MAX1080/MAX1081 19-1685 Rev 0 5/00 300ksps/400ksps, Single-Supply, Low-Power, 8-Channel, Serial 10-Bit ADCs with Internal Reference General Description Features The MAX1080/MAX1081 10-bit analog-to-digital convert- 8-Channel Single-Ended or 4-Channel ers (ADCs) combine an 8-channel analog-input multiplex- Pseudo-Differential Inputs er, high-bandwidth track/hold (T/H), and serial interface Internal Multiplexer and Track/Hold with high conversion speed and low power consumption. The MAX1080 operates from a single +4.5V to +5.5V sup- Single-Supply Operation ply the MAX1081 operates from a single +2.7V to +3.6V +4.5V to +5.5V (MAX1080) supply. Both devices analog inputs are software config- urable for unipolar/bipolar and single-ended/pseudo-dif- +2.7V to +3.6V (MAX1081) ferential operation. Internal +2.5V Reference The 4-wire serial interface connects directly to 400ksps Sampling Rate (MAX1080) SPI/QSPI and MICROWIRE devices without external logic. A serial strobe output allows direct connection to Low Power: 2.5mA (400ksps) TMS320-family digital signal processors. The MAX1080/ 1.3mA (REDP) MAX1081 use an external serial-interface clock to perform successive-approximation analog-to-digital conversions. 0.9mA (FASTPD) The devices feature an internal +2.5V reference and a ref- 2A (FULLPD) erence-buffer amplifier with a 1.5% voltage-adjustment range. An external reference with a 1V to V range may SPI/QSPI/MICROWIRE/TMS320-Compatible 4-Wire DD1 also be used. Serial Interface The MAX1080/MAX1081 provide a hard-wired SHDN pin Software-Configurable Unipolar or Bipolar Inputs and four software-selectable power modes (normal opera- 20-Pin TSSOP Package tion, reduced power (REDP), fast power-down (FASTPD), and full power-down (FULLPD)). These devices can be programmed to automatically shut down at the end of a Ordering Information conversion or to operate with reduced power. When using TEMP. PIN- INL the power-down modes, accessing the serial interface PART RANGE PACKAGE (LSB) automatically powers up the devices, and the quick turn- on time allows them to be shut down between all conver- MAX1080ACUP 0C to +70C 20 TSSOP 1/2 sions. This technique can cut supply current below 100mA MAX1080BCUP 0C to +70C 20 TSSOP 1 at lower sampling rates. MAX1080AEUP -40C to +85C 20 TSSOP 1/2 The MAX1080/MAX1081 are available in a 20-pin TSSOP Ordering Information continued at end of data sheet. package. These devices are higher-speed versions of the MAX148/MAX149. For more information, refer to the Pin Configuration respective data sheet. TOP VIEW Applications 20 CH0 1 V DD1 Portable Data Logging 2 CH1 19 V DD2 Data Acquisition CH2 3 SCLK 18 Medical Instruments MAX1080 CH3 4 17 CS MAX1081 Battery-Powered Instruments CH4 5 16 DIN Pen Digitizers CH5 6 15 SSTRB Process Control CH6 7 14 DOUT CH7 8 13 GND REFADJ COM 9 12 Typical Operating Circuit appears at end of data sheet. SHDN 11 REF 10 SPI and QSPI are trademarks of Motorola, Inc. TSSOP MICROWIRE is a trademark of National Semiconductor Corp. Maxim Integrated Products 1 For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800. For small orders, phone 1-800-835-8769.300ksps/400ksps, Single-Supply, Low-Power, 8-Channel, Serial 10-Bit ADCs with Internal Reference ABSOLUTE MAXIMUM RATINGS V to GND .............................................................. -0.3V to 6V Continuous Power Dissipation (T = +70C) DD A V to V ......................................................... -0.3V to 0.3V 20-Pin TSSOP (derate 7.0mW/C above +70C) ........ 559mW DD1 DD2 CH0CH7, COM to GND.......................... -0.3V to (V + 0.3V) Operating Temperature Ranges DD1 REF, REFADJ to GND .............................. -0.3V to (V + 0.3V) MAX108 CUP ................................................. 0C to +70C DD1 Digital Inputs to GND................................................. -0.3V to 6V MAX108 EUP............................................... -40C to +85C Digital Outputs to GND ............................ -0.3V to (V + 0.3V) Storage Temperature Range ............................ -60C to +150C DD2 Digital Output Sink Current .................................................25mA Lead Temperature (soldering, 10s) ................................ +300C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICSMAX1080 (V = V = +4.5V to +5.5V, COM = GND, f = 6.4MHz, 50% duty cycle, 16 clocks/conversion cycle (400ksps), external DD1 DD2 SCLK +2.5V at REF, REFADJ = V , T = T to T , unless otherwise noted. Typical values are at T = +25C.) DD1 A MIN MAX A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC ACCURACY (Note 1) Resolution 10 Bits 0.5 MAX1080A Relative Accuracy (Note 2) INL LSB MAX1080B 1.0 Differential Nonlinearity DNL No missing codes over temperature 1.0 LSB Offset Error 3.0 LSB Gain Error (Note 3) 3.0 LSB Gain-Error Temperature 0.8 ppm/C Coefficient Channel-to-Channel Offset-Error 0.1 LSB Matching DYNAMIC SPECIFICATIONS (100kHz sine-wave input, 2.5Vp-p, 400ksps, 6.4MHz clock, bipolar input mode) Signal-to-Noise plus Distortion SINAD 60 dB Ratio Total Harmonic Distortion THD Up to the 5th harmonic -70 dB Spurious-Free Dynamic Range SFDR 70 dB Intermodulation Distortion IMD f = 99kHz, f =102kHz 76 dB IN1 IN2 Channel-to-Channel Crosstalk f = 200kHz, V = 2.5Vp-p -78 dB IN IN (Note 4) Full-Power Bandwidth -3dB point 6 MHz Full-Linear Bandwidth SINAD > 58dB 350 kHz CONVERSION RATE Conversion Time (Note 5) t 2.5 s CONV Track/Hold Acquisition Time t 468 ns ACQ Aperture Delay 10 ns Aperture Jitter <50 ps Serial Clock Frequency f 0.5 6.4 MHz SCLK Duty Cycle 40 60 % 2 MAX1080/MAX1081