W25Q80 Datasheet, PDF (39/61 Pages) Winbond – 8M-BIT, 16M-BIT AND 32M-BIT SERIAL FLASH MEMORY WITH DUAL AND QUAD SPI

W25Q80, W25Q16, W25Q32
10.2.22 Power-down (B9h)
Although the standby current during normal operation is relatively low, standby current can be further
reduced with the Power-down instruction. The lower power consumption makes the Power-down
instruction especially useful for battery powered applications (See ICC1 and ICC2 in AC
Characteristics). The instruction is initiated by driving the /CS pin low and shifting the instruction code
“B9h” as shown in figure 22.
The /CS pin must be driven high after the eighth bit has been latched. If this is not done the Power-
down instruction will not be executed. After /CS is driven high, the power-down state will entered within
the time duration of tDP (See AC Characteristics). While in the power-down state only the Release from
Power-down / Device ID instruction, which restores the device to normal operation, will be recognized.
All other instructions are ignored. This includes the Read Status Register instruction, which is always
available during normal operation. Ignoring all but one instruction makes the Power Down state a useful
condition for securing maximum write protection. The device always powers-up in the normal operation
with the standby current of ICC1.
Figure 22. Deep Power-down Instruction Sequence Diagram
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Publication Release Date: September 26, 2007
Preliminary - Revision B