Product Portfolio Brief SEMTECH WIRELESS & SENSING PRODUCTS Data Acquisition Solutions Low power, high precision World’s most flexible acquisition solutions Semtech’s over-sampled ADC technology allows users to achieve high performance functionality using low cost sensor and minimal power supply. Semtech offers a range of low-power mixed-signal ICs for Data Acquisition. The range includes The ZoomingADC™ high resolution ADC with serial interface and with MCU, as well as digital temperature sensors. Applications • Portable, battery operated instruments • RF powered instruments • Solar powered instruments • 4-20 mA loop powered sensors Semtech Data Acquisition Solutions are characterized by their miniaturization, flexibility and low-power operation. Key Features • ZoomingADC: - 16 bit ADC - Embedded programmable gain 1/12 to 1000 - Embedded sensor offset compensation - Low power, 200 uA for 16b at 1kHz • Wireless sensors • On chip CPU: • Pressure sensors - Wide voltage range, 2.4 – 5.5 V • Magnetic sensors - Low power, 300 uA/MIPS • Acceleration and tilt sensors • Humidity sensors • Temperature monitoring - Printers - Servers - Set Top Boxes • Digital temperature sensor: - Precision +/- 0.5°C typ - Low power, 250 uA at 10 Hz - Up to 4 temperature zones - Resistive error cancellation - Projectors W W W .SE MTE C H .C OM Data Acquisition Solutions SX8733, SX8743 and SX8744 SX8733 P1 1 AL1 AL2 6 P2 5 VDD 4 SMBCLK ALARM + + - D1+ 2 D1D2+ D2- SMBDAT VDD 1 P3 2 SX8743 MUX VSS 3 + ADC SMBUS 8 SMBCLK VDD 1 7 SMBDAT P1 2 SX8744 AL1 AL2 P1 4 +++- + ADC SMBUS SMBCLK 7 SMBDAT 6 P4 5 VSS AL1 AL2 6 P4 P2 3 5 VSS NC 4 ALARM D1+ D1- +- D2+ D2- + - General Description Applications The SX8733, SX8743 and SX8744 are digital temperature sensors with a 2-wire SMBus interface. It provides a lowcost solution to monitor the temperature of remote diodes as well as its own temperature with an on-chip PN junction sensor. • Printer Depending on the device version, 2, 3 or 4 programmable ports are included. They offer the possibility to trig under/over- temperature alarms which can be used as an interrupt or to connect up to 3 external sensors in singleended mode or 2 external sensors in differential mode. The parasitic resistances in series with the temperature monitoring diode can be cancelled by an algorithmic, a 3-point or a Kelvin (4-wire) method. MUX 3 D1+ D1D2+ D2D3+ D3- MUX P2 ALARM 8 + ADC SMBUS • Server • Set top box • Projector • Batteries charger monitoring Key Product Features • 1 internal and up to 3 external sensors • Remote diode temp. accuracy of ±0.5°C on the temp. range 25°C to 100°C The SX8744 is pin-to-pin compatible with the LM86 part. • 2 temp. output formats: 0°C to 127°C and -40°C to 140°C with 0.125°C resolution The SX8733 (2 programmable ports) is available in MLPD- 6 package. • Parasitic series resistance cancellation: Algorithmic, 3- point and Kelvin (4-wire) The SX8743 (4 programmable ports) and SX8744 (3 programmable ports) are available in MSOP-8 package. • Under-/over- temp. alarms with programmable thresholds programmable conversion rate for optimal power consumption Ordering Information Part Number Feature Package SX8733EWLTRT 2 Programmable ports MLPD-6 SX8743EMSTRT 4 Programmable ports MSOP-8 SX8744EMSTRT 3 Programmable ports MSOP-8 • 250 uA active current @ 10Hz sampling rate • SMBus v2.0 interface supports timeout • Pb-Free, halogen free, RoHS/WEEE compliant W W W. S E M T E C H .C O M -2- Data Acquisition Solutions Low-Power Precision Temperature Monitoring SX8733 / SX8743 / SX8744 include an on-chip PN junction to measure local temperature TJ. The device has a 2-level current source and an ADC to measure each diode’s forward voltage to compute the temperature. The input multiplexer allows 3 external and 1 internal sensors to be connected to the ADC. Two alarms can provide to the system the information that a sensor temperature has reached the programmable threshold. The chip is configured with a 2-wire SMBus serial line. A wide range of operating modes are proposed to measure from a single temperature zone up to 4 zones, and generate up to two alarms triggered by different temperature levels. Sensor can be connected in differential mode for best cancellation of noise or single ended to allow for more sensors. Algorithms are included to cancel the effect of lines resistivity. 0 1 2 3 4 5 6 7 8 9 External Sensor Mode 1 1 1 0 2 2 1 1 1 1 Differential x x x x Single-ended x Algorithmic track resistance cancellation x x 3-point track resistance cancellation x x x x 10 11 12 13 14 15 16 1 2 2 x x x x 2 2 3 17 3 18 19 20 3 x x x x x x x x x x x Kelvin (4-wire) track resistance cancellation Alarm # 1 x x x x 2 x 0 0 0 2 0 0 1 1 2 2 2 0 0 2 2 1 1 1 1 0 In a typical application, the SX8743 will monitor its own temperature and one sensor. When any of these is higher than a predefined threshold, it shall send an alarm to trigger its host CPU. One alarm could also be directly connected to a fan to cool down the system without waking the host. W W W. S E M T E C H .C O M -3- Data Acquisition Solutions Solutions using the ZoomingADCTM 1. Industrial Pressure Sensor Realizing an industrial pressure sensor with an XE8805A is quite straightforward. A bridge sensor element has its bias connected between one of the DAC buffers of the XE8805A, and the sensing pins are connected to one pair of input of the ZoomingADC. A temperature sensor is connected to a second input pair of the ZoomingADC, if temperature correction is required. The PGA (zoom of the ZoomingADC) converts the millivolt output of the bridge to a bigger signal than the ADC can convert with full resolution. 4-20 mA Sensing Block Diagram 5V ADC Resolution Speed MCU PGA M U X VE88LC05 Global function (ZoomingADC + MCU for correction computation) uses less than 1.5 milliampere, so there is still ample current to bias the sensor in a 4-20 mA loop. 2. Barometer The barometer is a pressure sensor and can use the same architecture as above (industrial pressure sensor). 4-20 mA Sensing Application ROM, Flash Then the signal can be provided to the output via the UART for digital sensor interfaces, or via the second DAC for analog output (like 4-20 mA loop). The barometer is a very low bandwidth sensor, so its mean current consumption can be significantly reduced by using the XE8801A, with its very flexible sleep modes. The XE8801A can maintain a precise real time clock with less than 2 microampere. By measuring the pressure every second, the mean current consumption of a barometer based on the XE8801A is lower than 3 microampere. For a barometer with an LCD display, one can develop with the XE8802, as it has a LCD driver. For small displays, the lowest cost solution is to use resistors to create a simple multiplexer around the digital port of the XE8801A. Signal-DAC Gain Offset Clocks UART PIO RAM XE8801A Circuit Diagram Bias-DAC Bridge Bias The MCU is available for further correction of the signal amplitude and offset. Its high efficiency makes it possible to have rapid computation while using very little current. The following polynomial can be computed with a 16 bits resolution in 150 microsecond with a total current in the MCU of 600 microampere. Out= (A0+A1•T) •Vin+B0+B1• T W W W. S E M T E C H .C O M -4- Data Acquisition Solutions Solutions using the ZoomingADCTM 3. Miniature Compass A compass is another sensor that can benefit from a ZoomingADC. The sensing element can be a “Hall”, “AMR” or a “GMR” sensor, depending on what principle is used for detection of the magnetic field. DAC Flash Memory UART DAC RISC CPU PWM MSGs1 Value Unit Sensor Sensitivity 3.2 mV/V/Oe Sensor offset 10 mV/V Full scale signal under earth magnetic field (30 µT) +/- 1 mV/V Rem: Oe stands for Oersted. 1 Oe is 1 Gauss in vacuum, 1 Gauss is 100 µT (microTesla). One of the main advantages of the ZoomingADC for this type of application is that one has enough analog differential inputs and digital outputs to change the direction of the sensor bias and get rid of its large offset. ZoomingADCTM Settings Value Unit Sensor Signal (Offset + Signal) 10 +/- 1 mV/V Signal out of Preamp. 1, gain 10 100 +/- 10 mV/V Signal out of Preamp. 2, gain 10, offset -1 0 +/- 100 mV/V Signal out of Preamp. 3, gain 5 0 +/- 500 mV/V ADC (Full scale is +/- Vref/2) +/- 32767 LSB Miniature solutions can be made, as no external components are needed to read the Hall sensor with an XE8801A or an XE8805A. 4. Air Quality Monitor Air quality monitoring can be done with one or a few chemical sensing elements (i.e. Microsens MSGS3001 device). These sensing elements must be precisely biased to have correct sensitivity and a long life. RS232 Xtal2 MSGs2 LCD ADC Temp ZoomingADC Parameter (Typical AMR Sensor) MAX232 Vref MTP Program RESET Power Supply The sensing elements function by rapidly heating a small silicon bridge on which a sensitive resistor is placed. Resistivity of this element changes with the concentration of the chemicals to be detected. By having good control of the applied voltage, one can also significantly lower the global energy required for reading the sensing elements. This ends with ultra low-power solutions, even if the heating of the sensing element requires several 10 milliwatts. The mean power requirement can be as low as a few 10 microwatts. 5. Wireless Sensing The low power and excellent computing capabilities of the XE8000 series make them perfectly suited for RF linked sensors. The XE8000 can directly interface with a transceiver (like the ultra low-power XE1200 series from Semtech) to send the acquired data over a RF signal to a main station. The low power-capabilities of the XE8000 allows it to run on batteries for years, even when working with an RF link. 6. Other Sensors Most current sensors generate a voltage or a current that is proportional to the signal to be measured. All these sensors can be read directly by the ZoomingADC with the help of an additional resistor to produce a signal-in current. W W W. S E M T E C H .C O M -5- Data Acquisition Solutions What is the ZoomingADCTM ZoomingADC™ technology was developed as a result of more than 10 years of knowledge of high-end mixed signal circuits for industrial applications. It includes all the functions necessary to read a piezo-resistive bridge. Excellent INL over temperature INL: Gain 1000 -40°C PGA1=10; PGA2=10; PGA3=10; set_osr=7; set_nelconv=3; Vbat=5V; Vref=5V; Vcommon=0V + + + + + + - - - - - - - Gain1 + Offset 2 Gain2 + - + - Signal ADC INL [LSB] ZoomingADC Architecture Offset3 Gain3 It compensates for a low sensitivity sensor with a high gain, and cancels the sensor’s offset through a controlled addition of the reference to the signal path. The ZoomingADC also includes the necessary output peripherals, such as UART and parallel I/O. Some products also include an LCD driver or buffered ADC. INL: Gain 1000 85°C PGA1=10; PGA2=10; PGA3=10; set_osr=7; set_nelconv=3; Vbat=5V; Vref=5V; Vcommon=0V INL [LSB] In addition to the advanced ADC, the circuit also has a complete microcontroller (MCU) for managing the ZoomingADC, and for processing the data. This controller can carry out a simple polynomial correcting in a few microseconds. Vin [mV] Features • 16 bits incremental programmable oversampled ADC • Up to 16 bits in 1 ms, 12 bits in 250 µs, or 8 bits in 75 µs Vin [mV] The ZoomingADC resolution can be programmed versus the acquisition time: Resolution vs Acquisition Time • Pre amplification gain up to 1000 in steps of 10% • Offset cancellation up to 15 FS in steps of 10% Resolution [bits] • Complete internal offset cancellation scheme Time [µs] W W W. S E M T E C H .C O M -6- Tools Selection Guide Evaluation Tools SX87xx Tools • Evaluation board with USB connection and experimentation wrap area • Simple GUI with full visibility on all registers USB SX87xx Products Product Package SX8723E083TDT MLPD-12 SX8724E082TDT MLPQ-16 SX8725E083TDT MLPD-12 SX8723CWLTDT MLPD-12 SX8724CWLTDT MLPQ-16 SX8725CWLTDT MLPD-12 SX8733EWL MLPD-6 SX8743EMS MSOP-8 SX8744EMS MSOP-8 Evaluation Kit XE8000EV121 based on SX8724E082TDT SX8000EV126 SX/XE88xx Tools RS-232 RIDE Base OR • Editor • Assembler • C Computer • Linker • Simulator (4k) • In-Socket - Debugger RIDE Enterprise • RIDE Base + • Unlimited simulator • Code Compressor • Multi-processor • Script Support Programmers BPmicro, Phyton XE8000MP Multi-purpose board PICE-XE Phyton, LC02 or 06 based, serves all Target Application XE8000EV1xx Chip specific evaluation board Short Tools Selection Guide Most XE88xx customers develop using the free version of Raisonance RIDE (downloaded from Raisonance website), XE8000MP and the corresponding XE8000EV1xx. XE88xx Products Product Package XE8801AMI027 LQFP44 XE8802MI035 LQFP100 XE8805AMI028 LQFP64 Provider: ProStart II Software MP Board RIDE XE8000MP Multi-purpose board Rais. * Emulator PICE Evaluation Board Semtech Main POD XE8000EV101 XE8000EV110 XE8000EV104 Adapter AR1-XE-02-Q44 MR1-XE-01 PR1-XE-020 AR1-XE-02-Q100 AR1-XE-02-Q64 Phyton, www.phyton.com Rais. *= Raisonance. www.raisonance.com W W W. S E M T E C H .C O M -7- Product Line Card ZoomingADC with serial interfaces Part Number Supply Voltage Supply Current Inputs Main Function Other Features Packages SX8723 2.4V to 5.5V 200 µA 2 differential inputs high resolution acquisition path ZoomingADC with 1 to 1000 gain 16 bit over-sampled ADC Embedded voltage reference, 2-wire i/f, 2 parallel I/Os MLPD12 4x4 mm2 SX8724 2.4V to 5.5V 200 µA 3 differential inputs high resolution acquisition path ZoomingADC with 1 to 1000 gain 16 bit over-sampled ADC Embedded voltage reference, 2-wire i/f, 4 parallel I/Os MLPQ16 4x4 mm2 SX8725 2.4V to 5.5V 200 µA 1 differential input high resolution acquisition path ZoomingADC with 1 to 1000 gain 16 bit over-sampled ADC Embedded voltage reference, 2-wire i/f, 2 parallel I/Os MLPD12 4x4 mm2 SX8723C 2.4V to 5.5V 200 µA 2 differential inputs high resolution acquisition path ZoomingADC with 1 to 1000 gain 16 bit over-sampled ADC Embedded voltage reference, I2C interface, 2 parallel I/Os MLPD12 4x4 mm2 SX8724C 2.4V to 5.5V 200 µA 3 differential inputs high resolution acquisition path ZoomingADC with 1 to 1000 gain 16 bit over-sampled ADC Embedded voltage reference, I2C interface, 4 parallel I/Os MLPQ16 4x4 mm2 SX8725C 2.4V to 5.5V 200 µA 1 differential input high resolution acquisition path ZoomingADC with 1 to 1000 gain 16 bit over-sampled ADC Embedded voltage reference, I2C interface, 2 parallel I/Os MLPD12 4x4 mm2 Digital temperature sensing SX8733 2.7 to 5.5 V 250 µA Internal sensor, up to 2 external sensors Precision temperature acquisition SMBus interface, resistive cancellation MLPD-6 3x3 mm2 SX8743 2.7 to 5.5 V 250 µA Internal sensor, up to 3 external sensors Precision temperature acquisition SMBus interface, resistive cancellation MSOP-8 3x3 mm2 SX8744 2.7 to 5.5 V 250 µA Internal sensor, up to 2 external sensors Precision temperature acquisition, LM86 pin compatible SMBus interface, resistive cancellation MSOP-8 3x3 mm2 ZoomingADC with high efficiency MCU and serial interfaces XE8801A SX8801R** 2.4V to 5.5V XE8802 2.4V to 5.5V XE8805A 2.4V to 5.5V 4 differential inputs high resolution acquisition path ZoomingADC with 1 to 1000 gain 16 bit over-sampled ADC MCU and RAM for local data processing UART, 24 parallel I/O programmable clock PWM DACs LQFP44 200 µA 4 differential inputs high resolution acquisition path ZoomingADC with 1 to 1000 gain 16 bit over-sampled ADC MCU and RAM for local data processing UART, up to 60 parallel I/O, PWM DACs programmable clock, 4 low-power comparators 120 segments LCD driver with voltage reference LQFP100 200 µA 4 differential inputs high resolution acquisition path ZoomingADC with 1 to 1000 gain 16 bit over-sampled ADC MCU and RAM for local data processing UART, 24 parallel I/O programmable clock 2 DACs with buffers LQFP64 200 µA ** SX8801R is a ROM (Ready only memory) version of the XE8801A Visit our website to locate the most current product specifications, datasheets and contact information for your local Semtech Field Applications Engineer. Semtech, the Semtech logo, Semtech International AG logo are registered marks of Semtech Corporation. ©2010, Semtech Corporation. All Rights Reserved. ZADC-PB-0111 WWW.S EMT ECH.COM