B1
公开(公告)日:2017-10-17
申请号:US15278684
申请日:2016-09-28
Applicant: SanDisk Technologies LLC
Inventor: Primit Modi , Venkatesh Ramachandra
IPC: G11C16/24 , H01L27/092 , G11C16/30
CPC classification number: G11C16/24 , G11C16/30 , H01L27/092 , H03K19/00315
Abstract: A driver circuit, such as could be used as an off-chip driver for an I/O pin on a memory circuit, is presented. The driver has a PMOS connected between a supply level and the driver's output node. In an active mode, the bulk terminal of the PMOS is connected to the supply level; and in a standby mode, the PMOS's bulk terminal is set to a higher level. This reduces the leakage current through the PMOS in the standby mode, allowing for smaller device with a lower capacitance to be used.
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公开(公告)号:US11210241B1
公开(公告)日:2021-12-28
申请号:US17068957
申请日:2020-10-13
Applicant: SANDISK TECHNOLOGIES LLC
Inventor: Nitin Gupta , Ashish Savadia , Jayanth Thimmaiah , Ramakrishnan Subramanian , Rampraveen Somasundaram , Shiv Harit Mathur , Vinayak Ghatawade , Siddesh Darne , Venkatesh Ramachandra , Elkana Richter
Abstract: A data storage system includes a storage medium including plurality of memory cells, a storage controller in communication with the storage medium, an electrical interface circuitry configured to pass data via a channel disposed between the storage medium and the storage controller; and voltage training circuitry configured to train a high-level output voltage (VOH) for each of a plurality of data lines of the channel. Training the VOH includes, for each of the plurality of data lines of the channel, calibrating a pull-up driver of the storage controller against an on-die termination circuit of the storage medium, calibrating a pull-down driver of the storage controller against the pull-up driver of the storage controller, and calibrating an on-die termination circuit of the storage controller against a pull-up driver of the storage medium.
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公开(公告)号:US20220405190A1
公开(公告)日:2022-12-22
申请号:US17348910
申请日:2021-06-16
Applicant: SanDisk Technologies LLC
Inventor: Jang Woo Lee , Srinivas Rajendra , Anil Pai , Venkatesh Ramachandra
Abstract: Technology is disclosed herein for semi receiver side write training in a non-volatile memory system. The transmitting device has delay taps that control the delay between a data strobe signal and data signals sent on the communication bus. The delay taps on the transmitting device are more precise that can typically be fabricated on the receiving device (e.g., NAND memory die). However, the receiving device performs the comparisons between test data and expected data, which alleviates the need to read back the test data. After the different delays have been tested, the receiving device informs the transmitting device of the shortest and longest delays for which data was validly received. The transmitting device then sets the delay taps based on this information. Moreover, the write training can be performed in parallel on many receiving devices, which is very efficient.
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公开(公告)号:US20200076412A1
公开(公告)日:2020-03-05
申请号:US16206321
申请日:2018-11-30
Applicant: SanDisk Technologies LLC
Inventor: Srinivas Rajendra , Tianyu Tang , Venkatesh Ramachandra
IPC: H03K5/156 , H03K5/134 , G11C7/22 , G11C11/4076 , H01L27/11524
Abstract: A duty cycle correction circuit includes an AND/OR logic circuit that reduces duty cycle distortion in a pair of input signals. The AND/OR logic circuit includes a first push-pull circuit configured to generate a first output signal in response to receipt of a first pair of delayed input signals, and a second push-pull circuit configured to generate a second output signal in response to receipt of a second pair of delayed input signals. The first and second push-pull circuits may have matching beta ratios. Additionally, a latch is coupled to output nodes of the first and second push-pull circuits. The latch is configured to maintain magnitude levels at the output nodes during delay offset periods of the first and second pairs of delayed input signals.
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公开(公告)号:US10447247B1
公开(公告)日:2019-10-15
申请号:US15965099
申请日:2018-04-27
Applicant: SanDisk Technologies LLC
Inventor: Tianyu Tang , Venkatesh Ramachandra
Abstract: A duty cycle correction system corrects for duty cycle distortion by measuring average time interval durations of consecutive intervals of an input signal. The system generates complementary ramp signals that have cross-points indicating midpoints of the intervals, and detects those cross-points. An output circuit of the duty cycle correction system generates an output signal that performs rising and falling transitions in response to the detected cross-points.
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公开(公告)号:US10284182B2
公开(公告)日:2019-05-07
申请号:US15639153
申请日:2017-06-30
Applicant: SanDisk Technologies LLC
Inventor: Primit Modi , Venkatesh Ramachandra , Tianyu Tang , Srinivas Rajendra
Abstract: A complementary signal path may include an amplifier circuit configured to receive a pair of complementary input signals and a data alignment circuit configured to output a pair of complementary output signals in response to the pair of complementary input signals. A control circuit may detect duty cycle distortion in the pair of complementary output signals and perform a duty cycle correction process to remove the distortion. To do so, the control circuit may search for target current amounts in response to the duty cycle distortion and inject a control current into the amplifier circuit at the target current amounts.
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