Datasheet

Electrical characteristics STM32F405xx, STM32F407xx
102/167 Doc ID 022152 Rev 2
Figure 34. I/O AC characteristics definition
11
F
max(IO)out
Maximum frequency
(4)
C
L
= 30 pF, V
DD >
2.70 V - - 100
(5)
MHz
C
L
= 30 pF, V
DD >
1.8 V - - 50
(5)
C
L
= 10 pF, V
DD >
2.70 V - - 200
(5)
C
L
= 10 pF, V
DD >
1.8 V - - TBD
t
f(IO)out
Output high to low level fall
time
C
L
= 20 pF, 2.4 < V
DD
< 2.7 V - - TBD
ns
C
L
= 10 pF, V
DD
> 2.7 V - - TBD
t
r(IO)out
Output low to high level rise
time
C
L
= 20 pF, 2.4 < V
DD
< 2.7 V - - TBD
C
L
= 10 pF, V
DD
> 2.7 V - - TBD
-t
EXTIpw
Pulse width of external signals
detected by the EXTI
controller
10 - - ns
1. Based on characterization data, not tested in production.
2. The I/O speed is configured using the OSPEEDRy[1:0] bits. Refer to the STM32F20/21xxx reference manual for a
description of the GPIOx_SPEEDR GPIO port output speed register.
3. TBD stands for “to be defined”.
4. The maximum frequency is defined in Figure 34.
5. For maximum frequencies above 50 MHz, the compensation cell should be used.
Table 46. I/O AC characteristics
(1)(2)(3)
(continued)
OSPEEDRy
[1:0] bit
value
(1)
Symbol Parameter Conditions Min Typ Max Unit
ai14131
10%
90%
50%
t
r(IO)out
OUTPUT
EXT ERNAL
ON 50pF
Maximum frequency is achieved if (t
r
+ t
f
) ≤ 2/3)T and if the duty cycle is (45-55%)
10 %
50%
90%
when loaded by 50pF
T
t
r(IO)out