MAX1245ACPP+

19-1066; Rev 1; 11/09 +2.375V, Low-Power, 8-Channel, Serial 12-Bit ADC ____________________________Features The MAX1245 12-bit data-acquisition system combines an 8-channel multiplexer, high-bandwidth track/hold, and serial interface with high conversion speed and ultra-low power consumption. It operates from a single +2.375V to +3.3V supply, and its analog inputs are software configurable for unipolar/bipolar and single-ended/differential operation. o Single +2.375V to +3.3V Operation o 8-Channel Single-Ended or 4-Channel Differential Analog Inputs o Low Power: 0.8mA (100ksps) 10µA (1ksps) 1µA (power-down mode) o Internal Track/Hold, 100kHz Sampling Rate o SPI/QSPI/MICROWIRE/TMS320-Compatible 4-Wire Serial Interface o Software-Configurable Unipolar or Bipolar Inputs o 20-Pin DIP/SSOP Packages The 4-wire serial interface directly connects to SPI™, QSPI™, and MICROWIRE™ devices without external logic. A serial strobe output allows direct connection to TMS320-family digital signal processors. The MAX1245 works with an external reference, and uses either the internal clock or an external serial-interface clock to perform successive-approximation analog-to-digital conversions. This device provides a hard-wired SHDN pin and a software-selectable power-down, and can be programmed to automatically shut down at the end of a conversion. Accessing the serial interface powers up the MAX1245, and the quick turn-on time allows it to be shut down between conversions. This technique can cut supply current to under 10µA at reduced sampling rates. The MAX1245 is available in a 20-pin DIP package and an SSOP that occupies 30% less area than an 8-pin DIP. For supply voltages from +2.7V to +5.25V, use the pincompatible MAX147. ________________________Applications Portable Data Logging Medical Instruments Battery-Powered Instruments Data Acquisition ___________Typical Operating Circuit +2.5V 0V to +2.048V ANALOG INPUTS VDD VDD CH0 0.1µF CPU MAX1245 +2.048V 0.1µF VREF CS SCLK DIN DOUT SSTRB SHDN PART* TEMP RANGE I/O SCK (SK) MOSI (SO) MISO (SI) PIN-PACKAGE INL (LSB) ±1/2 MAX1245ACPP 0°C to +70°C 20 Plastic DIP MAX1245BCPP 0°C to +70°C 20 Plastic DIP MAX1245ACAP 0°C to +70°C 20 SSOP 20 SSOP ±1 ±1/2 ±1 MAX1245BCAP 0°C to +70°C MAX1245AEPP -40°C to +85°C 20 Plastic DIP ±1/2 MAX1245BEPP -40°C to +85°C 20 Plastic DIP ±1 MAX1245AEAP -40°C to +85°C 20 SSOP ±1/2 MAX1245BEAP -40°C to +85°C 20 SSOP ±1 *Contact factory for availability of alternate surface-mount packages. ___________________Pin Configuration TOP VIEW CH0 1 20 VDD CH1 2 19 SCLK CH2 3 18 CS CH3 4 DGND AGND COM CH7 ________________Ordering Information MAX1245 17 DIN CH4 5 16 SSTRB CH5 6 15 DOUT CH6 7 14 DGND CH7 8 13 AGND COM 9 12 VDD SHDN 10 11 VREF VSS DIP/SSOP SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX1245 ________________General Description MAX1245 +2.375V, Low-Power, 8-Channel, Serial 12-Bit ADC ABSOLUTE MAXIMUM RATINGS SSOP (derate 8.00mW/°C above +70°C) ................... 640mW CERDIP (derate 11.11mW/°C above +70°C) .............. 889mW Operating Temperature Ranges MAX1245_C_P ................................................... 0°C to +70°C MAX1245_E_P ................................................ -40°C to +85°C Storage Temperature Range ............................ -60°C to +150°C Lead Temperature (soldering, 10sec) ............................ +300°C VDD to AGND, DGND .............................................. -0.3V to +6V AGND to DGND.................................................... -0.3V to +0.3V CH0–CH7, COM to AGND, DGND ............ -0.3V to (VDD + 0.3V) VREF to AGND........................................... -0.3V to (VDD + 0.3V) Digital Inputs to DGND............................................ -0.3V to +6V Digital Outputs to DGND ........................... -0.3V to (VDD + 0.3V) Digital Output Sink Current .................................................25mA Continuous Power Dissipation (TA = +70°C) Plastic DIP (derate 11.11mW/°C above +70°C) ......... 889mW 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 (VDD = +2.375V to +3.3V, VCOM = 0V, fCLK = 1.5MHz, external clock (50% duty cycle), 15 clocks/conversion cycle (100ksps), VREF = 2.048V applied to VREF pin, TA = TMIN to TMAX, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS DC ACCURACY (Note 1) Resolution MIN TYP MAX 12 Relative Accuracy (Note 2) INL Differential Nonlinearity DNL UNITS Bits MAX1245A ±0.5 MAX1245B ±1.0 No missing codes over temperature LSB ±1 LSB Offset Error ±0.5 ±4 LSB Gain Error (Note 3) ±0.5 ±4 LSB Gain Temperature Coefficient ±0.25 ppm/°C Channel-to-Channel Offset Matching ±0.2 LSB DYNAMIC SPECIFICATIONS (10kHz sine-wave input, 0Vp-p to 2.048Vp-p, 100ksps, 1.5MHz external clock, bipolar input mode) Signal-to-Noise + Distortion Ratio SINAD 68 dB Total Harmonic Distortion THD Spurious-Free Dynamic Range SFDR Up to the 5th harmonic -76 76 dB dB Channel-to-Channel Crosstalk 50kHz, 2Vp-p (Note 4) -85 dB Small-Signal Bandwidth -3dB rolloff 2.25 MHz 1.0 MHz Full-Power Bandwidth CONVERSION RATE Conversion Time (Note 5) Track/Hold Acquisition Time tCONV tACQ Internal clock, SHDN = open 5.5 7.5 Internal clock, SHDN = VDD 35 65 µs External clock = 1.5MHz, 12 clocks/conversion 8 2.0 µs External clock = 1.5MHz Aperture Delay 40 ns Aperture Jitter