iC-MH
12 BIT ANGULAR HALL ENCODER
Rev B1, Page 12/23
Test modes for signal calibration
For signal calibration iC-MH has several test settings
which make internal reference quantities and the am-
plified Hall voltages of the individual sensors accessi-
ble at external pins A, B, Z and U for measurement pur-
poses. 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 ob-
served on the oscilloscope.
iC-MH
PSIN
A
B
Z
HPSP
HPSN
HNSP
HNSN
VPSIN
B
B
B
B
VNSIN
U
NSIN
HALL SENSORS
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:
VNA
C021107-1
Test Mode: Analog SIN
Figure 7: Output signals of the sine Hall sensors in
test mode Analog SIN
Output signals in test mode
Mode
TEST Pin A Pin B Pin Z Pin U
0x00
0x20 HPSP HPSN HNSP HNSN
Normal
Analog SIN
A
B
Z
U
iC-MH
PCOS
A
B
Z
HPCP
HPCN
HNCP
HNCN
Analog COS 0x21 HPCP HPCN HNCP HNCN
Analog OUT 0x22 PSIN NSIN PCOS NCOS
VPCOS
B
B
B
Analog REF 0x43 VREF IBM
Digital CLK 0xC0 CLKD
VBG
VOSR
B
VNCOS
U
NCOS
HALL SENSORS
Table 14: Test modes and available output signals
VNA
C021107-2
Test Mode: Analog COS
The output voltages are provided as differential sig-
nals with an average voltage of 2.5 V. The gain is de-
termined 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.
Figure 8: Output signals of the cosine Hall sensors
in test mode Analog COS
iC-MH
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.
PSIN
PCOS
A
B
Z
PSIN
VSIN
B
B
B
NSIN
PCOS
NCOS
B
VCOS
U
NCOS
NSIN
HALL SENSORS
VNA
C021107-3
Test Mode: Analog OUT
Figure 9: Differential sine and cosine signals in test
mode Analog OUT
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 interpo- Test mode Analog REF
lation accuracy which can be obtained is determined In this mode various internal reference voltages are
by the quality of signals Vsin and Vcos and can be influ- provided. VREF is equivalent to half the supply voltage
enced in this particular test mode by the calibration of (typically 2.5 V) and is used as a reference voltage for
the offset, gain and amplitude ratio.
the Hall sensor signals. VBG is the internal bandgap
ICHAUS [ IC-HAUS GMBH ]
