Datasheet

Table Of Contents
DS13105 Rev 4 89/135
STM32WLE5J8/JB/JC Electrical characteristics
127
5.3.9 External clock source characteristics
High-speed external user clock generated from an external source
The high-speed external (HSE32) clock can be supplied with a 32 MHz crystal oscillator or
by a TCXO (temperature controlled crystal oscillator).
Crystal oscillator
The devices include internal programmable capacitances that can be used to tune the
crystal frequency in order to compensate the PCB parasitic one.
Characteristics in the tables below, are measured over recommended operating conditions,
unless otherwise specified. Typical values are referred to T
A
= 25 °C and V
DD
= 3 V.
Table 50. Regulator modes transition times
(1)
Symbol Parameter Conditions Typ Max Unit
t
WULPRUN
Wakeup time from LPRun to Run mode
(2)
Code run with MSI = 2 MHz 19.6 TBD
µs
t
VOST
Regulator transition time from Range 2 to
Range 1
(3)
Code run with HSI16
21.9 32.2
Regulator transition time from Range 1 to
Range 2
(3)
23.1 33.9
1. Guaranteed by characterization results (V
DD
= 3 V, T = 25 °C).
2. Time until REGLPF flag is cleared in PWR_SR2.
3. Time until VOSF flag is cleared in PWR_SR2.
Table 51. HSE32 crystal requirements
(1)
Symbol Parameter Conditions Min Typ Max Unit
f
NOM
Oscillator frequency - - 32 - MHz
f
TOL
Frequency tolerance
Includes initial accuracy, stability over
temperature, aging and frequency pulling
due to incorrect load capacitance.
- - 20 ppm
C
L
Load capacitance - 6 - 8 pF
ESR Equivalent series resistance - - - 100
P
D
Drive level - - - 100 µW
1. 32 MHz XTAL is specified for two specific references: NX2016SA and NX1612SA.
Table 52. HSE32 oscillator characteristics
Symbol Parameter Conditions Min Typ Max Unit
t
SUA(HSE)
Startup time for 80% amplitude
stabilization
V
DDRF
stabilized,
SUBGHZ_HSEINTRIMR = 0x12,
-40 to +125 °C temperature range
-1000-
µs
t
SUR(HSE)
Startup time
for HSEREADY signal
V
DDRF
stabilized,
SUBGHZ_HSEINTRIMR = 0x12,
-40 to +125 °C temperature range
- 180 -