STA321 datasheet(19/157 Pages) STMICROELECTRONICS

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STA321

Electrical specifications

Doc ID 15351 Rev 3

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3.5

Embedded DC regulator

The power supply to the digital STA321 core and PLL is provided via embedded linear DC

regulators as shown below in Figure 6. When pin REG_BYPASS is tied to ground, the DC

regulators are active so that a voltage in the range 2.5 V to 3.6 V applied to pins VDD_REGx

or PVDD provides a regulated internal voltage to the core and the PLL. The voltages Vddi

and Vddipll range from 1.55 V to 1.95 V depending on operating conditions.

Figure 6.

Embedded DC regulator scheme

If the application allows multiple supplies or the power supply requirements are a

fundamental constraint, pin REG_BYPASS can be tied high and a 1.8 V external supply can

be applied directly to pins VDD_REGx and PVDD. In this case the operating range for such

an external supply is 1.55 V to 1.95 V.

Embedded DC regulators imply also static power consumption that must be take into

account when the power-down modes are active. The STA321 provides a deep powerdown

mode where also the regulators are active but in a low power consumption mode (see

Section 4.3.2 on page 27).

Core

PLL

STA321

VDD_REG1

VDD_REG2

PVDD

Vddi

Vddipll

REG_BYPASS

STA321 数据表(PDF) 19 Page - STMicroelectronics