MAX1246/MAX1247 19-1071 Rev 2 10/01 +2.7V, Low-Power, 4-Channel, Serial 12-Bit ADCs in QSOP-16 General Description Features The MAX1246/MAX1247 12-bit data-acquisition systems 4-Channel Single-Ended or 2-Channel combine a 4-channel multiplexer, high-bandwidth Differential Inputs track/hold, and serial interface with high conversion Single-Supply Operation: speed and low power consumption. The MAX1246 oper- +2.7V to +3.6V (MAX1246) ates from a single +2.7V to +3.6V supply the MAX1247 operates from a single +2.7V to +5.25V supply. Both +2.7V to +5.25V (MAX1247) devices analog inputs are software configurable for Internal 2.5V Reference (MAX1246) unipolar/bipolar and single-ended/differential operation. Low Power: 1.2mA (133ksps, 3V supply) The 4-wire serial interface connects directly to SPI/ 54A (1ksps, 3V supply) QSPI and MICROWIRE devices without external 1A (power-down mode) logic. A serial strobe output allows direct connection to TMS320-family digital signal processors. The MAX1246/ SPI/QSPI/MICROWIRE/TMS320-Compatible MAX1247 use either the internal clock or an external seri- 4-Wire Serial Interface al-interface clock to perform successive-approximation Software-Configurable Unipolar or Bipolar Inputs analog-to-digital conversions. 16-Pin QSOP Package (same area as 8-pin SO) The MAX1246 has an internal 2.5V reference, while the MAX1247 requires an external reference. Both parts have a reference-buffer amplifier with a 1.5% voltage- adjustment range. These devices provide a hard-wired Ordering Information SHDN pin and a software-selectable power-down, and can be programmed to automatically shut down at the INL PART TEMP RANGE PIN-PACKAGE end of a conversion. Accessing the serial interface auto- (LSB) matically powers up the MAX1246/MAX1247, and the MAX1246ACPE 0C to +70C 16 Plastic DIP 1/2 quick turn-on time allows them to be shut down between MAX1246BCPE 0C to +70C 16 Plastic DIP 1 all conversions. This technique can cut supply current to under 60A at reduced sampling rates. The MAX1246/ MAX1246ACEE 0C to +70C 16 QSOP 1/2 MAX1247 are available in a 16-pin DIP and a small QSOP MAX1246BCEE 0C to +70C 16 QSOP 1 that occupies the same board area as an 8-pin SO. Ordering Information continued at end of data sheet. For 8-channel versions of these devices, see the MAX146/MAX147 data sheet. Applications Typical Operating Circuit Portable Data Logging Medical Instruments +3V Pen Digitizers V CH0 V DD DD 0.1 F Data Acquisition 0V TO DGND +2.5V Battery-Powered Instruments ANALOG MAX1246 INPUTS AGND Process Control CPU CH3 COM I/O VREF CS 4.7 F SCLK SCK (SK) DIN MOSI (SO) Pin Configuration appears at end of data sheet. DOUT MISO (SI) REFADJ 0.047 F SSTRB V SPI and QSPI are registered trademarks of Motorola, Inc. SS SHDN MICROWIRE is a registered trademark of National Semiconductor Corp. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLE+2.7V, Low-Power, 4-Channel, Serial 12-Bit ADCs in QSOP-16 ABSOLUTE MAXIMUM RATINGS V to AGND, DGND................................................. -0.3V to 6V QSOP (derate 8.36mW/C above +70C)................... 667mW DD AGND to DGND...................................................... -0.3V to 0.3V CERDIP (derate 10.00mW/C above +70C).............. 800mW CH0CH3, COM to AGND, DGND ............ -0.3V to (V + 0.3V) Operating Temperature Ranges DD VREF to AGND........................................... -0.3V to (V + 0.3V) MAX1246 C E/MAX1247 C E .......................... 0C to +70C DD Digital Inputs to DGND .............................................. -0.3V to 6V MAX1246 E E/MAX1247 E E........................ -40C to +85C Digital Outputs to DGND ........................... -0.3V to (V + 0.3V) MAX1246 MJE/MAX1247 MJE .................... -55C to +125C DD Digital Output Sink Current .................................................25mA Storage Temperature Range ............................ -60C to +150C Continuous Power Dissipation (T = +70C) Lead Temperature (soldering, 10s) ................................ +300C A Plastic DIP (derate 10.53mW/C above +70C) ......... 842mW 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 +3.6V (MAX1246) V = +2.7V to +5.25V (MAX1247) COM = 0V f = 2.0MHz external clock (50% duty cycle) DD DD SCLK 15 clocks/conversion cycle (133ksps) MAX12464.7F capacitor at VREF pin MAX1247external reference, VREF = 2.5V applied to VREF pin T = T to T unless otherwise noted.) A MIN MAX PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC ACCURACY (Note 1) Resolution 12 Bits MAX124 A 0.5 Relative Accuracy (Note 2) INL MAX124 B 1.0 LSB MAX1247C 2.0 No Missing Codes NMC 12 Bits MAX124 A/MAX124 B 1 Differential Nonlinearity DNL LSB MAX124 C 0.8 MAX124 A 0.5 3 Offset Error LSB MAX124 B 0.5 4 Gain Error (Note 3) 0.5 4 LSB Gain Temperature Coefficient 0.25 ppm/C Channel-to-Channel Offset 0.25 LSB Matching DYNAMIC SPECIFICATIONS (10kHz sine-wave input, 0V to 2.500Vp-p, 133ksps, 2.0MHz external clock, bipolar input mode) MAX124 A/MAX124 B 70 73 Signal-to-Noise + Distortion SINAD dB Ratio MAX1247C 73 MAX124 A/MAX124 B -88 -80 Up to the 5th Total Harmonic Distortion THD dB harmonic MAX1247C -88 MAX124 A/MAX124 B 80 90 Spurious-Free Dynamic Range SFDR dB MAX1247C 90 Channel-to-Channel Crosstalk 65kHz, 2.500V (Note 4) -85 dB P-P Small-Signal Bandwidth -3dB rolloff 2.25 MHz Full-Power Bandwidth 1.0 MHz 2 MAX1246/MAX1247