STM32WB55 datasheet(159/193 Pages) STMICROELECTRONICS

159 / 193 page

DS11929 Rev 11

159/193

STM32WB55xx STM32WB35xx

Electrical characteristics

169

The SDA and SCL I/O requirements are met with the following restriction: the SDA and SCL

I/O pins are not “true” open-drain. When configured as open-drain, the PMOS connected

between the I/O pin and VDD is disabled, but is still present. The 20 mA output drive

requirement in Fast-mode Plus is supported partially.

This limits the maximum load Cload supported in Fast-mode Plus, given by these formulas:



tr(SDA/SCL) = 0.8473 x Rp x Cload



Rp(min) = [VDD - VOL(max)] / IOL(max)

where Rp is the I2C lines pull-up. Refer to Section 6.3.17 for the I2C I/Os characteristics.

All I2C SDA and SCL I/Os embed an analog filter, refer to Table 92 for its characteristics.

SPI characteristics

Unless otherwise specified, the parameters given in Table 93 for SPI are derived from tests

performed under the ambient temperature, fPCLKx frequency and supply voltage conditions

summarized in Table 24: General operating conditions.



Output speed is set to OSPEEDRy[1:0] = 11



Capacitive load C = 30 pF



Measurement points are done at CMOS levels: 0.5 ₓ VDD

Refer to Section 6.3.17 for more details on the input/output alternate function characteristics

(NSS, SCK, MOSI, MISO for SPI).

Table 92. I2C analog filter characteristics(1)

1. Guaranteed by design.

Symbol

Parameter

Min

Max

Unit

tAF

Maximum pulse width of spikes that

are suppressed by the analog filter

50(2)

2. Spikes with widths below tAF(min) are filtered.

110(3)

3. Spikes with widths above tAF(max) are not filtered

STM32WB55 Datasheet(PDF) 159 Page - STMicroelectronics

STM32WB55 Datasheet(HTML) 159 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL