AC Parameters: I²C Interface

Figure 1. I²C Synchronous Data Timing

Table 1. AC Characteristics of I²C Interface⁽²⁾. Unless otherwise specified, applicable over recommended operating range from T_A = -40°C to +85°C, V_CC = +2.0V to +5.5V, C_L = 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	75	ms
Time bus must be free before a new transmission can start1	tBUF	500	—	ns

Notes:

1. 1.Values are based on characterization and are not tested.
2. 2.AC measurement conditions:
   • R_L (connects between SDA and V_CC): 1.2 kΩ (for V_CC = +2.0V to +5.0V)
   • Input pulse voltages: 0.3V_CC to 0.7V_CC
   • Input rise and fall times: ≤ 50 ns
   • Input and output timing reference voltage: 0.5V_CC