Datasheet
DocID024030 Rev 10 97/239
STM32F427xx STM32F429xx Electrical characteristics
198
6.3.2 VCAP1/VCAP2 external capacitor
Stabilization for the main regulator is achieved by connecting an external capacitor C
EXT
to
the VCAP1/VCAP2 pins. C
EXT
is specified in Table 19 .
Figure 24. External capacitor C
EXT
1. Legend: ESR is the equivalent series resistance.
Table 18. Limitations depending on the operating power supply range
Operating
power supply
range
ADC operation
Maximum Flash
memory access
frequency with
no wait states
(f
Flashmax
)
Maximum HCLK
frequency vs Flash
memory wait states
(1)(2)
I/O operation
Possible Flash
memory
operations
V
DD
=1.7 to
2.1 V
(3)
Conversion time
up to 1.2 Msps
20 MHz
(4)
168 MHz with 8 wait
states and over-drive
OFF
No I/O
compensation
8-bit erase and
program
operations only
V
DD
= 2.1 to
2.4 V
Conversion time
up to 1.2 Msps
22 MHz
180 MHz with 8 wait
states and over-drive
ON
No I/O
compensation
16-bit erase and
program
operations
V
DD
= 2.4 to
2.7 V
Conversion time
up to 2.4 Msps
24 MHz
180 MHz with 7 wait
states and over-drive
ON
I/O compensation
works
16-bit erase and
program
operations
V
DD
= 2.7 to
3.6 V
(5)
Conversion time
up to 2.4 Msps
30 MHz
180 MHz with 5 wait
states and over-drive
ON
I/O compensation
works
32-bit erase and
program
operations
1. Applicable only when the code is executed from Flash memory. When the code is executed from RAM, no wait state is
required.
2. Thanks to the ART accelerator and the 128-bit Flash memory, the number of wait states given here does not impact the
execution speed from Flash memory since the ART accelerator allows to achieve a performance equivalent to 0 wait state
program execution.
3. V
DD
/V
DDA
minimum value of 1.7 V is obtained with the use of an external power supply supervisor (refer to Section 3.17.2:
Internal reset OFF).
4. Prefetch is not available.
5. The voltage range for USB full speed PHYs can drop down to 2.7 V. However the electrical characteristics of D- and D+
pins will be degraded between 2.7 and 3 V.
Table 19. VCAP1/VCAP2 operating conditions
(1)
1. When bypassing the voltage regulator, the two 2.2 µF V
CAP
capacitors are not required and should be
replaced by two 100 nF decoupling capacitors.
Symbol Parameter Conditions
CEXT Capacitance of external capacitor 2.2 µF
ESR ESR of external capacitor < 2 Ω
069
(65
5
/HDN
&
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.