Package Dimensions
FLASH MEMORY
READY/BUSY
The device has a R/B output that provides a hardware method of indicating the completion of a page program, erase and random
read completion. The R/B pin is normally high but transitions to low after program or erase command is written to the command reg-
ister or random read is started after address loading. It returns to high when the internal controller has finished the operation. The pin
is an open-drain driver thereby allowing two or more R/B outputs to be Or-tied. Because pull-up resistor value is related to tr(R/B)
and current drain during busy(ibusy) , an appropriate value can be obtained with the following reference chart(Fig 12). Its value can
be determined by the following guidance.
Rp
ibusy
VCC
Ready Vcc
R/B
2.0V
open drain output
0.8V
Busy
tf
tr
GND
Device
Fig 12 Rp vs tr ,tf & Rp vs ibusy
@ Vcc = 3.3V, Ta = 25°C , CL = 100pF
381
3.3
Ibusy
300n
3m
290
1.1
1.65
189
200n
100n
2m
1m
tr
tf
96
0.825
4.2
4.2
2K
4.2
3K
4.2
4K
1K
Rp(ohm)
Rp value guidance
VCC(Max.) - VOL(Max.)
3.2V
Rp(min) =
=
IOL + SIL
8mA + SIL
where IL is the sum of the input currents of all devices tied to the R/B pin.
Rp(max) is determined by maximum permissible limit of tr
27
SAMSUNG [ SAMSUNG ]
