ATMEGA48_10-07 Datasheet, PDF (307/378 Pages) ATMEL Corporation – 8-bit Microcontroller with 4/8/16K Bytes In-System Programmable Flash

ATmega48/88/168
28.6 2-wire Serial Interface Characteristics
Table 28-5 describes the requirements for devices connected to the 2-wire Serial Bus. The ATmega48/88/168 2-wire Serial
Interface meets or exceeds these requirements under the noted conditions.
Timing symbols refer to Figure 28-4.
Table 28-5. 2-wire Serial Bus Requirements
Symbol Parameter
VIL
VIH
(1)
Vhys
(1)
VOL
(1)
tr
(1)
tof
(1)
tSP
I_i
C_i(1)
f_SCL
Input Low-voltage
Input High-voltage
Hysteresis of Schmitt Trigger Inputs
Output Low-voltage
Rise Time for both SDA and SCL
Output Fall Time from V_IHmin to V_ILmax
Spikes Suppressed by Input Filter
Input Current each I/O Pin
Capacitance for each I/O Pin
SCL Clock Frequency
Rp
Value of Pull-up resistor
Condition
3 mA sink current
10 pF < C_b < 400 pF⁽³⁾
0.1V_CC < V_i < 0.9V_CC
f_CK(4) > max(16f_SCL, 250kHz)⁽⁵⁾
f_SCL ≤ 100 kHz
f_SCL > 100 kHz
t_HD;STA Hold Time (repeated) START Condition
t_LOW
Low Period of the SCL Clock
t_HIGH
High period of the SCL clock
t_SU;STA Set-up time for a repeated START condition
t_HD;DAT
Data hold time
t_SU;DAT
Data setup time
t_SU;STO Setup time for STOP condition
t_BUF
Bus free time between a STOP and START
condition
f_SCL ≤ 100 kHz
f_SCL > 100 kHz
f_SCL ≤ 100 kHz
f_SCL > 100 kHz
f_SCL ≤ 100 kHz
f_SCL > 100 kHz
f_SCL ≤ 100 kHz
f_SCL > 100 kHz
f_SCL ≤ 100 kHz
f_SCL > 100 kHz
f_SCL ≤ 100 kHz
f_SCL > 100 kHz
f_SCL ≤ 100 kHz
f_SCL > 100 kHz
f_SCL ≤ 100 kHz
f_SCL > 100 kHz
Notes: 1. In ATmega48/88/168, this parameter is characterized and not 100% tested.
2. Required only for f_SCL > 100 kHz.
Min
-0.5
0.7V_CC
0.05V_CC(2)
0
20 + 0.1C_b(3)(2)
20 + 0.1C_b(3)(2)
0
-10
–
0
-^V---^C----^C----–-----⁰---^.-⁴---^V---
3 mA
-^V---^C----^C----–-----⁰---^.-⁴---^V---
3 mA
4.0
0.6
4.7
1.3
4.0
0.6
4.7
0.6
0
0
250
100
4.0
0.6
4.7
1.3
Max
0.3 V_CC
V_CC + 0.5
–
0.4
300
250
50⁽²⁾
10
10
400
1_----0_--0_---0_-----n_---s_-
C_b
3_---0_---0_-----n_---s_-
C_b
–
–
–
–
–
–
–
–
3.45
0.9
–
–
–
–
–
–
Units
V
ns
µA
pF
kHz
Ω
µs
ns
µs
2545S–AVR–07/10
307