IC-MH_17 Datasheet, PDF (13/26 Pages) IC-Haus GmbH – 12-BIT ANGULAR HALL ENCODER

iC-MH
12-BIT ANGULAR HALL ENCODER
TEST MODES FOR SIGNAL CALIBRATION
Rev C2, Page 13/26
For signal calibration iC-MH has several test settings
which make internal reference quantities and the ampli-
fied Hall voltages of the individual sensors accessible at
external pins A, B, Z and U for measurement purposes.
This enables the settings of the offset (VOSS, VOSC),
gain (GAING, GAINF) and amplitude ratio of the cosine
to the sine signal (GCC) to be directly observed on the
oscilloscope.
Test mode can be triggered by connecting pin VZAP
to VPD and programming the TEST register (address
0x0E). The individual test modes are listed in the fol-
lowing table:
Output signals in test mode
Mode
TEST Pin A Pin B Pin Z Pin U
Normal
0x00 A
B
Z
U
Analog SIN 0x20 HPSP HPSN HNSP HNSN
Analog COS 0x21 HPCP HPCN HNCP HNCN
Analog OUT 0x22 PSIN NSIN PCOS NCOS
Analog REF 0x43 VREF IBM VBG VOSR
Digital CLK 0xC0 CLKD
Table 14: Test modes and available output signals
The output voltages are provided as differential signals
with an average voltage of 2.5 V. The gain is determined
by register values GAING and GAINF and should be
set so that output amplitudes from the sine and cosine
signals of about 1 V are visible.
iC-MH
PSIN
A
B
B
B
Z
B
B
U
NSIN
HALL SENSORS
C021107-1
VNA
Test Mode: Analog SIN
HPSP
HPSN
HNSP
HNSN
V_PSIN
V_NSIN
Figure 7: Output signals of the sine Hall sensors in
test mode Analog SIN
iC-MH
PCOS
A
B
B
B
Z
B
B
U
NCOS
HALL SENSORS
C021107-2
VNA
Test Mode: Analog COS
HPCP
HPCN
HNCP
HNCN
V_PCOS
V_NCOS
Figure 8: Output signals of the cosine Hall sensors
in test mode Analog COS
Test Modes Analog SIN and Analog COS
In these test modes it is possible to measure the sig-
nals from the individual Hall sensors independent of
one another. The name of the signal is derived from
the sensor name and position. HPSP, for example,
is the (amplified) Hall voltage of sensor PSIN at the
positive signal path; similarly, HNCN is the Hall voltage
of sensor NCOS at the negative signal path. The effec-
tive Hall voltage is accrued from the differential voltage
between the positive and negative signal paths of the
respective sensor.
iC-MH
PSIN
PCOS
A
B
B
B
Z
B
B
U
NCOS
NSIN
HALL SENSORS
C021107-3
VNA
Test Mode: Analog OUT
PSIN
NSIN
PCOS
NCOS
V_SIN
V_COS
Test Mode Analog OUT
In this test mode the sensor signals are available at the
outputs as they would be when present internally for
further processing on the interpolator. The interpolation
accuracy which can be obtained is determined by the
quality of signals V_sin and V_cos and can be influenced in
this particular test mode by the calibration of the offset,
gain and amplitude ratio.
Figure 9: Differential sine and cosine signals in test
mode Analog OUT
Test Mode Analog REF
In this mode various internal reference voltages are
provided. VREF is equivalent to half the supply voltage
(typically 2.5 V) and is used as a reference voltage for
the Hall sensor signals. VBG is the internal bandgap