MAX148/MAX149 19-0464 Rev 5 1/12 +2.7V to +5.25V, Low-Power, 8-Channel, Serial 10-Bit ADCs General Description Features The MAX148/MAX149 10-bit data-acquisition systems S 8-Channel Single-Ended or 4-Channel Differential combine an 8-channel multiplexer, high-bandwidth Inputs track/hold, and serial interface with high conversion S Single-Supply Operation: +2.7V to +5.25V speed and low power consumption. They operate from a S Internal 2.5V Reference (MAX149) single +2.7V to +5.25V supply, and sample to 133ksps. S Low Power: 1.2mA (133ksps, 3V Supply) Both devices analog inputs are software configurable for unipolar/bipolar and single-ended/differential operation. 54A (1ksps, 3V Supply) The 4-wire serial interface connects directly to SPI/ 1A (Power-Down Mode) QSPIK and MICROWIREK devices without external S SPI/QSPI/MICROWIRE/TMS320-Compatible 4-Wire logic. A serial-strobe output allows direct connection to Serial Interface TMS320-family digital signal processors. The MAX148/ S Software-Configurable Unipolar or Bipolar Inputs MAX149 use either the internal clock or an external seri- al-interface clock to perform successive-approximation S 20-Pin DIP/SSOP Packages analog-to-digital conversions. The MAX149 has an internal 2.5V reference, while the Ordering Information MAX148 requires an external reference. Both parts have a reference-buffer amplifier with a Q1.5% voltage- PIN- INL PART TEMP RANGE adjustment range. PACKAGE (LSB) MAX148ACPP+ 0C to +70C 20 PDIP 1/2 These devices provide a hard-wired SHDN pin and a software-selectable power-down, and can be pro- MAX148BCPP+ 0C to +70C 20 PDIP 1 grammed to automatically shut down at the end of a MAX148ACAP+ 0C to +70C 20 SSOP 1/2 conversion. Accessing the serial interface automatically MAX148BCAP+ 0C to +70C 20 SSOP 1 powers up the MAX148/MAX149, and the quick turn-on Ordering Information continued at end of data sheet. time allows them to be shut down between all conver- Contact factory for availability of alternate surface-mount sions. This technique can cut supply current to under package. 60FA at reduced sampling rates. +Denotes a lead(Pb)-free/RoHS-compliant package. The MAX148/MAX149 are available in 20-pin PDIP and 20-pin SSOP packages. For 4-channel versions of these devices, see the MAX1248/MAX1249 data sheet. Typical Operating Circuit +3V Applications V DD CH0 V DD Portable Data Logging 0.1FF O TO DGND +2.5V Data Acquisition ANALOG INPUTS MAX149 Medical Instruments AGND CH7 Battery-Powered Instruments CPU COM V REF Pen Digitizers 4.7FF CS I/O Process Control SCLK SCK (SK) DIN MOSI (SO) READJ DOUT MISO (SI) 0.01FF SSTRB Pin Configuration appears at end of data sheet. V SS SHDN QSPI is a trademark of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp. 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.+2.7V to +5.25V, Low-Power, 8-Channel, Serial 10-Bit ADCs ABSOLUTE MAXIMUM RATINGS V to AGND, DGND ..............................................-0.3V to +6V Operating Temperature Ranges DD AGND to DGND ...................................................-0.3V to +0.3V MAX148 C P/MAX149 C P .............................. 0NC to +70NC CH0CH7, COM to AGND, DGND ........... -0.3V to (V + 0.3V) MAX148 E P/MAX149 E P ............................ -40NC to +85NC DD MAX149BMAP ............................................... -55NC to +125NC V , REFADJ to AGND ...........................-0.3V to (V + 0.3V) REF DD Storage Temperature Range ............................ -60NC to +150NC Digital Inputs to DGND ...........................................-0.3V to +6V Lead Temperature (soldering, 10s) ................................+300NC Digital Outputs to DGND .......................... -0.3V to (V + 0.3V) DD Soldering Temperature (reflow) ......................................+260NC Digital Output Sink Current ................................................25mA Continuous Power Dissipation (T = +70NC) A PDIP (derate 11.11mW/NC above +70NC) ...................889mW SSOP (derate 8.00mW/NC above +70NC) ....................640mW 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 CHARACTERISTICS (V = +2.7V to +5.25V COM = 0 f = 2.0MHz external clock (50% duty cycle) 15 clocks/conversion cycle (133ksps) DD SCLK MAX1494.7FF capacitor at V pin MAX148external reference, V = 2.500V applied to V pin T = T to T , unless REF REF REF A MIN MAX otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC ACCURACY (Note 1) Resolution 10 Bits MAX14 A 0.5 Relative Accuracy (Note 2) INL LSB MAX14 B 1.0 Differential Nonlinearity DNL No missing codes over temperature 1 LSB MAX14 A 0.15 1 Offset Error LSB MAX14 B 0.15 2 MAX14 A 1 Gain Error (Note 3) LSB MAX14 B 2 Gain Temperature Coefficient 0.25 ppm/C Channel-to-Channel Offset 0.05 LSB Matching DYNAMIC SPECIFICATIONS (10kHz Sine-Wave Input, 0 to 2.500V , 133ksps, 2.0MHz External Clock, Bipolar Input Mode) P-P Signal-to-Noise + Distortion SINAD 66 dB Noise Total Harmonic Distortion THD Up to the 5th harmonic -70 dB Spurious-Free Dynamic Range SFDR 70 dB Channel-to-Channel Crosstalk 65kHz, 2.500V (Note 4) -75 dB P-P Small-Signal Bandwidth -3dB rolloff 2.25 MHz Full-Power Bandwidth 1.0 MHz CONVERSION RATE Internal clock, SHDN = unconnected 5.5 7.5 Internal clock, SHDN = V 35 65 DD Conversion Time (Note 5) t s CONV External clock = 2MHz, 12 clocks/ 6 conversion Track/Hold Acquisition Time t 1.5 s ACQ Aperture Delay 30 ns Aperture Jitter < 50 ps 2 MAX148/MAX149