Data Sheet AS8446

Revision 1.8, Date 2005-03-17

Page 24 of 35

Electrical Parameters and Functionality of the Subblocks

5V Regulator

PARAMETER

SYMBOL

MIN

TYP

MAX

UNIT

NOTE

Regulated Output Voltage

VDD

4.8

5.0

5.15

V

(1)

Load Current at VDD

IOUT

40

mA

(2), (3), (4)

Under voltage detection threshold

VDDunder

4.3

V

Over voltage detection threshold

VDDover

5.6

V

capacitor of 4.7

µF to 10µF needs to be connected at the VDD pin.

Note (2): Valid for Vbat

≥ 6.5V; for 6.0V ≤ Vbat < 6.5V the load current is limited to 2.5mA.

Note (3): There is also the possibility to use an external regulator (Bipolar transistor). It is up to the user to select

the suitable external components.

Note (4): The max. power dissipation on chip must be respected

(estimation: Pchip_vdd = ((Vbatmax - 5 V ) * Ivdd_ex + Vbat * Ivdd_in) < 400 mW )

Design Example

Figure 12: Design example for operation of external voltage regulator

Power on Reset

21

3

4

50

2

13

4

5

5

4

3

2

1

Figure 13

Transfer characteristic of PORn circuitry

R

100

Ω

C

VDD

100 µF / 16V

T

1

V

BAT

220 nF

(Ceramic)

V

DDctrl

V

DD

47 nF