ATmega16HVB datasheet(132/273 Pages) ATMEL

132 / 273 page

132

8042A–AVR–07/09

ATmega16HVB/32HVB

23. Voltage Regulator

23.1

Features

• Input voltage from 4-25V

• Fixed output voltage of 3.3V

• Battery Pack Short Detection

• Black-out Detection (BLOD)

23.2

Overview

ATmega16HVB/32HVB get its voltage supply through the VFET terminal. Operating range at the

VFET terminal is 4 - 25V. The on-chip LDO regulator regulates the VFET terminal down to 3.3V,

which is a suitable supply voltage for the internal logic, I/O lines and analog circuitry. Figure 23-

1 illustrates the Voltage Regulator.

Figure 23-1. Voltage Regulator.

To ensure safe operating condition the Voltage Regulator has built in protection mechanisms to

protect the internal circuitry if the voltage drops on either the input or output terminal. The Regu-

lator Monitoring includes

• Battery Pack Short Detector

• Black-out Detector

An external decoupling capacitor (CREG) of minimum 1 µF is needed to ensure stable regulator

operation. The same capacitor also serves as a reservoir capacitor to ensure that the chip is

able to operate for some time without voltage at the VFET terminal.

Regulator Monitor

and Control Interface

LDO Regulator

Databus

VFET

DISABLE VFET

IRQ

BLOD

POWER-OFF

CREG

VREG

Battery

Short Detect

ROCR

Black-out

Detect

ATmega16HVB Datasheet(PDF) 132 Page - ATMEL Corporation