Data Sheet

Data Sheet
Rev. 1.12/ December 2014
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Multi-Market Sensing Platforms
Precise and Deliberate
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Brief Description
Benefits
The ZSSC3015 sensor signal conditioner IC is
adjustable to nearly all piezo-resistive bridge
sensors. Measured and corrected bridge values are
provided at the Sig™ pin, which can be configured
as an analog voltage output or as a one-wire serial
digital output.

No external trimming components required

PC-controlled configuration and calibration via
ZACwire™ one-wire interface – simple, low cost

High accuracy (as high as ±0.1% FSO @ -25 to
85°C; ±0.25% FSO @ -50 to 150°C)

Single-pass calibration – quick and precise
The ZACwire™ digital one-wire interface (OWI) can
be used for a simple PC-controlled calibration
procedure to program a set of calibration coefficients
into an on-chip EEPROM. The calibrated ZSSC3015
and a specific sensor are mated digitally: fast,
precise, and without the cost overhead associated
with trimming by external devices or laser. Integrated
diagnostics functions make the ZSSC3015 particularly well suited for automotive applications.
Features













Digital compensation of sensor offset, sensitivity,
temperature drift, and nonlinearity
Programmable analog gain and digital gain;
accommodates bridges with spans < 1mV/V
and high offset
Many diagnostic features on chip (e.g., EEPROM
signature, bridge connection checks, bridge short
detection, power loss detection)
Independently programmable high and low
clipping levels
24-bit customer ID field for module traceability
Internal temperature compensation reference (no
external components)
Option for external temperature compensation
with addition of single diode
Output options: rail-to-rail ratiometric analog
voltage (12-bit resolution), absolute analog
voltage, ZACwire™ digital one-wire interface
Fast power-up to data out response; output
available 5ms after power-up
Current consumption depends on programmed
sample rate and mode: 1mA down to 300µA (typ.)
Fast response time: 1.4ms typical
High voltage protection: ≤ 30V with external JFET
AEC-Q100 qualified
Available Support

Evaluation Kit available

Mass Calibration System available

Support for industrial mass calibration available

Quick circuit customization possible for large
production volumes
Physical Characteristics

Wide operation temperature: –50°C to +150°C

Supply voltage 2.7 to 5.5V; with external JFET,
5.5 to 30V

Small SOP8 package
ZSSC3015 Application Circuit
Vsupply
+2.7 to +5.5 V
VDD
Sig™
OUT/OWI
ZSSC3015
VBP
Vgate
VBN
VSS
0.1 F
Ground
For more information, contact ZMDI via [email protected]
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12 —December 26, 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.
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
JFET1
(Optional if supply is 2.7 to 5.5 V)
ZSSC3015 Block Diagram
S
0.1 F
Highly Versatile Applications
in Many Markets Including
VDD (2.7 to 5.5 V)
 Industrial
 Building Automation
Vgate
RBicdLite-Auto
PTAT
Sensor
Diagnostics
Temperature
Reference
Voltage
Reference
VBP
Optional
Ext. Diode
for Temp
 White Goods
INMUX
PREAMP
Power Save
EEPROM
with Charge
Pump
ExtTemp
(Optional)
Bsink
 Automotive
POR/Oscillator
 Portable Devices
 Your Innovative Designs
12-Bit
DAC
ZSSC3015
A
VBN
 Office Automation
5.5 V to 30 V
VSUPPLY
D
_
D
14-Bit ADC
Digital
Core
SigTM
+
ZACwireTM
Interface
Power Lost
Diagnostic
Analog Block
VSS
Digital Block
Rail-to-Rail Ratiometric Voltage Output Applications
Absolute Analog Voltage Output Applications
BSS169
Vsupply
S
+2.7 to +5.5 V
1 Bsink
2 VBP
3 ExtTemp
4 VBN
VSS 8
TM
Sig
OUT
7
VDD 6
1 Bsink
VSS 8
2 VBP
SigTM 7
3 ExtTemp
Vgate 5
ZSSC3015
Optional Bsink
0 V to 1 V
Ratiometric
Rail-to-Rail
OWI/ZACwireTM
OUTBUF1
4 VBN
0.1 F
Optional Bsink
D
Vsupply
+5.5 to +30 V
OUT
VDD 6
Vgate 5
0.1 F
ZSSC3015
Ground
Ground
Part Ordering Examples (See section 11 in the data sheet for additional options.)
Sales Code
Description
Package
ZSSC3015NE1B
ZSSC3015 Die — Temperature range: -50°C to +150°C
Unsawn on Wafer
ZSSC3015NE1C
ZSSC3015 Die — Temperature range: -50°C to +150°C
Sawn on Wafer Frame
ZSSC3015NE2T(R) ZSSC3015 SOP8 (150 mil) — Temperature range: -50°C to +150°C
Tube: add “-T” to sales code. Reel: add “-R”
ZSSC3015KIT
Kit
ZSSC3015 SSC Evaluation Kit: Communication Board, SSC Board, Sensor Replacement
Board, USB cable, 5 IC samples, instructions for downloading SSC Evaluation Software
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
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
Unit B, 906-1
660, Daewangpangyo-ro
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. 1.12 —December 26, 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.
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Contents
1
Electrical Characteristics ................................................................................................... 8
1.1. Absolute Maximum Ratings ......................................................................................... 8
1.2. Recommended Operating Conditions .......................................................................... 8
1.3. Electrical Parameters ................................................................................................... 9
1.4. Analog Inputs versus Output Resolution .................................................................... 11
2
Circuit Description ........................................................................................................... 13
2.1. Signal Flow and Block Diagram ................................................................................. 13
2.2. Analog Front End ....................................................................................................... 14
2.2.1. Bandgap/PTAT and PTAT Amplifier ..................................................................... 14
2.2.2. Bridge Supply ....................................................................................................... 14
2.2.3. PREAMP Block ..................................................................................................... 14
2.2.4. Analog-to-Digital Converter (ADC)........................................................................ 15
2.3. Digital Signal Processor ............................................................................................. 15
2.3.1. EEPROM .............................................................................................................. 16
2.3.2. One-Wire Interface – ZACwire™ .......................................................................... 17
2.4. Output Stage .............................................................................................................. 17
2.4.1. Digital to Analog Converter (Output DAC) with Programmable Clipping Limits .... 17
2.4.2. Output Buffer and Output Short Circuit Protection ................................................ 18
2.4.3. Voltage Reference Block ...................................................................................... 18
2.5. Clock Generator / Power-On Reset (CLKPOR) ......................................................... 19
2.6. Diagnostic Features ................................................................................................... 19
2.6.1. EEPROM Integrity ................................................................................................ 20
2.6.2. Sensor Connection Check .................................................................................... 20
2.6.3. Sensor Short Check.............................................................................................. 21
2.6.4. Power Loss Detection ........................................................................................... 21
2.6.5. ExtTemp Connection Checks ............................................................................... 21
3
Functional Description ..................................................................................................... 22
3.1. General Working Mode .............................................................................................. 22
3.2. Normal Mode Sample Rate ........................................................................................ 24
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
3.3. ZACwire™ Communication Interface ......................................................................... 25
3.3.1. Properties and Parameters ................................................................................... 25
3.3.2. Bit Encoding ......................................................................................................... 25
3.3.3. Write Operation from Master to ZSSC3015 .......................................................... 26
3.3.4. ZSSC3015 Read Operations ................................................................................ 26
3.3.5. High Level Protocol............................................................................................... 29
3.4. Command/Data Bytes Encoding ................................................................................ 30
3.5. Calibration Sequence ................................................................................................. 31
3.6. EEPROM Bits ............................................................................................................ 33
3.7. Calibration Math ......................................................................................................... 36
3.7.1. Correction Coefficients ......................................................................................... 36
3.7.2. Interpretation of Binary Numbers for Correction Coefficients ................................ 37
3.8. Reading EEPROM Contents ...................................................................................... 40
4
Application Circuit Examples ........................................................................................... 41
4.1. Three-Wire Rail-to-Rail Ratiometric Output................................................................ 41
4.2. Absolute Analog Voltage Output ................................................................................ 42
4.3. Three-Wire Ratiometric Output with Over-Voltage Protection .................................... 43
4.4. Digital Output ............................................................................................................. 43
4.5. Output Resistor/Capacitor Limits ............................................................................... 43
5
EEPROM Restoration ...................................................................................................... 44
5.1. Default EEPROM Contents ........................................................................................ 44
5.1.1. 1V_Trim/JFET_Trim ............................................................................................. 44
5.2. EEPROM Restoration Procedure ............................................................................... 44
6
Pin Configuration and Package ....................................................................................... 46
7
ESD/Latch-Up-Protection ................................................................................................ 47
8
Test.................................................................................................................................. 47
9
Quality and Reliability ...................................................................................................... 47
10 Customization .................................................................................................................. 47
11 Ordering Sales Codes ..................................................................................................... 48
12 Related Documents ......................................................................................................... 48
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
13 Definitions of Acronyms ................................................................................................... 49
14 Document Revision History ............................................................................................. 50
List of Figures
Figure 2.1
Figure 2.2
Figure 3.1
Figure 3.2
Figure 3.3
Figure 3.4
Figure 3.5
Figure 3.6
Figure 3.7
Figure 3.8
Figure 3.9
Figure 4.1
Figure 4.2
Figure 4.3
Figure 5.1
Figure 6.1
ZSSC3015 Block Diagram ................................................................................................................ 13
DAC Output Timing for Highest Update Rate ................................................................................... 17
General Working Mode ..................................................................................................................... 23
Manchester Duty Cycle ..................................................................................................................... 25
19-Bit Write Frame ............................................................................................................................ 26
Read Acknowledge ........................................................................................................................... 26
Digital Output (NOM) Bridge Readings ............................................................................................ 27
Digital Output (NOM) Bridge Readings with Temperature ............................................................... 27
Read EEPROM Contents ................................................................................................................. 28
Transmission of a Number of Data Packets ..................................................................................... 28
ZACwire™ Output Timing for Lower Update Rates.......................................................................... 29
Rail-to-Rail Ratiometric Voltage Output – Temperature Compensation via External Diode ............ 41
Absolute Analog Voltage Output – Temperature Compensation via External Diode with External
JFET Regulation ............................................................................................................................... 42
Ratiometric Output, Temperature Compensation via Internal PTAT ................................................ 43
EEPROM Validation and Restoration Procedure ............................................................................. 45
ZSSC3015 Pin-Out Diagram ............................................................................................................ 46
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
List of Tables
Table 1.1
Table 1.2
Table 1.3
Table 1.4
Table 2.1
Table 2.2
Table 3.1
Table 3.2
Table 3.3
Table 3.4
Table 3.5
Table 3.6
Table 3.7
Table 3.8
Table 3.9
Table 3.10
Table 3.11
Table 3.12
Table 6.1
ADC Resolution Characteristics for an Analog Gain of 6 ................................................................. 11
ADC Resolution Characteristics for an Analog Gain of 24 ............................................................... 11
ADC Resolution Characteristics for an Analog Gain of 48 ............................................................... 12
ADC Resolution Characteristics for an Analog Gain of 96 ............................................................... 12
1V Reference Trim (1V vs. Trim for Nominal Process Run) ............................................................. 19
Summary of Diagnostic Features ..................................................................................................... 20
Update Rate for Analog Output ........................................................................................................ 24
ZACwire™ Parameters ..................................................................................................................... 25
Idle Time between Packets versus Update Rate.............................................................................. 28
Total Transmission Time for Different Update Rate and Output Configurations .............................. 29
Command/Data Bytes Encoding....................................................................................................... 30
ZSSC3015 EEPROM Bits ................................................................................................................. 33
Correction Coefficients ..................................................................................................................... 36
Gain_B [13:0] Weightings ................................................................................................................. 37
Offset_B Weightings ......................................................................................................................... 38
Gain_T Weightings ........................................................................................................................... 38
Offset_T Weightings ......................................................................................................................... 39
EEPROM Read Order ...................................................................................................................... 40
ZSSC3015 Pin Configuration ............................................................................................................ 46
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
1
Electrical Characteristics
1.1.
Absolute Maximum Ratings
The absolute maximum ratings are stress ratings only. The ZSSC3015 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.”
Parameter
Symbol
Min
Analog Supply Voltage
VDD
Voltages at Analog I/O – In Pin
VINA
VOUTA
Voltages at Analog I/O – Out Pin
Electrostatic Discharge – Human Body Model (see section 7)
Max
Unit
-0.3
6.0
V
-0.3
VDD+0.3
V
-0.3
VDD+0.3
V
±4000
V
Storage Temperature Range (10 hours)
TSTOR
-50
150
°C
Storage Temperature Range (<10 hours)
TSTOR <10h
-50
170
°C
1.2.
Recommended Operating Conditions
Parameter
Analog Supply Voltage to Ground
Analog Supply Voltage (with external JFET Regulator)
Common Mode Voltage
Ambient Temperature Range
1), 2)
External Capacitance between VDD and Ground
Output Load Resistance to VSS or VDD
Output Load Capacitance
Bridge Resistance
3)
4)
5), 6)
Power-On Rise Time
Symbol
Min
Typ
Max
Unit
VDD
2.7
5.0
5.5
V
VSUPP
5.5
7
30
V
VCM
1
VDDA – 1.3
V
TAMB
-50
150
C
CVDD
100
220
470
nF
RL,OUT
5
10
15
nF
100
k
100
ms
CL,OUT
RBR
k
0.3
tPON
1)
Note that the maximum EEPROM programming temperature is 85°C.
2)
If buying die, designers should use caution not to exceed maximum junction temperature by proper package selection.
3)
Only needed for Analog Output Mode; not needed for Digital Output Mode. When a pull-down resistor is used as load resistor, the power loss detection
diagnostic for loss of VSS cannot be assured at RL=5k; RL=10k is recommended for this configuration.
4)
Using the output for digital calibration, CL,OUT is limited by the maximum rise time tZAC,rise. See section 1.3.
5)
Note: Minimum bridge resistance is only a factor if using the Bsink feature. The RDS(ON) of the Bsink transistor is 8 to 10Ω when operating at VDD=5V. This
gives rise to a ratiometricity inaccuracy that becomes greater with low bridge resistances.
6)
Note: Minimum bridge resistance is important if using certain diagnostic features. It must be at least 0.3kΩ at VDD=2.7V and at least 0.6kΩ at VDD=5V for the
Sensor Short Check to function properly. For details, see section 2.6.3.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
1.3.
Electrical Parameters
Note: See important table notes at end of table. For parameters marked with an asterisk * there is no verification in mass production; the
parameter is guaranteed by design and/or quality observation.
Parameter
Symbol
Supply Voltage
VDD
Supply Current (varies with
update rate and output mode)
IDD
Conditions
Min
Typ
Max
Unit
2.7
5.0
5.5
V
At slowest update rate
0.3
At fastest update rate
1.0
1.4
20
100
mA
Temperature Coefficient –
*
PTAT Source
TCPTAT
Power Supply Rejection Ratio*
PSRR
60
POR
1.4
Power-On Reset Level
ppm/K
dB
2.6
V
EEPROM
Number Write Cycles
nWRI_EEP
At 85C
100k
Cycles
Data Retention
tWRI_EEP
At 100C
10
Years
10
nA
14
Bit
±8
LSB
±1
LSB
Analog Front-End (AFE)
Leakage Current—Pins VBP
and VBN
IIN_LEAK
Sensor connection and short check
must be disabled. See sections 2.6.2
and 2.6.3.
Analog-to-Digital Converter (ADC)
ADC Resolution
rADC
Integral Nonlinearity (INL)
1)
Differential Nonlinearity (DNL)*
INLADC
Based on ideal slope.
DNLADC
Digital-to-Analog Converter (DAC) and Buffer for Analog Output
Maximum Output Current
IOUT
Maximum current maintaining accuracy.
Resolution
Res
Referenced to VDD.
12
Bit
Absolute Error
EABS
DAC input to output.
±0.2%
VDD
Differential Nonlinearity *
DNL
No missing codes.
-0.9
+3.0
LSB12Bit
Upper Output Voltage Limit
VOUT
RL = 5 k.
95%
Lower Output Voltage Limit
VOUT
With 5k pull down, 0-1V output.
Output Short Circuit
Protection Limit
ISC
Analog Output Noise
Peak-to-Peak
VNOISE,PP
Data Sheet
December 26, 2014
Depends on operating conditions. Short
circuit protection must be enabled via
Diag_cfg (EEPROM word [102:100]).
See section 2.4.2.
2.2
3
Shorted input.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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.
mA
VDD
16.5mV
mV
20
mA
5±1LSB
mV
9 of 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Diagnostics
Upper Diagnostic Output Level
VDIA,H
Lower Diagnostic Output Level
VDIA,L
Minimum Load Resistor for
Power Loss
RL,OUT_PS
97.5%
VDD
2.5%
2)
Pull-up or pull-down in Analog Output
Mode
5
VDD
k
External Temperature Measurement
ExtTemp Signal Input Range
Required External Temperature
Diode Sensitivity
Temperature Span with
External Temperature Diode
VTSE
150
800
mV
STTSE
1.9
3.25
mV/K
TTSE_SP
-50
150
°C
6
8
ms
ZACwire™ Serial Interface
See section 3.3.1 for specifications related to the ZACwire™ serial interface.
System Response
Start-Up Time (Power-up to
data output)
tSTA
Fast Startup
Response Time – Analog
Output
tRESP-A
Update_rate = 0
0.88
1.4
3.2
ms
Response and Transmission
Time for Digital Output
tRES, DIG
Update_rate = 0
1.7
2.75
5.5
ms
Overall Linearity Error– Digital
ELIND
Bridge input to output
0.025
0.04
%
Overall Linearity Error – Analog
ELINA
Bridge input to output
0.1
0.2
%
Overall Ratiometricity Error
REout
±10%VDD; not using Bsink feature
0.025
0.1
%
Overall Accuracy – Digital
(only IC, without sensor bridge)
ACoutD
3), 4)
Overall Accuracy – Analog
(only IC, without sensor bridge)
-25°C to 85°C
0.1%
-50°C to 150°C
0.25%
-25°C to 85°C
0.35%
-50°C to 150°C
0.5%
ACoutA
%FSO
%FSO
1)
Note: This is  8 LSBs for the 14-bit analog-to-digital conversion. This results in absolute accuracy to 11-bits on the conversion result. Nonlinearity is typically
better at temperatures less than 125°C.
2)
When using a pull-down resistor as load resistor, the power loss detection diagnostic for loss of VSS cannot be assured at RL=5k; RL=10k is recommended for
this configuration.
3)
Not included is the quantization noise of the DAC. The 12-bit DAC has a quantization noise of  ½ LSB = 0.61mV (@ 5V VDD) = 0.0125%.
4)
Analog output range 2.5% to 95%.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
1.4.
Analog Inputs versus Output Resolution
The ZSSC3015 has a fully differential chopper-stabilized pre-amplifier with 4 programmable gain settings. The
output of the pre-amplifier is input to a 14-bit charge-balanced ADC. Span, offset, temperature, and nonlinearity
correction are performed in the digital domain. Then the resulting corrected bridge value can be output in analog
form through a 12-bit DAC or as a 16-bit serial digital packet. The resolution of the output depends on the input
span (bridge sensitivity) and the analog gain setting programmed. Digital gains can vary from [0,32). Analog gains
available are 6, 24, 48, and 96.
Note: At higher analog gain settings, there will be higher output resolution, but the ability of the ZSSC3015 to
handle large offsets decreases. This is expected because the offset is also amplified by the analog gain and can
therefore saturate the ADC input.
The following tables outline the guaranteed minimum resolution for a given bridge sensitivity range.
Table 1.1
ADC Resolution Characteristics for an Analog Gain of 6
Analog Gain 6
Input Span [mV/V]
Min
1)
Typ
Max
Allowed Offset
1
(+/- % of Span)
Minimum Guaranteed
Resolution [Bits]
57.8
80.0
105.8
38%
12.4
50.6
70.0
92.6
53%
12.2
43.4
60.0
79.4
73%
12.0
36.1
50.0
66.1
101%
11.7
28.9
40.0
52.9
142%
11.4
21.7
30.0
39.7
212%
11.4
In addition to Tco, Tcg.
Table 1.2
ADC Resolution Characteristics for an Analog Gain of 24
Analog Gain 24
Input Span [mV/V]
Min
1)
Typ
Max
Allowed Offset
1
(+/- % of Span)
Minimum Guaranteed
Resolution [Bits]
18.1
25.0
33.1
17%
12.7
14.5
20.0
26.5
38%
12.4
7.2
10.0
13.2
142%
11.4
3.6
5.0
6.6
351%
10.4
1.8
2.5
3.3
767%
9.4
0.9
1.2
1.6
1670%
8.4
In addition to Tco, Tcg.
Data Sheet
December 26, 2014
Important Note: The yellow shadowed fields indicate that for these input spans
with the selected analog gain setting, the quantization noise is higher than 0.1% FSO.
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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.
11 of 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Table 1.3
ADC Resolution Characteristics for an Analog Gain of 48
Analog Gain 48
Input Span [mV/V]
Min
1)
Typ
Max
Allowed Offset
1
(+/- % of Span)
Minimum Guaranteed
Resolution [Bits]
10.8
15.0
19.8
3%
13.0
7.2
10.0
13.2
38%
12.4
4.3
6.0
7.9
107%
11.7
2.9
4.0
5.3
194%
11.1
1.8
2.5
3.3
351%
10.4
1.0
1.4
1.85
678%
9.6
0.72
1.0
1.32
976%
9.1
In addition to Tco, Tcg.
Table 1.4
Important Note: The yellow shadowed fields indicate that for these input spans
with the selected analog gain setting, the quantization noise is higher than 0.1% FSO.
ADC Resolution Characteristics for an Analog Gain of 96
Analog Gain 96
Input Span [mV/V]
1)
Allowed Offset
1
(+/- % of Span)
Minimum Guaranteed
Resolution [Bits]
Min
Typ
Max
4.3
6.0
7.9
21%
12.7
2.9
4.0
5.3
64%
12.1
1.8
2.5
3.3
142%
11.4
1.0
1.4
1.85
306%
10.6
0.72
1.0
1.32
455%
10.1
In addition to Tco, Tcg.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
2
Circuit Description
2.1.
Signal Flow and Block Diagram
The ZSSC3015 resistive bridge sensor interface ICs were specifically designed as cost-effective solutions for
sensing in building automation, automotive, industrial, office automation, and white goods applications. The
ZSSC3015 employs ZMDI’s high precision bandgap with proportional-to-absolute-temperature (PTAT) output;
low-power 14-bit analog-to-digital converter (ADC, A2D, A-to-D); and an on-chip digital signal processor (DSP)
core with EEPROM to precisely calibrate the bridge output signal.
Three selectable outputs, two analog and one digital, offer the ultimate in versatility across many applications.
The ZSSC3015 rail-to-rail ratiometric analog Vout signal (0V to ~5 V Vout @ VDD=5V) suits most building automation
and automotive requirements (12-bit resolution). Typical office automation and white goods applications require
the 0 to ~1V Vout signal, which in the ZSSC3015 is referenced to the internal bandgap. The ZSSC3015 is capable
of running in high-voltage (5.5 to 30 V) systems when combined with an external JFET.
Direct interfacing to P controllers is facilitated via ZMDI’s single-wire serial ZACwire™ digital interface.
Figure 2.1 ZSSC3015 Block Diagram
JFET1
(Optional if supply is 2.7 to 5.5 V)
S
0.1 F
VDD (2.7 to 5.5 V)
Sensor
Diagnostics
Temperature
Reference
Voltage
Reference
Ext Temp
Bsink
INMUX
PREAMP
Power Save
EEPROM
with Charge
Pump
POR/Oscillator
12-Bit
DAC
ZSSC3015
A
VBN
(Optional)
Vgate
RBicdLite
PTAT
VBP
Optional
Ext. Diode
for Temp
5.5 V to 30 V
VSUPPLY
D
_
D
14-Bit ADC
Digital
Core
SigTM
+
OUTBUF1
ZACwireTM
Interface
0 V to 1 V
Ratiometric
Rail-to-Rail
OWI/ZACwireTM
Power Lost
Diagnostic
Analog Block
Digital Block
Data Sheet
December 26, 2014
VSS
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
13 of 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
2.2.
Analog Front End
2.2.1.
Bandgap/PTAT and PTAT Amplifier
The highly linear Bandgap/PTAT section provides the PTAT signal to the ADC, which allows accurate temperature conversion. In addition, the ultra-low ppm Bandgap section provides a stable voltage reference over
temperature for the operation of the rest of the ZSSC3015. If the bridge is not near the ZSSC3015, an external
diode can be used for temperature measurement/compensation.
The temperature signal (internal PTAT or external diode) is amplified through a path in the PREAMP block and
fed to the ADC for conversion. The most significant 12-bits of this converted result are used for temperature
measurement and temperature correction of bridge readings. When temperature is output in Digital Mode, only
the most significant 8 bits are given.
When external temperature is selected, add a diode from the ExtTemp pin to ground. The diode is biased with
approximately 50µA during temperature measurement cycles. The voltage level on ExtTemp is amplified through
the PREAMP section and converted by the ADC. Ensure that the ExtTemp signal is in the range of 150mV to
o
800mV to prevent saturation of the ADC. If the selected diode has a sensitivity in the range of 1.9mV/ C to
o
o
3.25mV/ C, a corrected temperature output (in Digital Mode) can be achieved for a 200 C temperature span
o
o
(-50 C to 150 C).
2.2.2.
Bridge Supply
The voltage-driven bridge is usually connected to VDD and ground. As a power savings feature, the ZSSC3015
also includes a switched transistor to interrupt the bridge current via pin 1 (Bsink). The transistor switching is
synchronized to the analog-to-digital conversion and released after finishing the conversion. To utilize this feature,
the low supply of the bridge should be connected to Bsink instead of ground.
Depending on the programmable update rate, the average current consumption (including bridge current) can be
reduced to approximately 20%, 5%, or 1%. Note this feature has no power savings benefit if using the fastest
update rate mode.
2.2.3.
PREAMP Block
The differential signal from the bridge is amplified through a chopper-stabilized instrumentation amplifier with very
high input impedance designed for low noise and low drift. This pre-amp provides gain for the differential signal
and re-centers its DC to VDD/2. The output of the PREAMP section is fed into the ADC. The calibration sequence
performed by the digital core includes an auto-zero sequence to null any drift in the pre-amp state over
temperature.
The pre-amp can be set to a gain of 6, 24, 48, or 96 through EEPROM. See Pamp_Gain in section 3.6.
The inputs to the pre-amp from (VBN/VBP pins) can be reversed via an EEPROM configuration bit. See “flip
polarity” under A2D_Offset in section 3.6.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
2.2.4.
Analog-to-Digital Converter (ADC)
nd
A 14-bit 2 order charge-balancing ADC is used to convert signals coming from the pre-amplifier. The converter,
designed in full differential switched capacitor technique, is used for converting the various signals in the digital
domain.
This principle offers the following advantages:

High noise immunity because of the differential signal path and integrating behavior

Independence from clock frequency drift and clock jitter

Fast conversion time due to second order mode
Parameters of the ADC can be controlled with EEPROM settings given in section 3.6.
Four selectable values for the zero point of the input voltage allow conversion to adapt to the sensor’s offset
parameter. With the Flip Polarity Mode and the negative digital gain options, this results in seven possible zero
point adjustments (not eight because the -1/2,1/2 offset setting is the same regardless of gain polarity).
The conversion rate varies with the programmed update rate. The fastest conversation rate is 1k samples/s.
Based on a best fit, the integral nonlinearity (INL) is less than 4 LSB14Bit.
2.3.
Digital Signal Processor
A digital signal processor (DSP) is used for processing the converted bridge data as well as performing
temperature correction and computing the temperature value for output on the digital channel.
The digital core reads correction coefficients from EEPROM and can correct for the following:
 Bridge Offset
 Bridge Gain
 Variation of Bridge Offset over Temperature (Tco)
 Variation of Bridge Gain over Temperature (Tcg)
 A single second-order effect (SOT) (Second Order Term)
The EEPROM contains a single SOT that can be applied to correct one and only one of the following:
nd
 2 order behavior of bridge measurement
nd
 2 order behavior of Tco
nd
 2 order behavior of Tcg
If the SOT applies to correcting the bridge reading, then the correction formula for the bridge reading is
represented as a two-step process as follows:
ZB  Gain _ B(1  T  Tcg )  ( BR _ Raw  /  Offset _ B  T  Tco)
(1)
RB  ZB(1.25  SOT  ZB )
(2)
Where:
™
BR
=
Corrected Bridge reading that is output as digital or analog on Sig pin
ZB
=
Intermediate result in the calculations
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
BR_Raw =
Raw Bridge reading from ADC
T_Raw
=
Raw Temp reading converted from PTAT signal or external diode
Gain_B
=
Bridge Gain term
Offset_B =
Bridge Offset term
Offset_B_sign = Sign bit for Bridge Offset term
Tcg
=
Temperature Coefficient Gain
Tco
=
Temperature Coefficient Offset
T
=
(T_Raw – TSETL)
TSETL
=
T_Raw reading at which low calibration was performed (typically 25°C)
SOT
=
Second Order Term
If the SOT applies to correcting the 2
nd
order behavior of Tco, then the formula for bridge correction is as follows:
BR  Gain _ B(1  T  Tcg )  [ BR _ Raw  /  Offset _ B  T ( SOT  T  Tco)]
If the SOT applies to correcting the 2
nd
(3)
order behavior of Tcg, then the formula for bridge correction is as follows:
BR  Gain _ B[1  T ( SOT  T  Tcg )]  [ BR _ Raw  /  Offset _ B  T  Tco]
(4)
The bandgap reference gives a very linear PTAT signal, so temperature correction can always simply be
accomplished with a linear gain and offset term.
Corrected Temperature Reading:
T  Gain _ T (T _ Raw  Offset _ T )
(5)
Where:
T_Raw
2.3.1.
=
Raw Temperature reading converted from PTAT signal or external diode
Offset_T =
Offset Coefficient for Temperature
Gain_T
Gain Coefficient for Temperature
=
EEPROM
The EEPROM contains the calibration coefficients for gain and offset, etc., and the configuration bits, such as
output mode, update rate, etc. The ZSSC3015 also offers 3 user-programmable storage bytes for module
traceability. When programming the EEPROM, an internal charge pump voltage is used; therefore a high voltage
supply is not needed. The EEPROM is implemented as a shift register. During an EEPROM read, the contents
are shifted 8 bits before each transmission of one byte occurs. The charge pump is internally regulated to 12.5 V,
and the programming time is 6ms.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
See section 2.6.1 regarding EEPROM signatures for verifying EEPROM integrity.
Note: EEPROM writing can only be performed at temperatures lower than 85ºC.
2.3.2.
One-Wire Interface – ZACwire™
The ZSSC3015 communicates via a one-wire serial interface. There are different commands available for the
following:

Reading the conversion result of the ADC (Get_BR_Raw, Get_T_Raw)

Calibration commands

Reading from the EEPROM (dump of entire contents)

Writing to the EEPROM (trim setting, configuration, and coefficients)
2.4.
Output Stage
2.4.1.
Digital to Analog Converter (Output DAC) with Programmable Clipping Limits
A 12-bit DAC based on sub-ranging resistor strings is used for the digital-to-analog output conversion in the
analog ratiometric and absolute analog voltage modes. Options during calibration configure the system to operate
in either of these modes. The design allows for excellent testability as well as low power consumption.
The DAC allows programming a lower and upper clipping limit for the output signal (analog and digital). See
Up_Clip_Lim and Low_Clip_Lim in section 3.6. The internal 14-bit calculated bridge value is compared against the
14-bit value formed by {11,Up_Clip_Lim[6:0],11111} for the upper limit and {00,Low_Clip_Lim[6:0],00000} for the
lower limit. If the calculated bridge value is higher than the upper limit or less than the lower limit, the analog
output value is clipped to this value; otherwise it is output as is.
Example for the upper clipping level: If the Up_Clip_Lim[6:0] = 0000000, then the 14-bit value used for the
clipping threshold is 11000000011111. This is 75.19% of full scale. Since there are 7 bits of upper clipping limit,
there are 127 possible values between 75.19% and 100%. Therefore the resolution of the clipping limits 0.195%.
Example for the lower clipping level: If the Low_Clip_Lim[6:0] = 1111111, then the 14-bit value used for the
clipping threshold is 00111111100000. This is 24.8% of full scale. Since there are 7 bits of lower clipping limit,
there are 127 possible values between 0 and 24.8%. Therefore the resolution of the lower clipping limit is 0.195%.
Figure 2.2 shows the data timing of the DAC output for the update rate setting 00. Refer to the ZSSC3015
Response Time Spreadsheet for details.
Figure 2.2 DAC Output Timing for Highest Update Rate
Settling Time
58 s
AD Conversion
680 s
Calculation
225 s
Settling Time
58 s
DAC output
occurs here
Data Sheet
December 26, 2014
AD Conversion
680 s
Calculation
225 s
DAC output
next update
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
2.4.2.
Output Buffer and Output Short Circuit Protection
A rail-to-rail op amp configured as a unity gain buffer can drive resistive loads (whether pull-up or pull-down) as
low as 5k and capacitances up to 15nF (for pure analog output). In addition, to limit the error due to amplifier
offset voltage, an error compensation circuit is included which tracks and reduces offset voltage to < 1mV.
The output of the ZSSC3015 output can be permanently shorted to VDD or VSS without damaging the device.
The output driver contains a current-limiting block that detects a hard short and limits the current to a safe level.
The output short circuit protection current can vary from a minimum of 3mA to a maximum of 20mA depending on
operating conditions. Output short circuit protection can be enabled via Diag_cfg (EEPROM [102:100]). Enabling
this protection is recommended when using the analog output. See Table 3.6 for settings.
2.4.3.
Voltage Reference Block
A linear regulator control circuit is included in the Voltage Reference block to interface with an external JFET to
allow operation in systems where the supply voltage exceeds 5.5V. This circuit can also be used for over-voltage
protection. The regulator set point has a coarse adjustment controlled by the JFET_cfg EEPROM bits that can
adjust the set point around 5.0 or 5.5V. (See Table 3.6 for bit locations and section 2.3.1 regarding writing to the
EEPROM.). The 1V trim setting (see below) can also act as a fine adjust for the regulation set point. The 5V
reference can be trimmed within +/-15mV.
Note: If using the external JFET for over-voltage protection purposes (i.e., 5V at JFET drain and expecting 5V at
JFET source), there will be a voltage drop across the JFET; therefore ratiometricity will be slightly compromised
depending on the rds(on) of the chosen JFET. A J107 is the best choice because it has only an 8mV drop worst
case. If using as regulation instead of over-voltage, a MMBF4392 or BSS169 also works well.
The Voltage Reference block uses the absolute reference voltage provided by the bandgap to produce two
regulated on-chip voltage references. A 1V reference is used for the output DAC high reference when the part is
configured in 0-1V Analog Output Mode. For this reason, the 1V reference must be very accurate and includes
trim so that its value can be trimmed within +/- 3mV of 1.00V. The 1V reference is also used as the on-chip
reference for the JFET regulator. The regulation set point of the JFET regulator can be fine-tuned using the 1V
trim.
The reference trim setting is selected with the 1V_Trim/JFET_Trim bits in EEPROM. See Table 3.6 for bit
locations. Table 2.1 shows the order of trim codes with 0111 for the lowest reference voltage and 1000 for the
highest reference voltage.
Important: Optimal reference trim is determined during wafer-level testing and final package testing. Back-up
copies of these bits are stored in bits in the CUST_ID0 bits for applications requiring accurate references. In this
case, see section 5 for important notes and instructions for verifying the integrity of the 1V_Trim/JFET_Trim bits
and if necessary, restoring the value from the CUST_ID0 bits before calibration.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Table 2.1
1V Reference Trim (1V vs. Trim for Nominal Process Run)
1Vref/
5Vref_trim3
1Vref/
5Vref_trim2
1Vref/
5Vref_trim1
1Vref/
5Vref_trim0
Highest Reference Voltage
1
0
0
0
…
1
0
0
1
…
1
0
1
0
…
1
0
1
1
…
1
1
0
0
…
1
1
0
1
…
1
1
1
0
…
1
1
1
1
…
0
0
0
0
…
0
0
0
1
…
0
0
1
0
…
0
0
1
1
…
0
1
0
0
…
0
1
0
1
…
0
1
1
0
Lowest Reference Voltage
0
1
1
1
Order
2.5.
Clock Generator / Power-On Reset (CLKPOR)
If the power supply exceeds 2.5V (maximum), the reset signal de-asserts and the clock generator starts operating
at a frequency of approximately 570kHz (±10%). The exact value only influences the conversion cycle time and
communication to the outside world but not the accuracy of signal processing.
2.6. Diagnostic Features
The ZSSC3015 offers a full suite of diagnostic features to ensure robust system operation in the most “missioncritical” applications. If the part is programmed in Analog Output Mode, then diagnostic states are indicated by an
output below 2.5% of VDD or above 97.5% of VDD. If the part is programmed in Digital Output Mode, then
diagnostic states will be indicated by a transmission with a generated parity error.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Table 2.2 gives a summary of the diagnostic features, which are explained in detail in the following sections.
EEPROM settings that control diagnostic functions are given in section 3.6.
Table 2.2
Summary of Diagnostic Features
Analog
Diagnostic Level
Detected Fault
ZACwire™ Diagnostic
*
Delay in Detection
†
EEPROM signature
Lower
Generates parity error
Loss of bridge positive
Upper
Generates parity error
2ms
Loss of bridge negative
Upper
Generates parity error
2ms
Open bridge connection
Upper
Generates parity error
2ms
Bridge input short
Upper
Generates parity error
2ms
ExtTemp pin open
Lower
Generates parity error
300ms
Lower
Generates parity error
300ms
ExtTemp pin shorted to BP/BN
Upper
Generates parity error
3ms
Loss of VDD
Lower
Transmissions stop
Dependent on RL and CL
Loss of VSS
Upper
Transmissions stop
Dependent on RL and CL
ExtTemp pin shorted to PWR/GND
‡
2.6.1.
11ms after power-on
EEPROM Integrity
The contents of the EEPROM are protected by an 8-bit LFSR signature (linear feedback shift register). This signature is regenerated and stored in EEPROM every time EEPROM contents are changed. This signature is generated and checked for a match after Power-On Reset prior to entering Normal Operation Mode. If the generated
signature fails to match, the part will output a diagnostic state on the output.
In addition to an extensive temporal and code interlock mechanism used to prevent false writes to the EEPROM,
the ZSSC3015 offers an EEPROM lock mechanism for high-security applications. When EEPROM bits 105:103
are programmed with “011” or “110,” this 3-bit field will disable the VPP charge pump and will not allow further
writes to the EEPROM.
2.6.2.
Sensor Connection Check
Four dedicated comparators permanently check the range of the bridge inputs (BP/BN) to ensure they are within
the envelope of 0.8V to 0.85VDD during all conversions. The two sensor inputs have a switched ohmic path to
ground and if left floating, would be discharged. If any of the wires connecting the bridge break, this mechanism
will detect it and put the ZSSC3015 in a diagnostic state. This same diagnostic feature can also detect a short
between BP/BN and the ExtTemp signal if an external diode is being used for temperature measurement. See
Table 2.2 in section 2.6 for more information.
*
All timings assume nominal operating frequency of 570kHz.
Assumes standard command window. If fast startup is enabled, the delay is 4ms.
‡
A short from ExtTemp to BP/BN might not be detected in some circuit configurations.
†
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
2.6.3.
Sensor Short Check
If a short occurs between BP/BN (bridge inputs), it would normally produce an in-range output signal and therefore would not be detected as a fault. This diagnostic mode, if enabled, will deliberately look for such a short. After
the measurement cycle of the bridge, it will deliberately pull the BP bridge input to ground for 4sec. At the end of
this 4sec window, it will check to see if the BN input “followed” it down below the 0.8V comparator checkpoint. If
so, a short must exist between BP/BN, and the ZSSC3015 will output a diagnostic state. The bridge will have a
minimum of 480sec recovery time prior to the next measurement. See Table 2.2 in section 2.6 for more
information.
The bridge resistance must be taken into account if the Sensor Short diagnostic feature is used. At V DD = 2.7V,
the minimum bridge resistance is 0.3Kand at VDD = 5V, the minimum bridge resistance is 0.6K
2.6.4.
Power Loss Detection
If the power or GND connection to the module containing the sensor bridge and ZSSC3015 is lost, the ZSSC3015
will output a diagnostic state if a pull-up or pull-down terminating resistor greater than or equal to 5k is
connected in the final application. This diagnostic mode only functions when the part is configured in Analog
Output Mode. For more information, see Table 2.2 in section 2.6.
2.6.5.
ExtTemp Connection Checks
When external temperature is selected and connection checking is enabled, the part performs range checking on
the converted temperature value. If the internal ADC reading of the temperature is less than 1/32 of full scale or
greater than 63/64 of full scale then a diagnostic state is asserted. If the ExtTemp pin is shorted to ground, the
ADC reads less than 1/32. Because 100µA is sourced onto the ExtTemp pin during conversions, it naturally pulls
up during these times. If the ExtTemp pin is open, it produces an ADC reading greater than 63/64 of full scale.
Both these bad connection conditions would be detected and result in a diagnostic output. If internal temperature
is selected or sensor connection check is not enabled, then this diagnostic check is not enabled. See Table 2.2 in
section 2.6 for more information.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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.
21 of 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
3
Functional Description
3.1.
General Working Mode
The command/data transfer takes place via the one-wire Sig™ pin using the ZACwire
protocol.
TM
serial communication
After power-on, the ZSSC3015 provides a command window for 3.5ms or 10ms. (The command window length
depends on the setting of the Fast_Startup EEPROM bit; see section 3.6). During the command window, the
ZSSC3015 is waiting for a Start_CM command. Without this command, the Normal Operation Mode (NOM) starts.
In this mode, raw bridge values are converted and the corrected values are presented on the output in analog or
digital format (depending on the configuration stored in EEPROM). If the ZSSC3015 receives the Start_CM
command during the command window, it remains in Command Mode (CM). The CM allows changing to one of
the other modes via command. (See section 3.4 for command encoding.) If the Start_RM command is sent, the
ZSSC3015 enters the Raw Mode (RM). Without correction, the raw values are transmitted to the digital output in a
predefined order. The RM can only be stopped by a power down. Raw Mode is used by the calibration software
for collection of raw bridge and temperature data so the correction coefficients can be calculated.
If diagnostic features are enabled and a diagnostic fault is detected, diagnostic states are indicated as follows
depending on the programmed mode:


In Analog Output Mode:
Diagnostic states are indicated by an output below 2.5% of VDD or above 97.5% of VDD.
In Digital Output Mode:
Diagnostic states will be indicated by a transmission with a generated parity error.
For more details, see section 2.6.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Figure 3.1 General Working Mode
Power ON
Command
Window (3.5ms or 10ms);
Send Start_CM
Start_CM
No Command
Normal Operation Mode
Start_NOM
Command Mode
Start_RM
Raw Mode
No commands possible.
Measurement cycle stopped.
Measurement cycle.
Measurement cycle.
Full command set.
SigTM pin provides raw bridge
and temperature values in the
format:
- Bridge_high (1st byte)
- Bridge_low
(2nd byte)
- Temp
(3rd byte)
Conditioning calculations
(corrected bridge and
temperature values).
Command routine will be
processed after each
command
Depending on the
configuration, the SigTM pin is
- 0 V to 1 V;
- Rail-to-rail ratiometric;
- Digital output
Diagnostic functions.
Power OFF
Error Detection
Diagnostic
State*
* See section 2.6.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
23 of 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
3.2.
Normal Mode Sample Rate
When the ZSSC3015 is in Normal Operation Mode, the output rate depends mainly on the settings for the update
rate and Output Mode. Table 3.1 shows the nominal sample rate for analog output across update rate settings for
Analog Output Mode. See section 3.3.4 for information on reading the ZSSC3015 and the overall update and
transmission time when in Digital Mode. The average response time shown in Table 3.1 accounts for 1.5 samples
at nominal frequency and temperature. The worst-case response time accounts for process and temperature
deviation on the oscillator. The worst case only occurs if the input changes immediately prior to a special
measurement. See the ZSSC3015 Response Time Spreadsheet for details on the average and worst-case
response time depending on the ZSSC3015 configuration.
Table 3.1
Update Rate for Analog Output
Update Rate Setting
Sample Rate
00
0.96
01
Worst Case Response Time
Unit
1.44
3.3
ms
4.4
6.68
15.7
ms
10
20.2
31.58
72.4
ms
11
105.2
171.02
377.4
ms
Data Sheet
December 26, 2014
Average Response Time
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
24 of 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
3.3.
ZACwire™ Communication Interface
3.3.1.
Properties and Parameters
Table 3.2
ZACwire™ Parameters
Parameter
ZACwire™ frequency
1)
Symbol
Min
Typ
Max
fZAC
30
36
40
7
9
10
Pull-up resistor (on-chip)
RZAC,pu
Pull-up resistor (external)
RZAC,pu_ext
ZACwire™ rise time
ZACwire™ line resistance
2)
ZACwire™ load capacitance
Voltage low level
3)
Voltage high level
3)
2)
30
150
Unit
kHz
Comments
Command Mode or
Update Rate = 0 or 1
Update Rate = 2 or 3
kΩ
On-chip pull-up resistor switched on during
Digital Output Mode and during Command
Mode (first 3ms after power up)
Ω
If the master communicates via a push-pull
stage, no pull-up resistor is needed;
otherwise, a pull-up resistor with a value of
at least 150Ω must be connected.
Any user RC network included in Sig™
path must meet this rise time
tZAC,rise
5
µs
RZACload
3.9
kΩ
1
15
nF
0
0.2
VDD
Rail-to-rail CMOS driver
VDD
Rail-to-rail CMOS driver
CZAC,load
0
VZAC,low
VZAC,high
0.8
1
1)
Output frequency only. The master should communicate with the ZSSC3015 at 20kHz to 52kHz when it is in Command Mode.
2)
The rise time must be tZAC,rise = 2  RZACload  CZACload  5s . If using a pull-up resistor instead of a line resistor, it must meet this specification. The absolute
maximum for CZACload is 15nF.
3)
No verification in mass production; the parameter is guaranteed by design and/or quality observation.
3.3.2. Bit Encoding
Figure 3.2 Manchester Duty Cycle
Start Bit
Start bit = 50% duty cycle used to set up strobe time
Logic 1
Logic 1 = 75% duty cycle
Logic 0
Logic 0 = 25% duty cycle
Stop Bit
Stop Bit = The ZACwire™ bus will be held high for 1 bit
length between consecutive data packets.
Stop Bit
Data Sheet
December 26, 2014
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
See Technical Note – ZACwire™ Communication for more details on the ZACwire™ protocol.
3.3.3.
Write Operation from Master to ZSSC3015
The calibration master sends a 19-bit packet frame to the ZSSC3015.
Figure 3.3 19-Bit Write Frame
19-bit Frame (WRITE)
S 7 6 5 4 3 2 1 0 P 7 6 5 4 3 2 1 0 P
Command Byte
Data Byte
S Start Bit
P Parity Bit of Command or Data Byte
2 Command Bit (example: Bit 2)
2 Data Bit (example: Bit 2)
The incoming serial signal will be sampled at a 570kHz clock rate. This protocol is very tolerant to clock skew, and
can easily tolerate a wide range of baud rates. The incoming baud rate should be in the 8kHz to 52kHz range
(36kHz nominal).
3.3.4.
ZSSC3015 Read Operations
The incoming frame will be checked for proper parity on both command and data bytes, as well as for any edge
time-outs prior to a full frame being received.
After a command/data pair is received, the ZSSC3015 will perform that command. After the command has been
successfully executed by the ZSSC3015, it will acknowledge success by a transmission of an A5HEX byte back to
the master. If the master does not receive an A5H transmission within 130ms of issuing the command, it must
assume the command was either improperly received or could not be executed.
Figure 3.4 Read Acknowledge
1 DATA Byte Packet
(10-bit byte A5H)
S Start Bit
S 1 0 1 0 0 1 0 1 P
P Parity Bit of Data Byte
Data Byte
0 Data Bit (Low)
1 Data Bit (High)
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
The ZSSC3015 transmits 10-bit bytes (1 start bit, 8 data bits, 1 parity bit). During calibration and configuration,
transmissions are normally either A5HEX or data. A5HEX indicates successful completion of a command. There are
two different digital output modes configurable (digital output with temperature and digital output with only bridge
data). During Normal Operation Mode, if the part is configured for digital output of the bridge reading, it first
transmits the high byte of bridge data, followed by the low byte. The bridge data is 14 bits in resolution, so the
upper two bits of the high byte are always zero-padded. There is a stop bit time between bytes in a packet. This
means that for the time of a bit width, the signal level is high.
Figure 3.5 Digital Output (NOM) Bridge Readings
2 DATA Byte Packet
(Digital Bridge Output )
S Start Bit
S 0 0 5 4 3 2 1 0 P Stop S 7 6 5 4 3 2 1 0 P
Data Byte
Bridge High
Data Byte
Bridge Low
P Parity Bit of Data Byte
2 Data Bit (example: Bit 2)
Stop
Stop Bit
The second option for Digital Output Mode is digital output bridge reading with temperature. It will be transmitted
as 3 data packets. The temperature byte represents an 8-bit temperature quantity spanning from -50 to 150°C.
Figure 3.6 Digital Output (NOM) Bridge Readings with Temperature
3 DATA Byte Packet
(Digital Bridge Output with Temperature )
S 0 0 5 4 3 2 1 0 P Stop S 7 6 5 4 3 2 1 0 P Stop S 7 6 5 4 3 2 1 0 P
Data Byte
Bridge High
Data Byte
Bridge Low
Data Byte
Temperature
The EEPROM transmission occurs in a packet with 20 data bytes, as shown in Figure 3.7.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Figure 3.7 Read EEPROM Contents
20 DATA Byte Packet
(Read EEPROM)
S 7 6 5 4 3 2 1 0 P Stop S 7 6 5 4 3
EEPROM
Byte 1
...
EEPROM
Byte 2
5 4 3 2 1 0 P Stop S 7 6 5 4 3 2 1 0 P Stop S 1 0 1 0 0 1 0 1 P
EEPROM
Byte 18
EEPROM
Byte 19
Data Byte A5H
There is a variable idle time between packets. This idle time varies with the update rate setting in EEPROM.
Figure 3.8 Transmission of a Number of Data Packets
Packet Transmission
(This example shows 2 DATA packets)
210P
IDLE
IDLE
IDLE
S 0 0 5 4 3 2 1 0 PStop S 7 6 5 4 3 2 1 0 P
S 0 0 5 4 3 2 1 0 PStop S 7 6 5 4 3 2 1 0 P
S0054
Time
Time
Time
Table 3.3 shows the idle time between packets versus the update rate. This idle time can vary by nominal +/-15%
between parts and over a temperature range of -50 to 150ºC. The idle time is extended by the time of one
conversion at each special measurement.
Table 3.3
Idle Time between Packets versus Update Rate
Update Rate Setting
Idle Time between
Packets
Idle Time at Special
Measurements every (xx)
Packets
00
1ms
1.83ms (128)
01
4.33ms
5.16ms (64)
10
20.3ms
21.1ms (16)
11
106ms
107ms (8)
Transmissions from the ZSSC3015 occur at one of two speeds depending on the update rate programmed in
EEPROM. If the user chooses one of the two fastest update rates (00 BIN or 01BIN) then the baud rate of the digital
transmission will be 36kHz. However, if the user chooses one of the two slower update rates (10BIN or 11BIN), then
the baud rate of the digital transmission will be 9kHz.
The total transmission time for both digital output configurations is shown in Table 3.4.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Table 3.4
Total Transmission Time for Different Update Rate and Output Configurations
Transmission Time –
Bridge Only Readings
Transmission Time –
Bridge & Temperature Readings
Update Rate
Setting
Baud Rate*
Idle Time
00
36 kHz
1.0 ms
21 bits
27.7 µs
1.6 ms
32 bits
27.7 µs
1.9 ms
01
36 kHz
4.33 ms
21 bits
27.7 µs
4.9 ms
32 bits
27.7 µs
5.2 ms
10
9 kHz
20.3 ms
21 bits
111.1 µs
22.6 ms
32 bits
111.1 µs
23.9 ms
11
9 kHz
106 ms
21 bits
111.1 µs
108.3 ms
32 bits
111.1 µs
109.6 ms
* Typical values. See Table 3.2 for details.
For lower update rates, the output is followed by a power-down as shown in Figure 3.9.
Figure 3.9 ZACwire™ Output Timing for Lower Update Rates
Calculation
225 s
ZACwireTM
Output
Power Down
(determined by
Update Rate)
Power-On
Settling
114 s
Settling Time
58 s
ADC Conversion
680 s
Calculation
225 s
ZACwireTM
Output
It is easy to program any standard microcontroller to communicate with the ZSSC3015. ZMDI can provide sample
®
code for a MicroChip PIC microcontroller.
3.3.5.
High Level Protocol
The ZSSC3015 will listen for a command/data pair to be transmitted for the 3.5ms or 10ms (depending on the
setting of the Fast_Startup EEPROM bit; see section 3.6) after the de-assertion of its internal Power-On Reset
(POR). If a transmission is not received within this time frame, then it will transition to Normal Operation Mode
(NOM). In the NOM, it will output bridge data in 0-1V analog, rail-to-rail ratiometric analog, or digital depending on
how the part is currently configured.
If the ZSSC3015 receives a Start_CM command within the first 3.5ms or 10ms after the de-assertion of POR,
then it will go into Command Mode (CM). In this mode, calibration/configuration commands will be executed. The
ZSSC3015 will acknowledge successful execution of commands by transmission of A5 HEX. The calibrating
/configuring master will know a command was not successfully executed if no response is received within 130ms
after issuing the command. Once in command interpreting/executing mode, the ZSSC3015 will stay in this mode
until power is removed or a Start_NOM (Start Normal Operation Mode) command is received. The Start_CM
command is used as an interlock mechanism to prevent a spurious entry into Command Mode on power up. The
first command received within the command window must be a Start_CM command to enter into command
interpreting mode. Any other commands will be ignored.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
3.4.
Command/Data Bytes Encoding
The 2-byte command sent to the ZSSC3015 consists of 1 byte of command information and 1 byte of data
information. Regardless of whether the command requires data or not, 2 bytes MUST be sent. Table 3.5 lists all
the command/data pairings. (X=don’t care.)
Table 3.5
Command/Data Bytes Encoding
Note: HEX = Hexadecimal
Command
Byte
Data
Description
00HEX
XXHEX
Read EEPROM command via Sig™ pin.
20HEX
5XHEX
DAC Ramp Test Mode. Gain_B[13:3] contains the starting point, and the increment is
(Offset_B/8). The increment will be added every 125µsec.
30HEX
WDHEX
Trim/Configure: 3 nibble determines what is trimmed/configured. The 4 nibble is data to be
programmed.
rd
rd
W=
What
D=
Data
th
th
3 Nibble
4 Nibble Data
0HEX
DHEX
Program EEPROM bits [2:0] ZMDI_cfg . Least significant 3
bits are used.
1HEX
DHEX
Trim 1V reference. Least significant 4 bits of data used.
2HEX
DHEX
Offset Mode. Least significant 4 bits of data used.
3HEX
DHEX
Set output mode. Least significant 2 bits used.
4HEX
DHEX
Set update rate. Least significant 2 bits used.
5HEX
DHEX
Configure JFET regulation.
6HEX
DHEX
Program the Tc_cfg register. Least significant 3 bits used.
Most significant bit of data nibble should be 0.
7HEX
DHEX
Program EEPROM bits [99:96] {SOT_cfg,Pamp_Gain}.
DHEX
**
**
EEPROM locked! Int. PTAT used for temperature.
0x0,0x1,0x2
EEPROM unlocked. Int. PTAT used for temperature.
0x6
EEPROM locked! Ext. diode used for temperature.
0x4,0x5,0x7
EHEX
Description
Program EEPROM bits [105:103]:
0x3
§
§
DHEX
EEPROM unlocked. Ext. diode used for temperature.
Program EEPROM bits [102:100] Diag_cfg
3 bits used.
††
. Least significant
40HEX
00HEX
Start_NOM => Ends Command Mode; transition to Normal Operation Mode.
40HEX
10HEX
Start_RM = Start the Raw Mode (RM).
In this mode, if Gain_B = 800HEX and Gain_T = 80HEX, then the digital output will simply be the
raw values of the ADC for the Bridge reading and the PTAT conversion.
50HEX
90HEX
Start_CM => Start the Command Mode; used to enter the command interpreting mode.
For more details, refer to section 3.8.
For more details, refer to section 3.6.
For more details, refer to section 3.6.
††
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Command
Byte
Data
Description
60HEX
YYHEX
Program SOT (Second Order Term).
70HEX
YYHEX
Program TSETL. (Set the MSB to 0.)
80HEX
YYHEX
Program Gain_B upper 7-bits. (Set the MSB to 0.)
90HEX
YYHEX
Program Gain_B lower 8-bits.
A0HEX
YYHEX
Program Offset_B upper 6-bits. (Set the two MSBs to 0.)
B0HEX
YYHEX
Program Offset_B lower 8-bits.
C0HEX
YYHEX
Program Gain_T.
D0HEX
YYHEX
Program Offset_T.
E0HEX
YYHEX
Program Tco.
E8HEX
YYHEX
Disable EEPROM lock until next reset.
F0HEX
YYHEX
Program Tcg.
08HEX
YYHEX
Program Upper Clipping Limit. (Set the MSB to 0.)
18HEX
YYHEX
Program Lower Clipping Limit. (Set the MSB to 0.)
28HEX
YYHEX
Program Cust_ID0.
38HEX
YYHEX
Program Cust_ID1.
48HEX
YYHEX
Program Cust_ID2.
3.5.
Calibration Sequence
Although the ZSSC3015 can work with many different types of resistive bridges, assume a pressure bridge is
being used for the following discussion on calibration.
For this pressure sensing application, calibration essentially involves collecting raw bridge and temperature data
from the ZSSC3015 for different known pressures and temperatures. This raw data can then be processed by the
calibration master (typically a PC) to compute the coefficients, and the calculated coefficients can then be written
to the ZSSC3015.
ZMDI can provide software and hardware with samples to perform the calibration.
There are three main steps to calibration:
1.
Assigning a unique identification to the ZSSC3015. This identification is programmed in EEPROM and
can be used as an index into the database stored on the calibration PC. This database will contain all the
raw values of bridge readings and temperature readings for that part, as well as the known pressure (for
this application) and temperature the bridge was exposed to. This unique identification can be stored in a
concatenation of the following EEPROM registers: Cust_ID0, Cust_ID1, Cust_ID2. These registers can
also form a permanent serial number.
2. Data collection. Data collection involves getting raw data from the bridge at different known pressures and
temperatures. This data is then stored on the calibration PC using the unique identification of the
ZSSC3015 as the index to the database.
3. Coefficient calculation and write. After enough data points have been collected to calculate all the desired
coefficients then the coefficients can be calculated by the calibrating PC and written to the ZSSC3015.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Step 1 – Assigning Unique Identification
Assigning a unique identification number is as simple as using the commands Program Cust_ID0, Program
Cust_ID1 and Program Cust_ID2. These three 8-bit registers allow for more than 16 million unique devices.
Step 2 – Data Collection
The number of unique (pressure, temperature) points that calibration must be performed at depends on the user’s
needs. The minimum is a 2-point calibration, and the maximum is a 5-point calibration. To acquire raw data from
the part, set the ZSSC3015 to enter Raw Mode. This is done by issuing a Start_CM (Start Command Mode
5090HEX) command/data pair to the ZSSC3015 followed by a Start_RM (Start Raw Mode 4010HEX) command/data
pair. Now if the Gain_B term has been set to unity (800 HEX) and the Gain_T term has been set to unity (80 HEX),
then the part will be in the Raw Mode and will output raw data on its Sig™ pin instead of corrected bridge and
temperature. Capture several of these data points with the user’s calibration system (capturing 16 each of bridge
and temperature raw measurements is recommended) and average them. For highest accuracy, start gathering
calibration data after the first special measurement has been completed. Store these raw bridge and temperature
settings in the database along with the known pressure and temperature. The output format during Raw Mode is
Bridge_High, Bridge_Low, Temp. Each of these is an 8-bit quantity. The upper 2-bits of Bridge_High are zerofilled. The Temp data (8 bits only) would not be enough information for accurate temperature calibration.
Therefore the upper three bits of temperature information are not given, but rather assumed known. Therefore
effectively 11-bits of temperature information are provided in this mode.
Step 3 – Coefficient Calculations
The math to perform the coefficient calculation is very complicated and will not be discussed in detail. There is a
rough overview in the “Calibration Math” section. ZMDI will provide software to perform the coefficient calculation.
After the coefficients are calculated, the final step is to write them to the EEPROM of the ZSSC3015.
The number of calibration points required can be as few as two or as many as five. This depends on the precision
desired and the behavior of the resistive bridge in use.
1. 2-point calibration can be used if only a gain and offset term are needed for a bridge with no temperature
compensation for either term.
st
2. 3-point calibration would be used to obtain 1 order compensation for either a Tco or Tcg term but not
both.
nd
3. 3-point calibration could also be used to obtain 2 order correction for the bridge but no temperature
compensation of the bridge output.
st
4. 4-point calibration would be used to obtain 1 order compensation for both Tco and Tcg.
st
nd
5. 4-point calibration could also be used to obtain 1 order compensation for Tco and a 2 order correction
for the bridge measurement.
st
st
6. 5-point calibration would be used to obtain both 1 order Tco correction and 1 order Tcg correction, plus
nd
nd
nd
a 2 order correction that could be applied to one and only one of the following: 2 order Tco, 2 order
nd
Tcg, or 2 order bridge.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
32 of 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
3.6.
EEPROM Bits
Table 3.6 shows the bit order and default settings for the EEPROM, which are programmed through the serial
interface. See section 5 for important information for die/wafer customers.
Table 3.6
ZSSC3015 EEPROM Bits
EEPROM
Range
Default
Settings
Description
Notes
2:0
ZMDI_cfg
0HEX
ZMDI_cfg[0] = Oscillator Frequency – Program to 0.
ZMDI_cfg[1] = Offset_B_sign. Flip the sign of the Offset_B
coefficient to be negative.
ZMDI_cfg[2] = Fast_Startup. Change the command window to be
3.5ms instead of 10ms.
6:3
1V_Trim/JFET_Trim
ssssBIN
See Table 2.1 in section 2.4.3.
where “s” is the partspecific factory bit
setting for the
reference voltage
trim value.
(Back-up copies are
stored in CUST_ID0
for applications requiring accurate
references. See
section 5 for important notes.)
10:7
A2D_Offset
3HEX
(Normal polarity,
positive gain; ADC
offset =
[-1/2,1/2])
The upper two bits are flip polarity and invert bridge input
(negative gain) respectively. If both are used in conjunction,
negative offset modes can be achieved.
00BIN => Normal polarity, positive gain
01BIN => Normal polarity, negative gain
10BIN => Flip polarity, positive gain
11BIN => Flip polarity, negative gain
The lower two bits form the ADC offset selection.
Offset selection:
11BIN => [-1/2,1/2] mode bridge inputs
10BIN => [-1/4,3/4] mode bridge inputs
01BIN => [-1/8,7/8] mode bridge inputs
00BIN => [-1/16,15/16] mode bridge inputs
Data Sheet
December 26, 2014
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
EEPROM
Range
12:11
Default
Settings
Description
Output_Select
2HEX
(Rail-to-Rail
Ratiometric Output
Mode)
14:13
Update_Rate
2HEX
(20ms (50Hz))
16:15
JFET_cfg
3HEX
(Over-voltage
protection)
Notes
00BIN => Digital (3 bytes with parity)
Bridge High {00,[5:0]}
Bridge Low [7:0]
Temp [7:0]
01BIN => 0-1V Analog
10BIN => Rail-to-Rail Ratiometric
11BIN => Digital (2 bytes with parity) (No Temp)
Bridge High {00,[5:0]}
Bridge Low [7:0]
00BIN => 1ms (1kHz)
01BIN => 4ms (250Hz)
10BIN => 20ms (50Hz)
11BIN => 100ms (10Hz)
00BIN => No JFET regulation (lower power)
01BIN => No JFET regulation (lower power)
10BIN => JFET regulation centered around 5.0V
11BIN => JFET regulation centered around 5.5V
(i.e., over-voltage protection)
31:17
Gain_B
800HEX
Bridge Gain (also see bits 10:7):
Gain_B[14] => multiply x 8
Gain_B[13:0] => 14-bit unsigned number representing a
number in the range [0,8)
45:32
Offset_B
0HEX
Unsigned 14-bit offset for bridge correction.
53:46
Gain_T
80HEX
Temperature gain coefficient used to correct PTAT
or ExtTemp reading.
61:54
Offset_T
0HEX
Temperature offset coefficient used to correct PTAT
or ExtTemp reading.
68:62
TSETL
0HEX
Stores Raw PTAT or ExtTemp reading at temperature in which
low calibration points were taken.
76:69
Tcg
0HEX
Coefficient for temperature correction of bridge gain term:
Tcg = 8-bit magnitude of Tcg term. Sign is determined by Tc_cfg
(bits 87:85).
84:77
Tco
0HEX
Coefficient for temperature correction of bridge offset term.
Tco = 8-bit magnitude of Tco term. Sign and scaling are
determined by Tc_cfg (bits 87:85).
87:85
Tc_cfg
0HEX
This 3-bit term determines options for temperature compensation
of the bridge.
Tc_cfg[2] => If set, Tcg is negative
Tc_cfg[1] => Scale magnitude of Tco term by 8, and if SOT
applies to Tco, scale SOT by 8
Tc_cfg[0] => If set, Tco is negative
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
EEPROM
Range
Default
Settings
Description
Notes
nd
95:88
SOT
0HEX
2 Order Term. This term is a 7-bit magnitude with sign.
SOT[7] = 1  negative
SOT[7] = 0  positive
SOT[6:0] = magnitude [0-127]
nd
This term can apply to a 2 order Tcg, Tco, or bridge correction.
(See SOT_cfg below.)
99:96
{SOT_cfg,
Pamp_Gain}
5HEX
Bits [99:98] = SOT_cfg
00BIN = SOT applies to Bridge
01BIN = SOT applies to Tcg
10BIN = SOT applies to Tco
11BIN = Prohibited
Bits [97:96] = Pre-Amp Gain
00BIN => 6
01BIN => 24 (default setting)
10BIN => 48
11BIN => 96
Diag_cfg
7HEX
102:100
(SOT applies to Tcg;
Pre-Amp Gain = 24)
(Output short circuit
protection, sensor
short checking, and
sensor connection
checking enabled)
105:103
Lock_ExtTemp
0HEX
(Unlocked; internal
PTAT used for
temperature)
This 3-bit term applies to diagnostic features:
Diag_cfg[2]  Enable output short circuit protection
Diag _cfg[1]  Enable sensor short checking
Diag_cfg[0]  Enable sensor connection checking
EEPROM lock:
011BIN or 110BIN => locked
All other
=> unlocked
Important: When EEPROM is locked, the internal charge pump
is disabled and the EEPROM cannot be programmed.
Bit 105 (the MSB of this field) is also used for selecting external
temperature measurement.
000,001,010,011=>Internal PTAT used for temp
100,101,110,111=>External diode used for temp
112:106
Up_Clip_Lim
7FHEX
7-bit value used to select an upper clipping limit for the output. It
affects both analog and digital output. The 14-bit upper clipping
limit value is {11,Up_Clip_Lim[6:0],11111}. 127 different clipping
levels are selectable between 75.19% and 100% of VDD.
119:113
Low_Clip_Lim
0HEX
7-bit value used to select a lower clipping limit for the output. It
affects both analog and digital output. The 14-bit lower clipping
limit value is {00,Low_Clip_Lim[6:0],00000}. 127 different clipping
levels are selectable between 0% and 24.8% of VDD.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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.
35 of 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
EEPROM
Range
127:120
Default
Settings
Description
Cust_ID0
ssHEX
where “s” is a partspecific factory bit
setting.
During factory testing, two back-up
copies of the optimal
setting for the
1V_Trim/JFET_Trim
bits are stored in
[123:120] and in
[127:124]. See important notes in
section 5.
Notes
Customer ID byte 0.
Can be used to store a customer part identification number.
Caution: If the application requires accurate voltage references,
do not overwrite this byte until completing the procedures in
section 5.
135:128
Cust_ID1
0
Customer ID byte 1.
Can be used to store a customer part identification number.
143:136
Cust_ID2
0
Customer ID byte 2.
Can be used to store a customer part identification number.
151:144
Signature
3.7.
Calibration Math
3.7.1.
Correction Coefficients
‡‡
8-bit EEPROM signature. Generated through a LFSR . This
signature is checked on power-on to ensure integrity of EEPROM
contents.
All terms are calculated external to the ZSSC3015 and then programmed to its EEPROM through the serial
interface.
Table 3.7
Correction Coefficients
Coefficient
Offset_B_sign
Gain_B
Offset_B
Gain_T
Offset_T
‡‡
Description
A sign bit to allow for positive and negative Offset_B terms.
Gain term used to compensate span of Bridge reading.
Offset term used to compensate offset of Bridge reading.
Gain term used to compensate span of Temp reading.
Offset term used to compensate offset of Temp reading.
Linear feedback shift register.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Coefficient
3.7.2.
Description
SOT
Second Order Term. The SOT can be applied as a second-order correction term for one of the
following:
 Bridge measurement
 Temperature coefficient of offset (Tco)
 Temperature coefficient of gain (Tcg)
The EEPROM bits 99:98 determine which term SOT corrects.
TSETL
RAW_PTAT or ExtTemp reading (upper 7-bits) at low temperature at which calibration was performed
(typically room temperature).
Tcg
Temperature correction coefficient of bridge gain term.
Note: This term has an 8-bit magnitude and a sign bit (Tc_cfg[2]).
Tco
Temperature correction coefficient of bridge offset term.
Note: This term has an 8-bit magnitude, a sign bit (Tc_cfg[0]), and a scaling bit (Tc_cfg[1]), which can
multiply its magnitude by 8.
Interpretation of Binary Numbers for Correction Coefficients
BR_Raw should be interpreted as an unsigned number in the set [0, 16383] with a resolution of 1.
T_Raw should be interpreted as an unsigned number in the set [0, 16383], with a resolution of 4.
3.7.2.1. Gain_B Interpretation
Gain_B should be interpreted as a value in the set [0, 64]. The MSB (bit 14) is a scaling bit that will multiply the
effect of the Gain_B[13:0] term by 8. The remaining bits Gain_B[13:0] represent a number in the range of [0,8)
with Gain_B[13] having a weighting of 4, and each subsequent bit has a weighting of ½ the previous bit.
Table 3.8
Gain_B [13:0] Weightings
Bit Position
Weighting
13
2 =4
12
2 =2
11
2 =1
10
2
…
…
3
2
-8
2
2
-9
1
2
-10
0
2
-11
2
1
0
-1
Examples:
The binary number: 010010100110001BIN = 4.6489; Gain_B[14] is 0, so the number represented by
Gain_B[13:0] is not multiplied by 8.
The binary number: 101100010010110BIN = 24.586; Gain_B[14] is 1, so the number represented by
Gain_B[13:0] is multiplied by 8.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
3.7.2.2. Offset_B Interpretation
Offset_B is a 14-bit unsigned binary number, the Offset_B_sign bit is pre-pended to the number to create a 15-bit
2’s complement signed value. The bit weightings of {Offset_B_sign, Offset_B[13:0]} are shown in Table 3.9.
Table 3.9
Offset_B Weightings
Bit Position
Weighting
Offset_B_sign
-16384
13
8192
12
4096
11
2048
.
.
.
1
1
2 =2
0
2 =1
0
For example, the binary number 0 1111 1111 1100BIN = 4092.
However, with the Offset_B_sign bit set, the binary number 1 1111 1111 1100 BIN = -4.
3.7.2.3. Gain_T Interpretation
Gain_T should be interpreted as a number in the set [0,2]. Gain_T[7] has a weighting of 1, and each subsequent
bit has a weighting of ½ the previous bit.
Table 3.10 Gain_T Weightings
Bit Position
Weighting
7
2 =1
6
2 = 0.5
5
2 = 0.25
4
2
-3
3
2
-4
2
2
-5
1
2
-6
0
2
-7
Data Sheet
December 26, 2014
0
-1
-2
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
3.7.2.4. Offset_T Interpretation
Offset_T is an 8-bit signed binary number in two’s complement form. The MSB has a weighting of -128. The
following bits then have a weighting of 64, 32, 16 …
Table 3.11 Offset_T Weightings
Bit Position
Weighting
7
-128
6
2 = 64
5
2 = 32
4
2 = 16
3
2 =8
2
2 =4
1
2 =2
0
2 =1
6
5
4
3
2
1
0
For example, the binary number 00101001BIN = 41DEC.
3.7.2.5. Tco Interpretation
Tco is specified as having an 8-bit magnitude with an additional sign bit and a scalar bit (Tc_cfg). When the scalar
bit is set, the signed Tco is multiplied by 8.
o
 Tco Resolution: 0.175 μV/V/ C
(referenced to input)
o
 Tco Range:
± 44.6 μV/V/ C
(referenced to input)
If the scaling bit is used, then the above resolution and range are scaled by 8 to give the following results:
o
 Tco Scaled Resolution: 1.40 μV/V/ C (referenced to input)
o
 Tco Scaled Range:
± 357 μV/V/ C (referenced to input)
3.7.2.6. Tcg Interpretation
Tcg is specified as an 8-bit magnitude with an additional sign bit (Tc_cfg).
o
 Tcg Resolution: 17.0 ppm/ C
o
 Tcg Range:
±4335 ppm/ C
3.7.2.7. SOT Interpretation
nd
SOT is a 2 order term that can apply to one and only one of the following: bridge nonlinearity correction, Tco
nonlinearity correction, or Tcg nonlinearity correction.
As it applies to bridge nonlinearity correction:
 Resolution: 0.25% @ Full Scale
 Range:
+25% @ Full Scale to -25% @ Full Scale
(Saturation in internal arithmetic will occur at greater negative nonlinearities.)
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
As it applies to Tcg:
o
2
 Resolution: 0.3 ppm/( C)
o
2
 Range:
+/- 38ppm/( C)
As it applies to Tco:
2 settings are possible. It is possible to scale the effect of SOT by 8. If Tc_cfg[1] is set, then both Tco and
SOT’s contribution to Tco are multiplied by 8.
o
2
 Resolution at unity scaling: 1.51nV/V/( C) (referenced to input)
o
2
 Range: +/- 0.192µV/V/( C) (referenced to input)
 Resolution at 8x scaling: 12.1nV/V/(oC)2 (referenced to input)
2
 Range: +/- 1.54µV/V/(oC) (referenced to input)
3.8.
Reading EEPROM Contents
The contents of the entire EEPROM memory can be read out using the Read EEPROM command (00 HEX). This
command causes the ZSSC3015 to output consecutive bytes on the ZACwire™ interface. After each
transmission, the EEPROM contents are shifted by 8 bits. The bit order of these bytes is given in Table 3.12.
Table 3.12 EEPROM Read Order
Bit 7
Bit 6
Bit 5
Bit 4
Byte 1
Bit 3
Bit 2
Bit 1
Bit 0
Offset_B[7:0]
Byte 2
Gain_T[1:0]
Byte 3
Offset_T[1:0]
Gain_T[7:2]
Byte 4
TSETL[1:0]
Offset_T[7:2]
Offset_B[13:8]
Byte 5
Tcg[2:0]
TSETL[6:2]
Byte 6
Tco[2:0]
Tcg[7:3]
Byte 7
Tc_cfg[2:0]
Tco[7:3]
Byte 8
SOT[7:0]
Byte 9
Lock[0]
Diag_cfg[2:0]
Byte 10
SOT_cfg/Pamp_Gain[3:0]
Up_Clip_Lim[5:0]
Byte 11
Lock[2:1]
Low_Clip_Lim[6:0]
Byte 12
Cust_ID0[7:0]
Byte 13
Cust_ID1[7:0]
Byte 14
Cust_ID2[7:0]
Byte 15
Signature[7:0]
Byte 16
A2D_Offset[0]
Byte 17
JFET_cfg[0]
Byte 18
ZMDI_cfg[2:0]
1V_Trim/JFET_Trim[3:0]
Update_Rate[1:0]
Output Select[1:0]
JFET_cfg[1]
Gain_B[14:7]
Byte 20
A5HEX
December 26, 2014
A2D_Offset[3:1]
Gain_B[6:0]
Byte 19
Data Sheet
Up_Clip_Lim[6]
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
4
Application Circuit Examples
The minimum output analog load resistor is RL= 5k. This optional load resistor can be configured as a pull-up or
pull-down. If it is configured as a pull-down, it cannot be part of the module to be calibrated because this would
prevent proper operation of the ZACwire™. If a pull-down load is desired, it must be added to system after
module calibration.
There is no output load capacitance needed.
4.1.
Three-Wire Rail-to-Rail Ratiometric Output
This example shows an application circuit for rail-to-rail ratiometric voltage output configuration with temperature
compensation via an external diode.
Figure 4.1 Rail-to-Rail Ratiometric Voltage Output – Temperature Compensation via External Diode
Vsupply
+2.7 to +5.5 V
1 Bsink
VSS 8
2 VBP
SigTM 7
3 ExtTemp
4 VBN
Optional Bsink
OUT
VDD 6
Vgate 5
ZSSC3015
0.1 F
Ground
The optional bridge sink allows a power savings of bridge current. The output voltage can be either


Rail-to-rail ratiometric analog output (ratiometric to VDD = Vsupply).
0 to 1V analog output. The absolute voltage output reference is trimmable 1V (+/-2mV) in the
1V Output Mode via a 4-bit EEPROM field. See section 2.4.3.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
4.2.
Absolute Analog Voltage Output
The figure below shows an application circuit for an absolute voltage output configuration with temperature compensation via external diode and external JFET regulation for all industry standard applications.
Figure 4.2 Absolute Analog Voltage Output – Temperature Compensation
via External Diode with External JFET Regulation
BSS169
S
1 Bsink
VSS 8
2 VBP
SigTM 7
3 ExtTemp
4 VBN
Optional Bsink
D
Vsupply
+5.5 to +30 V
OUT
VDD 6
Vgate 5
ZSSC3015
0.1 F
Ground
The output signal range can be one of the following options:
 0 to 1 V analog output. The absolute voltage output reference is trimmable: 1V (+/-2 mV) in the 1V Output
Mode via a 4-bit EEPROM field (see section 2.4.3).
 Rail-to-rail analog output. The on-chip reference for the JFET regulator block is trimmable: 5 V (±~10 mV)
in the Ratiometric Output Mode via a 4-bit EEPROM field. (See section 2.4.3).
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
4.3.
Three-Wire Ratiometric Output with Over-Voltage Protection
The figure below shows an application circuit for a ratiometric output configuration with temperature compensation
via the internal PTAT. In this application, the JFET is used for voltage protection. JFET_cfg (16:15) in the
EEPROM is configured to 5.5V. There is an additional maximum error of 8mV caused by the non-zero rON of the
limiter JFET.
Figure 4.3 Ratiometric Output, Temperature Compensation via Internal PTAT
J107 Vishay
S
1 Bsink
VSS 8
2 VBP
SigTM 7
3 ExtTemp
4 VBN
Optional Bsink
D
Vsupply
+5.0 to +5.5 V
OUT
VDD 6
Vgate 5
ZSSC3015
0.1 F
Ground
4.4.
Digital Output
For all three circuits, the output signal can also be digital. Depending on the output select bits, the bridge signal or
the bridge signal and temperature signal are sent. For the digital output, no load resistor or load capacity is
necessary. No pull-down resistor is allowed. If a line resistor or pull-up resistor is used, the requirement for the
rise time must be met (< 5s). The ZSSC3015 output includes an internal pull-up resistor of about 30k. The
digital output can easily be read by firmware from a microcontroller, and ZMDI can provide the customer with
software for developing the interface.
4.5.
Output Resistor/Capacitor Limits
The limits for external components depend on the programmed output mode:
 Pure Analog Output Mode (calibration is done before): The only limit is the minimum load resistance of 5k.
 Pure Digital Output Mode with end-of-line calibration: The RC time constant of the ZACwire™ line must have
a rise time  5µs.
 Analog output with digital communication during calibration: The RC time constant of the ZACwire™ line must
have a rise time  5µs.
Warning: Any series line resistance forms a voltage divider in conjunction with the pull-up load device. If a series
line resistance is needed, choose a low value relative to the pull-up load device.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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 50
ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
5
EEPROM Restoration
If needed, the default settings for the ZSSC3015 (see Table 3.6) can be reprogrammed as described in section 3.
The following sections describe EEPROM content validation and handling during and/or after system assembly.
Important: During the sawing and dicing process, there is a possibility of the EEPROM contents flipping, and
prevention cannot be guaranteed. This is primarily a concern for the factory trim settings, which are customized to
each part. If purchasing packaged parts, the EEPROM contents have already been returned to their default
values and this section can be ignored.
The EEPROM default values programmed during the different test levels have been selected so that customer
has the option to refresh/reprogram trim bits that might have flipped during sawing or dicing.
Important: The EEPROM lock is stored in the bit range 105:103. A value of 6 HEX or 3HEX will lock the EEPROM,
disabling the charge pump needed for EEPROM writing. The lock may be temporarily ignored by using the
EEPROM Force Unlock command (E800HEX) in Command Mode. This will re-enable the charge pump until the
next reset. Alternatively, the EEPROM Force Unlock command could be issued in Command Mode and the lock
itself may be reprogrammed in EEPROM at this time. The complete contents can also be validated using the
EEPROM signature stored in bits [151:144], (see “Signature” in Table 3.6).
5.1.
Default EEPROM Contents
During the wafer level test (wafer/dice delivery) and during final test for SOP8 packaged parts, the EEPROM is
programmed with the default values listed in the Table 3.6.
During the wafer level test, the trim bits in 1V_Trim/JFET_Trim [6:3] are set to die-specific values.
5.1.1.
1V_Trim/JFET_Trim
The 5V reference for the JFET regulation is factory trimmed during the final test to 5V±15mV using the 1V_Trim/
JFET_Trim bit setting. The 4-bit setting stored in EEPROM bits [6:3] is copied twice to the Cust_ID0 bits [127:124]
and [123:120] to ensure the factory settings are retained so that the customer can reprogram these values in the
1V_Trim/JFET_Trim bits if needed.
5.2.
EEPROM Restoration Procedure
After module assembly, the EEPROM content should be refreshed. If JFET regulation is not used for the customer’s application, write the default values shown in Table 3.6 to the EEPROM bit range [143:7] and retain the
existing values in the bit range [6:0]. If JFET regulation is required, the bit restoration procedure shown in the flow
chart in Figure 5.1 must be used to keep the factory settings that were programmed during the testing.
Note: The EEPROM signature is re-calculated and updated after every EEPROM writing.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
Figure 5.1 EEPROM Validation and Restoration Procedure
Start CM
Restore Factory Trimming?
N
Y
Read EEPROM
Check JFET_Trim bits
[123:120]=[127:124]
Check JFET_Trim bits
[6:3]=[127:124]
N
Y
Keep bits [6:3]
Check JFET_Trim bits
[6:3]=[123:120]
N
Y
Write
[123:120] to[6:3]
N
Y
Keep bits [6:3]
Perform New
JFET_Trim
Write EEPROM
default values
[143:7]
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
6
Pin Configuration and Package
The standard package of the ZSSC3015 is an SOP-8 (3.81mm / 150mil body) with a lead-pitch 1.27mm / 50mil.
Figure 6.1 ZSSC3015 Pin-Out Diagram
Table 6.1
Bsink
1
8
VSS
VBP
2
7
SigTM
ExtTemp
3
6
VDD
VBN
4
5
Vgate
ZSSC3015 Pin Configuration
Pin No.
Name
Description
1
Bsink
Optional ground connection for bridge ground. Used for power savings.
2
VBP
Positive bridge connection
3
ExtTemp
External diode connection
4
VBN
Negative bridge connection
5
Vgate
Gate control for external JFET regulation/over-voltage protection
6
VDD
Supply voltage (2.7 to 5.5 V)
7
Sig™
ZACwire™ interface (analog out, digital out, calibration interface)
8
VSS
Ground supply
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
7
ESD/Latch-Up-Protection
All pins have an ESD protection of 4000V and a latch-up protection of 100 mA or of +8V/ –4V (to VSS/VSSA).
ESD protection referenced to the Human Body Model is tested with devices in SOP-8 packages during product
qualification. The ESD test follows the Human Body Model with 1.5kΩ/100pF based on MIL 883, Method 3015.7.
8
Test
The test program is based on this datasheet. The final parameters that will be tested during series production are
listed in the tables of section 1.
The digital part of the ZSSC3015 includes IDDQ and a scan chain with a boundary scan, which can be activated
and controlled during wafer test. Further test support for testing of the analog parts on wafer level is included in
the DSP.
9
Quality and Reliability
The ZSSC3015 is qualified according to the AEC-Q100 standard, operating temperature grade 0. A fit rate <5fit
(temp=55°C, S=60%) is guaranteed. A typical fit rate of the C7A-technology, which is used for ZSSC3015, is
2.7fit.
10
Customization
For high-volume applications that require an upgraded or downgraded functionality compared to the ZSSC3015,
ZMDI can customize the circuit design by adding or removing certain functional blocks.
For this customization, ZMDI has a considerable library of sensor-dedicated circuitry blocks, which enable ZMDI
to provide a custom solution quickly. Please contact ZMDI for further information.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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.
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RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
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Ordering Sales Codes
Sales Code
Description
Package
ZSSC3015NE1B
ZSSC3015 Die — Temperature range: -50°C to +150°C
Unsawn on Wafer
ZSSC3015NE1C
ZSSC3015 Die — Temperature range: -50°C to +150°C
Sawn on Wafer Frame
ZSSC3015NE2T(R) ZSSC3015 SOP8 (150 mil) — Temperature range: -50°C to +150°C
Tube: add “-T” to sales code
Reel: add “-R”
ZSSC3015NA1B
ZSSC3015 Die — Temperature range: -40°C to +125°C
Unsawn on Wafer
ZSSC3015NA1C
ZSSC3015 Die — Temperature range: -40°C to +125°C
Sawn on Wafer Frame
ZSSC3015NA2T(R) ZSSC3015 SOP8 (150 mil) — Temperature range: -40°C to +125°C
Tube: add “-T” to sales code
Reel: add “-R”
ZSSC3015KIT
Kit
ZSSC3015 SSC Evaluation Kit: Communication Board, SSC Board, Sensor Replacement Board,
USB cable, 5 IC samples, instructions for downloading SSC Evaluation Software from www.zmdi.com
Contact ZMDI Sales for support and sales of ZMDI’s ZSSC3015 Mass Calibration System.
12
Related Documents
Note: X_xy refers to the latest version of the document.
Documents marked with an asterisk (*) can be found on the ZMDI “SSC Evaluation Tools” page (www.zmdi.com/ssc-tools).
Documents marked with two asterisks (**) require a login account for access on the web. For detailed instructions,
visit www.zmdi.com/login-account-setup-procedure.
Documents marked with three asterisks (***) are only available on request (see contact information on page Error! Bookmark not defined.).
Document
File Name
ZSSC3015 Feature Sheet
ZSSC3015_RBic_dLite-Auto_Feature_Sheet_Rev_X_xy.pdf
ZACwire™ SSC Evaluation Kit Documentation
ZACwire_SSC_Evaluation_Kit_Rev_X_xy.pdf
SSC Evaluation Kits Feature Sheet *
(includes ordering codes)
SSC_Evaluation_Kits_FeatureSheet_Rev_X_xy.pdf
ZSSC3015 Technical Note – ZMDI Wafer Dicing
Guidelines
ZMDI_Wafer_Dicing_Guidelines_Rev_X_xy.pdf
ZSC31010, ZSC31015, and ZSSC3015 Technical
Note – ZACWire™ SSC Calibration Sequence,
DLL and EXE**
ZACWire_SSC_Tech_Notes_Cal_DLL_EXE_Rev_X_xy.pdf
ZSSC3015 Technical Note – Die Dimensions and
Pad Coordinates ***
ZSSC3015_dLiteAuto_Tech_Notes_Die_Pads_Rev_X_xy.pdf
ZSSC3015 Response Time Spreadsheet ***
ZSSC3015_Response_Time.xlsx
Technical Note – ZACwire™ Communication ***
ZSC31010_15_ZSSC3015_RBic_Tech_Notes_ZACwire_Rev_X_xy.pdf
Visit the ZSSC3015 product page (www.zmdi.com/zssc3015) on ZMDI’s website www.zmdi.com or contact your
nearest sales office for the latest version of these documents.
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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.
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RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
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Definitions of Acronyms
Term
Description
ADC
Analog-to-Digital Converter
AFE
Analog Front-End
BUF
Buffer
CM
Command Mode
CMC
Calibration Microcontroller
DAC
Digital-to-Digital Converter
DNL
Differential Nonlinearity
DSP
Digital Signal Processor
DUT
Device Under Test
ESD
Electrostatic Discharge
FSO
Full-Scale Output
INL
Integrated Nonlinearity
LSB
Least Significant Bit
MUX
Multiplexer
NOM
Normal Operation Mode
OWI
One-Wire Interface
POR
Power-On Reset Level
PSRR
Power Supply Rejection Ratio
PTAT
Proportional To Absolute Temperature
RM
Raw Mode
SOT
Second Order Term
Data Sheet
December 26, 2014
© 2014 Zentrum Mikroelektronik Dresden AG — Rev. 1.12
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.
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ZSSC3015
RBicdLite-Auto™ Sensor Signal Conditioner with Diagnostics
14
Document Revision History
Revision
1.00
Date
Description
January 28, 2013
First release.
March 25, 2013
Edits for timing diagrams. Revision to block diagram.
Updates for part numbers, contact information, and imagery for cover and headers.
Minor edits.
1.10
May 6, 2013
Addition of specifications for EEPROM retention and cycles in section 1.3.
Update for cover image.
1.11
July 3, 2014
Update to section 1.2 regarding minimum bridge resistance values. Update to section
2.6.3 regarding minimum bridge resistance values.
Updates for order table, product references, “Related Documents” section, and ZMDI
contact information.
1.12
December 26, 2014
Correction for default definition for EEPROM bits 99:96 in Table 3.6.
Update for contact information.
1.01-1.02
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
December 26, 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
Unit B, 906-1
660, Daewangpangyo-ro
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. 1.12
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.
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