306666-11 Datasheet, PDF (42/99 Pages) Numonyx B.V – Numonyx StrataFlash Embedded Memory

P30
Figure 25: Reset Operation Waveforms
(A) Reset during
read mode
V_IH
RST# [P]
V_IL
(B) Reset during
program or block erase
P1 ≤ P2
(C) Reset during
program or block erase
P1 ≥ P2
V_IH
RST# [P]
V_IL
V
IH
RST# [P]
V_IL
P1
R5
Abort
P2
R5
Complete
Abort
P2
R5
Complete
P3
(D) VCC Power-up to
RST# high
V_CC
V_CC
0V
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.
Datasheet
42
November 2007
Order Number: 306666-11