W25B40 Datasheet, PDF (5/36 Pages) Winbond – 4M-BIT SERIAL FLASH MEMORY WITH BOOT AND PARAMETER SECTORS

3. PIN CONFIGURATION
W25B40/W25B40A
Figure 1. W25B40 / W25B40A Pin Assignments, 8-pin SOIC (Package Code SN)
4. PIN DESCRIPTION
PIN NO.
1
2
3
4
5
6
7
8
PIN NAME
/CS
DO
/WP
GND
DI
CLK
/HOLD
VCC
I/O
FUNCTION
I
Chip Select Input
O
Data Output
I
Write Protect Input
Ground
I
Data Input
I
Serial Clock Input
I
Hold Input
Power Supply
4.1 Package Types
The standard package for the W25B40 / W25B40A is an 8-pin plastic SOIC with 150-mil body
(Winbond package code SN) (NexFlash package code N). The pinout for the package is shown in
Figure 1. Package diagram and dimensions are illustrated at the end of this data sheet.
4.2 Chip Select (/CS)
The SPI Chip Select (/CS) pin enables and disables device operation. When /CS is high the device is
deselected and the Serial Data Output (DO) pin is at high impedance. When deselected, the devices
power consumption will be at standby levels unless an internal erase, program or status register cycle
is in progress. When /CS is brought low the device will be selected, power consumption will increase
to active levels and instructions can be written to and data read from the device. After power-up, /CS
must transition from high to low before a new instruction will be accepted. The /CS input must track
the VCC supply level at power-up (see “Write Protection” and figure 18). If needed a pull-up resister
on /CS can be used to accomplish this.
Publication Release Date: January 6, 2006
-5-
Revision M