MAX1280BEUP

19-1684; Rev 0; 5/00 400ksps/300ksps, Single-Supply, Low-Power, 8-Channel, Serial 12-Bit ADCs with Internal Reference General Description The MAX1280/MAX1281 12-bit ADCs combine an 8-channel analog-input multiplexer, high-bandwidth track/hold, and serial interface with high conversion speed and low power consumption. The MAX1280 operates from a single +4.5V to +5.5V supply; the MAX1281 operates from a single +2.7V to +3.6V supply. Both devices’ analog inputs are software configurable for unipolar/bipolar and singleended/pseudo-differential operation. The 4-wire serial interface connects directly to SPI™/QSPI™/MICROWIRE™ devices without external logic. A serial strobe output allows direct connection to TMS320-family digital signal processors. The MAX1280/ MAX1281 use an external serial-interface clock to perform successive-approximation analog-to-digital conversions. Both parts feature an internal +2.5V reference and a reference-buffer amplifier with a ±1.5% voltageadjustment range. An external reference with a 1V to VDD1 range may also be used. The MAX1280/MAX1281 provide a hard-wired SHDN pin and four software-selectable power modes (normal operation, reduced power, fast power-down, and full power-down). These devices can be programmed to automatically shut down at the end of a conversion or to operate with reduced power. When using the powerdown modes, accessing the serial interface automatically powers up the devices, and the quick turn-on time allows them to be powered down between all conversions. This technique can cut supply current to under 100µA at reduced sampling rates. The MAX1280/MAX1281 are available in 20-pin TSSOP packages. These devices are higher-speed versions of the MAX146/MAX147 (for more information, see the respective data sheet). Features o 8-Channel Single-Ended or 4-Channel Pseudo-Differential Inputs o Internal Multiplexer and Track/Hold o Single-Supply Operation +4.5V to +5.5V (MAX1280) +2.7V to +3.6V (MAX1281) o Internal +2.5V Reference o 400ksps Sampling Rate (MAX1280) o Low Power 2.5mA (400ksps) 1.3mA (Reduced-Power Mode) 0.9mA (Fast Power-Down Mode) 2µA (Full Power-Down) o SPI/QSPI/MICROWIRE/TMS320-Compatible 4-Wire Serial Interface o Software-Configurable Unipolar or Bipolar Inputs o 20-Pin TSSOP Package MAX1280/MAX1281 Ordering Information PART MAX1280BCUP MAX1280BEUP TEMP. RANGE 0°C to +70°C -40°C to +85°C PINPACKAGE 20 TSSOP 20 TSSOP INL (LSB) ±1 ±1 Ordering Information continued at end of data sheet. Pin Configuration TOP VIEW CH0 1 CH1 2 CH2 3 CH3 4 CH4 5 CH5 6 CH6 7 CH7 8 COM 9 20 VDD1 19 VDD2 18 SCLK Applications Portable Data Logging Data Acquisition Medical Instruments Battery-Powered Instruments Pen Digitizers Process Control MAX1280 MAX1281 17 CS 16 DIN 15 SSTRB 14 DOUT 13 GND 12 REFADJ 11 REF SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp. SHDN 10 TSSOP ________________________________________________________________ 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. 400ksps/300ksps, Single-Supply, Low-Power, 8-Channel, Serial 12-Bit ADCs with Internal Reference MAX1280/MAX1281 ABSOLUTE MAXIMUM RATINGS VDD_ to GND ............................................................ -0.3V to +6V VDD1 to VDD2 ........................................................ -0.3V to +0.3V CH0–CH7, COM to GND.......................... -0.3V to (VDD1 + 0.3V) REF, REFADJ to GND .............................. -0.3V to (VDD1 + 0.3V) Digital Inputs to GND .............................................. -0.3V to +6V Digital Outputs to GND ............................ -0.3V to (VDD2 + 0.3V) Digital Output Sink Current .................................................25mA Continuous Power Dissipation (TA = +70°C) 20-Pin TSSOP (derate 7.0mW/°C above +70°C) .........559mW Operating Temperature Ranges MAX128_BCUP .................................................. 0°C to +70°C MAX128_BEUP ............................................... -40°C to +85°C Storage Temperature Range ............................ -60°C to +150°C Lead Temperature (soldering, 10s) ................................ +300°C 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—MAX1280 (VDD1 = VDD2 = +4.5V to +5.5V, COM = GND, fSCLK = 6.4MHz, 50% duty cycle, 16 clocks/conversion cycle (400ksps), external +2.5V at REF, REFADJ = VDD1, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER DC ACCURACY (Note 1) Resolution Relative Accuracy (Note 2) Differential Nonlinearity Offset Error Gain Error (Note 3) Gain-Error Temperature Coefficient Channel-to-Channel Offset-Error Matching ±0.8 ±0.1 INL DNL No missing codes over temperature 12 ±1.0 ±1.0 ±6.0 ±6.0 Bits LSB LSB LSB LSB ppm/°C LSB SYMBOL CONDITIONS MIN TYP MAX UNITS DYNAMIC SPECIFICATIONS (100kHz sine-wave input, 2.5Vp-p, 400ksps, 6.4MHz clock, bipolar input mode) Signal-to-Noise plus Distortion Ratio Total Harmonic Distortion Spurious-Free Dynamic Range Intermodulation Distortion Channel-to-Channel Crosstalk (Note 4) Full-Power Bandwidth Full-Linear Bandwidth CONVERSION RATE Conversion Time (Note 5) Track/Hold Acquisition Time Aperture Delay Aperture Jitter Serial Clock Frequency Duty Cycle fSCLK 0.5 40 tCONV tACQ 10 68dB Up to the 5th harmonic 70 -81 80 76 -78 6 350 dB dB dB dB dB MHz kHz 2 _______________________________________________________________________________________ 400ksps/300ksps, Single-Supply, Low-Power, 8-Channel, Serial 12-Bit ADCs with Internal Reference ELECTRICAL CHARACTERISTICS—MAX1280 (continued) (VDD1 = VDD2 = +4.5V to +5.5V, COM = GND, fSCLK = 6.4MHz, 50% duty cycle, 16 clocks/conversion cycle (400ksps), external +2.5V at REF, REFADJ = VDD1, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS Unipolar, VCOM = 0 VCH_ Bipolar, VCOM or VCH_ = VREF/2, referenced to COM or CH_ On/off leakage current, VCH_ = 0 or VDD1 ±0.001 18 VREF TA = +25°C 2.480 2.500 30 TC VREF 0 to 1mA output load 4.7 0.01 1.22 For small adjustments, from 1.22V To power down the internal reference 1.4 2.05 1.0 200 VDD1 + 50mV 350 320 5 3.0 0.8 0.2 VIN = 0 or VDD2 15 ISINK = 5mA ISOURCE = 1mA CS = 5V CS = 5V 15 4 ±10 0.4 ±1 µA mA ±100 VDD1 ±15 0.1 2.0 10 10 2.520 MIN TYP MAX VREF ±VREF/2 ±1 V µA pF V mA ppm/°C mV/mA µF µF V mV V V/V UNITS ANALOG INPUTS (CH7–CH0, COM) Input Voltage Range, SingleEnded and Differential (Note 6) Multiplexer Leakage Current Input Capacitance INTERNAL REFERENCE REF Output Voltage REF Short-Circuit Current REF Output Temperature Coefficient Load Regulation (Note 7) Capacitive Bypass at REF Capacitive Bypass at REFADJ REFADJ Output Voltage REFADJ Input Range REFADJ Buffer Disable Threshold Buffer Voltage Gain EXTERNAL REFERENCE (Reference buffer disabled, reference applied to REF) REF Input Voltage Range (Note 8) VREF = 2.500V, fSCLK = 6.4MHz REF Input Current DIGITAL INPUTS (DIN, SCLK, CS, SHDN) Input High Voltage Input Low Voltage Input Hysteresis Input Leakage Input Capacitance DIGITAL OUTPUTS (DOUT, SSTRB) Output Voltage Low Output Voltage High Three-State Leakage Current Three-State Output Capacitance VOL VOH IL COUT V V µA pF VINH VINL VHYST IIN CIN V V V µA pF VREF = 2.500V, fSCLK = 0 In power-down, fSCLK = 0 V MAX1280/MAX1281 _______________________________________________________________________________________ 3 400ksps/300ksps, Single-Supply, Low-Power, 8-Channel, Serial 12-Bit ADCs with Internal Reference MAX1280/MAX1281 ELECTRICAL CHARACTERISTICS—MAX1280 (continued) (VDD1 = VDD2 = +4.5V to +5.5V, COM = GND, fSCLK = 6.4MHz, 50% duty cycle, 16 clocks/conversion cycle (400ksps), external +2.5V at REF, REFADJ = VDD1, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER POWER SUPPLY Positive Supply Voltage (Note 9) VDD1, VDD2 Operating mode (Note 10) Supply Current Supply Current Power-Supply Rejection PSR IVDD1 + IVDD2 VDD1 = VDD2 = 5.5V Reduced-power mode (Note 11) Fast power-down (Note 11) Full power-down (Note 11) VDD1 = VDD2 = 5V ±10%, midscale input 4.5 2.5 1.3 0.9 2 ±0.5 5.5 4.0 2.0 1.5 10 ±2.0 µA mV mA V SYMBOL CONDITIONS MIN TYP MAX UNITS ELECTRICAL CHARACTERISTICS—MAX1281 (VDD1 = VDD2 = +2.7V to +3.6V, COM = GND, fSCLK = 4.8MHz, 50% duty cycle, 16 clocks/conversion cycle (300ksps), external +2.5V at REF, REFADJ = VDD1, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER DC ACCURACY (Note 1) Resolution Relative Accuracy (Note 2) Differential Nonlinearity Offset Error Gain Error (Note 3) Gain-Error Temperature Coefficient Channel-to-Channel OffsetError Matching ±1.6 ±0.2 INL DNL No missing codes over temperature 12 ±1.0 ±1.0 ±6.0 ±6.0 Bits LSB LSB LSB LSB ppm/°C LSB SYMBOL CONDITIONS MIN TYP MAX UNITS DYNAMIC SPECIFICATIONS (75kHz sine-wave input, 2.5Vp-p, 300ksps, 4.8MHz clock, bipolar input mode) Signal-to-Noise plus Distortion Ratio Total Harmonic Distortion Spurious-Free Dynamic Range Intermodulation Distortion Channel-to-Channel Crosstalk (Note 4) Full-Power Bandwidth Full-Linear Bandwidth SINAD THD SFDR IMD fIN1 = 73kHz, fIN2 = 77kHz fIN = 150kHz, VIN = 2.5Vp-p -3dB point SINAD > 68dB Up to the 5th harmonic 70 -81 80 76 -78 3 250 dB dB dB dB dB MHz kHz 4 _______________________________________________________________________________________ 400ksps/300ksps, Single-Supply, Low-Power, 8-Channel, Serial 12-Bit ADCs with Internal Reference ELECTRICAL CHARACTERISTICS—MAX1281 (continued) (VDD1 = VDD2 = +2.7V to +3.6V, COM = GND, fSCLK = 4.8MHz, 50% duty cycle, 16 clocks/conversion cycle (300ksps), external +2.5V at REF, REFADJ = VDD1, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER CONVERSION RATE Conversion Time (Note 5) Track/Hold Acquisition Time Aperture Delay Aperture Jitter Serial Clock Frequency Duty Cycle ANALOG INPUTS (CH7–CH0, COM) Input Voltage Range, SingleEnded and Differential (Note 6) Multiplexer Leakage Current Input Capacitance INTERNAL REFERENCE REF Output Voltage REF Short-Circuit Current REF Output Temperature Coefficient Load Regulation (Note 7) Capacitive Bypass at REF Capacitive Bypass at REFADJ REFADJ Output Voltage REFADJ Input Range REFADJ Buffer Disable Threshold Buffer Voltage Gain EXTERNAL REFERENCE (Reference buffer disabled, reference applied to REF) REF Input Voltage Range (Note 8) VREF = 2.500V, fSCLK = 4.8MHz REF Input Current DIGITAL INPUTS (DIN, SCLK, CS, SHDN) Input High Voltage Input Low Voltage Input Hysteresis Input Leakage Input Capacitance VINH VINL VHYST IIN CIN VIN = 0 or VDD2 15 0.2 ±1 2.0 0.8 V V V µA pF VREF = 2.500V, fSCLK = 0 In power-down, fSCLK = 0 1.0 200 VDD1 + 50mV 350 320 5 µA V For small adjustments, from 1.22V To power down the internal reference 1.4 2.05 TC VREF 0 to 0.75mA output load 4.7 0.01 1.22 ±100 VDD1 - 1 VREF TA = +25°C 2.480 2.500 15 ±15 0.1 2.0 10 10 2.520 V mA ppm/°C mV/mA µF µF V mV V V/V Unipolar, VCOM = 0 VCH_ Bipolar, VCOM or VCH_ = VREF/2, referenced to COM or CH_ On/off leakage current, VCH_ = 0 or AVDD ±0.001 18 VREF ±VREF/2 ±1 V µA pF fSCLK Normal operating mode 0.5 40 tCONV tACQ Normal operating mode Normal operating mode 10