phyCARD-M [PCA-A-M1-xxx]
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©
PHYTEC Messtechnik GmbH 2010 L-750e_1
4.2
Standby Voltage (VBAT)
For applications requiring a standby mode a secondary voltage source
of 3.3V can be attached to the phyCARD-M at pin X2B6. This voltage
source is supplying the core and on-chip peripherals of the i.MX35
(e.g. EMI, PLL, etc.), as well as the SDRAM and the EEPROM at U6
while the primary system power (VCC_3V3) is removed. Applications
not requiring a standby mode can connect the VBAT pin to the
primary system power supply (VCC = 3.3V), or can leave it open.
4.3
On-board Voltage Regulator (U1)
The phyCARD-M provides an on-board switching regulator (U1) to
source the five different voltages (1.375V, 1.5V, 1.8V, 2.775V, and
3.3V) required by the processor and on-board components.
Figure
8 presents a graphical depiction of the powering scheme.
The switching regulator has two input voltage rails as can be seen in
Figure
8. 3V3 and 3V3 Backup. 3V3 is supplied only from the
primary voltage input pins VDD_3V3_IN of the phyCARD-M,
whereas 3V3 Backup is supplied from the primary voltage input pins
VDD_3V3_IN and the secondary voltage input pin VBAT. The
following list summarizes the relation between the different voltage
rails and the devices on the phyCARD-M:
External voltages: VCC_3V3 and VBAT (optional)
•
VDD_3V3_IN: 3V3
Voltage Regulator, Reset Controller
•
VBAT: 3V3 BACKUP Voltage Regulator
