TCA7408 Datasheet, PDF (14/25 Pages) Texas Instruments – Low-Voltage 8-Bit I2C and SMBus I/O Expander with Interrupt Output, RESET, I/ODirection Registers, and Programmable Pull-up/Pull-down

TCA7408
SCPS235 – NOVEMBER 2011
www.ti.com
I2C INTERFACE TIMING REQUIREMENTS
PARAMETER
STANDARD MODE
I²C BUS
f_scl
t_sch
t_scl
t_sp
t_sds
t_sdh
t_icr
t_icf
t_ocf
t_buf
t_sts
t_sth
t_sps
t_vd(data)
t_vd(ack)
I²C clock frequency
I²C clock high time
I²C clock low time
I²C spike time
I²C serial data setup time
I²C serial data hold time
I²C input rise time
I²C input fall time
I²C output fall time; 10 pF to 400 pF bus
I²C bus free time between Stop and Start
I²C Start or repeater Start condition setup time
I²C Start or repeater Start condition hold time
I²C Stop condition setup time
Valid data time; SCL low to SDA output valid
Valid data time of ACK condition; ACK signal from SCL low to
SDA (out) low
MIN MAX
0
100
4
4.7
50
250
0
1000
300
300
4.7
4.7
4
4
1
1
FAST MODE
I²C BUS
MIN
0
0.6
1.3
100
0
20 + 0.1C_b
20 + 0.1C_b
20 + 0.1C_b
1.3
0.6
0.6
0.6
0.3
MAX
400
50
300
300
300
0.9
0.3
0.9
FAST MODE PLUS
(FM+) I²C BUS
(V_DDI = 2.3 – 5.5 V)
MIN
MAX
0
1000
0.26
0.5
50
50
0
120
120
120
0.5
0.26
0.26
0.26
0.45
0.45
UNIT
kHz
μs
μs
ns
ns
ns
ns
ns
μs
μs
μs
μs
μs
μs
μs
RESET TIMING REQUIREMENTS
PARAMETER
t_W
t_REC
t_RESET
Reset pulse duration
Reset recovery time
Time to reset
SWITCHING CHARACTERISTICS
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
t_iv
Interrupt valid time
GPIO port
INT
t_ir
Interrupt reset delay time
SCL
INT
t_pv
Output data valid
SCL
GPIO7–GPIO0
t_ps
Input data setup time
GPIO port
SCL
t_ph
Input data hold time
GPIO port
SCL
STANDARD MODE, FAST MODE,
FAST MODE PLUS (FM+)
I²C BUS
MIN
MAX
250
TBD
250
STANDARD MODE, FAST MODE,
FAST MODE PLUS (FM+)
I²C BUS
MIN
MAX
20
250
250
0
300
UNIT
ns
ns
ns
UNIT
ns
ns
ns
ns
ns
14
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