JS48F4400P0VB00 datasheet(42/99 Pages) NUMONYX

42 / 99 page

P30

Datasheet

November 2007

Order Number: 306666-11

8.3

Power Supply Decoupling

Flash memory devices require careful power supply de-coupling. Three basic power

supply current considerations are 1) standby current levels, 2) active current levels,

and 3) transient peaks produced when CE# and OE# are asserted and deasserted.

When the device is accessed, many internal conditions change. Circuits within the

device enable charge-pumps, and internal logic states change at high speed. All of

these internal activities produce transient signals. Transient current magnitudes depend

on the device outputs’ capacitive and inductive loading. Two-line control and correct

de-coupling capacitor selection suppress transient voltage peaks.

Because Numonyx Multi-Level Cell (MLC) flash memory devices draw their power from

VCC, VPP, and VCCQ, each power connection should have a 0.1 µF ceramic capacitor to

ground. High-frequency, inherently low-inductance capacitors should be placed as close

as possible to package leads.

Additionally, for every eight devices used in the system, a 4.7 µF electrolytic capacitor

should be placed between power and ground close to the devices. The bulk capacitor is

meant to overcome voltage droop caused by PCB trace inductance.

Figure 25: Reset Operation Waveforms

(A) Reset during

read mode

(B) Reset during

program or block erase

≤ P2

program or block erase

≥ P2

RST# [P]

Abort

Complete

Abort

Complete

(D) VCC Power-up to

RST# high

JS48F4400P0VB00 Datasheet(PDF) 42 Page - Numonyx B.V