SP8538 SIGNAL PROCESSING EXCELLENCE Micropower Sampling 12-Bit A/D Converter ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Low Cost 12-Bit Serial Sampling ADC Guaranteed +1.0 LSB Max INL Guaranteed No Missing Codes 8-Pin NSOIC Plastic Package Low Power @ 250µA including Automatic Shutdown: 1nA(typ) Programmable Input Configuration: Full differential or 2 channel single-ended Single Supply 3.0V to 5.5V operation Half Duplex Digital Serial Interface Sample Rate: 40µS Pin Compatible Upgrade to LTC 1298 DESCRIPTION The SP8538 is a very low power 12-Bit data acquisition chip. The SP8538 typically draws 250µA of supply current when sampling at 25 kHz. Supply current drops linearly as the sample rate is reduced. The ADC automatically powers down when not performing conversions, drawing only leakage current. The SP8538 is available in 8-Pin NSOIC packages, specified over Commercial and Industrial temperature ranges. The SP8538 is best suited for Battery-Operated Systems, Portable Data Acquisition Instrumentation, Battery Monitoring, and Remote Sensing applications. The serial port allows efficient data transfer to a wide range of microprocessors and microcontrollers over 3 or 4 wires. VCC GND REFL REFH Internal VCC 12 REFL REFH DAC Csample P CH0 COMPARATOR MUX SAR PARALLEL TO SERIAL SHIFT REGISTER Dout CH1 Csample N DIN CS INPUT DATA REG TIMING & CONTROL LOGIC CLK SP8538 Block Diagram SP8538DS/01 SP8538 Micropower Sampling 12-Bit A/D Converter 1 © Copyright 1999 Sipex Corporation ABSOLUTE MAXIMUM RATINGS These are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. (TA=+25˚C unless otherwise noted) ..................................................... VCC to GND ................................................................................. 7.0V Vin to GND .............................................................. -0.3 to VCC +0.3V Digital input to GND ................................................ -0.3 to VCC +0.3V Digital output to GND .............................................. -0.3 to VCC +0.3V Operating Temperature Range Commercial (J, K Version) ........................................... 0˚C to 70˚C Industrial (A, B Version) .......................................... -40˚C to +85˚C Lead Temperature (Solder 10Sec) ............................................ +300˚C Storage Temperature .................................................. -65˚C to +150˚C Power Dissipation to 70˚C ........................................................ 500mW SPECIFICATIONS Unless otherwise noted the following specifications apply for VCC=5V or 3.3V with limits applicable for Tmin to Tmax. Typical applies for Ta=25˚C. PARAMETERS DC ACCURACY Resolution Integral Linearity J,A K,B VCC=5.0V VCC=3.3V MIN. TYP. MAX. MIN. TYP. MAX. 12 12 UNITS Bits +0.6 +2.0 +0.6 +1.0 +0.6 +2.0 +0.6 +1.0 LSB LSB Differential Linearity Error J,A K,B +0.75 +2.0 +0.75 +1.0 +0.75 +2.0 +0.75 +1.0 LSB LSB Gain Error J,A K,B +2.0 +10 +2.0 +8 +2.0 +10 +2.0 +8 LSB LSB Offset Error J,A K,B +1.5 +1.5 +3.0 +3.0 LSB LSB ANALOG INPUT Input Signal FS Range Input Impedance On Channel Off Channel Input Bias Current Analog Input Range 0 +5 +3 VCC 0 CONDITIONS +8 +5 No Missing Codes VCC 20 100 3 100 .001 1 -.05 VCC+.05 -.05 20 100 3 100 .001 1 VCC+.05 pF MΩ pF MΩ µA Volts In Parallel with 100mΩ In Parallel with 100mΩ MULTIPLEXER Crosstalk (fD = Nyquist) Feedthrough (fD = Nyquist) -90 -90 -90 -90 dB dB Off to On Channel Off to On Channel fD= Disturbance CONVERSION SPEED Sample Time 1.5 1.5 See Timing Diagrams Conversion Time 12 12 clock cycles clock cycles kHz µS µS µS Complete Cycle Clock Period Clock High Time Clock Low Time SP8538DS/01 25 2.25 1.0 1.0 5.85 10.0 4.5 4.5 SP8538 Micropower Sampling 12-Bit A/D Converter 2 See Timing Diagrams See Timing Diagrams See Timing Diagrams See Timing Diagrams See Timing Diagrams © Copyright 1999 Sipex Corporation SPECIFICATIONS (cont.) Unless otherwise noted the following specifications apply for VCC=5V or 3.3V with limits applicable for Tmin to Tmax. Typical applies for Ta=25˚C. PARAMETERS DIGITAL INPUTS Input Low Voltage, VIL Input High Voltage, VIH Input Current IIN Input Capacitance DIGITAL OUTPUTS Data Format Data Coding VOH VOL VCC=5.0V VCC=3.3V MIN. TYP. MAX. MIN. TYP. MAX. UNITS 0.8 2.0 0.8 2.0 +2.0 +2.0 3.0 3.0 4.0 2.0 0.4 0.4 Volts Volts µA pF Volts Volts AC ACCURACY Spurious free Dynamic Range (SFDR) 86 86 dB Total Harmonic Distortion (THD) -83 -80 dB Signal to Noise & Distortion (SINAD) 73 72 dB 73.5 72.5 dB Signal to Noise (SNR) SAMPLING DYNAMICS Acquisition Time to 0.01% -3dB Small Signal BW Aperture Delay Aperture Jitter Common-Mode Rejection Ratio POWER SUPPLIES VCC Supply Current Operation Mode 2 70 3.38 5 20 150 80 70 4 30 150 80 See Timing Diagram VDD=5V +5%, IOH=-0.4mA VDD=5V +5%, IOH=+1.6mA For all FFT’s (Full Differential Mode) If VCC = 5V fsample = 25kHz fin = 12kHz If VCC = 3.3V fsample = 5.8kHz fin = 2.8kHz µs MHz nS pS dB fCM = 12.5kHz @ 5 volts 2.8kHz @ 3.3 volts Volts 250 400 0.001 0.5 Power Dissipation Operating Mode Shutdown Mode 1.25 SP8538DS/01 15.0 VDD=5V +5% VDD=5V +5% +3.0 +5.0 +5.5 +3.0 +3.3 +5.5 Shutdown Mode TEMPERATURE RANGE Commercial Industrial Storage 3 CONDITIONS 2 2.5 0˚ to +70˚C -40˚ to +85˚C -65˚ to +150˚C 300 µA (CS=0) 25kHz, 5 volt conversion rate. 5.8kHz 3.3 volts 0.001 0.5 µA (CS=1) 150 0.5 0.99 1.7 0˚ to +70˚C -40˚ to +85˚C -65˚ to +150˚C mW µW ˚C ˚C ˚C SP8538 Micropower Sampling 12-Bit A/D Converter 3 © Copyright 1999 Sipex Corporation SPECIFICATIONS (cont.) Recommended Operating Conditions SYMBOL VCC PARAMETERS Supply Voltage MIN. +3.0 fCLK Clock Frequency tCVC Total Cycle Time 40 thDI Hold Time DIN After CLK^ 50 tsuCS Setup Time CSv Before CLK^ 100 tsuDI Setup Time, DIN Stable Before CLK^ 100 tWHCLK CLK High Time TWHCLK CLK Low Time TWHCS CS High Time between Data Transfers Cycles VCC=5.0V TYP. MAX. +5.0 +5.5 100 50 kHz µS 170 0 UNITS Volts 0 nS 150 nS 150 nS 1 4.5 µS 1 4.5 µS 100 150 nS 10 PIN ASSIGNMENTS Pin 1- CS - Chip Select. CS 1 8 CH0 2 GND 4 VCC=3.3V TYP. MAX. +3.3 +5.5 444 PIN DESCRIPTION CH1 3 MIN. +3.0 SP8538 VCC/VREF Pin 2- CH0 - Channel 0 7 SCLK Pin 3- CH1 - Channel 1 6 DOUT Pin 4- GND - Ground 5 DIN Pin 5- DIN - Data In Pin 6 - DOUT - Data Out Pin 7- SCLK - Serial Clock Pin 8- VCC/VREF - Supply & Reference Voltage SP8538DS/01 SP8538 Micropower Sampling 12-Bit A/D Converter 4 © Copyright 1999 Sipex Corporation DESCRIPTION The device uses a capacitive DAC architecture which provides the sampling behavior. This results in full Nyquist performance at the fastest throughput rate (25 KHz) the device is capable of. The SP8538 is a 12 bit sampling ADC with a programmable two channel multiplexer and serial data interface. The ADC samples and converts 12 bits of data in 40 µS with a 5V supply voltage applied. The SP8538 will also operate at a 3.3V supply at 170µS throughput. The device automatically shuts down to a +0.5 µA (MAX) level as soon as the chip is deselected (CS=1). Serial data output is available in an MSB first or LSB first format. The power supply voltage is variable from 3.0V to 5.5V which provides supply flexibility. At the 5.0V supply level, conversion plus sampling time is 40µS and supply current is 250µA (1.25 mW). With a 3.3V supply the conversion plus sampling time is 170µS and current is reduced to 150µA (0.5 mW). FEATURES The device features automatic shutdown and will shutdown to a +0.5 µA power level as CS is brought high (de-selected). Power is proportional to conversion duty cycle and varies from 250 µA at 40µS (Duty cycle = 100%) to 6.25µa at 1.6 ms (Duty cycle = 2.5%). Two program bits, which are shifted into the device prior to conversion, determine the input configuration. In the single ended MUX configuration the input signal will be applied to either channel 0 or channel 1 and will be ground referenced. The maximum full scale range is VCC. In the full differential mode, the signal will be applied between channel 0 and channel 1. The signals applied at each input may both be dynamic. This is in contrast with pseudo differential devices which must have input low held at a constant level during conversion. The converter will provide significant common mode rejection when used in full differential manner. Both inputs must remain between ground and VCC for proper conversion. 0DRESSING Mux Addressing SGL/DIFF ODD/SIGN 0 0 0 1 1 0 1 1 Examples: Conversion rate 40 µS 80 µS 160 µS Channel # 0 1 VINH VINL VINH VINL VINH VINH GND ICC @ 5V 250 µA 125 µA 62.5 µA Duty Cycle 100% 50% 25% Comments Full Differential Mode VINL VINL Single Ended Mux Mode ADC TRANSFER FUNCTION INPUT VOLTAGE (VINH-VINL)* INPUT VOLTAGE AT VCC/VREF = 5V OUTPUT CODE 0 LSB 1 LSB 2048 LSB 4094 LSB 4095 LSB 0V 0.00122V 2.5000V 4.9976V 4.9988V 000000000000 000000000001 100000000000 111111111110 111111111111 * See Mux Addressing Table for a definition of VINH - VINL. SP8538DS/01 SP8538 Micropower Sampling 12-Bit A/D Converter 5 © Copyright 1999 Sipex Corporation 1.6 mS 6.25 µA 2.5% The device can be configured such that it delivers serial data MSB first requiring 17 clock periods for a full conversion. Alternately, the device can be programmed to deliver 12 bits of data MSB first, followed by the same 12 bits of data LSB first. This sequence will require 28 clock periods to complete. Please refer to the timing diagram. is tested in a similar manner until the SAR contains a code which represents the signal input to within +1/2 LSB. During this process the SAR content has been shifted out of the ADC serially. If the MSB first format was chosen, the data will appear at the DOUT pin MSB through LSB in 17 clock periods. If the LSB first format was chosen then during conversion the data will appear at the DOUT pin just as before (MSB through LSB) but the LSB will be followed by D1, D2 through the MSB. This sequence will require 28 clock periods. Note that the Chip Select Bar pin must be toggled high between conversions. The DOUT pin will be in a high impedance state whenever Chip Select Bar is high. After Chip Select Bar has been toggled and brought low again, the converter is ready to accept another START bit and begin a new conversion. Circuit Operation The device will ignore any leading zeros applied to the DIN pin even if CS is low. After Chip Select Bar (CS) is brought low and the START bit is clocked in to the converter, the conversion sequence is initiated. Three additional bits are clocked in immediately following the START bit: SGL/DIFF, ODD/ SIGN & MSBF. The second and third bits clocked in determine the MUX configuration (see MUX addressing table). The fourth bit determines the data output format (MSB first or LSB first). Please refer to the timing diagram. Full Differential Sampling The SP8538 can be configured for single-ended sampling (i.e. CH0-ground or CH1-ground) or full differential sampling (CH0-CH1 or CH1-CH0). In the full differential sampling configuration, both inputs are sampled and held simultaneously. Because of the balanced differential sampling, dynamic common mode noise riding along the input signal is cancelled above and beyond DC noise. This is a significant improvement over psuedo-differential sampling schemes, where the low side of the input must remain constant during the conversion, and therefore only DC noise (i.e. signal offset) is cancelled. If AC common mode noise is left to be converted along with the differental component, the output signal will be degraded. The SGL/DIFF bit when zero sets the input MUX for full differential mode and when one, sets the input MUX for single ended mode. The ODD/SIGN bit when zero sets channel zero as the positive input (ground referred for single ended operation and referred to channel one in differential mode). With the ODD/SIGN bit one, channel one will be the positive input (ground referred for single ended operation and referred to channel zero in differential mode). With MSBF set to one, the output data stream will be MSB through LSB, with MSBF set to zero the output data stream will be MSB through LSB followed by the same data in LSB through MSB format. Full differential sampling allows flexibility in converting the input signal. If the signal low- side is already tied to a ground elsewhere in the system, it can be hardwired to the low side channel (i.e. CH0 or CH1) which acts as a signal ground sense, breaking a potential ground loop. It is also possible to drive the inputs balanced differential, as long as both inputs are within the power rails. In this configuration, both the high and low signals have the same impedance looking back to ground, and therefore pick up the same noise along the physical path from signal source (i.e. sensor, transducer, battery) to converter. This noise becomes common mode, and is cancelled out The SP8538 is a SAR converter with full differential multiplexed front end, capacitive DAC, precision comparator, Successive Approximations Register, control logic and data output register. After the input is sampled and held the conversion process begins. The DAC MSB is set and its output is compared with the signal input, if the DAC output is less than the input, the comparator outputs a one which is latched into the SAR and simultaneously made available at the ADC serial output pin. Each bit SP8538DS/01 SP8538 Micropower Sampling 12-Bit A/D Converter 6 © Copyright 1999 Sipex Corporation by the differential sampling of the SP8538. Layout Considerations do so at right angles. Parallel analog and digital lines should be separated by a circuit board trace which is connected to common. To preserve the high resolution and linearity of the SP8538 attention must be given to circuit board layout, ground impedance and bypassing. The SP8538 VCC pin is also the reference pin for the device. This means that noise on the VCC pin will be proportionally represented as noise in the converters output data. A noise signal of 1.22mV (at a 5V supply) will produce 1 LSB of error in the output data. The VCC pin should be bypassed to the ground pin with a parallel combination of a 6.8µF tantalum and a 0.1µF ceramic capacitor. To maintain maximum system accuracy, the supply connected to the VCC pin should be well isolated from digital supplies and wide load variations. A separate conductor from the supply regulator to the A/D converter will limit the effects of digital switching elsewhere in the system. Power supply noise can degrade the converters performance. Especially corrupting are noise and spikes from a switching power supply. A circuit board layout which includes separate analog and digital ground planes will prevent the coupling of noise into sensitive converter circuits and will help to preserve the dynamic performance of the device. In single ended mode, the analog input signal should be referenced to the ground pin of the converter. This prevents any voltage drops that occur in the power supply's common return from appearing in series with the input signal. In full differential mode, the high and low side board traces should run close to each other, with the same layout. This will insure that any noise coupling will be common mode, and cancelled by the converters (patent pending) full differential architecture. To avoid introducing distortion when driving the A/D converter input, the input signal source should be able to charge the SP8538's equivalent 20 pF of input capacitance from zero volts to the signal level in 1.5 clock periods. If separate analog and digital ground planes are not possible, care should be used to prevent coupling between analog and digital signals. If analog and digital lines must cross, they should POWER UP SAMPLE X CS 1 CLK X POWER DOWN CONVERT 4 10 16 20 28 X X START O/S X DIN S/D LSBFN HI-Z “0” DOUT HI-Z D11 D1 D0 D1 D11 LSB FIRST CONVERSION POWER UP SAMPLE X CS 1 CLK X POWER DOWN CONVERT 4 10 16 17 X X START O/S X DIN DOUT S/D MSBF HI-Z “0” HI-Z D1 D0 D11 MSB FIRST CONVERSION SP8538 Timing Diagram SP8538DS/01 SP8538 Micropower Sampling 12-Bit A/D Converter 7 © Copyright 1999 Sipex Corporation Icc versus Sampling Rate (clock rate = 100kHz) Vcc = 3.3V Icc (µA) Icc (µA) Icc versus Sampling Rate (clock rate = 500kHz) Vcc = 5V conversion time (µs) conversion time (µs) Vcc = 3.30V Vcc = 5.00V 0 0 4095 FFT 20 dB/div Input CMRR, CMRR (dB) Spectral Density dB Vcc = 5V 0 Frequency 13.9Kz SNR = -73.31 dB THD = -78.53 dB SINAD = -72.17 dB SFDR = -80.15 dB Vin amp = -0.02 dB Input CMFrequency SP8538DS/01 4095 SP8538 Micropower Sampling 12-Bit A/D Converter 8 © Copyright 1999 Sipex Corporation Icc vs. Temperature µA LSB Gain Error vs. Temperature temperature (C) temperature (C) Offset vs. Temperature dB LSB Spurious Free Dynamic Range temperature (C) Frequency SINAD dB dB Signal to Noise Ratio Frequency Frequency dB Total Harmonic Distortion Frequency SP8538DS/01 SP8538 Micropower Sampling 12-Bit A/D Converter 9 © Copyright 1999 Sipex Corporation PACKAGE: PLASTIC DUAL–IN–LINE (NARROW) E1 E D1 = 0.005" min. (0.127 min.) A1 = 0.015" min. (0.381min.) D A = 0.210" max. (5.334 max). C A2 L B1 B e = 0.100 BSC (2.540 BSC) Ø eA = 0.300 BSC (7.620 BSC) ALTERNATE END PINS (BOTH ENDS) DIMENSIONS (Inches) Minimum/Maximum (mm) 8–PIN 14–PIN 16–PIN 18–PIN 20–PIN 22–PIN A2 0.115/0.195 (2.921/4.953) 0.115/0.195 (2.921/4.953) 0.115/0.195 (2.921/4.953) 0.115/0.195 (2.921/4.953) 0.115/0.195 (2.921/4.953) 0.115/0.195 (2.921/4.953) B 0.014/0.022 (0.356/0.559) 0.014/0.022 (0.356/0.559) 0.014/0.022 (0.356/0.559) 0.014/0.022 (0.356/0.559) 0.014/0.022 (0.356/0.559) 0.014/0.022 (0.356/0.559) B1 0.045/0.070 (1.143/1.778) 0.045/0.070 (1.143/1.778) 0.045/0.070 (1.143/1.778) 0.045/0.070 (1.143/1.778) 0.045/0.070 (1.143/1.778) 0.045/0.070 (1.143/1.778) C 0.008/0.014 (0.203/0.356) 0.008/0.014 (0.203/0.356) 0.008/0.014 (0.203/0.356) 0.008/0.014 (0.203/0.356) 0.008/0.014 (0.203/0.356) 0.008/0.014 (0.203/0.356) D 0.355/0.400 0.735/0.775 0.780/0.800 0.880/0.920 0.980/1.060 1.145/1.155 (9.017/10.160) (18.669/19.685) (19.812/20.320) (22.352/23.368) (24.892/26.924) (29.083/29.337) E 0.300/0.325 (7.620/8.255) 0.300/0.325 (7.620/8.255) 0.300/0.325 (7.620/8.255) 0.300/0.325 (7.620/8.255) 0.300/0.325 (7.620/8.255) 0.300/0.325 (7.620/8.255) E1 0.240/0.280 (6.096/7.112) 0.240/0.280 (6.096/7.112) 0.240/0.280 (6.096/7.112) 0.240/0.280 (6.096/7.112) 0.240/0.280 (6.096/7.112) 0.240/0.280 (6.096/7.112) L 0.115/0.150 (2.921/3.810) 0.115/0.150 (2.921/3.810) 0.115/0.150 (2.921/3.810) 0.115/0.150 (2.921/3.810) 0.115/0.150 (2.921/3.810) 0.115/0.150 (2.921/3.810) Ø 0°/ 15° (0°/15°) 0°/ 15° (0°/15°) 0°/ 15° (0°/15°) 0°/ 15° (0°/15°) 0°/ 15° (0°/15°) 0°/ 15° (0°/15°) SP8538DS/01 SP8538 Micropower Sampling 12-Bit A/D Converter 10 © Copyright 1999 Sipex Corporation PACKAGE: PLASTIC SMALL OUTLINE (SOIC) (NARROW) E H h x 45° D A Ø e B A1 L DIMENSIONS (Inches) Minimum/Maximum (mm) SP8538DS/01 8–PIN 14–PIN 16–PIN A 0.053/0.069 (1.346/1.748) 0.053/0.069 (1.346/1.748) 0.053/0.069 (1.346/1.748) A1 0.004/0.010 (0.102/0.249 0.004/0.010 (0.102/0.249) 0.004/0.010 (0.102/0.249) B 0.014/0.019 (0.35/0.49) 0.013/0.020 (0.330/0.508) 0.013/0.020 (0.330/0.508) D 0.189/0.197 (4.80/5.00) 0.337/0.344 0.386/0.394 (8.552/8.748) (9.802/10.000) E 0.150/0.157 (3.802/3.988) 0.150/0.157 (3.802/3.988) 0.150/0.157 (3.802/3.988) e 0.050 BSC (1.270 BSC) 0.050 BSC (1.270 BSC) 0.050 BSC (1.270 BSC) H 0.228/0.244 (5.801/6.198) 0.228/0.244 (5.801/6.198) 0.228/0.244 (5.801/6.198) h 0.010/0.020 (0.254/0.498) 0.010/0.020 (0.254/0.498) 0.010/0.020 (0.254/0.498) L 0.016/0.050 (0.406/1.270) 0.016/0.050 (0.406/1.270) 0.016/0.050 (0.406/1.270) Ø 0°/8° (0°/8°) 0°/8° (0°/8°) 0°/8° (0°/8°) SP8538 Micropower Sampling 12-Bit A/D Converter 11 © Copyright 1999 Sipex Corporation ORDERING INFORMATION Model ........................................................ Linearity (LSB) ..................... Temperature Range ............................................................... Package SP8538BN .......................................................... ±1.0 .................................... –40˚C to +85˚C .............................................. 8-pin, 0.3" Plastic DIP SP8538KN .......................................................... ±1.0 ..................................... –0˚C to +70˚C ............................................... 8-pin, 0.3" Plastic DIP SP8538BS .......................................................... ±1.0 .................................... –40˚C to +85˚C ......................................... 8-pin, 0.15" Plastic SOIC SP8538KS .......................................................... ±1.0 ..................................... –0˚C to +70˚C .......................................... 8-pin, 0.15" Plastic SOIC SP8538AN .......................................................... ±2.0 .................................... –40˚C to +85˚C .............................................. 8-pin, 0.3" Plastic DIP SP8538JN ........................................................... ±2.0 ..................................... –0˚C to +70˚C ............................................... 8-pin, 0.3" Plastic DIP SP8538AS .......................................................... ±2.0 .................................... –40˚C to +85˚C ......................................... 8-pin, 0.15" Plastic SOIC SP8538JS ........................................................... ±2.0 ..................................... –0˚C to +70˚C .......................................... 8-pin, 0.15" Plastic SOIC Please consult the factory for pricing and availability on a Tape-On-Reel option. Corporation SIGNAL PROCESSING EXCELLENCE Sipex Corporation European Sales Offices: Far East: Headquarters and Sales Office 22 Linnell Circle Billerica, MA 01821 TEL: (978) 667-8700 FAX: (978) 670-9001 e-mail: [email protected] ENGLAND: Sipex Corporation 2 Linden House Turk Street Alton Hampshire GU34 IAN England TEL: 44-1420-549527 FAX: 44-1420-542700 e-mail: [email protected] JAPAN: Nippon Sipex Corporation Yahagi No. 2 Building 3-5-3 Uchikanda, Chiyoda-ku Tokyo 101 TEL: 81.3.3256.0577 FAX: 81.3.3256.0621 Sales Office 233 South Hillview Drive Milpitas, CA 95035 TEL: (978) 934-7500 FAX: (978) 935-7600 GERMANY: Sipex GmbH Gautinger Strasse 10 82319 Starnberg TEL: 49.81.51.89810 FAX: 49.81.51.29598 e-mail: [email protected] Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others. SP8538DS/01 SP8538 Micropower Sampling 12-Bit A/D Converter 12 © Copyright 1999 Sipex Corporation