iC-NQL
13-bit Sin/D CONVERTER WITH SSI INTERFACE
Rev B1, Page 17/24
SIGNAL MONITORING and ERROR MESSAGES
Vpp
SELAMPL Adr 0x0C, Bit 2
Vth
AMPL
Adr 0x0C, Bit 1:0
Max ( |Sin| , |Cos| )
Voltage threshold Vth
0.60 x VDDA
Code
0x00
0x01
0x02
0x03
Output amplitude*
1.4 Vpp (0.28 x VDDA)
2.0 Vpp (0.40 x VDDA)
2.6 Vpp (0.51 x VDDA)
3.1 Vpp (0.62 x VDDA)
0.64 x VDDA
0.68 x VDDA
0.72 x VDDA
Sin2 + Cos2
Figure 13: Signal monitoring of minimum amplitude.
Code
0x04
0x05
0x06
0x07
Notes
Vthmin ↔ Vthmax
0.48 ↔ 0.68 x VDDA
0.56 ↔ 0.76 x VDDA
0.64 ↔ 0.84 x VDDA
0.72 ↔ 0.92 x VDDA
Output amplitude*
2.4 Vpp ↔ 3.4 Vpp
2.8 Vpp ↔ 3.8 Vpp
3.2 Vpp ↔ 4.2 Vpp
3.6 Vpp ↔ 4.6 Vpp
Vthmax
Vthmin
*) Entries are calculated with VDDA = 5 V.
Table 24: Signal Amplitude Monitoring
Figure 14: Sin2 + Cos2 signal monitoring.
AERR
Code
0x00
Adr 0x03, Bit 1
Amplitude error message
disabled
Each phase in the configuration process is signaled by
NERR = low; the signal is only reset following a suc-
cessful CRC (cyclic redundancy check).
0x01
enabled
If the data transfer from the EEPROM is faulty and the
CRC unsuccessful, then the configuration phase is au-
tomatically repeated.
Table 25: Amplitude Error
FERR
Code
0x00
0x01
Note
Adr 0x03, Bit 0
The process aborts following a third unsuccessful at-
tempt and the error message output remains set to low.
Excessive frequency error message
disabled
enabled
To enable the successful diagnosis of faults other types
of error are signaled at NERR using a PWM code as
given in the key on the left.
Input frequency monitoring is operational for
resolutions ≥ 16
Table 26: Frequency Error
Two error bits are provided to enable communication
via the SSI interface; these bits can decode four differ-
ent types of error. If NERR is held at low by an external
source, such as an error message from the system, for
example, this can also be verified via the SSI interface.
Configuration Error
-
Messaging always released
Table 27: Configuration Error
Error events are stored for the SSI data output and
deleted afterwards. Errors at NERR are displayed for a
minimum of ca. 10 ms, as far as no SSI readout causes
a deletion.
Error Keys
Failure Mode
Pin NERR
HI
Error bits E1, E0 with
SSI
No error
11
Amplitude error
LO/HI = 75 %
01
(AERR = 0: HI)
(11)
If an error in amplitude occurs the conversion pro-
cess is terminated and the incremental output signals
halted. An error in amplitude rules out the possibility of
an error in frequency.
Frequency error
LO/HI = 50 %
(FERR = 0: HI)
10
(11)
Configuration
Undervoltage
System error
LO
LO
00
00
00
NERR = low caused
by an external error
signal
Table 28: Error Keys
ICHAUS [ IC-HAUS GMBH ]
