Datasheet
PCA6408A All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
Product data sheet Rev. 1 — 27 September 2012 24 of 40
NXP Semiconductors
PCA6408A
Low-voltage, 8-bit I
2
C-bus and SMBus I/O expander
15. Parameter measurement information
Table 18. Switching characteristics
Over recommended operating free air temperature range; C
L
100 pF; unless otherwise specified. See Figure 28.
Symbol Parameter Conditions Standard-mode
I
2
C-bus
Fast-mode
I
2
C-bus
Unit
Min Max Min Max
t
v(INT)
valid time on pin INT from P port to INT -1-1s
t
rst(INT)
reset time on pin INT from SCL to INT -1-1s
t
v(Q)
data output valid time from SCL to P port - 400 - 400 ns
t
su(D)
data input set-up time from P port to SCL 0 - 0 - ns
t
h(D)
data input hold time from P port to SCL 300 - 300 - ns
a. SDA load configuration
b. Transaction format
c. Voltage waveforms
C
L
includes probe and jig capacitance. t
f(o)
is measured with C
L
of 10 pF or 400 pF.
All inputs are supplied by generators having the following characteristics: PRR 10 MHz; Z
o
=50; t
r
/t
f
30 ns.
All parameters and waveforms are not applicable to all devices.
Byte 1 = I
2
C-bus address; Byte 2 = Input register port data.
(1) See Figure 11
.
Fig 26. I
2
C-bus interface load circuit and voltage waveforms
002aag977
DUT
C
L
= 50 pF
R
L
= 1 kΩ
SDA
V
DD(I2C-bus)
STOP
condition
(P)
Data
Bit 0
(LSB)
Data
Bit 7
(MSB)
ACK
(A)
R/W
Bit 0
(LSB)
Address
Bit 1
Address
Bit 7
(MSB)
START
condition
(S)
STOP
condition
(P)
two bytes for read Input port register
(1)
002aag952
t
LOW
t
HIGH
t
r
t
f
0.7 × V
DD(I2C-bus)
0.3 × V
DD(I2C-bus)
0.7 × V
DD(I2C-bus)
0.3 × V
DD(I2C-bus)
t
SP
t
BUF
t
f
t
HD;STA
t
r
SCL
SDA
t
SU;DAT
t
HD;DAT
t
f(o)
t
VD;ACK
t
VD;DAT
t
VD;ACK
t
SU;STA
t
SU;STO
002aag978
repeat START condition
STOP condition