ST72651AR6 STMicroelectronics, ST72651AR6 Datasheet - Page 31

• Manufacturer Part Number: ST72651AR6
• Description: LOW-POWER, FULL-SPEED USB 8-BIT MCU WITH 32K FLASH, 5K RAM, FLASH CARD I/F, TIMER, PWM, ADC, I2C, SPI
• Manufacturer: STMicroelectronics

Specifications of ST72651AR6

• Dual Supply Management: analog voltage detector on the USB power line to enable smart power switching from USB power to battery (on E suffix devices).
• Programmable Internal Voltage Regulator For Memory Cards (2.8v To 3.5v) Supplying: Flash Card I/O lines (voltage shifting)
• 5 Usb Endpoints: 1 control endpoint
• Dtc (data Transfer Coprocessor): Universal Serial/Parallel communications interface, with software plug-ins for current and future protocol standards

6.4 POWER SUPPLY MANAGEMENT
6.4.1 Single Power Supply Management
In applications operating only when connected to
the USB (Flash writers, Backup systems), the mi-
crocontroller must operate from a single power
supply (i.e. USB bus power supply or the local
power source in the case of self-powered devic-
es). Devices with LVD (no E suffix) or without LVD
(E suffix) can support this configuration.
In order to enable the Single Power Supply Man-
agement, the PLGIE bit in the PCR register should
kept cleared by software (reset default value).
In this case, pin V
controller must be connected together and sup-
plied by a 4.0 to 5.5V voltage supply, either from
the USB cable or from the local power source. See
Figure
Figure 22. Single Power Supply Mode
.
In this mode:
– The PLL is running at 48 MHz
– The on-chip USB interface is enabled
– The core can run at up to 8MHz internal frequen-
– The microcontroller can be either USB bus pow-
– The USBEN function is not used. The PF4 pin
6.4.2 Dual Power Supply Management
In case of a device that can be used both when
powered by the USB or from a battery (Digital Au-
dio Player, Digital Camera, PDA), the microcon-
troller can operate in two power supply modes:
4.0 - 5.5 V
cy
ered or supplied by the local power source (self
powered)
can be configured to work as a normal I/O by pro-
gramming the Option Byte.
Note: Ground lines not shown
22.
DD
and USBV
V
V
V
USBV
DD1
DDA
DD2
DD
ST7
of the micro-
DD
Doc ID 7215 Rev 4
Stand-alone Mode and USB Mode. This configura-
tion is only available on devices without LVD (E
suffix). Devices with LVD are kept under reset
when the power supply drops below the LVD
threshold voltage and thus Stand-Alone mode can
not be entered.
In order to enable Dual Power Supply Manage-
ment:
– the USBEN pin function must be selected by pro-
– the user software must set the PLGIE bit in the
Stand-Alone Mode
This mode is to be used when no USB communi-
cation is needed. The microcontroller in this mode
can run at very low voltage, making the design of
low power / battery supplied systems easy. In this
mode:
– The USB cable is unplugged (no voltage input on
– The PLL is off
– The on-chip USB interface is disabled
– The core can run at up to 6 MHz internal frequen-
– The DTC operates at a frequency of 6MHz
– USBEN is kept floating by H/W.
– The microcontroller is supplied through the V
USB Mode
When connected to the USB, the microcontroller
can run at full speed, still saving battery power by
using USB power or self power source. To go into
USB mode, a voltage from 4.0V to 5.5V must be
provided to the USBV
– The USB cable is plugged in
– USBV
– The PLL is running at 48 MHz
– The on-chip USB interface is enabled
– The core can run at up to 8 MHz internal frequen-
– The DTC operates at a frequency of 24MHz
– USBEN is set to output low level by hardware.
– The microcontroller can be USB bus powered
gramming the option byte.
PCR register in the initialization routine.
USBV
cy
pin
voltage, either from the USB cable or from the
self powering source
cy
This signal can be used to control an external
transistor (USB SWITCH) to change the power
supply configuration (see
DD
DD
pin)
pin is supplied by a 4.0 to 5.5V supply
DD
pin. In this mode:
Figure
ST72651AR6
23).
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DD
1