ISD91200 Series Technical Reference Manual
Release Date: Sep 16, 2019
- 26 -
Revision 2.4
5.2.3
System Power Distribution
The ISD91200 implements several power domains:
Analog power from VCCA and VSSA provides the power for analog module operation.
Digital power from VCCD and VSSD supplies the power to the IO ring and the internal regulator
which provides 1.5V power for digital operation.
VCCLDO supplies the LDO regulator whose output is available on pin VLDOx. This supply
powers the IO ring for GPIOA<7:0>.
An internal Standby reference (SB REG) generates a 1.5V rail to part of the logic including the IO
ring, Standby RAM and RTC during standby mode for low power operation.
The outputs of internal voltage regulators; VREG and VDDB, require external decoupling capacitors
which should be located close to the corresponding pin. The following diagram shows the power
distribution of this device.
SD ADC
Brownout
Detector
POR50
POR15
OPA
SB
REG
Analog Comparator
VCCA
VSSA
XO32K
XI32K
N573FXX
Power Distribution
SAR ADC
10 KHz
Osc.
RTC
32 K
OSC
1.5 V Standby Supply
SB
RAM
Speaker
Driver
V
C
C
S
P
K
V
S
S
S
P
K
Active in Standby Power Down Mode
Active in Deep and Standby Power Down Mode
FLASH
Digital
Logic
RAM
BUFFER
1.5V
LDO
IO Cell
5 V to 3.3 V
LDO
3.3V
1.5V Main Supply
V
C
C
D
V
S
S
D
VDDBS
VDDB
VREG
1uF
4.7uF
IO cell
GPIOA<15:8>
GPIOB<15:0>
50 MHz
Osc.
GPIOA<7:0>
Note:
GPIOA11 is
DPD wakeup pin
CSCAN
Figure 5-2 ISD91200 Power Distribution Diagram