MAX1295/MAX1297 19-1530 Rev 3 12/02 265ksps, +3V, 6-/2-Channel, 12-Bit ADCs with +2.5V Reference and Parallel Interface General Description Features The MAX1295/MAX1297 low-power, 12-bit analog-to- 12-Bit Resolution, 0.5 LSB Linearity digital converters (ADCs) feature a successive-approxi- +3V Single-Supply Operation mation ADC, automatic power-down, fast wake-up Internal +2.5V Reference (2s), an on-chip clock, +2.5V internal reference, and a high-speed 12-bit parallel interface. They operate with Software-Configurable Analog Input Multiplexer a single +2.7V to +3.6V analog supply. 6-Channel Single-Ended/ Power consumption is only 5.4mW at the maximum 3-Channel Pseudo-Differential (MAX1295) sampling rate of 265ksps. Two software-selectable 2-Channel Single-Ended/ power-down modes enable the MAX1295/MAX1297 to 1-Channel Pseudo-Differential (MAX1297) be shut down between conversions accessing the par- Software-Configurable Unipolar/Bipolar allel interface returns them to normal operation. Powering down between conversions can reduce sup- Analog Inputs ply current below 10A at lower sampling rates. Low Current Both devices offer software-configurable analog inputs 1.9mA (265ksps) for unipolar/bipolar and single-ended/pseudo-differen- 1.0mA (100ksps) tial operation. In single-ended mode, the MAX1295 has 400A (10ksps) six input channels and the MAX1297 has two (three 2A (Shutdown) input channels and one input channel, respectively, Internal 3MHz Full-Power Bandwidth Track/Hold when in pseudo-differential mode). Parallel 12-Bit Interface Excellent dynamic performance and low power, combined with ease of use and small package size, make these con- Small Footprint verters ideal for battery-powered and data-acquisition 28-Pin QSOP (MAX1295) applications or for other circuits with demanding power- 24-Pin QSOP (MAX1297) consumption and space requirements. The MAX1295/MAX1297 tri-states INT when CS goes high. Pin Configurations Refer to MAX1265/MAX1267 if tri-stating INT is not desired. The MAX1295 is offered in a 28-pin QSOP package, while TOP VIEW the MAX1297 comes in a 24-pin QSOP. For pin-compati- D9 1 28 D10 ble +5V, 12-bit versions, refer to the MAX1294/MAX1296 D8 2 27 D11 data sheet. D7 3 26 V DD Applications D6 4 25 REF Industrial Control Systems Data Logging D5 5 24 REFADJ Energy Management Patient Monitoring MAX1295 D4 6 23 GND Data-Acquisition Systems Touchscreens D3 7 22 COM Ordering Information D2 8 21 CH0 D1 9 20 CH1 INL PART TEMP RANGE PIN-PACKAGE (LSB) D0 10 19 CH2 MAX1295ACEI 0C to +70C 28 QSOP 0.5 INT 11 18 CH3 MAX1295BCEI 0C to +70C 28 QSOP 1 RD 12 17 CH4 MAX1295AEEI -40C to +85C 28 QSOP 0.5 WR 13 16 CH5 MAX1295BEEI -40C to +85C 28 QSOP 1 CLK 14 15 CS MAX1297ACEG 0C to +70C 24 QSOP 0.5 QSOP MAX1297BCEG 0C to +70C 24 QSOP 1 Pin Configurations continued at end of data sheet. MAX1297AEEG -40C to +85C 24 QSOP 0.5 MAX1297BEEG -40C to +85C 24 QSOP 1 Typical Operating Circuits appear at end of data sheet. 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 AVAILABLE265ksps, +3V, 6-/2-Channel, 12-Bit ADCs with +2.5V Reference and Parallel Interface ABSOLUTE MAXIMUM RATINGS V to GND..............................................................-0.3V to +6V 28-Pin QSOP (derate 8.00mW/C above +70C)........667mW DD CH0CH5, COM to GND............................-0.3V to (V + 0.3V) Operating Temperature Ranges DD REF, REFADJ to GND.................................-0.3V to (V + 0.3V) MAX1295 C /MAX1297 C ........................0C to +70C DD Digital Inputs to GND ...............................................-0.3V to +6V MAX1295 E /MAX1297 E ......................-40C to +85C Digital Outputs (D0D11, INT) to GND.......-0.3V to (V + 0.3V) Storage Temperature Range .............................-65C to +150C DD Continuous Power Dissipation (T = +70C) Lead Temperature (soldering, 10s) .................................+300C A 24-Pin QSOP (derate 9.5mW/C above +70C)..........762mW 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, COM = GND, REFADJ = V , V = +2.5V, 4.7F capacitor at REF pin, f = 4.8MHz (50% duty cycle), DD DD REF CLK T = T to T , unless otherwise noted. Typical values are at T = +25C.) A MIN MAX A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC ACCURACY (Note 1) Resolution RES 12 Bits MAX129 A 0.5 Relative Accuracy (Note 2) INL LSB MAX129 B 1 Differential Nonlinearity DNL No missing codes over temperature 1 LSB Offset Error 4 LSB Gain Error (Note 3) 4 LSB Gain Temperature Coefficient 2.0 ppm/C Channel-to-Channel Offset 0.2 LSB Matching DYNAMIC SPECIFICATIONS (f = 50kHz, V = 2.5V , 265ksps, external f = 4.8MHz, bipolar input mode) IN(sine-wave) IN P-P CLK 67 70 Signal-to-Noise Plus Distortion SINAD dB Total Harmonic Distortion THD -78 dB (including 5th-order harmonic) Spurious-Free Dynamic Range SFDR 80 dB Intermodulation Distortion IMD f = 49kHz, f = 52kHz 76 dB IN1 IN2 Channel-to-Channel Crosstalk f = 125kHz (Note 4) -78 dB IN Full-Linear Bandwidth SINAD > 68dB 250 kHz Full-Power Bandwidth -3dB rolloff 3 MHz CONVERSION RATE External clock mode 3.3 Conversion Time (Note 5) t External acquisition/internal clock mode 2.5 3.0 3.5 s CONV Internal acquisition/internal clock mode 3.2 3.6 4.1 Track/Hold Acquisition Time t 625 ns ACQ Aperture Delay External acquisition or external clock mode 50 ns External acquisition or external clock mode <50 Aperture Jitter ps Internal acquisition/internal clock mode <200 External Clock Frequency f 0.1 4.8 MHz CLK Duty Cycle 30 70 % 2 MAX1295/MAX1297