MLX90257 Relative Integrated Pressure Sensor Features and Benefits Relative Integrated Pressure sensor Less than ±1% error range overall Programmable through the connector (3 pins) Trimmable offset and sensitivity On-Chip Signal Conditioning Output proportional to the applied pressure Ratiometric output Rail-to-rail output Diagnostics of broken supply wires and broken sensor Output protected against short-circuits at both battery terminals Different pressure ranges available Application Examples Medical diagnostics Pumps Industrial applications Robotics Ordering Information Part No. MLX90257 MLX90257 Temperature Suffix L (-40°C to 150°C) L (-40°C to 150°C) Package Code UF (die on foil) UF (die on foil) Option -2 -4 Description 3 to 7 Bar Full Scale 15 to 30 Bar Full Scale 1. Functional Diagram 2. Description VDD Chopper demodulator Temperature sensor ADC Gain calibration DAC DIGITAL CORE Diagnostics OUT The MLX90257 is an integrated relative pressure sensor (2 pressure ports) realized in CMOS technology with micromachining options. It consists of an analog signal chain that interacts with the digital core and on-chip temperature sensor in order to provide uniform overall sensing characteristics after calibration and to cancel the temperature related parameter drifts. The output is proportional to the applied pressure with an adjustable slope and offset. It is ratiometric and goes rail-to-rail with a 3mA source and sink capability. Different pressure ranges are available (from 1.2 to 10 Bar full scale ranges, see above ordering information). 3901090257 Rev. 006 Page 1 of 9 Data Sheet Mar/08 MLX90257 Relative Integrated Pressure Sensor TABLE OF CONTENTS 1. FUNCTIONAL DIAGRAM...................................................................................................................... 1 2. DESCRIPTION....................................................................................................................................... 2 3. ABSOLUTE MAXIMUM RATINGS ....................................................................................................... 3 4. MLX90257 ELECTRICAL SPECIFICATIONS ...................................................................................... 3 5. GENERAL DESCRIPTION .................................................................................................................... 4 6. UNIQUE FEATURES ............................................................................................................................. 4 7. PERFORMANCE GRAPHS................................................................................................................... 5 8. APPLICATION INFORMATION ............................................................................................................ 6 9. DIE DIMENSION AND PAD COORDINATES....................................................................................... 7 10. CALIBRATION AND PROGRAMMING PROCEDURE ........................................................................ 7 11. ESD PRECAUTIONS............................................................................................................................. 8 12. DISCLAIMER ......................................................................................................................................... 9 3901090257 Rev. 006 Page 2 of 9 Data Sheet Mar/08 MLX90257 Relative Integrated Pressure Sensor 3. Absolute Maximum Ratings Parameter Min Max Supply Voltage, VDD -14V 16V Output Voltage, Vout -0.5V 16V Storage Temperature Range, TS -55°C 165°C ESD Sensitivity (AEC Q100 002) -2 kV 2 kV Exceeding the absolute maximum ratings may cause permanent damage. Exposure to absolutemaximum-rated conditions for extended periods may affect device reliability. 4. MLX90257 Electrical Specifications DC Operating Parameters TA = -40oC to 150oC, VDD = 5V (unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Units OPERATIONAL FEATURES Supply Voltage VDD Operating 4.5 5 5.5 V Supply Current IDD VDD = 5V ± 10%, excluding output current 4 6 10 mA Output Current Capability Iout VDD = 5V -3 3 mA Pressure output @ zero pressure Vout VDD = 5V 0.46 0.5 0.54 V Pressure output @ full scale pressure Vout VDD = 5V 4.46 4.5 4.54 V Low Clamping Level Vout 5 10 % VDD High Clamping Level Vout 90 95 % VDD 2 % VDD 5 % VDD DIAGNOSTIC FEATURES Output when sensor is broken Sensor broken Output when VDD is broken Pull-Up > 4.7K Output when VSS is broken Pull-Down > 10K Response Time (to reach 1% error) 3901090257 Rev. 006 95 % VDD 2 Page 3 of 9 ms Data Sheet Mar/08 MLX90257 Relative Integrated Pressure Sensor 5. General Description This chip integrates a pressure sensor and the associated signal conditioning on the same die. The supply voltage VDD directly supplies the pressure sensor. A chopped instrumentation stage amplifies the differential output signal of the sensor. The gain of this amplifier can be adjusted with 3 bits. The input stage is followed by a differential to single-ended conversion. The reference voltage for this stage is generated by a 10 bit DAC and varies linearly with temperature in order to perform the offset and offset drift compensation. A digital hardware multiplier calculates this compensation. The temperature signal, serving as input for this multiplier, is generated from the ADC of the output signal of the internal temperature sensor. The chopped signal is demodulated with a switched capacitor stage. The buffered output serves as reference for a 10 bit DAC to perform the span and span drift compensation. The DAC is controlled by the digital part. Finally the signal is given out by a class AB rail-to-rail amplifier capable of sourcing and sinking large currents. A 3-point temperature and 2-point pressure calibration is required (room temperature, a low temperature and a high temperature), to achieve an error less than ±1% over the complete pressure and temperature range (the output error is referred to the output span). PTC (Programming Through Connector) protocol is used to perform calibration. 6. Unique Features Diagnostic Limits Diagnostic of broken sensor: The output will be forced to ground (or a very low level) when the sensor membrane breaks. Diagnostic of broken wires: The output will be forced to ground (or a very low level) when the supply wire breaks, even when a pull-up is still connected to the output pin. The output will be forced to the supply voltage (or a very high level) when the ground wire breaks, even when a pull-down is still connected to the output pin. Output Protection The output is protected against short-circuits at either battery terminals. The output can handle voltages between -0.5V and 16V (independent of supply voltage). Memlock Function The memory consists of ZAP cells. When all calibration parameters are programmed, the chip can be locked. This to avoid unwanted data to be written into the memory cells. Once the chip is locked in a normal application, it is not possible to unlock. Clamping Levels The user can enable the clamping of the output to ensure that the output can not enter the fault band in normal application. 3901090257 Rev. 006 Page 4 of 9 Data Sheet Mar/08 MLX90257 Relative Integrated Pressure Sensor 7. Performance Graphs The graphs below show measured output voltages taken at 20 differential pressure points (0 mBar to 2000 mBar between pressure ports), at 21 ambient temperature points (-50 to 150 Celsius) and with Vdd set to 4.5 V, 5 V and 5.5 V. Vout versus Pressure with Ta = -50..150 C 100 90 80 70 Vout %Vdd 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 Pressure %FS (FS = 2000 mBar) Note : FS means Output Voltage Full Scale (4 V). Measured Error is below 1 % of FS for all ambient temperature and pressure points (see graphs below). Error versus Ambient Temperature with P = 0..2000 mBar 1.5 1 Error in % of FS 0.5 0 -0.5 -1 -1.5 -50 -30 -10 10 30 50 70 90 110 130 150 Ambient Temperature C 3901090257 Rev. 006 Page 5 of 9 Data Sheet Mar/08 MLX90257 Relative Integrated Pressure Sensor Error versus Pressure with Ta = - 50..150 C 1.5 1 Error in % of FS 0.5 0 -0.5 -1 -1.5 0 250 500 750 1000 1250 1500 1750 2000 1750 2000 Pressure mBar 4.5V and 5.5V Ratiometricity Error versus Pressure with Ta = - 50..150 C 0.5 0.4 0.3 Error in % of FS 0.2 0.1 0 -0.1 -0.2 -0.3 -0.4 -0.5 0 250 500 750 1000 1250 1500 Pressure mBar 8. Application Information Very few off-chip components are needed (only 2 decoupling capacitors). Only 3 pins are used (Vdd, Vss, Out), see pad layout drawing in paragraph 9. Calibration and Programming is made through Out pin. 3901090257 Rev. 006 Page 6 of 9 Data Sheet Mar/08 MLX90257 Relative Integrated Pressure Sensor 9. Die dimension and pad coordinates Available upon request. 10. Calibration and Programming Procedure Programming in Temporary Memory The programming is done through the connector: only the application pins (supply, ground and output) need to be used. The programming can be enabled by forcing the supply high enough (VCC_T). Through the OUT pin one can input the data. The data is Pulse Width Modulated. At the end of the programming, keep OUT high until VCC has reached its normal level (VCC_N). Thereafter disconnect OUT. The time in between should be less than 100us. Zapping of the Permanent Memory Only 1 bit can be zapped at a time. First program 1 bit to ‘1’. A higher supply (VCC_Z) is needed to be able to zap the bit. The zapping is done when OUT is high (OUT_Z). A high current will flow during the zapping. It is recommended to limit this current to 200mA. The memlock-bit should be zapped as last bit, as this disables programming function. 3901090257 Rev. 006 Page 7 of 9 Data Sheet Mar/08 MLX90257 Relative Integrated Pressure Sensor In order to check zapping, one can program Test Mode 22 = 10110b. Also 1 bit of the temporary memory should be ‘1’. If the zap cell – corresponding to the place of the ‘1’ in the temporary memory – is zapped, then the supply current will be at least 35mA. Otherwise the supply current will be approximately the same as in normal mode (maximum 10mA). Values in between indicate a bad zap. Parameters Parameter t0n t0p tpz tpn tz0 tr tf trz tfz th0 tl0 th1 tl1 tz tz0 td0 tdp tuz tun tdz VCC_N VCC_P VCC_Z OUT_L OUT_H OUT_Z Minimum 1us 2us 1us 1us 2us 0.5us 0.5us 0.5us 0.5us 50us 200us 200us 50us 5ms 100us 100us 100us 100us 5us 5us 4.5V 8V 14V 0V 4V 12V Maximum 100us 200us 100us 100us 300us 5us 5us 15us 20us 100us 300us 300us 100us 6ms 1ms 1ms 1ms 1ms 50us 50us 5.5V 12V 16V 1V 5V 14V Meaning Rise Time of Supply from 0V to VCC_N Rise Time of Supply from 0V to VCC_P Rise Time of Supply from VCC_P to VCC_Z Fall Time of Supply from VCC_P to VCC_N Fall Time of Supply from VCC_Z to 0V Rise Time of Out from OUT_L to OUT_H Fall Time of Out from OUT_H to OUT_L Rise Time of Out from OUT_H to OUT_Z Fall Time of Out from OUT_Z to OUT_L High Time for 0 Low Time for 0 High Time for 1 Low Time for 1 zap time OUT & VCC = Z & 0V OUT & VCC = OUT_L & 0V OUT & VCC = OUT_L & VCC_P OUT & VCC = OUT_H & VCC_Z OUT & VCC = OUT_H & VCC_N OUT & VCC = OUT_L & VCC_Z Normal Supply Programming Supply Zapping Supply Low Output High Output Output for zapping An application note describes in more details this calibration procedure. Calibration software is also available on request. 11. ESD Precautions Electronic semiconductor products are sensitive to Electro Static Discharge (ESD). Always observe Electro Static Discharge control procedures whenever handling semiconductor products. 3901090257 Rev. 006 Page 8 of 9 Data Sheet Mar/08 MLX90257 Relative Integrated Pressure Sensor 12. Disclaimer Devices sold by Melexis are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. Melexis makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. Melexis reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with Melexis for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by Melexis for each application. The information furnished by Melexis is believed to be correct and accurate. However, Melexis shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interrupt of business or indirect, special incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of Melexis’ rendering of technical or other services. © 2002 Melexis NV. All rights reserved. For the latest version of this document. Go to our website at www.melexis.com Or for additional information contact Melexis Direct: Europe and Japan: All other locations: Phone: +32 1367 0495 E-mail: [email protected] Phone: +1 603 223 2362 E-mail: [email protected] ISO/TS 16949 and ISO14001 Certified 3901090257 Rev. 006 Page 9 of 9 Data Sheet Mar/08