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Rainbow Electronics DS1780 User Manual

Page 24

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DS1780

24 of 28

DC ELECTRICAL CHARACTERISTICS:
Fan RPM-to-Digital Converter

(-40°C to +125°C, 2.8V

V

DD

5.75V)

PARAMETER

SYMBOL

CONDITION

MIN

TYP

MAX

UNITS

NOTES

0°C

TA

100°C

±6

Accuracy

-40°C

TA

+125°C

±12

%

Full scale count

255

decimal

Divisor=1; Fan

Count=153

8800

Divisor=2; Fan

Count=153

4400

Divisor=4; Fan

Count=153

2200

FAN1 & FAN2
Normal Input RPM

Divisor=8; Fan

Count=153

1100

RPM

8

Internal Oscillator
Frequency

+25°C

TA

+75°C

21.15

22.5

23.85

kHz

DC ELECTRICAL CHARACTERISTICS:
Analog Output V

OUT

(-40°C to +125°C, 2.8V

V

DD

5.75V)

PARAMETER

SYMBOL

CONDITION

MIN

TYP

MAX

UNITS

NOTES

DAC Resolution

8

bits

Voltage Range

0

1.25

V

Error

DAC

ERR

±5

% of

FSR

Output Current

I

OUT

2.0

mA

Load Capacitance

C

LOAD

100

pF

DC ELECTRICAL CHARACTERISTICS:
Digital Outputs: A0NT

OUT

(-40°C to +125°C, 2.8V

V

DD

5.75V)

PARAMETER

SYMBOL

CONDITION

MIN

TYP

MAX

UNITS

NOTES

I

OUT

=±5 mA at

V

DD

=4.25V

Logical “1”
Output Voltage

V

OUT

(1)

I

OUT

=±3 mA at

V

DD

=2.85V

2.4

V

I

OUT

=±5 mA at

V

DD

=5.75V

Logical “0”
Output Voltage

V

OUT

(0)

I

OUT

=±3 mA at

V

DD

=3.45V

0.4

V