ZSSC3218 Data Sheet Rev 1.03

Data Sheet
Rev. 1.03 / November 2014
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner
Mobile Sensing ICs
Smart and Mobile
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Brief Description
Benefits
The measured and corrected sensor values are
provided at the digital output pins, which can be
2
configured as I C™* (≤ 3.4MHz) or SPI (≤ 20MHz).
Digital compensation of signal offset, sensitivity,
temperature, and non-linearity is accomplished via a
26-bit internal digital signal processor (DSP) running
a correction algorithm. Calibration coefficients are
stored on-chip in a highly reliable, non-volatile,
multiple-time programmable (MTP) memory. Programming the ZSSC3218 is simple via the serial
interface. The interface is used for the PC-controlled
calibration procedure, which programs the set of
calibration coefficients in memory. The ZSSC3218
provides accelerated signal processing, increased
resolution, and improved noise immunity in order to
support high-speed control, safety, and real-time
sensing applications with the highest requirements
for energy efficiency.
Features







Flexible, programmable analog front-end design;
up to 18-bit analog-to-digital converter (ADC)
Fully programmable gain amplifier for optimizing
sensor signals: gain range 6.6 to 216 (linear)
Internal auto-compensated temperature sensor
Digital compensation of individual sensor offset;
st
nd
1 and 2 order digital compensation of sensor
st
nd
gain as well as 1 and 2 order temperature gain
and offset drift
Programmable interrupt operation
High-speed sensing: e.g. 16-bit conditioned
-1
sensor signal measurement rate >500s
Typical sensor elements can achieve an accuracy of better than ±0.10% FSO** at -40 to 85°C
Integrated 26-bit calibration math digital signal
processor (DSP)
Fully corrected signal at digital output
Layout customized for die-die bonding with
sensor for high-density chip-on-board assembly
One-pass calibration minimizes calibration costs
No external trimming, filter, or buffering components required
Highly integrated CMOS design
Integrated reprogrammable non-volatile memory
Excellent for low-voltage and low-power battery
applications
Optimized for operation in calibrated resistive
(e.g., pressure) sensor or calibrated absolute
voltage (e.g., thermopile) sensor modules








Physical Characteristics

Supply voltage range: 1.68V to 3.6V
Current consumption: 1.0mA (operating mode)
Sleep State current: 20nA (typical)
Temperature resolution: <0.003K/LSB
Best-in-class energy-efficiency:
with 16-bit resolution: <140pJ/step
with 18-bit resolution: <50pJ/step
Operation temperature: –40°C to +85°C
Small die size
Delivery options: die for wafer bonding







* I2C™ is a trademark of NXP.
** FSO = Full Scale Output.
ZSSC3218 Application Example
VSS
VDD
VDD
ry
Batte
Stacked-Die Sensor Module
VDD
VSS
ZSSC3218
VDDB
RES
MISO
INP(+)
SS
RES
VDDB
EOC
SS
VSS
sensor element
INP
INN
VSSB
EOC
MOSI
SDA
INN(-)
VSSB
MOSI
SDA
SCLK
SCL
Microcontroller
Signal Output /
Post-processing
The ZSSC3218 is a sensor signal conditioner (SSC)
integrated circuit for high-accuracy amplification and
analog-to-digital conversion of a differential or
pseudo-differential input signal. Designed for highresolution sensor module applications, the
st
nd
ZSSC3218 can perform offset, span, and 1 and 2
order temperature compensation of the measured
signal. Developed for correction of resistive bridge or
absolute voltage sensors, it can also provide a
corrected temperature output measured with an
internal sensor.

MISO
SCLK
SCL
For more information, contact ZMDI via [email protected]
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03 — November 17, 2014. All rights reserved. The material contained herein may not be reproduced, adapted, merged,
translated, stored, or used without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
VDDB
ZSSC3218
Block Diagram
VTP
VTN
Vreg int
Temperature
Reference
Sensor
VDD
AGND / CM
Generator
Bias Current
Generator
Power Ctr.
Voltage
Regulator
VSS
Sensor
Bridge
INP
INN
Multiplexer
ZSSC3218
A
PreAmplifier
D
DSP Core
(Calculations,
Communication)
18 Bit
VSSB
SPI
Power-ON
Reset
Clock
Generator
Applications
 Barometric altitude measurement for
portable navigation or emergency call
systems
 Altitude measurement for car navigation
 Weather forecast
 Fan control
 Industrial, pneumatic, and liquid pressure
 High-resolution temperature measurements
 Object-temperature radiation (via thermopile)
Oscillator
System
Control
Unit
MTP
I²CTM
Sales Code
Description
Package
ZSSC3218BI1B
Die—temperature range: –40°C to +85 °C; thickness 304µm
Unsawn wafer
ZSSC3218BI2B
Die—temperature range: –40°C to +85 °C; thickness 725µm
(w/o backlapping)
Unsawn wafer
ZSSC3218BI1D ES
Die—temperature range: –40°C to +85 °C; thickness 304µm,
engineering samples
Sawn die in waffle pack
ZSSC3218BI3R ES
PQFN24—temperature range: –40°C to +85 °C; engineering
samples
Packaged die
Sales and Further Information
www.zmdi.com
EOC
SCLK/SCL
SS
MOSI/SDA
MISO
RES
[email protected]
Zentrum Mikroelektronik
Dresden AG
Global Headquarters
Grenzstrasse 28
01109 Dresden, Germany
ZMD America, Inc.
1525 McCarthy Blvd., #212
Milpitas, CA 95035-7453
USA
Central Office:
Phone +49.351.8822.306
Fax
+49.351.8822.337
USA Phone 1.855.275.9634
Phone +1.408.883.6310
Fax
+1.408.883.6358
European Technical Support
Phone +49.351.8822.7.772
Fax
+49.351.8822.87.772
DISCLAIMER: This information applies to a product under development. Its characteristics and specifications are subject to change without notice.
Zentrum Mikroelektronik Dresden AG (ZMD AG) assumes no obligation regarding future manufacture unless otherwise agreed to in writing. The
information furnished hereby is believed to be true and accurate. However, under no circumstances shall ZMD AG be liable to any customer,
licensee, or any other third party for any special, indirect, incidental, or consequential damages of any kind or nature whatsoever arising out of or
in any way related to the furnishing, performance, or use of this technical data. ZMD AG hereby expressly disclaims any liability of ZMD AG to any
customer, licensee or any other third party, and any such customer, licensee and any other third party hereby waives any liability of ZMD AG for
any damages in connection with or arising out of the furnishing, performance or use of this technical data, whether based on contract, warranty,
tort (including negligence), strict liability, or otherwise.
European Sales (Stuttgart)
Phone +49.711.674517.55
Fax
+49.711.674517.87955
Zentrum Mikroelektronik
Dresden AG, Japan Office
2nd Floor, Shinbashi Tokyu Bldg.
4-21-3, Shinbashi, Minato-ku
Tokyo, 105-0004
Japan
ZMD FAR EAST, Ltd.
3F, No. 51, Sec. 2,
Keelung Road
11052 Taipei
Taiwan
Phone +81.3.6895.7410
Fax
+81.3.6895.7301
Phone +886.2.2377.8189
Fax
+886.2.2377.8199
Zentrum Mikroelektronik
Dresden AG, Korea Office
U-space 1 Building
11th Floor, Unit JA-1102
670 Sampyeong-dong
Bundang-gu, Seongnam-si
Gyeonggi-do, 463-400
Korea
Phone +82.31.950.7679
Fax
+82.504.841.3026
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03— November 17, 2014. All rights reserved. The material contained herein may not be reproduced, adapted, merged,
translated, stored, or used without the prior written consent of the copyright owner.
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Table of Contents
1
2
IC Characteristics .......................................................................................................................................... 7
1.1.
Absolute Maximum Ratings .................................................................................................................... 7
1.2.
Operating Conditions .............................................................................................................................. 7
1.3.
Electrical Parameters ............................................................................................................................. 8
1.4.
Power Supply Rejection Ratio (PSRR) vs. Frequency ......................................................................... 10
Circuit Description ....................................................................................................................................... 11
2.1.
Brief Description ................................................................................................................................... 11
2.2.
Signal Flow and Block Diagram ............................................................................................................ 11
2.3.
Analog Front End .................................................................................................................................. 12
2.3.1.
Amplifier ......................................................................................................................................... 12
2.3.2.
Analog-to-Digital Converter ............................................................................................................ 14
2.3.3.
Selection of Gain and Offset – Sensor System Dimensioning ...................................................... 16
2.3.4.
Temperature Measurement ........................................................................................................... 17
2.3.5.
External Sensor Supply: Bridge Sensors ....................................................................................... 17
2.3.6.
External Sensor: Absolute Voltage Source Sensors ..................................................................... 17
2.4.
3
Digital Section ....................................................................................................................................... 18
2.4.1.
Digital Signal Processor (DSP) Core ............................................................................................. 18
2.4.2.
MTP Memory.................................................................................................................................. 18
2.4.3.
Clock Generator ............................................................................................................................. 18
2.4.4.
Power Supervision ......................................................................................................................... 18
2.4.5.
Interface ......................................................................................................................................... 18
Functional Description ................................................................................................................................. 19
3.1.
Power Up .............................................................................................................................................. 19
3.2.
Measurements ...................................................................................................................................... 19
3.3.
Interrupt (EOC Pin) ............................................................................................................................... 20
3.4.
Operational Modes ............................................................................................................................... 22
3.4.1.
3.5.
2
SPI/I C™ Commands .................................................................................................................... 25
Communication Interface ...................................................................................................................... 28
3.5.1.
Common Functionality ................................................................................................................... 28
3.5.2.
SPI.................................................................................................................................................. 29
3.5.3.
I C™ ............................................................................................................................................... 31
3.6.
2
Multiple Time Programmable (MTP) Memory ...................................................................................... 33
3.6.1.
Programming Memory.................................................................................................................... 33
3.6.2.
Memory Contents ........................................................................................................................... 34
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
4 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
3.7.
Calibration Sequence ........................................................................................................................... 43
3.7.1.
Calibration Step 1 – Assigning Unique Identification ..................................................................... 43
3.7.2.
Calibration Step 2 – Data Collection .............................................................................................. 44
3.7.3.
Calibration Step 3a) – Coefficient Calculations ............................................................................. 45
3.7.4.
Calibration Step 3b) – Post-Calibration Offset Correction ............................................................. 45
3.7.5.
SSC Measurements ....................................................................................................................... 45
3.8.
The Calibration Math ............................................................................................................................ 46
3.8.1.
Bridge Signal Compensation ......................................................................................................... 46
3.8.2.
Temperature Signal Compensation ............................................................................................... 49
3.8.3.
Measurement Output Data Format ................................................................................................ 50
4
Package Information and Pad Assignments ............................................................................................... 51
5
Quality and Reliability .................................................................................................................................. 55
6
Ordering Sales Codes ................................................................................................................................. 55
7
Related Documents ..................................................................................................................................... 55
8
Glossary ...................................................................................................................................................... 56
9
Document Revision History ......................................................................................................................... 57
Table of Figures
Figure 2.1
ZSSC3218 Functional Block Diagram, Resistive-Bridge Sensor .................................................. 11
Figure 2.2
ZSSC3218 Functional Block Diagram, Voltage-Source Sensor .................................................... 12
Figure 2.3
Gain and Offset Setup ................................................................................................................... 17
Figure 3.1
Interrupt Functionality .................................................................................................................... 21
Figure 3.2
Operational Flow Chart: Power Up ................................................................................................ 23
Figure 3.3
Operational Flow Chart: Command Mode and Normal Mode (Sleep and Cyclic) ......................... 24
Figure 3.4
SPI Configuration CPHA=0............................................................................................................ 29
Figure 3.5
SPI Configuration CPHA=1............................................................................................................ 30
Figure 3.6
SPI Command Request ................................................................................................................. 30
Figure 3.7
SPI Read Status ............................................................................................................................ 31
Figure 3.8
SPI Read Data ............................................................................................................................... 31
Figure 3.9
I2C™ Command Request .............................................................................................................. 32
2
Figure 3.10 I C™ Read Status .......................................................................................................................... 32
2
Figure 3.11 I C™ Read Data ............................................................................................................................ 32
Figure 4.1
ZSSC3218 Pad Placement ............................................................................................................ 51
Figure 4.2
General PQFN24 Package Dimensions ........................................................................................ 53
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
5 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
List of Tables
Table 1.1
Maximum Ratings ............................................................................................................................ 7
Table 1.2
Operating Conditions ....................................................................................................................... 7
Table 1.3
Requirements for VDD Power-on Reset .......................................................................................... 8
Table 1.4
Electrical Parameters ....................................................................................................................... 8
Table 2.1
Amplifier Gain: Stage 1 .................................................................................................................. 13
Table 2.2
Amplifier Gain: Stage 2 .................................................................................................................. 13
Table 2.3
Gain Polarity .................................................................................................................................. 13
Table 2.4
ADC Conversion Times for a Single Analog-to-Digital Conversion ............................................... 14
Table 2.5
ADC Offset Shift............................................................................................................................. 15
Table 2.6
Typical Conversion Times vs. Noise Performance with Full Sensor Signal Conditioning for AZSM,
SM, AZTM, and TM (Bridge-Type Sensor) .................................................................................... 15
Table 3.1
SPI/I C™ Commands .................................................................................................................... 25
Table 3.2
Get_Raw Commands .................................................................................................................... 27
Table 3.3
General Status Byte ....................................................................................................................... 28
Table 3.4
Mode Status ................................................................................................................................... 29
Table 3.5
MTP Memory Content Assignments .............................................................................................. 34
Table 3.6
Measurement Results of ADC Raw Measurement Request (two’s complement) ......................... 50
Table 3.7
Calibration Coefficients (Factors and Summands) in Memory (sign-magnitude) .......................... 50
Table 3.8
Output Results from SSC-Correction Math or DSP—Sensor and Temperature ........................... 50
Table 3.9
Interrupt Thresholds TRSH1 and TRSH2—Format as for SSC-Correction Math Output ............. 50
Table 4.1
Pad Assignments ........................................................................................................................... 52
Table 4.2
Die Connection and Bond Parameter ............................................................................................ 52
Table 4.3
Physical Package Dimensions ....................................................................................................... 53
Table 4.4
Pin Assignments PQFN24 ............................................................................................................. 54
2
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
6 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
1
IC Characteristics
1.1.
Absolute Maximum Ratings
Note: The absolute maximum ratings are stress ratings only. The ZSSC3218 might not function or be operable
above the recommended operating conditions. Stresses exceeding the absolute maximum ratings might also
damage the device. In addition, extended exposure to stresses above the recommended operating conditions
might affect device reliability. ZMDI does not recommend designing to the “Absolute Maximum Ratings.”
Table 1.1
Maximum Ratings
PARAMETER
SYMBOL
Min
Voltage Reference
VSS
Analog Supply Voltage
Voltage at all Analog and Digital IO Pins
Input Current into any Pin except RES, SS
1), 2)
Electrostatic Discharge Tolerance – Human Body Model (HBM1)
Storage Temperature
3)
TYP
MAX
UNITS
0
0
V
VDD
-0.4
3.63
V
VA_IO, VD_IO
-0.5
VDD+0.5
V
IIN
-100
100
mA
VHBM1
±4000
-
V
TSTOR
-50
125
°C
1)
Latch-up current limit for RES, ZMDI-test and SS: ±70mA.
2)
Latch-up resistance; reference for pin is 0V.
3)
HBM1: C = 100pF charged to VHBM1 with resistor R = 1.5k in series based on MIL 883, Method 3015.7. ESD protection
referenced to the Human Body Model is tested with devices in ceramic dual in-line packages (CDIP) during product qualification.
1.2.
Operating Conditions
The reference for all voltages is Vss.
Table 1.2
Operating Conditions
PARAMETER
SYMBOL
MIN
TYP
MAX
UNIT
Supply Voltage
VDD
1.68
-
3.6
V
VDD Rise Time
tVDD
200
μs
Bridge Current
1.8
1)
IVDDB
Operation Temperature Range
External (Parasitic) Capacitance between VDDB and VSS
1)
mA
16.5
TAMB
-40
CL
0.01
-
85
°C
50
nF
Power supply rejection is reduced if a current in the range of 16.5mA > IVDDB > 1.8mA is drawn out of VDDB.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
7 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
A dynamic power-on-reset circuit is implemented in order to achieve minimum current consumption in idle mode.
The VDD low level and the subsequent rise time and VDD rising slope must meet the requirements in Table 1.1
to guarantee an overall IC reset; lower VDD low levels allow slower rising of the subsequent on-ramp of VDD.
Other combinations might also be possible. For example, the reset trigger can be influenced by increasing the
power-down time and lowering the VDD rising slope requirement. Alternatively, the RES pin can be connected
and used to control safe resetting of the ZSSC3218. RES is active-low; a VDD-VSS-VDD transition at the RES
pin leads to a complete IC reset.
Table 1.3
Requirements for VDD Power-on Reset
PARAMETER
SYMBOL
MIN
TYP
MAX
UNIT
tSPIKE
3
-
-
µs
VDD Low Level
VDDlow
0
-
0.2
V
VDD Rising Slope
SRVDD
10
-
-
V/ms
Power Down Time (duration of VDD Low Level)
1.3.
Electrical Parameters
All parameter values are valid only under the specified operating conditions. All voltages are referenced to Vss.
Table 1.4
Electrical Parameters
Note: See important table notes at the end of the table.
Parameter
Symbol
Conditions/Comments
Min
Typ
Max
Unit
1.60
1.68
1.75
V
1050
1500
µA
20
250
nA
Supply
External Sensor Supply Voltage,
ADC Reference Voltage
VDDB
Current Consumption
IVDD
Internally generated
Active State, average
Power Supply Rejection
20·log10(VDD/VDDB)
(see section 1.4)
Sleep State, idle current,  85°C
VDD = 1.8V
17
60
88
dB
VDD = 2V
32
65
91
dB
18
Bit
1.1
MHz
1.1
kHz
2.3
kHz
PSRVDD
Analog-to-Digital Converter (ADC, A2D)
Resolution
rADC
ADC Clock Frequency
fADC
Internal ADC clock
fS,raw
Conversions per second for single
18-bit external sensor A2D
conversion (w/o AZ)
Conversions per second for single
16-bit temperature sensor A2D
conversion (w/o AZ)
Conversion Rate
Data Sheet
November 17, 2014.
12
0.9
1
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
8 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Parameter
Symbol
Conditions/Comments
Min
Typ
Max
Unit
Amplifier
Gain
Gamp
64 steps
6.6
Gain Error
Gerr
Referenced to nominal gain
-2.5
216
-
2.5
%
0.01
%FSO
300
Hz
1.05
V
50
kΩ
999
Ω
Sensor Signal Conditioning Performance
IC Accuracy Error
1)
ErrA,IC
Conversion Rate, 18-Bit SSC
fS, SSC
Accuracy error for sensor that is
ideally linear (in temperature and
measurand)
Conversion per second for fully
corrected 18-bit measurement
270
Input
Input Voltage Range
External Sensor Bridge
Resistance
VINP, VINN
Input voltage range at INP and INN
RBR
Full power supply disturbance
rejection (PSRR) capabilities
Reduced PSRR, but full
functionality
0.65
1
10
100
Power-Up
tSTA1
VDD ramp up to interface
communication (see section 3.1)
1
ms
tSTA2
VDD ramp up to analog operation
2.5
ms
tWUP1
Sleep to Active State interface
communication
0.5
ms
tWUP2
Sleep to Active State analog
operation
2
ms
4.4
MHz
Start-up Time
Wake-up Time
Oscillator
Internal Oscillator Frequency
fCLK
3.6
4
Internal Temperature Sensor
Temperature Resolution
-40°C to +85°C
0.003
K/LSB
Interface and Memory
Maximum capacitance at MISO
line: 40pF at VDD=1.8V
SPI Clock Frequency
fC,SPI
I²C™ Clock Frequency
fC,I2C
Program Time
tprog
MTP programming time per 16-bit
register
Endurance
nMTP
Number of reprogramming cycles
Data Retention
tRET_MTP
1000h at 125°C
1)
1
5
1000
10000
10
20
MHz
3.4
MHz
16
ms
numeric
a
Percentage referred to maximum full-scale output (FSO); e.g. for 18-bit measurements: ErrA,IC [%FSO] = 100 · MAX{ | ADCmeas – ADCideal | } / 218.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
9 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
1.4.
Power Supply Rejection Ratio (PSRR) vs. Frequency
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
10 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
2 Circuit Description
2.1.
Brief Description
The ZSSC3218 provides a highly accurate amplification of bridge sensor signals. The compensation of sensor
offset, sensitivity, temperature drift, and non-linearity is accomplished via a 26-bit DSP core running a correction
algorithm with calibration coefficients stored in a non-volatile memory. The ZSSC3218 can be configured for a
wide range of resistive bridge sensor types and for absolute voltage source sensors. A digital interface (SPI or
2
I C™) enables communication. The ZSSC3218 supports two operational modes: Normal Mode and Command
Mode. Normal Mode is the standard operating mode. Typically in Normal Mode, the ZSSC3218 wakes up from a
Sleep State (low power), runs a measurement in Active State, and automatically returns to the Sleep State. (See
section 3.4 for details on operational modes.)
2.2.
Signal Flow and Block Diagram
See Figure 2.1 and Figure 2.2 for the ZSSC3218 block diagram for different input sensors. The sensor bridge
supply VDDB and the power supply for analog circuitry are provided by a voltage regulator, which is optimized for
power supply disturbance rejection (PSRR). See section 1.4 for a graph of PSRR versus frequency. To improve
noise suppression, the digital blocks are powered by a separate voltage regulator. A power supervision circuit
monitors all supply voltages and generates appropriate reset signals for initializing the digital blocks.
The System Control Unit controls the analog circuitry to perform the three measurement types: external sensor,
temperature, and offset measurement. The multiplexer selects the signal input to the amplifier, which can be the
external signals from the input pins INP and INN or the internal temperature reference sensor signals. A full
measurement request will trigger an automatic sequence of all measurement types and all input signals.
Figure 2.1 ZSSC3218 Functional Block Diagram, Resistive-Bridge Sensor
VDDB
VTP
VTN
Vreg int
Temperature
Reference
Sensor
VDD
AGND / CM
Generator
Bias Current
Generator
Power Ctr.
Voltage
Regulator
VSS
Sensor
Bridge
INP
INN
Multiplexer
ZSSC3218
A
PreAmplifier
D
DSP Core
(Calculations,
Communication)
18 Bit
VSSB
SPI
Power-ON
Reset
Data Sheet
November 17, 2014.
Clock
Generator
Oscillator
EOC
System
Control
Unit
MTP
I²CTM
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
SCLK/SCL
SS
MOSI/SDA
MISO
RES
11 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Figure 2.2 ZSSC3218 Functional Block Diagram, Voltage-Source Sensor
VDDB
VTP
VTN
Vreg int
Temperature
Reference
Sensor
VDD
AGND / CM
Generator
Bias Current
Generator
Power Ctr.
Voltage
Regulator
VSS
Multiplexer
V source
ZSSC3218
INP
INN
A
PreAmplifier
D
DSP Core
(Calculations,
Communication)
18-Bit
VSSB
SPI
Power-On
Reset (POR)
Clock
Generator
Oscillator
EOC
System
Control
Unit
MTP
I²CTM
SCLK/SCL
SS
MOSI/SDA
MISO
RES
The amplifier consists of two stages with programmable gain values.
The ZSSC3218 employs a programmable analog-to-digital converter (ADC) optimized for conversion speed and
noise suppression. The programmable resolution from 12 to 18 bits provides flexibility for adapting the
conversion characteristics. To improve power supply noise suppression, the ADC uses the bridge supply VDDB as
its reference voltage leading to a ratiometric measurement topology if the external sensor is a bridge-type
element.
The remaining IC-internal offset and the sensor element offset, i.e., the overall system offset for the amplifier and
ADC, can be canceled by means of an offset and auto-zero measurement, respectively.
st
nd
The DSP accomplishes the auto-zero, span, and 1 and 2 order temperature compensation of the measured
external sensor signal. The correction coefficients are stored in the MTP memory.
2
The ZSSC3218 supports SPI and I C™ interface communication for controlling the ZSSC3218, configuration,
and measurement result output.
2.3.
Analog Front End
2.3.1. Amplifier
The amplifier has a fully differential architecture and consists of two stages. The amplification of each stage and
the external sensor gain polarity are programmable via settings in the Measurement Configuration Register
SM_config1 and SM_config2 (addresses 12HEX and 16HEX; see section 3.6.2) in the MTP memory (for details, see
section 2.4.2).
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
12 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
*
The first 6 bits of SM_config are the programmable gain settings Gain_stage1 and Gain_stage2. The options for
the programmable gain settings are listed in Table 2.1 and Table 2.2.
Table 2.1
Amplifier Gain: Stage 1
Gain_stage1
SM_config Bit G2
SM_config Bit G1
SM_config Bit G0
Gainamp1
0
0
0
6
0
0
1
12
0
1
0
20
0
1
1
30
1
0
0
40
1
0
1
60
1
1
0
80
1
1
1
120
Table 2.2
Amplifier Gain: Stage 2
Gain_stage2
SM_config Bit G5
SM_config Bit G4
SM_config Bit G3
Gainamp2
0
0
0
1.1
0
0
1
1.2
0
1
0
1.3
0
1
1
1.4
1
0
0
1.5
1
0
1
1.6
1
1
0
1.7
1
1
1
1.8
If needed, the polarity of the sensor bridge gain can be reversed by setting the Gain_polarity bit, which is bit 6 in
the SM_config register (see section 3.6.2). Changing the gain polarity is achieved by inverting the chopper clock.
Table 2.3 gives the settings for the Gain_polarity bit. This feature enables applying a sensor to the ZSSC3218
with swapped input signals at INN and INP; e.g., to avoid crossing wires for the final sensor module’s assembly.
Table 2.3
*
Gain Polarity
Gain_polarity (SM_config Bit 6)
Gain
Setting Description
0
+1
No polarity change.
1
-1
Gain polarity is inverted.
The register name SM_config is used for general register content and effect explanations for both SM_config1 and SM_config2 as the
registers’ bit assignments are exactly the same for both registers.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
13 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
2.3.2. Analog-to-Digital Converter
An analog-to-digital converter (ADC) is used to digitize the amplifier signal. To allow optimizing the trade-off
between conversion time and resolution, the resolution can be programmed from 12-bit to 18-bit (Adc_bits,
SM_config register; section 3.6.2). The ADC processes differential input signals.
Table 2.4
ADC Conversion Times for a Single Analog-to-Digital Conversion
Resolution (Bits)
Conversion Time in s (typical)
12
140
13
185
14
250
15
335
16
470
17
640
18
890
The ADC can perform an offset shift in order to adapt input signals with offsets to the ADC input range. The shift
feature is enabled by setting SM_config register’s bit [15] = 1 (Shift_method = 1). The respective analog offset
shift can be set up with bits [14:12], Offset in SM_config. The offset shift causes the ADC to perform an additional
amplification of the ADC’s input signal by factor 2. This must be considered for a correct analog sensor setup by
means of the pre-amplifier’s gain, the ADC offset shift, and the potential ADC gain.
The overall analog amplification  = 1 ∙ 2 ∙  can be determined for the following
potential use cases:

If no offset shift is selected, i.e., Shift_method = 0 and Offset = 000 in SM_config,
 = 1 ∙ 2 ∙ 1

If ADC offset shift is selected, i.e., Shift_method = 1 (Offset is arbitrary) in SM_config,
 = 1 ∙ 2 ∙ 2
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
14 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Table 2.5
ADC Offset Shift
Offset Shift in ADC
SM_config
Bit 15
(Shift_method)
Offset:
SM_config
Bit 14
Offset:
SM_config
Bit 13
Offset:
SM_config
Bit 12
GainADC
Compensation of Percentage
Offset in Input Signal
0
0
0
0
1
0%
1
0
0
0
2
0%
1
0
0
1
2
6.75%
1
0
1
0
2
12.50%
1
0
1
1
2
19.25%
1
1
0
0
2
25.00%
1
1
0
1
2
31.75%
1
1
1
0
2
38.50%
1
1
1
1
2
43.25%
Note: If no offset shift will be performed and the ADC will not apply the additional gain of factor 2 (leading to
GainADC = 1), then Shift_method = 0 and Offset = 000 in SM_config must be selected. Any other setup with
Shift_method = 0 and Offset ≠ 000 leads to erroneous analog setups.
Table 2.6
Typical Conversion Times vs. Noise Performance with Full Sensor Signal Conditioning for
AZSM, SM, AZTM, and TM (Bridge-Type Sensor)
1)
Typical Measurement Duration , Typical 3-Sigma Noise for SSC2)
MEASURE, (AAHEX)
Corrected Output
(ms)
(counts)
ADC Resolution:
Temperature Sensor
ADC Resolution:
External Sensor
16
12
2.2
2.4
16
13
2.3
2.5
16
14
2.4
3.0
16
15
2.6
4.4
16
16
2.8
5.7
16
17
3.2
10.5
16
18
3.7
18.0
1)
Measurement duration is defined as the time from the high/low transition at the EOC pin at the beginning of the measurement until
the low/high back-transition of the EOC signal at the end of a single measurement in Sleep Mode.
2)
Reference noise values normalized to the respective external sensor’s ADC resolution, obtained with the following setup:
20kΩ sensor bridge, 25°C, Gain=52, Offset=25%, VDD=1.8V.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
15 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
2.3.3.
Selection of Gain and Offset – Sensor System Dimensioning
The optimal gain (and offset) setup for a specific sensor element can be determined by the following steps:
1) Collect sensor element’s characteristic, statistical data (over temperature, ambient sensor parameter,
and over production tolerances):
a. Minimum differential output voltage:
Vmin
b. Maximum differential output voltage:
Vmax
Note: The best possible setup can only be determined if the absolute value of Vmax is bigger than the
absolute value of Vmin. If this is not the case, the gain polarity should be reversed by means of the
Gain_polarity bit in the MTP’s SM_config register.
2) Calculate:
a. Common mode level, i.e. differential offset of the sensor output:  = 0.5 ∙ ( +  )
b. Relative or percentage offset of the sensor output:  [%] =

 – 
∙ 100%
3) Determine which of the two following cases is valid.
a. If Offsetsensor[%] > 43% then select Offset = 111 (i.e., 43.25%)
b. If 0% < Offsetsensor[%] ≤ 43% then select Offset ≤ Offsetsensor[%] (Offset setup value;
see Table 2.5)
4) The totally required, optimum gain can be determined as
, =
1.4

)
100
 ∙(1−
then select nearest gain to Gaintotal,opt, where Gaintotal ≤ Gaintotal,opt
5) The gain setup can be separated into the three factors Gainamp1, Gainamp2 (for the 2-stage amplifier) and
GainADC (1 for no-shift or 2 for shift operation) according to: Gaintotal = Gainamp1 ∙ Gainamp2 ∙ GainADC .
a. If no offset shift is performed (Shift_method = 0 and Offset = 000), the amplifier gain is Gaintotal
b. If an offset shift is performed (Shift_method = 1), the amplifier gain is 0.5·Gaintotal
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
16 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Figure 2.3 Gain and Offset Setup
VDDB
INP
A
Gainamp1
Sensor
Bridge
Gainamp2
INN
DSP
SPI
GainADC
PreAmplifier
I²C™
D
Offset
VSSB
Vdifferential, IN
VAMP1, OUT
VAMP2, OUT
VADC, IN
Digital ADC Out, 18bit
1.4V
131k
0V
Gainamp1
Gainamp2
GainADC , -Offset
0V
digitize
zo o m
-1.4V
-131k
2.3.4. Temperature Measurement
The ZSSC3218 provides an internal temperature sensor measurement to allow compensation for temperature
effects. See section 1.3 for the temperature sensor resolution. The temperature output signal is a differential
voltage that is adapted by the amplifier for the ADC input.
For temperature measurements, the respective settings are defined and programmed in the MTP by ZMDI.
2.3.5. External Sensor Supply: Bridge Sensors
The ZSSC3218 provides dedicated supply pins VDDB and VSSB for resistive bridge-type sensors (bit [11]=0 in
SM_config, MTP registers 12HEX or 16HEX). The ADC reference voltages for the sensor bridge measurement are
derived from these internal voltages such that bridge supply disturbances are suppressed. The current drive
ability of VDDB is limited (see IVDDB in section 1.2).
2.3.6. External Sensor: Absolute Voltage Source Sensors
The ZSSC3218 can alternatively process signals from an absolute-voltage source sensor, e.g. a thermopile
element. The respective input-type selection can be done with bit[11]=1 in SM_config, MTP registers 12HEX or
16HEX. The respective sensor element must be connected between the pins INP and INN, whereas INN is
internally connected to the ZSSC3218’s analog ground (not! being VSSB). VDDB and VSSB should not be
connected if an absolute-voltage source sensor is applied. The offset shift should be set to maximum in this case,
Shift_method = 1 and Offset = 111 in SM_config. The required gain can be determined according to the
procedure described in section 2.3.3.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
17 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
2.4.
2.4.1.
Digital Section
Digital Signal Processor (DSP) Core
The “DSP Core” block performs the algorithm for correcting the sensor signal. The required coefficients are
stored in the MTP memory.
When the measurement results are available, the “end of conversion” signal is set at the EOC pin if no interruptthreshold has been set up (bits[8:7]=00 in memory register 02HEX). The internal EOC information is valid only if
both the measurement and calculation have been completed. Alternatively, the EOC pin can indicate exceeding
or underrunning of a certain threshold or leaving of valid-result range as described in section 3.3.
2.4.2.
MTP Memory
The ZSSC3218’s memory is designed with a real MTP structure. The memory is organized in 16-bit registers that
can be re-written multiple (at least 1000) times. The user has access to a 57 x 16-bit storage area for values such
as calibration coefficients. The required programming voltage is generated internally in the ZSSC3218. A
checksum (generation with command 90HEX) is evaluated be for integrity-check purposes of the entire memory.
2.4.3.
Clock Generator
The clock generator provides approximately 4MHz, and 1MHz clock signals as the time base for IC-internal
signal processing. The frequency is trimmed during production test.
2.4.4.
Power Supervision
The power supervision block as a part of the voltage regulator combined with the digital section monitors all
power supplies to ensure a defined reset of all digital blocks during power-up or power supply interruptions.
“Brown-out” cases at the supply that do not meet the power-on reset (POR) requirements (see Table 1.3), must
be resolved with a reset pulse at the RES pin.
2.4.5.
Interface
†
2
The ZSSC3218 can communicate with the user’s communication master or PC via an SPI or I C™ interface .
The interface type is selectable with the very first activity at the interface after power-up or reset, with the first
activity being
2 TM
a. If the first command is an I C command and SS pin has been inactive until receiving this command,
2 TM
the ZSSC3218 enters I C mode.
b. If the first interface action is the SS pin being set to active (HIGH-active or LOW-active depending on
SS_polarity bit[9] in memory interface register 02HEX), then the ZSSC3218 enters SPI mode.
During the initiation sequence (after power-up or reset), any potential transition on SS is ignored. Switching to the
SPI mode is only possible after the power-up sequence. If SS is not connected, the SS pin internal pull-up keeps
2 TM
the ZSSC3218 in I C mode.
To also provide interface accessibility in Sleep State (all features inactive except for the digital interface logic),
the interface circuitry is directly supplied by VDD.
† Functional I2C™ interface properties correspond to the NXP I²C™ bus specification Rev. 0.3 (June 2009).
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
18 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
3
Functional Description
3.1.
Power Up
Specifications for this section are given in sections 1.2 and 1.3. On power-up, the ZSSC3218 communication
interface is able to receive the first command after a time t STA1 from when the VDD supply is within operating
specifications. The ZSSC3218 can begin the first measurement after a time of tSTA2, from when the VDD supply is
operational. Alternatively, instead of a power-on-reset, a reset and new power-up-sequence respectively can be
triggered by an IC-reset signal (high low) at RES pin.
The wake up time from Sleep State to Active State (see section 3.4) after receiving the activating command is
defined as tWUP1 and tWUP2. In Command Mode, subsequent commands can be sent after tWUP1. The first
measurement starts after tWUP2 if a measurement request was sent.
3.2.
Measurements
Available measurement procedures are
 AZSM: auto-zero (external) sensor measurement
 SM: (external) sensor measurement
 AZTM: auto-zero temperature measurement
 TM: temperature measurement
AZSM: The configuration is loaded for measuring the external sensor; i.e., a resistive bridge or an absolute
voltage source. The “Multiplexer” block connects the amplifier input to the AGND analog ground reference. An
analog-to-digital (A2D) conversion is performed so that the inherent system offset for the respective configuration
is converted by the ADC to a digital word with a resolution according to the respective MTP configuration.
SM: The configuration is loaded for measuring the external sensor; i.e. a resistive bridge or an absolute voltage
source. The “Multiplexer” block connects the amplifier input to the INP and INN pins. An A2D conversion is
performed. The result is a digital word with a resolution according to the MTP configuration.
AZTM: The configuration for temperature measurements is loaded. The “Multiplexer” block connects the amplifier
input to AGND. An analog-to-digital conversion is performed so that the inherent system offset for the
temperature configuration is converted by the ADC with a resolution according to the respective MTP configuration.
TM: The configuration for temperature measurements is loaded. The “Multiplexer” block connects the amplifier
input to the internal temperature sensor. An A2D conversion is performed. The result is a digital word with a
resolution according to the MTP configuration.
The typical application’s measurement cycle is a complete SSC measurement (using the commands AAHEX to
AFHEX; see section 3.4.1) with AZSM, SM, AZTM, and TM followed by a signal correction calculation.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
19 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
3.3.
Interrupt (EOC Pin)
The EOC pin can be programmed to operate either as a pure “measurement busy” and end-of-conversion
indicator or as a configurable interrupt indicator. The respective basic operation must be programmed to the
INT_setup bits [8:7] in register 02HEX (see Table 3.5).
In addition, one or two 24-bit-quantized thresholds can be programmed (TRSH1 and TRSH2 in memory registers
13HEX, 14HEX, and 15HEX).
The respective thresholds are programmed left-aligned in the memory; i.e., they must be programmed with the
threshold’s MSB in the memory register’s MSB, etc. The number of LSB threshold bits that are used is equal to
the number of bits for the selected ADC resolution (determined by the Adc_bits field in registers 12HEX and
16HEX); unused LSB bits are ignored.
The interrupt functionality is only available for digital values from the SSC-calculation unit (i.e., after sensor signal
conditioning); raw values cannot be monitored by the interrupt feature. Figure 3.1 shows the different setup
options and the respective response at the EOC pin. The use of the interrupt functionality is recommended for
cyclic operation (command ABHEX with the respective power-down setup in the Interface Configuration memory
register 02HEX). The EOC level continuously represents the respective SSC-measurement results only during
cyclic operation. For single or oversample measurement requests without cyclic operation, the EOC output signal
is reset to logical zero at the beginning of each new measurement, even though the interrupt thresholds are
considered correctly at the end of each measurement (setting EOC to logical one or zero is dependent on the
interrupt setup).
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
20 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Figure 3.1 Interrupt Functionality
Measurement
Result
INT_setup=01:
Measurement < threshold1
Measurement
Result
max.
INT_setup=10:
Measurement > threshold1
max.
threshold 1
threshold 1
0
0
Time
Time
EOC / INT
EOC / INT
1
1
0
0
Time
Time
INT_setup=11
Measurement
Result
Case A:
threshold1 > threshold2
Measurement
Result
max.
max.
threshold 1
threshold 2
threshold 2
threshold 1
0
0
Time
EOC / INT
1
0
0
Time
November 17, 2014.
Time
EOC / INT
1
Data Sheet
Case B:
threshold1 < threshold2
Time
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
21 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
3.4.
Operational Modes
Figure 3.2 illustrates the ZSSC3218 power-up sequence and subsequent operation depending on the selected
2
interface communication mode (I C™ or SPI) as determined by interface-related first activities after power-up or
reset. If the first command after power-up is a valid I²C™ command, the interface will function as an I²C™
interface until the next power-on-reset. If there is no valid I²C™ command, but an active signal at the SS pin is
detected as the first valid activity, then the interface will respond as an SPI slave. With either interface, after the
voltage regulators are switched on, the ZSSC3218’s low-voltage section (LV) is active while the related interface
configuration information is read from memory. Then the LV section is switched off, the ZSSC3218 goes into
Sleep State, and the interface is ready to receive commands. The interface is always powered by VDD, so it is
referred to as the high voltage section (HV).
See Table 3.1 for definitions of the commands.
Figure 3.3 shows the ZSSC3218 operation in Normal Mode (with two operation principles: “Sleep” and “Cyclic”)
and Command Mode, including when the LV and HV sections are active as indicated by the color legend. The
Normal Mode automatically returns to Sleep State after executing the requested measurements, or periodically
wakes up and conducts another measurement according to the setting for the sleep duration configured by
CYC_period (bits[14:12] in memory register 02 HEX). In Command Mode, the ZSSC3218 remains active if a
dedicated command (Start_NOM) is sent, which is helpful during calibration. Command Mode can only be
entered if Start_CM is the first command received after POR.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
22 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Figure 3.2 Operational Flow Chart: Power Up
I2CTM slave address is loaded,
and SS_polarity determines if
SS pin is active high or low
IC Power On
Color Legend:
LV Operation
Command:= load I/O setup
HV Operation
IO_mode = I2C™
no
I2C™ Address /
CMD Valid?
no
SS Pin Active?
yes
IO_mode:=SPI
Power up LV
Power up LV
Data/Status
from LV
Save: IC ID / Data / Status
LV Operation
Data/Status
from LV
LV Operation
Save: Setup / Data /
Status
SPI Interface
I2C™ Interface
From this point until next POR,
the interface selection is fixed
yes
CommandMode
==active || Test==1
yes
CommandMode
==active || Test==1
no
no
Power Down (switch
off LV and wait for
command)
no
yes
no
no
Power Down (switch
off LV and wait for
command)
Receive: Command
no
Received CMD ID
== IC-ID
RST(SS)==1
yes
yes
Receive: Command
Read_bit == 1
(Data Fetch)
yes
Execute: Data Fetch
NOP
yes
Execute: Data Fetch
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
23 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Figure 3.3 Operational Flow Chart: Command Mode and Normal Mode (Sleep and Cyclic)
Start LV
Color Legend:
LV Operation
Get Command from HV
HV Operation
CYCLIC_ACTIVE?
yes
no
CMD==Start_CM
yes
no
SETUP_LV:= New
Command’s Setup
New command
CM active
Case (Command)
New Measurement
Command or
STOP_CYCLE?
INVALID_CMD
REGULAR_CMD
Power up all LV
Receive: Command
INVALID_CMD
STOP_CYCLE
no
Data/Status
from LV
Keep Existing
SETUP_LV
Do: SETUP_LV
Case (Command)
Power Down all LV
Except Oscillator
Execute: Command
CM inactive
REGULAR_CMD
Cyclic Measurement?
no
yes
CYCLIC_ACITVE!
to HV
Data/Status
from LV
Safe Command and
SETUP_LV
Reset LV
Start_NOM
Count Waiting Period
Execute: Command
End LV
Command Mode
Sleep Mode
Data Sheet
November 17, 2014.
Cyclic Mode
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
24 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
3.4.1.
2
SPI/I C™ Commands
2
The SPI/I C™ commands supported by the ZSSC3218 are listed in Table 3.1. The command to read an address
in the user memory is the same as its address. The command to write to an address in user memory is the
address plus 40HEX.
There is a ZMDI-reserved section of memory that can be read but not over-written by the user.
Table 3.1
2
SPI/I C™ Commands
Note: Every return starts with a status byte followed by the data word as described in section 3.5.1.
Command
(Byte)
Return
Description
Normal
Mode
Command
Mode
00HEX to 39HEX
16-bit user data
Read data in the user memory address
(00HEX to 39HEX) matching the command
(might not be using all addresses).
Yes
Yes
3AHEX to 3FHEX
16-bit ZMDI-reserved
memory data
Read data in ZMDI-reserved memory at
address (3AHEX to 3FHEX).
Yes
Yes
40HEX to 79HEX
followed by data
(0000HEX to
FFFFHEX)
—
Write data to user memory at address
specified by command minus 40HEX
(addresses 00HEX to 39HEX respectively; might
not be using all addresses).
Yes
Yes
90HEX
—
Calculate and write memory checksum
(CRC).
Yes
Yes
A0HEX to A7HEX
followed by
XXXXHEX
24-bit formatted raw data
Get_Raw This command can be used to
perform a measurement and write the raw
ADC data into the output register. The LSB of
the command determines how the AFE
configuration register is loaded for the
Get_Raw measurement (see Table 3.2).
Yes
Yes
A8HEX
—
Start_NOM Exit Command Mode and
transition to Normal Mode (Sleep or Cyclic).
No
Yes
A9HEX
—
Start_CM Exit Normal Mode and transition
to Command Mode (as very first command
after power-up).
Yes
No
Measure Trigger full measurement cycle
(AZSM, SM, AZTM, and TM, as described in
section 3.2) and calculation and storage of
data in the output buffer using the
configuration from MTP.
Yes
Yes
(see Table 3.2)
AAHEX
Data Sheet
November 17, 2014.
24-bit formatted fully
corrected sensor measurement data + 24-bit
corrected temperature
data
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
25 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Command
(Byte)
Return
Description
Normal
Mode
Command
Mode
ABHEX
24-bit formatted fully
corrected sensor measurement data + 24-bit
corrected temperature
data
Measure Cyclic This command triggers a
continuous full measurement cycle (AZSM,
SM, AZTM, and TM; see section 3.2) and
calculation and storage of data in the output
buffer using the configuration from MTP
followed by a pause determined by
CYC_period (bits[14:12] in memory register
02HEX).
Yes
Yes
ACHEX
24-bit formatted fully
corrected sensor measurement data + 24-bit
corrected temperature
data
Oversample-2 Measure Mean value generation: 2 full measurements are conducted
(as in command AAHEX), the measurements’
mean value is calculated, and data is stored
in the output buffer using the configuration
from MTP; no power down or pause between
the 2 measurements.
Yes
Yes
ADHEX
24-bit formatted fully
corrected sensor measurement data + 24-bit
corrected temperature
data
Oversample-4 Measure Mean value
generation: 4 full measurements (as in
command AAHEX) are conducted, the
measurements’ mean value is calculated,
and data is stored in the output buffer using
the configuration from MTP; no power down
or pause between the 4 measurements.
Yes
Yes
AEHEX
24-bit formatted fully
corrected sensor measurement data + 24-bit
corrected temperature
data
Oversample-8 Measure Mean value generation: 8 full measurements (as in command
AAHEX) are conducted, the measurements’
mean value is calculated, and data is stored
in the output buffer using the configuration
from MTP; no power down or pause between
the 8 measurements.
Yes
Yes
AFHEX
24-bit formatted fully
corrected sensor measurement data + 24-bit
corrected temperature
data
Oversample-16 Measure Mean value
generation: 16 full measurements (as in
command AAHEX) are conducted, the
measurements’ mean value is calculated,
and data is stored in the output buffer using
the configuration from MTP; no power down
or pause between the 16 measurements.
Yes
Yes
Select SM_config1 register (12HEX in
memory) For any measurement using the
memory contents for the analog front-end
and sensor setup, the respective setup is
loaded from the SM_config1 register; status
bit[1]==0 (default).
Yes
Yes
B0HEX
Data Sheet
November 17, 2014.
—
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
26 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Command
(Byte)
Return
Description
Normal
Mode
Command
Mode
B1HEX
—
Select SM_config2 register (16HEX in
memory) For any measurement using the
memory contents for the analog front-end
and sensor setup, the respective setup is
loaded from the SM_config2 register, status
bit[1]==1
Yes
Yes
BFHEX
—
STOP_CYC This command causes a powerdown halting the update / cyclic measurement operation and causing a transition to
Normal-Sleep operation.
Yes
Yes
FXHEX
Status followed by last
24-bit data
NOP Only valid for SPI (see sections 3.5.1
and 3.5.2).
Yes
Yes
Table 3.2
Get_Raw Commands
Command
Measurement
AFE Configuration Register
A0HEX followed by 0000HEX
SM – Sensor Measurement
SM_config1 register or SM_config2 register.
A1HEX followed by ssssHEX
SM – Sensor Measurement
ssss is the user’s configuration setting for the measurement provided via the interface. The format and purpose of configuration bits must be according to the
definitions for SM_config (see Table 3.5).
A2HEX followed by 0000HEX
SM-AZSM – Auto-Zero Corrected
1)
Sensor Measurement
SM_config
A3HEX followed by ssssHEX
SM-AZSM – Auto-Zero Corrected
2)
Sensor Measurement
ssss is the user’s configuration setting for the measurement provided via the interface. The format and purpose of configuration bits must be according to the
definitions for SM_config.
A4HEX followed by 0000HEX
TM – Temperature Measurement
ZMDI-defined register
A5HEX followed by ssssHEX
TM – Temperature Measurement
ssss is the user’s configuration setting for the measurement provided via the interface. The format and purpose of configuration bits must be according to the
definitions for SM_config and valid for temperature
measurement in this case (bits [15:12] will be ignored).
A6HEX followed by 0000HEX
TM-AZTM – Auto-Zero Corrected
1)
Temperature Measurement
ZMDI-defined register
A7HEX followed by ssssHEX
TM-AZTM – Auto-Zero Corrected
2)
Temperature Measurement
ssss is the user’s configuration setting for the measurement provided via the interface. The format and purpose of these configuration bits must be according to
the definitions for SM_config and valid for temperature
measurement in this case (bits [15:12] will be ignored).
1)
Recommended for raw data collection during calibration coefficient determination using the measurement setups pre-programmed in MTP.
2)
Recommended for raw data collection during calibration coefficient determination using un-programmed (not in MTP), external measurement
setups; e.g., for evaluation purposes.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
27 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
3.5.
Communication Interface
3.5.1.
Common Functionality
Commands are handled by the command interpreter in the LV section. Commands that need additional data are
not treated differently than other commands because the HV interface is able to buffer the command and all the
data that belongs to the command and the command interpreter is activated as soon as a command byte is
received.
Every response starts with a status byte followed by the data word. The data word depends on the previous
2
command. It is possible to read the same data more than once if the read request is repeated (I C™) or a NOP
command is sent (SPI). If the next command is not a read request (I²C™) or a NOP (SPI), it invalidates any
previous data.
The ZSSC3218 supports the parallel setup of two amplifier-ADC-configurations using SM_config1 and
SM_config2. Switching between the two setups can be done with the commands B0HEX and B1HEX. Note that the
respective activation command must always be sent prior to the measurement request.
The status byte contains the following bits in the sequence shown in Table 3.3:






Power indication (bit 6): 1 if the device is powered (VDDB on); 0 if not powered. This is needed for the SPI
Mode where the master reads all zeroes if the device is not powered or in power-on reset (POR).
Busy indication (bit 5): 1 if the device is busy, which indicates that the data for the last command is not
available yet. No new commands are processed if the device is busy.
Note: The device is always busy if cyclic measurement operation has been set up and started.
Currently active ZSSC3218 mode (bits [4:3]): 00 = Normal Mode; 01 = Command Mode; 1X = ZMDI
reserved.
Memory integrity/error flag (bit 2): 0 if integrity test passed; 1 if test failed. This bit indicates whether the
checksum-based integrity check passed or failed. The memory error status bit is calculated only during the
power-up sequence, so a newly written CRC will only be used for memory verification and status update
after a subsequent ZSSC3218 power-on reset (POR) or reset by means of the RES pin.
Config Setup (bit 1): This bit indicates which SM_config register is being used for the active configuration:
SM_config1 (12HEX) or SM_config2 (16HEX). The two alternate configuration setups allow for two different
configurations of the external senor channel in order to support up to two application scenarios with the
use of only one sensor-ZSSC3218 pair. This bit is 0 if SM_config1 was selected (default). This bit is 1 if
SM_config2 was selected.
ALU saturation (bit 0): If the last command was a measurement request, this bit is 0 if any intermediate
value and the final SSC result are in a valid range and no SSC-calculation internal saturation occurred in
the arithmetic logic unit (ALU). If the last command was a measurement request, this bit is 1 if an SSCcalculation internal saturation occurred. This bit is also 0 for any non-measurement command.
Table 3.3
General Status Byte
Bit
7
6
5
Meaning
0
Powered?
Busy?
Data Sheet
November 17, 2014.
4
3
Mode
2
1
0
Memory error?
Config Setup
ALU Saturation
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
28 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Table 3.4
Mode Status
Status[4:3]
Mode
00
Normal Mode (sleep and cyclic operations)
01
Command Mode
10
ZMDI reserved
11
ZMDI reserved
Further status information can be provided by the EOC pin. The EOC pin is set high when a measurement and
calculation have been completed (if no interrupt threshold is used, i.e. INT_setup==00 BIN; see section 3.3).
3.5.2.
SPI
The SPI Mode is available if the very first interface activity after ZSSC3218 power-up is an active signal at the
SS pin. The polarity and phase of the SPI clock are programmable via the CKP_CKE setting in bits [11:10] in
address 02HEX as described in Table 3.5. CKP_CKE is two bits: CPHA (bit 10), which selects which edge of
SCLK latches data, and CPOL (bit 11), which indicates whether SCLK is high or low when it is idle. The polarity
of the SS signal and pin are programmable via the SS_polarity setting (bit 9). The different combinations of
polarity and phase are illustrated in the figures below.
Figure 3.4 SPI Configuration CPHA=0
CPHA=0
SCLK (CPOL=0)
SCLK (CPOL=1)
MOSI
MSB
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
LSB
MISO
MSB
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
LSB
/SS
SAMPLE
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
29 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Figure 3.5 SPI Configuration CPHA=1
CPHA=1
SCLK (CPOL=0)
SCLK (CPOL=1)
MOSI
MSB
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
LSB
MISO
MSB
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
LSB
/SS
SAMPLE
In SPI mode, each command except NOP is started as shown in Figure 3.6. After the execution of a command
(busy = 0), the expected data can be read as illustrated in Figure 3.7 or if no data are returned by the command,
the next command can be sent. The status can be read at any time with the NOP command (see Figure 3.8).
Figure 3.6 SPI Command Request
Command Request
MOSI
Command
other than
NOP
CmdDat
<15:8>
CmdDat
<7:0>
MISO
Status
Data
Data
Note: A command request always consists of 3 bytes. If the command is shorter, then it must be completed with 0s.
The data on MISO depend on the preceding command.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
30 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Figure 3.7 SPI Read Status
Read Status
MOSI
Command
= NOP
MISO
Status
Figure 3.8 SPI Read Data
3.5.3.
2
I C™
2
2
I C™ Mode will be selected if the very first interface activity after ZSSC3218 power-up is an I C™ command. In
2
I C™ Mode, each command is started as shown in Figure 3.8. Only the number of bytes that are needed for the
command must be sent. An exception is the HS-mode where 3 bytes must always be sent as in SPI Mode. After
the execution of a command (busy = 0), the expected data can be read as illustrated in Figure 3.11 or if no data
are returned by the command, the next command can be sent. The status can be read at any time as described
in Figure 3.10.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
31 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Figure 3.9 I2C™ Command Request
Command Request (I2C™ Write)
S SlaveAddr
0 A Command
from master to slave
S
START condition
from slave to master
P
STOP condition
A
acknowledge
N
not acknowledge
A P
write
S SlaveAddr
0 A Command
A
CmdDat
<15:8>
A
CmdDat
<7:0>
A P
write
2
Figure 3.10 I C™ Read Status
Read Status (I2C™ Read)
S SlaveAddr
1 A
Status
N P
read
2
Figure 3.11 I C™ Read Data
Read Data (I2C™ Read)
(a) Example: after the completion of a Memory Read command
S SlaveAddr
1 A
Status
A
MemDat
<15:8>
A
MemDat
<7:0>
N P
read
(b) Example: after the completion of a Full Measurement command (AAHEX)
S SlaveAddr
1 A
Status
A
SensorDat
SensorDat
SensorDat
A
A
A
<15:8>
<7:0>
<23:16>
TempDat
<23:16>
A
TempDat
<15:8>
A
TempDat
<7:0>
N P
read
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
32 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
All mandatory I²C™-bus protocol features are implemented. Optional features such as clock stretching, 10-bit
slave address, etc., are not supported by the ZSSC3218’s interface.
In I²C-High-Speed Mode, a command consists of a fixed length of three bytes.
3.6.
Multiple Time Programmable (MTP) Memory
In the ZSSC3218, the memory is organized in 16-bit wide registers and can be programmed multiple times
(ca. 1000). There are 57 x 16-bit registers available for customer use. Each register can be re-programmed.
Basically, there are two MTP content sectors:

Customer Use:

ZMDI Use:
3.6.1.
accessible by means of regular write operations: 40HEX to 79HEX. It contains the customer
ID, interface setup data, measurement setup information, calibration coefficients, etc.
only accessible for write operations by ZMDI. The ZMDI sector contains specific trim
information and is programmed during manufacturing test by ZMDI.
Programming Memory
Programming memory is possible with any specified supply voltage level at VDD. The MTP programming voltage
itself is generated by means of an integrated charge pump, generating an internal memory programming voltage;
no additional, external voltage, other than VDD (as specified) is needed. A single 16-bit register write will be
completed within 16ms after the respective programming command has been sent. After the memory is
programmed, it must be read again to verify the validity of the memory contents.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
33 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
3.6.2.
Memory Contents
Table 3.5
MTP Memory Content Assignments
MTP
Address
Word / Bit
Range
Default
Setting
Description
Notes / Explanations
00HEX
15:0
0000HEX
Cust_ID0
Customer ID byte 0 (combines with memory word
01HEX to form customer ID).
01HEX
15:0
0000HEX
Cust_ID1
Customer ID byte 1 (combines with memory word
00HEX to form customer ID).
Slave_Addr
I²C™ slave address; valid range: 00HEX to 7FHEX
(default: 00HEX). Note: address codes 04HEX to 07HEX
2
are reserved for entering the I C™ High Speed
Mode.
Interface Configuration
6:0
000 0000BIN
Interrupt configuration, EOC pin functionality:
00
01
10
8:7
00BIN
INT_setup
02HEX
11
End-of-conversion signal
0-1 transition if threshold1 (TRSH1) is
exceeded and 1-0 transition if threshold1
is underrun again
0-1 transition if threshold1 is underrun and
1-0 transition if threshold1 is exceeded
again
EOC is determined by threshold settings
(see section 3.3):
If (TRSH1 > TRSH2) then EOC/INT (interrupt
level) = 0 if (TRSH1 > MEAS ≥ TRSH2)
where MEAS is the conditioned measurement result. Otherwise EOC/INT=1.
If (TRSH1 ≤ TRSH2) then EOC = 1 if
(TRSH1 ≤ MEAS < TRSH2). Otherwise
EOC = 0.
Determines the polarity of the Slave Select pin (SS)
for SPI operation:
9
Data Sheet
November 17, 2014.
0BIN
SS_polarity
0  Slave Select is active low (SPI and
ZSSC3218 are active if SS==0)
1  Slave Select is active high (SPI and
ZSSC3218 are active if SS==1)
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
34 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
MTP
Address
Word / Bit
Range
Default
Setting
Description
Notes / Explanations
Clock polarity and clock-edge select—determines
polarity and phase of SPI interface clock with the
following modes:
11:10
00BIN
CKP_CKE
00  SCLK is low in idle state, data latch with
rising edge and data output with falling
edge
01  SCLK is low in idle state, data latch with
falling edge and data output with rising
edge
10  SCLK is high in idle state, data latch with
falling edge and data output with rising
edge
11  SCLK is high in idle state, data latch with
rising edge and data output with falling
edge
Update period (ZSSC3218 sleep time, except
oscillator) in cyclic operation:
14:12
15
Data Sheet
November 17, 2014.
000BIN
0BIN
CYC_period
SOT_curve
000  not assigned
001  125ms
010  250ms
011  500ms
100  1000ms
101  2000ms
110  4000ms
111  not assigned
Type/shape of second-order curve correction for the
sensor signal.
0  parabolic curve
1  s-shaped curve
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
35 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
MTP
Address
Word / Bit
Range
Default
Setting
Description
Notes / Explanations
Signal Conditioning Parameters
03HEX
04HEX
05HEX
06HEX
15:0
15:0
15:0
15:0
0000HEX
0000HEX
0000HEX
0000HEX
Offset_S[15:0]
Bits [15:0] of the 24-bit-wide sensor offset correction
coefficient Offset_S. (The MSBs of this coefficient
including sign are Offset_S[23:16], which is bits
[15:8] in 0DHEX.)
Gain_S[15:0]
Bits [15:0] of the 24-bit-wide value of the sensor gain
coefficient Gain_S. (The MSBs of this coefficient
including sign are Gain_S[23:16], which is bits [7:0]
in 0DHEX.)
Tcg[15:0]
Bits [15:0] of the 24-bit-wide coefficient Tcg for the
temperature correction of the sensor gain. (The
MSBs of this coefficient including sign are
Tcg[23:16], which is bits [15:8] in 0EHEX.)
Tco[15:0]
Bits [15:0] of the 24-bit-wide coefficient Tco for
temperature correction of the sensor offset. (The
MSBs of this coefficient including sign are
Tco[23:16], which is bits [7:0] in 0EHEX.)
SOT_tco[15:0]
Bits [15:0] of the 24-bit-wide 2 order term SOT_tco
applied to Tco. (The MSBs of this term including sign
are SOT_tco[23:16], which is bits[15:8] in 0FHEX.)
SOT_tcg[15:0]
Bits [15:0] of the 24-bit-wide 2 order term SOT_tcg
applied to Tcg. (The MSBs of this term including sign
are SOT_tcg[23:16], which is bits[7:0] in 0FHEX.)
SOT_sens[15:0]
Bits [15:0] of the 24-bit-wide 2 order term
SOT_sens applied to the sensor readout.
(The MSBs of this term including sign are
SOT_sens[23:16], which is bits[15:8] in 10HEX.)
Offset_T[15:0]
Bits [15:0] of the 24-bit-wide temperature offset
correction coefficient Offset_T. (The MSBs of this
coefficient including sign are Offset_T[23:16], which
is bits[7:0] in 10HEX.)
Gain_T[15:0]
Bits [15:0] of the 24-bit-wide absolute value of the
temperature gain coefficient Gain_T.
(The MSBs of this coefficient including sign are
Gain_T[23:16], which is bits[15:8] in 11HEX.)
SOT_T[15:0]
Bits [15:0] of the 24-bit-wide 2 -order term SOT_T
applied to the temperature reading.
(The MSBs of this coefficient including sign are
SOT_T[23:16], which is bit[7:0] in 11HEX.)
nd
07HEX
15:0
0000HEX
nd
08HEX
15:0
0000HEX
nd
09HEX
0AHEX
0BHEX
15:0
15:0
15:0
0000HEX
0000HEX
0000HEX
nd
0CHEX
15:0
Data Sheet
November 17, 2014.
0000HEX
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
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36 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
MTP
Address
Word / Bit
Range
Default
Setting
Description
Notes / Explanations
7:0
00HEX
Gain_S[23:16]
Bits [23:16] including sign for the 24-bit-wide sensor
gain correction coefficient Gain_S. (The LSBs of this
coefficient are Gain_S[15:0] in register 04HEX.)
15:8
00HEX
Offset_S[23:16]
Bits [23:16] including sign for the 24-bit-wide sensor
offset correction coefficient Offset_S. (The LSBs are
Offset_S[15:0] in register 03HEX.)
Tco[23:16]
Bits [23:16] including sign for the 24-bit-wide
coefficient Tco for temperature correction for the
sensor offset. (The LSBs are Tco[15:0] in register
06HEX.)
Tcg[23:16]
Bits [23:16] including sign for the 24-bit-wide
coefficient Tcg for the temperature correction of the
sensor gain. (The LSBs are Tcg[15:0] in register
05HEX.)
SOT_tcg[23:16]
Bits [23:16] including sign for the 24-bit-wide 2
order term SOT_tcg applied to Tcg. (The LSBs are
SOT_tcg[15:0] in register 08HEX.)
0DHEX
00HEX
7:0
0EHEX
15:8
00HEX
nd
00HEX
7:0
0FHEX
nd
15:8
00HEX
SOT_tco[23:16]
Bits [23:16] including sign for the 24-bit-wide 2
order term SOT_tco applied to Tco. (The LSBs are
SOT_tco[15:0] in register 07HEX.)
7:0
00HEX
Offset_T[23:16]
Bits [23:16] including sign for the 24-bit-wide
temperature offset correction coefficient Offset_T.
(The LSBs are Offset_T[15:0] in register 0AHEX.)
SOT_sens[23:16]
Bits [23:16] including sign for the 24-bit-wide 2
order term SOT_sens applied to the sensor readout.
(The LSBs are SOT_sens[15:0] in register 09HEX.)
SOT_T[23:16]
Bits [23:16] including sign for the 24-bit-wide
nd
2 -order term SOT_T applied to the temperature
reading. (The LSBs are SOT_T[15:0] in register
0CHEX.)
Gain_T[23:16]
Bits [23:16] including sign for the 24-bit-wide
absolute value of the temperature gain coefficient
Gain_T. (The LSBs are Gain_T[15:0] in register
0BHEX.)
10HEX
nd
15:8
00HEX
00HEX
7:0
11HEX
15:8
Data Sheet
November 17, 2014.
00HEX
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
37 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
MTP
Address
Word / Bit
Range
Default
Setting
Description
Notes / Explanations
Measurement Configuration Register 1 (SM_config1)
st
Gain setting for the 1 PREAMP stage with
Gain_stage1  Gainamp1:
2:0
000BIN
Gain_stage1
000  6
001  12
010  20
011  30
100  40
101  60
110  80
111  120 (Might affect noise and accuracy
specifications depending on sensor setup)
nd
Gain setting for the 2 PREAMP stage with
Gain_stage2  Gainamp2:
5:3
000BIN
Gain_stage2
12HEX
6
0BIN
Gain_polarity
000  1.1
001  1.2
010  1.3
011  1.4
100  1.5
101  1.6
110  1.7
111  1.8
Set up the polarity of the sensor bridge’s gain
(inverting of the chopper) with
0  positive (no polarity change)
1  negative (180° polarity change)
Absolute number of bits for the ADC conversion
ADC_bits:
10:7
Data Sheet
November 17, 2014.
0000BIN
Adc_bits
0000  12-bit
0001  13-bit
0010  14-bit
0011  15-bit
0100  16-bit
0101  17-bit
0110  18-bit
0111 to 1111  not assigned
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
38 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
MTP
Address
Word / Bit
Range
11
Default
Setting
0BIN
Description
AbsV_enable
Notes / Explanations
Enable bit for thermopile input selection (INN
connected to AGND, INP connected to absolute
voltage source) with AbsV_enable:
0  absolute voltage input disabled (default)
1  absolute voltage input enabled (e.g. for a
thermopile)
Differential signal’s offset shift in the ADC;
compensation of signal offset by x% of input signal:
14:12
000BIN
Offset
000  no offset compensation
001  6.75% offset
010  12.5% offset
011  19.25% offset
100  25% offset
101  31.75% offset
110  38.5% offset
111  43.25% offset
Note: Bit 15 below must be set to 1 to enable the
offset shift.
Offset shift method switch:
15
0BIN
Shift_method
0  No offset shift. Offset (bits [14:12] in 12HEX)
must be set to 000BIN; GainADC = 1
1 Offset shift ADC; GainADC = 2
13HEX
15:0
0000HEX
TRSH1[15:0]
Bits [15:0] of the 24-bit-wide interrupt threshold1,
TRSH1. (The MSB bits for this threshold are
TRSH1[23:16], which is bits [7:0] of register 15HEX.)
14HEX
15:0
0000HEX
TRSH2[15:0]
Bits [15:0] of the 24-bit-wide interrupt threshold2,
TRSH2. (The MSB bits for this threshold are
TRSH2[23:16], which is bits[15:8] of register 15HEX.)
7:0
00HEX
TRSH1[23:16]
Bits [23:16] of the 24-bit-wide interrupt threshold1,
TRSH1. (The LSB bits for this threshold are
TRSH1[15:0], which is bits[15:0] of register 13HEX.)
15:8
00HEX
TRSH2[23:16]
Bits [23:16] of the 24-bit-wide interrupt threshold2,
TRSH2. (The LSB bits for this threshold are
TRSH2[15:0], which is bits[15:0] of register 14HEX.)
15HEX
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
39 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
MTP
Address
Word / Bit
Range
Default
Setting
Description
Notes / Explanations
Measurement Configuration Register 2 (SM_config2)
st
Gain setting for the 1 PREAMP stage with
Gain_stage1  Gainamp1:
2:0
000BIN
Gain_stage1
000  6
001  12
010  20
011  30
100  40
101  60
110  80
111  120 (Might affect noise and accuracy
specifications depending on sensor setup)
nd
Gain setting for the 2 PREAMP stage with
Gain_stage2  Gainamp2:
5:3
000BIN
Gain_stage2
16HEX
6
0BIN
Gain_polarity
000  1.1
001  1.2
010  1.3
011  1.4
100  1.5
101  1.6
110  1.7
111  1.8
Set up the polarity of the sensor bridge’s gain
(inverting of the chopper) with
0  positive (no polarity change)
1  negative (180° polarity change)
Absolute number of bits for the ADC conversion
ADC_bits:
10:7
Data Sheet
November 17, 2014.
0000BIN
Adc_bits
0000  12-bit
0001  13-bit
0010  14-bit
0011  15-bit
0100  16-bit
0101  17-bit
0110  18-bit
0111 to 1111  not assigned
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
40 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
MTP
Address
Word / Bit
Range
11
Default
Setting
0BIN
Description
AbsV_enable
Notes / Explanations
Enable bit for thermopile input selection (INN
connected to AGND, INP connected to absolute
voltage source) with AbsV_enable:
0  absolute voltage input disabled (default)
1  absolute voltage input enabled (e.g. for a
thermopile)
Differential signal’s offset shift in the ADC;
compensation of signal offset by x% of input signal:
14:12
000BIN
Offset
000  no offset compensation
001  6.75% offset
010  12.5% offset
011  19.25% offset
100  25% offset
101  31.75% offset
110  38.5% offset
111  43.25% offset
Note: Bit 15 below must be set to 1 to enable the
offset shift.
Offset shift method switch:
15
0BIN
Shift_method
0  No offset shift. Offset (bits[14:12] in 16HEX)
must be set to 000BIN; GainADC = 1
1  Offset Shift ADC, GainADC = 2
Post-Calibration Offset Correction Coefficients
17HEX
15:0
0000HEX
SENS_Shift[15:0]
Bits [15:0] of the post-calibration sensor offset shift
coefficient SENS_Shift. (The MSB bits of
SENS_Shift are bits [7:0] of register 19HEX.)
18HEX
15:0
0000HEX
T_Shift[15:0]
Bits [15:0] of the post-calibration temperature offset
shift coefficient T_Shift. (The MSB bits of T_Shift are
bits [15:8] of register 19HEX.)
7:0
00HEX
SENS_Shift[23:16]
Bits [23:16] of the post-calibration sensor offset shift
coefficient SENS_Shift. (The LSB bits of SENS_Shift
are in register 17HEX.)
15:8
00HEX
T_Shift[23:16]
Bits [23:16] of the post-calibration temperature offset
shift coefficient T_Shift. (The LSB bits of T_Shift are
in register 18HEX.)
19HEX
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
41 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
MTP
Address
Word / Bit
Range
Default
Setting
Description
Notes / Explanations
Free Memory – Arbitrary Use
20HEX
15:0
0000HEX
Not assigned (e.g., can be used for Cust_IDx
customer identification number)
21HEX
15:0
0000HEX
Not assigned (e.g., can be used for Cust_IDx
customer identification number)
Not assigned (e.g., can be used for Cust_IDx
customer identification number)
…
37HEX
15:0
0000HEX
Not assigned (e.g., can be used for Cust_IDx
customer identification number)
38HEX
15:0
0000HEX
Not assigned (e.g., can be used for Cust_IDx
customer identification number)
-
Generated (checksum) for the entire memory
through a linear feedback shift register (LFSR); signature is checked on power-up to ensure memory
content integrity
39HEX
15:0
Checksum
The memory integrity checksum (referred to as CRC) is generated through a linear feedback shift register with
the following polynomial:
16
15
2
g(x) = x + x + x + 1
with the initialization value: FFFFHEX.
If the CRC is valid, then the “Memory Error” status bit is set to 0.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
42 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
3.7.
Calibration Sequence
Calibration essentially involves collecting raw signal and temperature data from the sensor-ZSSC3218 system for
different known sensor-element values (i.e., for a resistive bridge or an absolute voltage source) and temperatures. This raw data can then be processed by the calibration master (assumed to be the user’s computer), and
the calculated calibration coefficients can then be written to on-chip memory.
Here is a brief overview of the three mains steps involved in calibrating the ZSSC3218.
1. Assigning a unique identification to the ZSSC3218. This identification is written to shadow RAM and
programmed in MTP memory. This unique identification can be stored in the two 16-bit registers
dedicated to the customer ID. It can be used as an index into a database stored on the calibration PC.
This database will contain all the raw values of the connected sensor-element readings and temperature
readings for that part, as well as the known sensor-element measurand conditions and temperature to
which the sensor-element was exposed.
2. Data collection. Data collection involves getting uncorrected (raw) data from the external sensor at
different known measurand values and temperatures. Then this data is stored on the calibration master
using the unique identification of the device as the index to the database.
3. Coefficient calculation and storage in MTP memory. After enough data points have been collected to
calculate all the desired coefficients, the coefficients can be calculated by the calibration master. Then
the coefficients can be programmed to the MTP memory.
Result. The sensor signal and the characteristic temperature effect on output will be linearized according to the
setup-dependent maximum output range.
It is essential to perform the calibration with a fixed programming setup during the data collection phase. In order
to prevent any accidental misprocessing, it is further recommended to keep the MTP memory setup stable during
the entire calibration process as well as in the subsequent operation. A ZSSC3218 calibration only fits the setup
used during its calibration. Changes of functional parameters after a successful calibration can decrease the
precision and accuracy performance of the ZSSC3218 as well as of the entire application.
The ZSSC3218 supports operation with different sensor setups by means of the SM_config1 and SM_config2
registers. However, only one calibration coefficient set is supported. Therefore, either an alternative ZSSC3218external signal calibration using the alternate SM_config settings must be performed to ensure that the programmed SSC coefficients are valid for both setups, or a full reprogramming of the SSC coefficients must be
performed each time the sensor setup is changed. The selection of the external sensor setup (i.e., the AFE
configuration) can be done with the interface commands B0HEX and B1HEX.
3.7.1.
Calibration Step 1 – Assigning Unique Identification
Assign a unique identification number to the ZSSC3218 by using the memory write command (40HEX + data and
41HEX + data; see Table 3.1 and Table 3.5) to write the identification number to Cust_ID0 at memory address
00HEX and Cust_ID1 at address 01HEX as described in section 3.6.1. These two 16-bit registers allow for more
than 4 billion unique devices.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
43 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Calibration Step 2 – Data Collection
3.7.2.
The number of unique points (measurand and/or temperature) at which calibration must be performed generally
depends on the requirements of the application and the behavior of the sensor in use. The minimum number of
points required is equal to the number of correction coefficients to be corrected with a minimum of three different
temperatures at three different sensor values. For a full calibration resulting in values for all 7 possible (external)
sensor coefficients and 3 possible temperature coefficients, a minimum of 7 pairs of sensor with temperature
measurements must be collected.
Within this minimum field of 3 measurand measurements x 3 temperature measurements, data must be collected
for the specific value pairs (at known conditions) and then processed to calculate the coefficients. In order to
obtain the potentially best and most robust coefficients, it is recommended that measurement pairs (temperature
vs. measurand) be collected at the outer corners of the intended operation range or at least at points that are
located far from each other. It is also essential to provide highly precise reference values as nominal, expected
values. The measurement precision of the external calibration-measurement equipment should be ten times
more accurate than the expected ZSSC3218 output accuracy after calibration in order to avoid accuracy losses
caused by the nominal reference values (e.g., measurand signal and temperature deviations).
Note: The coefficients SENS_shift and T_shift must not be determined during this calibration step. These coefficients can be pre-determined as zero until after initial calibration.
Note: An appropriate selection of measurement pairs can significantly improve the overall system performance.
The determination of the measurand-related coefficients will use all of the measurement pairs. For the
temperature-related correction coefficients, 3 (at three different temperatures) of the measurement pairs will be
used.
Note: There is an inherent redundancy in the 7 sensor-related and 3 temperature-related coefficients. Since the
temperature is a necessary output (which also needs correction), the temperature-related information is
mathematically separated, which supports faster and more efficient DSP calculations during the normal usage of
the sensor-ZSSC3218 system. The recommended approach for data collection is to make use of the rawmeasurement commands described in Table 3.2.
For external sensor values, either of the following commands can be used depending on the user’s requirements:

A2HEX + 0000HEX

A3HEX + ssssHEX
single sensor measurement for which the configuration register will be loaded from
the SM_Config1 register (12HEX in MTP); preprogramming the measurement setup
in the MTP is required.
single sensor measurement for which the SM_config configuration register (Gain,
ADC, Offset, etc.) will be loaded as the user’s configuration ssssHEX, which must
be provided externally via the interface as the data part of this command.
For temperature values, either of the following commands can be used depending on the user’s requirements:

A6HEX + 0000HEX
Data Sheet
November 17, 2014.
single temperature measurement for which the configuration register will be loaded
from an internal temperature configuration register (preprogrammed by ZMDI in
the MTP); preprogramming of the respective configuration is done by ZMDI prior to
ZSSC3218 delivery. This is the recommended approach for temperature data
collection.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
44 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC

3.7.3.
A7HEX + ssssHEX
single temperature measurement for which the configuration register (Gain, ADC,
Offset, etc.) will be loaded as the user’s configuration ssssHEX, which must be
provided externally via the interface as the data part of this command. The format
and purpose of these configuration bits must be according to the definitions for
SM_config and valid for temperature measurement in this case (bits [15:13] will be
ignored).
Calibration Step 3a) – Coefficient Calculations
The math to perform the coefficient calculation is complicated and will not be discussed in detail. There is a brief
overview in the next section. ZMDI provides software (DLLs) to perform the coefficient calculation (external to the
sensor-ZSSC3218 system) based on auto-zero corrected values. After the coefficients are calculated, the final
step is to write them to the MTP memory of the ZSSC3218.
3.7.4.
Calibration Step 3b) – Post-Calibration Offset Correction
There are two special SSC coefficients, SENS_shift and T_shift. Normally, these coefficients must be predetermined as zero during the initial sensor calibration. The primary purpose of these two coefficients is to cancel
additional offset shifts that could occur during or after final sensor assembly; e.g. if a respective sensor is finally
placed and soldered on an application board.
If the final sensor assembly induced any kind of offset (on either the temperature or external sensor signal), the
respective influence can be directly compensated by means of the SENS_shift and T_shift coefficients without
the need to change the original SSC coefficient set. However, this post-calibration offset correction must be done
under known ambient conditions (i.e., sensor measurand and/or temperature).
3.7.5.
SSC Measurements
After the completion of the calibration procedure, linearized external sensor and temperature readings can be
obtained using the commands AAHEX to AFHEX as described in Table 3.1.
Typically, only one external sensor is used in a single analog configuration using the setup in the SM_config1
MTP register (12HEX). However, the ZSSC3218 can support a second analog configuration that is set up in the
SM_config2 MTP register (16HEX). This might be useful in cases where only one sensor-ZSSC3218 pair must
support the measurand ranges for two different external sensors that have different precisions, required
amplification, and sensor offset.
If a respective switching between setups is to be performed, the SSC coefficients for the alternate external
sensor must be handled with one of the following methods:

The programmed SSC coefficients are not used for the alternate external sensor. The ZSSC3218 performs
only a factor-one transfer, i.e. no effective digital SSC correction – only a transfer of the auto-zero
corrected raw ADC readings to the ZSSC3218 output without any scaling, etc.

The coefficients are re-programmed each time the analog setup is changed.
SM_config1 is selected as the analog setup register by default, so no specific activation is needed if only
SM_config1 is used. If SM_config2 will also be used, the activation command B1HEX must be sent once prior to
the measurement request. To switch to using SM_config1, the activation command B0HEX must be sent prior to
use. This respective activation must be refreshed after any power-on-reset or RES pin reset.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
45 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
3.8.
The Calibration Math
3.8.1.
Bridge Signal Compensation
The saturation check in the ZSSC3218 detects saturation effects of the internal calculation steps, allowing the
final correction output to be determined despite the saturation. It is possible to get potentially useful signal
conditioning results that have had an intermediate saturation during the calculations. These cases are detectable
by observing the status bit[0] for each measurement result. Details about the saturation limits and the valid
ranges for values are provided in the following equations.
The calibration math description assumes a calculation with integer numbers. The description is numerically
correct concerning values, dynamic range, and resolution.
SOT_curve selects whether second-order equations compensate for sensor nonlinearity with a parabolic or
S-shaped curve. The parabolic compensation is recommended for most sensor types.
For the following equations, the terms are as follows:
2
S
=
Corrected sensor reading output via I C™ or SPI; range [0HEX to FFFFFFHEX]
S_Raw
=
Raw sensor reading from ADC after AZ correction; range [-0x7FFFF, 0x7FFFF]
Gain_S
=
Sensor gain term; range [-0x7FFFF, 0x7FFFF]
Offset_S
=
Sensor offset term; range [-0x7FFFF, 0x7FFFF]
Tcg
=
Temperature coefficient gain term; range [-0x7FFFF, 0x7FFFF]
Tco
=
Temperature coefficient offset term; range [-0x7FFFF, 0x7FFFF]
T_Raw
=
Raw temperature reading after AZ correction; range [-0x7FFFF, 0x7FFFF]
SOT_tcg
=
Second-order term for Tcg non-linearity; range [-0x7FFFF, 0x7FFFF]
SOT_tco
=
Second-order term for Tco non-linearity; range [-0x7FFFF, 0x7FFFF]
SOT_sens
=
Second-order term for sensor non-linearity; range [-0x7FFFF, 0x7FFFF]
SENS_shift
=
post-calibration, post-assembly sensor offset shift; range [-0x7FFFF, 0x7FFFF]

=
absolute value
ulll
=
bound/saturation number range from ll to ul, over/under-flow is reported as saturation in
the status byte
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
46 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
The correction formula for the differential signal reading is represented as a two-step process depending on the
SOT_curve setting.
Equations for the parabolic SOT_curve setting (SOT_curve = 0):
Simplified:
K1  2 23 
T _ Raw  4  SOT _ tcg


 T _ Raw  4  Tcg 
23
23
2
2


K 2  4  Offset_ S  S _ Raw 
Z SP 
S 
T _ Raw  4  SOT _ tco


 T _ Raw  4  Tco 
23
23
2
2


4  Gain _ S K1
 23  K 2  2 23
2 23
2
Z BP  4  SOT _ sens


 Z SP  223   SENS _ shift
223 
223

Data Sheet
November 17, 2014.
(delimited to positive number range)
(delimited to positive number range)
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
(1)
(2)
(3)
(4)
47 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Complete:
2 25 1
2 1 

2 25 1 

2 25 1

 23  T _ Raw  SOT _ tcg



K 1  2 
 
 T _ Raw 
 4Tcg 

23
21
 2
 225
 2
 225 




25

 2  25

2
25
(5)
2 25 1
2 1 

2 25 1 

2 25 1 
25

2

1





T _ Raw   SOT _ tco







K 2  4  Offset _ S   S _ Raw 
 
 T _ Raw 
 4Tco

21
 2 23


 225
  2
 225 




25




2

 225  25

2
25
Z SP

Gain _ S
 
 2 21

225 1
K

  231  K 2 
2
 225
2 1


23 
2


 225

25
(6)
225 1
(7)
0
224 1
2 1


225 1

Z SP  SOT _ sens

23

B  23  
 Z BP 
2 
 SENS _ shift 
 2  2 21

25


2

 225

 0
25
(8)
Equations for the S-shaped SOT_curve setting (SOT_curve = 1):
Simplified:
Z SS 
S 
4  Gain _ S K1
 23  K 2
2 23
2
(9)
Z SS  4  SOT _ sens


 Z SS  2 23   2 23  SENS _ shift
23
23
2 
2

(delimited to positive number range)
(10)
Complete:
Z SS
 Gain _ S

21
 2

 Z SS
S   23

 2

225 1
K

  231  K 2 
2

 225
225 1


 225
(11)
2 25 1
2 1
 SOT _ sens


 

Z
 2 23 
SS 
21
  2 25
 2
 25
2
Data Sheet
November 17, 2014.
25
2 25 1



  2 25
2 24 1


23
 2  SENS _ shift 

 0
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
(12)
48 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
3.8.2.
Temperature Signal Compensation
Temperature is measured internally. Temperature correction contains both linear gain and offset terms as well as
a second-order term to correct for any nonlinearities. For temperature, second-order compensation for
nonlinearity is always parabolic.
The correction formula is best represented as a two-step process as follows:
Simplified:
ZT 
4  Gain _ T
 T _ Raw  4  Offset _ T   2 23 (delimited to positive number range)
2 23
(13)
T 
Z T  4  SOT _ T


 Z T  2 23   T _ Shift
23
23
2  2

(14)
(delimited to positive number range)
Complete:
2 25 1
2 1
 Gain _ T

2 25 1 


Z T  

T
_
Raw

4
Offset
_
T
 2 23 
25
2
21

 225
 2
 0
25
(15)
2 24 1
2 1


2 25 1
 SOT _ T

Z

23

T
T  23   21  Z T 
2 
 T _ Shift 
 2  2

25


2

 225

 0
25
(16)
Where
2
T
=
Corrected temperature sensor reading output via I C™ or SPI; range [0HEX to FFFFFFHEX]
Gain_T
=
Gain coefficient for temperature; range [-7FFFFFHEX to 7FFFFFHEX]
T_Raw
=
Raw temperature reading after AZ correction; range [-7FFFFFHEX to 7FFFFFHEX]
Offset_T
=
Offset coefficient for temperature; range [-7FFFFFHEX to 7FFFFFHEX]
SOT_T
=
Second-order term for temperature source non-linearity; range [-7FFFFFHEX to 7FFFFFHEX]
T_Shift
=
Shift for post-calibration/post-assembly offset compensation; range [-7FFFFFHEX to
7FFFFFHEX]
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
49 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
3.8.3.
Measurement Output Data Format
The data format and bit assignment of the raw measurement and SSC-corrected outputs of the ZSSC3218 are
defined in the following tables. Any ADC measurement and SSC calculation output is formatted as a 24-bit wide
data word, regardless of the effective ADC resolution used. The values are either in two’s complement or signabsolute format.
Table 3.6
Measurement Results of ADC Raw Measurement Request (two’s complement)
Bit
23
Meaning,
Weighting
-2
Table 3.7
0
22
2
-1
23
22
Meaning,
weighting
0=positive
1=negative
2
-2
…
-3
…
2
1
2
0
-22
2
-23
1
21
2
0
20
…
-1
…
2
1
2
0
-20
2
-21
Output Results from SSC-Correction Math or DSP—Sensor and Temperature
Bit
23
Meaning,
weighting
2
Table 3.9
2
20
Calibration Coefficients (Factors and Summands) in Memory (sign-magnitude)
Bit
Table 3.8
21
0
22
2
-1
21
2
-2
20
…
-3
…
2
1
2
0
-21
2
-23
Interrupt Thresholds TRSH1 and TRSH2—Format as for SSC-Correction Math Output
Bit
23
Meaning,
weighting
2
Data Sheet
November 17, 2014.
0
22
2
-1
21
2
-2
20
…
-3
…
2
1
2
-21
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
0
2
-23
50 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
4 Package Information and Pad Assignments
The ZSSC3218 is available in die form or as engineering samples in the PQFN24 package. See Figure 4.1 for
additional die dimensions.
In Figure 4.1, the outer dimensions shown are (minimum) estimations for a die after sawing without remaining
scribe-line silicon around the core die. Therefore, the effective outer dimensions might differ slightly.
Figure 4.1 ZSSC3218 Pad Placement
Seal Ring
IC Core
VDD
ZMDI-test
VSS
ZMDI-test
ZMDI-test
RES
VDDB
INN
SS
ZMDI-test
INP
VSSB
EOC
MOSI/SDA
MISO
ZMDI-test
Data Sheet
November 17, 2014.
SCLK/SCL
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
51 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Table 4.1
Pad Assignments
Name
Direction
Type
VDD
IN
Supply
IC positive supply voltage for the IC.
VSS
IN
Supply
Ground reference voltage signal.
RES
IN
Digital
IC reset (low active, internal pull-up).
VDDB
OUT
Analog
Positive external bridge-sensor supply.
INN
IN
Analog
Negative sensor signal (or sensor-ground for absolute voltagesources sensors).
EOC
OUT
Digital
End of conversion or interrupt output.
MISO
OUT
Digital
Data output for SPI.
SS
IN
Digital
Slave select for SPI.
INP
IN
Analog
Positive sensor signal.
VSSB
OUT
Analog
Negative external bridge-sensor supply (sensor ground).
MOSI/SDA
IN/Out
Digital
Data input for SPI; data in/out for I²C™.
SCLK/SCL
IN
Digital
Clock input for I²C™/SPI.
ZMDI-test
-
-
Table 4.2
Description
Do not connect to these pads.
Die Connection and Bond Parameter
Parameter
Au Bond, Pull-Force
TYP
MAX
-
8g
Cu Bond, Pull-Force
Contact Push-Force to Pad
Probing Overdrive
not specified
0.05g/µm
0.1g/µm
-
55µm
Description / Notes
Soft bonding recommended.
Strongly not recommended.
Applied force during wafer sort and/or bond-wire connection.
Up to 4 touch downs at 85°C maximum; cantilever probe.
Generally, it is strongly recommended that bond and connection experiments be conducted in order to determine
a proper assembly setup (golden wire, time, power, bonding force, etc. by means of wire-pull test, ball-shear test,
and others) that does not lead to any IC and/or pad damages. Higher bond pull-forces maybe possible depending
directly on the bond tool and temperature.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
52 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Figure 4.2 General PQFN24 Package Dimensions
Table 4.3
Physical Package Dimensions
Parameter / Dimension
Min (mm)
Max (mm)
A
0.80
0.90
A1
0.00
0.05
b
0.18
0.30
e
0.5nom
HD
3.90
4.10
HE
3.90
4.10
L
0.35
0.45
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
53 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
Table 4.4
Pin Assignments PQFN24
Pin No.
Name
1)
Direction
Type
Description
1
ZMDI-test
-
-
2
RES
IN
Digital
IC reset (low active, internal pull-up).
3
VDDB
OUT
Analog
Positive external bridge-sensor supply.
4
INN
IN
Analog
Negative sensor signal (or sensor ground for absolute
voltage-source sensors).
5
EOC
OUT
Digital
End of conversion or interrupt output.
6
MISO
OUT
Digital
Data output for SPI.
7
ZMDI-test
-
-
Do not connect.
8
n.c.
-
-
-
9
n.c.
-
-
-
10
n.c.
-
-
-
11
n.c.
-
-
-
12
SCLK/SCL
IN
Digital
Clock input for I²C™/SPI.
13
MOSI/SDA
IN/Out
Digital
Data input for SPI; data in/out for I²C™.
14
VSSB
OUT
Analog
Negative external bridge-sensor supply (sensor
ground).
15
INP
IN
Analog
Positive sensor signal.
16
ZMDI-test
-
-
17
SS
IN
Digital
18
ZMDI-test
-
-
Do not connect.
19
ZMDI-test
-
-
Do not connect.
20
n.c.
-
-
-
21
n.c.
-
-
-
22
VDD
IN
Supply
23
n.c.
-
-
24
VSS
IN
Supply
25
Exposed Pad
-
-
1)
Do not connect.
Do not connect.
Slave select for SPI
IC positive supply voltage for the ZSSC3218.
Ground reference voltage signal.
Do not connect electrically.
n.c. stands for not connected / no connection required / not bonded.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
54 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
5 Quality and Reliability
The ZSSC3218 is available as a qualified IC for consumer-market applications. All data specified parameters are
guaranteed if not stated otherwise.
6
Ordering Sales Codes
Sales Code
Description
Package
ZSSC3218BI1B
Die—temperature range: –40°C to +85 °C, thickness 304µm
Unsawn wafer
ZSSC3218BI2B
Die—temperature range: –40°C to +85 °C, thickness 725µm
(w/o backlapping)
Unsawn wafer
ZSSC3218BI1D ES
Die—temperature range: –40°C to +85 °C, thickness 304µm,
engineering samples
Sawn die in waffle pack
ZSSC3218BI3R ES
PQFN24—temperature range: –40°C to +85 °C, engineering
samples
Packaged die
Contact ZMDI Sales for additional information.
7
Related Documents
Note: X_xy refers to the current revision of the document.
Document
File Name
ZSSC3218 Feature Sheet
ZSSC3218_Feature_Sheet_Rev_X_xy.pdf
Visit the ZSSC3218 product page www.zmdi.com/zssc3218 on ZMDI’s website www.zmdi.com or contact your
nearest sales office for ordering information or the latest version of these documents.
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
55 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
8
Glossary
Term
Description
A2D
Analog-to-Digital
ACK
Acknowledge (interface’s protocol indicator for successful data/command transfer)
ADC
Analog-to-Digital Converter or Conversion
ALU
Arithmetic Logic Unit
AZ
Auto-Zero (unspecific)
AZSM
Auto-Zero Measurement for (external) Sensor Path
AZTM
Auto-Zero Measurement for Temperature Path
Au
Gold
CLK
Clock
Cu
Copper
DAC
Digital-to-Analog Conversion or Converter
DF
Data Fetch (command type)
DSP
Digital Signal Processor
EOC
End of Conversion
FSO
Full Scale Output (value in percent relative to the ADC maximum output code; resolution dependent)
LSB
Least Significant Bit
LFSR
Linear Feedback Shift Register
MR
Measurement Request (command type)
MSB
Most Significant Bit
MTP
Multiple-Time Programmable Memory
NACK
Not Acknowledge (interface’s protocol indicator for unsuccessful data/command transfer)
POR
Power-on Reset
PreAmp
Preamplifier
PSRR
Power Supply Disturbance Rejection Ratio
SM
Signal Measurement
SOT
Second-Order Term
TC
Temperature Coefficient (of a resistor or the equivalent bridge resistance)
TM
Temperature Measurement
Data Sheet
November 17, 2014.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
56 of 57
ZSSC3218
High-End 18-Bit Sensor Signal Conditioner IC
9
Document Revision History
Revision
Date
Description
1.00
August 21, 2014
First release.
1.01
September 11, 2014
Update for Sleep State current on page 2.
Minor edits.
1.02
October 2, 2014
Update of SSC-noise values in Table 2.6.
1.03
November 17, 2014
Corrections in Table 3.5 for settings for CYC_period, Gain_stage1, Gain_stage2,
Adc_bits and Offset.
Correction for Figure 2.3.
Sales and Further Information
www.zmdi.com
[email protected]
Zentrum Mikroelektronik
Dresden AG
Global Headquarters
Grenzstrasse 28
01109 Dresden, Germany
ZMD America, Inc.
1525 McCarthy Blvd., #212
Milpitas, CA 95035-7453
USA
Central Office:
Phone +49.351.8822.306
Fax
+49.351.8822.337
USA Phone 1.855.275.9634
Phone +1.408.883.6310
Fax
+1.408.883.6358
European Technical Support
Phone +49.351.8822.7.772
Fax
+49.351.8822.87.772
DISCLAIMER: This information applies to a product under development. Its characteristics and specifications are subject to change without notice.
Zentrum Mikroelektronik Dresden AG (ZMD AG) assumes no obligation regarding future manufacture unless otherwise agreed to in writing. The
information furnished hereby is believed to be true and accurate. However, under no circumstances shall ZMD AG be liable to any customer,
licensee, or any other third party for any special, indirect, incidental, or consequential damages of any kind or nature whatsoever arising out of or
in any way related to the furnishing, performance, or use of this technical data. ZMD AG hereby expressly disclaims any liability of ZMD AG to any
customer, licensee or any other third party, and any such customer, licensee and any other third party hereby waives any liability of ZMD AG for
any damages in connection with or arising out of the furnishing, performance or use of this technical data, whether based on contract, warranty,
tort (including negligence), strict liability, or otherwise.
European Sales (Stuttgart)
Phone +49.711.674517.55
Fax
+49.711.674517.87955
Data Sheet
November 17, 2014.
Zentrum Mikroelektronik
Dresden AG, Japan Office
2nd Floor, Shinbashi Tokyu Bldg.
4-21-3, Shinbashi, Minato-ku
Tokyo, 105-0004
Japan
ZMD FAR EAST, Ltd.
3F, No. 51, Sec. 2,
Keelung Road
11052 Taipei
Taiwan
Phone +81.3.6895.7410
Fax
+81.3.6895.7301
Phone +886.2.2377.8189
Fax
+886.2.2377.8199
Zentrum Mikroelektronik
Dresden AG, Korea Office
U-space 1 Building
11th Floor, Unit JA-1102
670 Sampyeong-dong
Bundang-gu, Seongnam-si
Gyeonggi-do, 463-400
Korea
Phone +82.31.950.7679
Fax
+82.504.841.3026
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.03
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
57 of 57