VAR-320SBC Reference Guide
Copyright © 2008 Variscite
5. Power supply and management
5.1. Power Supply
The VAR-320SBC can operate from a single 3.3v - 4.8v DC supply.
Voltage supply can be connected directly to a Lio-ion battery, or external regulated DC supply.
The single DC supply must be connected to all V_BATT net pins:
V_BATT pins:
P1 :7,19,31,43,55,67,79,91,103,115,127,139.
P2 : 7,19,31,43,55,67,79,91,103,115,127,135
V_BATT is connected directly to the National LP3972 PMIC which provides stable, low-noise
supplies for all core voltage domains, with additional regulators for supplying peripheral ICs. All
supplies are fed by high-performance, low-dropout (LDO) voltage regulators.
Three high-efficiency DC-DC buck converters provide high-current, low-voltage supplies to the
processor core and memory. The main converter features Dynamic Voltage Management (DVM),
with programmable voltage and slew rate control.
5.2. Power consumption
VAR-320SBC power consumption depends on the active components and peripherals.
BSP implements Dynamic Voltage Management. Core changes its own frequency / Voltage
according to CPU usage percentage. Frequency / Voltage control is automatic when enabled.
VAR-320SBC basic configuration:
9
Marvell™ PXA320 624 MHz processor.
9
1Gbit NAND flash.
9
128MB DDR SDRAM.
9
3 UARTS
9
I2C
9
TOUCHSCREEN
9
SRAM turned off after boot sequence.
Test conditions. DC_IN, V_BATT = 4v
Power loading configuration
Typical
VAR-320SBC basic configuration, running at 624mhz
0.9Watt
VAR-320SBC basic configuration, running at 406mhz
0.85Watt
VAR-320SBC basic configuration, running at 104mhz
0.75Watt
Deep-sleep 3
mW
30