Figure 1. I2C Synchronous Data Timing
Table 1. AC Characteristics of I2C
Interface(2). Unless otherwise specified, applicable over recommended operating range from
TA = -40°C to +85°C, VCC =
+2.0V to +5.5V, CL = 1 TTL Gate and 100 pF.
Parameter |
Sym. |
Min. |
Max. |
Units |
SCL Clock
Frequency |
fSCL |
0 |
1 |
MHz |
SCL High Time |
tHIGH |
400 |
— |
ns |
SCL Low Time |
tLOW |
400 |
— |
ns |
Start Setup
Time |
tSU.STA |
250 |
— |
ns |
Start Hold Time |
tHD.STA |
250 |
— |
ns |
Stop Setup Time |
tSU.STO |
250 |
— |
ns |
Data In Setup
Time |
tSU.DAT |
100 |
— |
ns |
Data In Hold
Time |
tHD.DAT |
0 |
— |
ns |
Input Rise
Time1 |
tR |
— |
300 |
ns |
Input Fall
Time1 |
tF |
— |
100 |
ns |
Clock Low to Data Out
Valid |
tAA |
50 |
550 |
ns |
Data Out Hold
Time |
tDH |
50 |
— |
ns |
SMBus Time-Out
Delay |
tTIMEOUT |
25 |
35 |
ms |
Time bus must be free
before a new transmission can start1 |
tBUF |
500 |
— |
ns |
Notes:
- 1.Values are based on characterization and are not tested.
- 2.AC measurement conditions:
- RL (connects between SDA and VCC): 1.2 kΩ (for
VCC = +2.0V to +5.0V)
- Input pulse voltages: 0.3VCC to 0.7VCC
- Input rise and fall times: ≤ 50 ns
- Input and output timing reference voltage: 0.5VCC