STM32H523VCU6 datasheet(117/228 Pages) STMICROELECTRONICS

117 / 228 page

DS14540 Rev 1

117/228

STM32H523xx

Electrical characteristics

197

For CL1 and CL2, it is recommended to use high-quality external ceramic capacitors in the

5 to 20 pF range (typical), designed for high-frequency applications, and selected to match

the requirements of the crystal or resonator (see Figure 18). CL1 and CL2 usually have the

same size. The crystal manufacturer typically specifies a load capacitance, which is the

series combination of CL1 and CL2. PCB and MCU pin capacitance must be included (10 pF

can be used as a rough estimate for the combined pin and board capacitance) when sizing

CL1 and CL2.

Note:

For information on selecting the crystal, refer to AN2867 “Oscillator design guide for ST

microcontrollers”, available from www.st.com.

Figure 18. Typical application with an 8 MHz crystal

1. REXT value depends on the crystal characteristics.

Table 40. 4-50 MHz HSE oscillator characteristics(1)

1. Evaluated by design - Not tested in production.

Symbol

Parameter

Operating conditions(2)

2. Resonator characteristics given by the crystal/ceramic resonator manufacturer.

Min

Typ

Max

Unit

Oscillator frequency

MHz

Feedback resistor

200

kΩ

IDD(HSE) HSE current consumption

During startup(3)

3. This consumption level occurs during the first 2/3 of the tSU(HSE) startup time

VDD = 3 V, Rm = 20 Ω,

CL = 10 pF at 4 MHz

-0.44

VDD = 3 V, Rm = 20 Ω,

CL = 10 pF at 8 MHz

-0.44

VDD = 3 V, Rm = 20 Ω,

CL = 10 pF at 16 MHz

-0.55

VDD = 3 V, Rm = 20 Ω,

CL = 10 pF at 32 MHz

-0.67

VDD = 3 V, Rm = 20 Ω,

CL = 10 pF at 48 MHz

-1.17

Gmcritmax Maximum critical crystal gm

Startup

1.5

mA/V

tSU(HSE)(4)

4. tSU(HSE) is the startup time measured from the moment it is enabled (by software) to a stabilized 8 MHz

oscillation is reached. This value is measured for a standard crystal resonator and it can vary significantly

with the crystal manufacturer

Startup time

VDD is stabilized

ai17530b

OSC_OU T

OSC_IN

fHSE

CL1

STM32

8 MHz

resonator

Resonator with

integrated capacitors

Bias

controlled

gain

REXT(1)

CL2

STM32H523VCU6 Datasheet(PDF) 117 Page - STMicroelectronics

STM32H523VCU6 Datasheet(HTML) 117 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 Descarga

Enlace URL