IC-MR Datasheet, PDF (19/44 Pages) IC-Haus GmbH – 13-BIT S&H SIN/COS INTERPOLATOR WITH CONTROLLER INTERFACES

iC-MR 13-BIT S&H SIN/COS
preliminary
INTERPOLATOR WITH CONTROLLER INTERFACES
SIGNAL CONDITIONING
Rev A1, Page 19/44
Input configuration
All input stages are configured as instrumentation am-
plifiers and thus directly suitable for differential input
signals. Referenced input signals can be processed
by applying the input signals’ reference voltage to neg-
ative inputs.
Signal adjustment is possible only in operating modes
Analog 1 and Analog 2. Figure 8 shows the sine chan-
nel’s conditioning unit; the cosine channel’s set-up is
equivalent to it.
PSI
GFS
PSIN1
NSI
GFS
VREF
VREFI
SELREF
OR x OF x
0.5 V
0.25 V
0.05 x V(ACO)
VDC
NSIN1
k
PSIN2
GR
NSIN2
VPAH
SVDC
Figure 8: Signal-conditioning unit (sine channel)
INMODE
Code
0
1
Addr 0x0E, bit 7
Function
Differential input signals
Single-ended input signals
Table 12: Input mode differential/single-ended
Both voltage and current signals can be accepted as
input signals. For selection use register bit UIN.
UIN
Code
0
1
Addr 0x0E, bit 0
Function
Current input
Voltage input
are typical, refer to Electrical Characteristics for toler-
ances.
The input resistance should be set so that center po-
tentials SVDC and CVDC are between 125 mV and
250 mV (testable in operating mode Analog 2).
RIN
Code
00
01
10
11
Addr 0x0E, bit 2:1
Nominal Rin() Internal Rui()
1.7 kΩ
1.6 kΩ
2.5 kΩ
2.3 kΩ
3.5 kΩ
3.2 kΩ
4.9 kΩ
4.6 kΩ
Mode
Current input
Current input
Current input
Current input
Table 13: Operating mode current/voltage
Table 14: Input resistance
In current mode an input restistor Rin() becomes ac-
tive at each input pin, converting the current signal into
a voltage signal. The input resistance Rin() consists
of a pin resistor and the resistor Rui(), which is con-
nected to the adjustable bias source VREFI. Tab. 14
shows the selection options. Indicated values of Rin()
In voltage mode a voltage divider can be selected for
high input amplitudes. This voltage divider reduces the
input signal’s amplitude to about 25%. The internal cir-
cuit corresponds to the circuit in current mode, just the
resistor connecting the pin is altered.