IC-MSB_17 Datasheet, PDF (17/32 Pages) IC-Haus GmbH – SIN/COS SIGNAL CONDITIONER

iC-MSB^SAFETY, iC-MSB2
SIN/COS SIGNAL CONDITIONER WITH 1Vpp DRIVER
BIAS SOURCE AND TEMPERATURE SENSOR CALIBRATION
Rev F3, Page 17/32
Bias Source Calibration
The calibration of the bias current source in operation
mode Calibration 1 (Tab. 13) is prerequisite for ad-
herence to the given electrical characteristics and also
instrumental in the determination of the chip timing (e.g.
SCL clock frequency). For setup purposes the IBN
value is measured using a 10 kΩ resistor by pin VDDS
connected to pin NC. The setpoint is 200 µA which is
equivalent to a measurement voltage of 2 V.
Example: VTs(T₁) is approx. 650 mV, measured from
VDDS versus PS, with T₁ = 25 °C;
The necessary activation threshold voltage VTth(T₁) is
then calculated. The required warning temperature T₂,
temperature coefficients TCs and TCth (see Electrical
Characteristics, Section E) and measurement value
VTs(T₁) are entered into this calculation:
Note: The measurement delivers a false reading
when outputs are tristate (due to a configuration error
after cycling power, for instance).
CFGIBN
Code k
0x0
0x1
0x2
0x3
0x4
0x5
0x6
0x7
Adr 0x01, bit 7:4
IBN
∼
31
39−k
79 %
81 %
84 %
86 %
88 %
91 %
94 %
97 %
Code k
0x8
0x9
0xA
0xB
0xC
0xD
0xE
0xF
IBN
∼
31
39−k
100 %
103 %
107 %
111 %
115 %
119 %
124 %
129 %
Table 11: Bias Current Source Calibration
Temperature Sensor
The temperature monitor is calibrated in operating
mode Calibration Mode 3.
To set the required warning temperature T₂ the tem-
perature sensor voltage VTs at which the warning is
generated is first determined. To this end a voltage
ramp from VDDS towards GNDS is applied to pin PS
until pin ERR triggers an error message (for EMASKA =
0x20 and EMTD = 0x00).
VTth(T₁)
=
VTs(T₁) + TCs · (T₂ − T₁)
1 + TCth · (T₂ − T₁)
Example: For T₂ = T₁ + 100 K, VTth(T₁) must be pro-
grammed to 443 mV.
Activation threshold voltage VTth(T₁) is provided for a
high impedance measurement (10 MΩ) at output pin
NS (measurement versus VDDS) and must be set by
programming CFGTA(3:0) to the calculated value.
Example: Altering VTth(T₁) from 310 mV (measured
with CFGTA(3:0)= 0x0) to 443 mV is equivalent to
143 %, the closest value for CFGTA is 0x9;
CFGTA
Code k
0x0
0x1
0x2
0x3
0x4
0x5
0x6
0x7
Notes
Adr 0x01, bit 3:0
VTth
∼
65+3k
65
100 %
Code k
0x8
VTth
∼
65+3k
65
140 %
105 %
0x9
145 %
110 %
0xA
150 %
115 %
0xB
155 %
120 %
0xC
160 %
125 %
0xD
165 %
130 %
0xE
170 %
135 %
0xF
175 %
With CFGTA = 0xF Toff is 80 °C typ.,
with CFGTA = 0x0 Toff is 155 °C typ.
Table 12: Calibration of Temperature Monitoring