6 voltage regulator, At different ambient temperatures due to r – Rainbow Electronics ATA6630 User Manual

Page 19

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19

9117C–AUTO–10/09

ATA6628/ATA6630 [Preliminary]

5.6

Voltage Regulator

The voltage regulator needs an external capacitor for compensation and for smoothing the dis-
turbances from the microcontroller. It is recommended to use an electrolythic capacitor with
C > 1.8 µF and a ceramic capacitor with C = 100 nF. The values of these capacitors can be var-
ied by the customer, depending on the application.

The main power dissipation of the IC is created from the VCC output current I

VCC

, which is

needed for the application. In

Figure 5-2 on page 19

the safe operating area of the

ATA6628/ATA6630 is shown.

Figure 5-1.

VCC Voltage Regulator: Ramp-up and Undervoltage Detection

Figure 5-2.

Power Dissipation: Safe Operating Area versus VCC Output Current and Supply
Voltage V

S

at Different Ambient Temperatures Due to R

thja

= 35 K/W

For microcontroller programming, it may be necessary to supply the VCC output via an external
power supply while the V

S

Pin of the system basis chip is disconnected. This behavior is no

problem for the system basis chip.

NRE

S

5V/

3

.

3

V

t

t

t

V

S

5V/

3

.

3

V

V

th

u

n

T

re

s

_f

T

Re

s

et

T

VCC

5.5V/

3

.

8

V

12V

VCC

0

10

2 0

3

0

4 0

50

6 0

3

5

7

9

11

1

3

15

17

19

V

S

/V

I

VCC

/mA

T

a

m

b

= 125°C

T

a

m

b

= 105°C

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