rc4200 Fairchild Semiconductor, rc4200 Datasheet - Page 7

• Manufacturer Part Number: rc4200
• Description: Analog Multiplier
• Manufacturer: Fairchild Semiconductor

PRODUCT SPECIFICATION
Extended Range Divider
As with the extended range multiplier, resistors R
are added to cancel the cross-product error caused by the
biasing resistors, i.e.
To cancel cross-product and arithmetic offset:
R
and the result is:
REV. 1.2.1 6/14/01
V
-------------------------
V
--------------- -
where K =
V
--------------------- -
R
(Input)



X
0
ao
0
V
--------
R
R
R
V
X
V
R
V
X
1
1
X
R
V
Z
4
1
R
REF
+
R
b
+
b
REF
--------- -
R
V
b
V
----------------------- -
= R
ao
0
+
0
R
V
0
R1
V
----------------------- -
+
R
REF
R
0
=
0
--------- -
R
V
V
--------------------------- -
R a
d
ao
V
R
Figure 6. Extended Range Divider
az
Z
REF
V
-------------- or V
REF
R
d
R
+
+
R
, R
b
0
0
V
------------------------ -
V
--------------- -
1
V
R
+
Z
REF
R
R
R
az
R
V
Z
4
a
V
------------------------ -
4
0
b
R
R
REF
R
Z
R
 V REF


R b
az
c
V
b
I



I
4
1
2
REF
--------------- -
R
= R
8
1
7
2
+
R
R
b
ao
b
V
----------------
R
-V
Multiplier
+
REF
c
4
RC4200



R
+V
S
R
0
V
---------------- =
3
R
d
=
REF
a
c
R
2
=
REF
R



and R
b
az
V
------ -
R
----------- -
V
2
0
0
V
6
Z
+
X
K
V
--------------- -
R c
5
4
a
R
REF
I
I
R
3
C
4
b
 V Z


= R



------- -
RC5534
R
4
R
+V
c
+
R d
O
R
V
--------------- -
S
d
R
REF
R4
-V
az
D
+V
S
65-4200-08



and R
REF
(Output)
(Output)
V
V
O
Z
ao
Notice that it is necessary to match the above resistor cross-
products to within the amount of error tolerable in the out-
put offset, i.e., with a 10V F.S. output, 0.1% resistor cross-
product match will give 0.1% x 10V. untrimmable output
offset voltage.
Resistor Values
Inputs:
V
∆V
V
∆V
V
Outputs:
V
∆V
R
R
R
K
R
R
X
Z
REF
0
0
a
1
c
d
(min.) ≤ V
X
Z
0
(min.) ≤ V
(min.) ≤ V
=
=
=
=
=
=
= V
= V
= V
V
-------------- Design Requirement
= Constant (+7V to +18V)
R
------------ - , R
---------------- - , R
750µA
∆V
----------------------
600µAK
----------------------------------------------------------------------------- -
750µA∆V
------------------------------------------------------------------------------ -
250µA∆V
V
0
∆V
R
c
0
Z
X
V
R
X
b
(max.) = V
(max.) = V
0
(max.) = V
Z
d
∆V
0
(
Z
X
0
Z
≤ V
≤ V
az
≤ V
b
0
∆V
∆V
Z
=
Z
0
X
=
–
–
(max.)
(max.)
Z
0
(max.)
R
------------ - , R
X
0
700µA V
X
200µA V
∆V
----------------- - , R
(min.)
250µA
(min.)
V
R
c
(min.)
V
R
b
REF
REF
REF
4
ao
0
Z
(
4
(
=
max.
)
max.
=
R
------------ -
R
0
---------------- -
200µA
)
R
∆V
)
b
d
Z
RC4200
7