IC-MQF_15 Datasheet, PDF (26/38 Pages) IC-Haus GmbH – Sin/Cos INTERPOLATION IC WITH RS422 DRIVER

iC-MQF PROGRAMMABLE 12-BIT ^preliminary
Sin/Cos INTERPOLATION IC WITH RS422 DRIVER
SIGNAL LEVEL CONTROL and SIGNAL MONITORING
Rev C1, Page 26/38
iC-MQF’s signal level controller can keep the input sig-
nals for the sine-to-digital converter constant, regard-
less of temperature and aging effects, when using con-
trol output ACO for tracking the sensor supply.
ACOR(1:0) presets the output current range of pin
ACO, the control’s highside current source output, and
ACOT(1:0) defines its control mode.
The resulting internal signal amplitude and the control’s
operating range are both monitored and thus can be
used for error messaging.
Addr 0x15, bit 7:6
ACOR (1:0)
Code
Function
00
5 mA - Range
01
10 mA - Range
10
25 mA - Range
11
50 mA - Range
and phase correction values without interference by
signal level controlling.
Addr 0x15, bit 5:1
ACOS (4:0)
Code
Square control ACOT = 00
0x00
Vpp() ≈ 1800 mV (60 %)
0x01
...
0x19
Vpp() ≈ 1830 mV (61 %)
...
≈
1800
mV
77
77−(1.25∗Code)
Vpp() ≈ 3000 mV (98 %)
...
...
0x1F
Vpp() ≈ 3600 mV (120 %)
Table 34: Square Control Setpoint (internal sin/cos sig-
nal amplitude)
Table 32: ACO Output Current Range (applies for con-
trol modes and constant current source)
Addr 0x16, bit 1:0
ACOT (1:0)
Code
Function
00
Sine/cosine square control
01
Sum control
10
Constant current source
11
Not permitted (device test only)
Table 33: ACO Output Control Mode
Notice: Excessive input signals or internal signal clipping
can interfere control operation, so that the preset operating
point may not be reached (upon power up) or maintained
(upon disturbances). Use Control Error 2 and Signal Error 1
for monitoring and configure EMASKA accordingly.
The standard control mode is square control which
uses (sine² + cosine²) to adjust the ACO output current.
ACOS(4:0) determines the internal signal amplitudes
within the closed-loop control and, simultaneously, the
amplitude monitoring thresholds. The ideal setpoint
here is 3 Vpp referred to the sin/cos test signals avail-
able in operating mode Test 5.
Figure 8: Signal monitoring and test signals in Test 5
mode (example for ACOS(4:0) = 0x19).
Signal monitoring and limits
ADJ (4:0) Vt()min ... max ADJ (4:0) Vt()min ... max
0x00
0.72 V...2.34 V
0x19
1.2 V ...3.9 V
0x01
0.732 V...2.38 V ...
...
...
...
0x1F
1.44 V...4.68 V
Notes
All values nominal, see also Elec. Char. Nos. 605,
606
Table 35: Signal Monitoring
With sum control mode selected, the DC references
(VDC1 + VDC2) are used to adjust the output current of
pin ACO.
The constant current source is intended for signal condi-
tioning purposes, i.e. for the adjustment of gain, offset
The signal monitoring thresholds are tracked according
to ACOS (4:0) and fit for square control mode. When
using sum control mode a different operating point can
be required for which the monitoring thresholds may
not be suitable. In this case signal monitoring should
be disabled via the error mask (see EMASKA etc.).