Continuous sensing to determine read points

A method of reading a memory device, the method comprising:

• turning on a current source to provide current to selected strings of a selected group of multiple groups of strings of a memory array, with the selected strings selected by a block or sub-block configuration and with the multiple groups coupled to respective data lines of the memory array;
• applying a voltage waveform to a selected access line coupled to memory cells of the selected strings of the selected group, the voltage waveform having a positive slope;
• monitoring a total current to the respective data lines coupled to the selected strings of the selected group during a read operation;
• determining, from the monitoring of the total current, attainment of a selected value of a change of the total current with respect to time;
• and
• generating, in response to determining the attainment of the selected value, a latch signal in response to the determination to latch data status of the memory cells.

A memory device comprising:

• a memory array having multiple groups of strings of memory cells, the multiple groups coupled to respective data lines of the memory array;
• a current sensor to measure total current to the respective data lines coupled to a group of the groups of strings;
• a current source to provide current to the strings of the group;
• a memory controller including processing circuitry including one or more processors, the memory controller configured to perform operations in a read operation comprising:
• turning on the current source with the respective data lines coupled to the group in a non-conducting state;
• applying a ramp voltage to a selected access line coupled to memory cells of the strings of the group;
• monitoring the total current to the respective data lines coupled to the group;
• determining, from the monitoring of the total current, a minimum value of a change of the total current with respect to time;
• and
• generating a latch signal in response to the determination;
• and
• sense latches coupled to the respective data lines coupled to the group to capture data status in the read operation in response to receiving the latch signal.