PRODUCT SPECIFICATION
RC4200
2
Squaring Circuits V = K V
0
X
+VREF
R
R
R
c
R
d
b
a
R1
8
5
VX
(Input)
I
I
1
4
7
RC4200
Multiplier
R1
1
2
VO
(Output)
I
RO
2
4
I
3
3
6
+VS
-VS
RCX
RC5534
-VS
65-1875
Figure 10. Squaring Circuit
2
2
2
VX 2VXVREF VREF
V0VREF VREF VXVREF
-------2 + ------------------------- + ------------- = -------------------- + ------------- + ---------------------
2
R1Ra
R0Rd
RcRd
RcRd
R1
Ra
2
if Ra = RcRd and R1Ra = 2RCXRD
2
V0VREF
VX
R0Rd
2
--------------------
R0Rd
-------
or V0 = KVX where K =
2
--------------------
VREFR1
then
=
2
R1
V (min.) ≤ V ≤ V (max.) ∆V = V (max.) – V (min.)
X
X
X
X
X
X
V0
-------2
VX
K =
(Design Requirement)
∆VX
----------------
=
R1
Ra
200µA
∆VXVREF
--------------------------------------------------------------------------------
=
250µA∆VX – 200µA VX(max.)
VREF
----------------
Rd
Rc
=
=
250µA
2
Ra
------
Rd
R1Ra
------------
2Rd
Rcx
=
∆VX2K
------------------
160µA
R0
=
REV. 1.2.1 6/14/01
11
FAIRCHILD [ FAIRCHILD SEMICONDUCTOR ]
