AS4C64M32MD2-25BCN datasheet(13/129 Pages) ALSC

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Tx is the point where any power supply decreases under its minimum value specified in the DC operating condition

table.

Tz is the point where all power supplies are below 300 mV. After Tz, the device is powered off.

The time between Tx and Tz (tPOFF) shall be less than 2s.

The following conditions apply:

Between Tx and Tz, VDD1 must be greater than VDD2 - 200 mV.

Between Tx and Tz, VDD1 and VDD2 must be greater than VDD2 - 200 mV.

Between Tx and Tz, VDD1 and VDD2 must be greater than VDDQ - 200 mV.

Between Tx and Tz, VREF must always be less than all other supply voltages.

The voltage difference between any of VSS, VSSQ, and VSSCA pins may not exceed 100 mV.

Table 2 – Timing Parameters Power-Off

Symbol

Value

Unit

Comment

min

max

tPOFF

Maximum Power-Off ramp time

3.2.4 Uncontrolled Power-Off Sequence

The following sequence shall be used to power off the LPDDR2 device under uncontrolled condition.

Tx is the point where any power supply decreases under its minimum value specified in the DC operating condition

table. After turning off all power supplies, any power supply current capacity must be zero, except for any static charge

remaining in the system.

Tz is the point where all power supply first reaches 300 mV. After Tz, the device is powered off.

The time between Tx and Tz (tPOFF) shall be less than 2s. The relative level between supply voltages are

uncontrolled during this period.

VDD1 and VDD2 shall decrease with a slope lower than 0.5 V/usec between Tx and Tz.

Uncontrolled power off sequence can be applied only up to 400 times in the life of the device.

AS4C64M32MD2-25BCN

AS4C128M16MD2-25BCN

Confidential

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Rev.1.0 July 2016

AS4C64M32MD2-25BCN Datasheet(PDF) 13 Page - Alliance Semiconductor Corporation