Figure 24. Usb Timings: Definition Of Data Signal Rise And Fall Time - STMicroelectronics STM32L151CB Manual

STM32L151xx, STM32L152xx
Table 47.
Symbol
Input levels
V
DD
(4)
V
DI
(4)
V
CM
(4)
V
SE
Output levels
(5)
V
OL
(5)
V
OH
1. All the voltages are measured from the local ground potential.
2. To be compliant with the USB 2.0 full speed electrical specification, the USBDP (D+) pin should be pulled
up with a 1.5 kΩ resistor to a 3.0-to-3.6 V voltage range.
3. The STM32L15xxx USB functionality is ensured down to 2.7 V but not the full USB electrical characteristics
which are degraded in the 2.7-to-3.0 V V
4. Guaranteed by characterization, not tested in production.
5. Tested in production.
6. R is the load connected on the USB drivers.
L

Figure 24. USB timings: definition of data signal rise and fall time

Table 48.
Symbol
t
r
t
f
t
rfm
V
CRS
1. Guaranteed by design, not tested in production.
2. Measured from 10% to 90% of the data signal. For more detailed informations, please refer to USB
Specification - Chapter 7 (version 2.0).
USB DC electrical characteristics
Parameter
(2)
USB operating voltage
Differential input sensitivity
Differential common mode range Includes V
Single ended receiver threshold
Static output level low
Static output level high
Differen tial
Data L ines
V CRS
V S S
t f
USB: full speed electrical characteristics
Parameter
(2)
Rise time
(2)
Fall Time
Rise/ fall time matching
Output signal crossover voltage
Doc ID 17659 Rev 6
Conditions
I(USBDP, USBDM)
range
DI
R of 1.5 kΩ to 3.6 V
L
R of 15 kΩ to V
L
voltage range.
DD
Crossover
points
t r
Driver characteristics
Conditions
C = 50 pF
L
C = 50 pF
L
t /t
r f
Electrical characteristics
(1)
Min.
(3)
3.0
0.2
0.8
1.3
(6)
(6)
2.8
SS
(1)
Min Max
4 20
4 20
90 110
1.3 2.0
(1)
Max. Unit
3.6 V
2.5 V
2.0
0.3
V
3.6
ai14137
Unit
ns
ns
%
V
83/109