TDA8025 NXP Semiconductors, TDA8025 Datasheet - Page 10

• Manufacturer Part Number: TDA8025
• Description: IC card interface
• Manufacturer: NXP Semiconductors

w
w
NXP Semiconductors
TDA8025_1
Product data sheet
w
.
d
a
t
a
The voltage on PORADJ (V
where:
An activation can be triggered if
where
The resistance spread of R1 between a minimum value R1
R1
where
If R1 is the maximum spread of R1 and R2 is the maximum spread of R2 then:
where
Then
V
V
R1
R2
s
•
•
•
•
min
min
DD INTF
DD INTF actmin
max
max
min
=
V
ratio
V
where
same type).
h
DD(INTF)
th(max)
=
=
--------------- -
1
induces a spread of the ratio . This is also true for R2. Based on this:
=
=
e
+
------------------------ -
1
----------------------------------------------------------- -
1
1
R2
R1
+
+
R1
------ -
R2
e
R1
-------------- -
R1
-------------------------------------------------- -
R2
R2
is the maximum rising external threshold voltage
nom
1
nom
is the accuracy ratio of R1 and R2 (R1 and R2 are considered to be of the
is the interface supply voltage
max
nom
min
nom
t
–
+
V
=
th max
4
V
------------------- -
R2
1
R1
1
1
th max
u
+
–
min
=
=
-------------- -
Rev. 01 — 6 April 2009
-------------- -
R1
R2
.
R2
R1
R1
R2
nom
nom
V
PORADJ
nom
c
nom
DD INTF
o
=
1
1
) can be calculated as:
---------------------------------------------- -
1
m
–
+
+
-------------- -
R2
-------------- -
R1
-------------------------------------
R1
R2
V
------------------- -
R2
nom
R1
nom
nom
nom
th max
1
1 +
1 –
=
--------------------------------------- -
V
DD INTF actmin
V
min
PORADJ
V
th max
and a maximum value
=
TDA8025
© NXP B.V. 2009. All rights reserved.
IC card interface
V
DD INTF
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