19-1688; Rev 0; 5/00
300ksps/400ksps, Single-Supply, 4-Channel, Serial 12-Bit ADCs with Internal Reference
General Description
The MAX1282/MAX1283 12-bit analog-to-digital converters (ADCs) combine a 4-channel analog-input multiplexer, high-bandwidth track/hold (T/H), and serial interface with high conversion speed and low power consumption. The MAX1282 operates from a single +4.5V to +5.5V supply; the MAX1283 operates from a single +2.7V to +3.6V supply. Both devices’ analog inputs are software configurable for unipolar/bipolar and single-ended/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 MAX1282/ MAX1283 use an external serial-interface clock to perform successive-approximation analog-to-digital conversions. The devices feature an internal +2.5V reference and a reference-buffer amplifier with a ±1.5% voltage-adjustment range. An external reference with a 1V to VDD range may also be used. The MAX1282/MAX1283 provide a hardwired SHDN pin and four software-selectable power modes (normal operation, reduced power (REDP), fast power-down (FASTPD), and full power-down (FULLPD)). These devices can be programmed to automatically shut down at the end of a conversion or to operate with reduced power. When using the power-down modes, accessing the serial interface automatically powers up the devices, and the quick turnon time allows them to be shut down between all conversions. The MAX1282/MAX1283 are available in 16-pin TSSOP packages.
Features
o 4-Channel Single-Ended or 2-Channel Pseudo-Differential Inputs o Internal Multiplexer and Track/Hold o Single-Supply Operation +4.5V to +5.5V (MAX1282) +2.7V to +3.6V (MAX1283) o Internal +2.5V Reference o 400kHz Sampling Rate (MAX1282) o Low Power: 2.5mA (400ksps) 1.3mA (REDP) 0.9mA (FASTPD) 2µA (FULLPD) o SPI/QSPI/MICROWIRE/TMS320-Compatible 4-Wire Serial Interface o Software-Configurable Unipolar or Bipolar Inputs o 16-Pin TSSOP Package
MAX1282/MAX1283
Ordering Information
PART MAX1282BCUE MAX1282BEUE MAX1283BCUE MAX1283BEUE TEMP. RANGE 0°C to +70°C -40°C to +85°C 0°C to +70°C -40°C to +85°C PINPACKAGE 16 TSSOP 16 TSSOP 16 TSSOP 16 TSSOP INL (LSB) ±1 ±1 ±1 ±1
Applications
Portable Data Logging Data Acquisition Medical Instruments Battery-Powered Instruments Pen Digitizers Process Control
TOP VIEW
VDD1 1 CH0 2 CH1 3 CH2 4 CH3 5 COM 6 SHDN 7
Pin Configuration
16 VDD2 15 SCLK 14 CS
MAX1282/ MAX1283
13 DIN 12 SSTRB 11 DOUT 10 GND 9 REFADJ
Typical Operating Circuit appears at end of data sheet. SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp.
REF 8
TSSOP
________________________________________________________________ Maxim Integrated Products
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300ksps/400ksps, Single-Supply, 4-Channel, Serial 12-Bit ADCs with Internal Reference MAX1282/MAX1283
ABSOLUTE MAXIMUM RATINGS
VDD_ to GND ........................................................... -0.3V to +6V VDD1 to VDD2 ....................................................... -0.3V to +0.3V CH0–CH3, COM to GND .......................... -0.3V to (VDD_ +0.3V) REF, REFADJ to GND ................................ -0.3V to VDD_ +0.3V) Digital Inputs to GND .............................................. -0.3V to +6V Digital Outputs to GND............................. -0.3V to (VDD_ +0.3V) Digital Output Sink Current .................................................25mA Continuous Power Dissipation (TA = +70°C) 16-Pin TSSOP (derate 6.7mW/°C above +70°C) ........ 535mW Operating Temperature Ranges MAX1282BCUE/MAX1283BCUE ....................... 0°C to +70°C MAX1282BEUE/MAX1283BEUE ..................... -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—MAX1282
(VDD1 = VDD2 = +4.5V to +5.5V, COM = GND, fOSC = 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 ±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 (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
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300ksps/400ksps, Single-Supply, 4-Channel, Serial 12-Bit ADCs with Internal Reference MAX1282/MAX1283
ELECTRICAL CHARACTERISTICS—MAX1282 (continued)
(VDD1 = VDD2 = +4.5V to +5.5V, COM = GND, fOSC = 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, VCOM, VCH_ = 0 or VDD1 ±0.001 18 VREF TA = +25°C 2.480 2.500 15 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 = VDD2 CS = VDD2 15 4 ±10 0.4 ±1 V V V µA pF V V µA pF µA ±100 VDD1 - 1.0 ±15 0.05 2.0 10 10 2.520 MIN TYP MAX VREF ±VREF/2 ±1 V UNITS ANALOG INPUTS (CH3–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 = fMAX 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 VINH VINL VHYST IIN CIN VREF = 2.500V, fSCLK = 0 In full power-down mode, fSCLK = 0 V V mA ppm/°C mV/mA µF µF V mV V V/V
µA pF
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300ksps/400ksps, Single-Supply, 4-Channel, Serial 12-Bit ADCs with Internal Reference MAX1282/MAX1283
ELECTRICAL CHARACTERISTICS—MAX1282 (continued)
(VDD1 = VDD2 = +4.5V to +5.5V, COM = GND, fOSC = 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 Normal operating mode (Note 10) Supply Current IVDD1+ IVDD2 PSR VDD1 = VDD2 = 5.5V Reduced-power mode (Note 11) Fast power-down mode (Note 11) Full power-down mode (Note 11) Power-Supply Rejection VDD1 = VDD2 = 5V ±10%, midscale input 4.5 2.5 1.3 0.9 2.0 ±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—MAX1283
(VDD1 = VDD2 = +2.7V to +3.6V, COM = GND, fOSC = 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 Offset-Error 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 (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 SINAD THD SFDR IMD fIN1 = 73kHz, fIN2 = 77kHz f = 150kHz, VIN = 2.5Vp-p -3dB point SINAD > 68dB Up to the 5th harmonic 70 -70 72 76 -78 3 250 dB dB dB dB dB MHz kHz
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300ksps/400ksps, Single-Supply, 4-Channel, Serial 12-Bit ADCs with Internal Reference
ELECTRICAL CHARACTERISTICS—MAX1283 (continued)
(VDD1 = VDD2 = +2.7V to +3.6V, COM = GND, fOSC = 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 (CH3–CH0, COM) Input Voltage Range, Single Ended 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) Buffer Voltage Gain REF Input Voltage Range (Note 8) VREF = 2.500V, fSCLK = fMAX 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 full power-down mode, fSCLK = 0 1.0 200 For small adjustments, from 1.22V To power down the internal reference 1.4 2.05 2.05 VDD1 + 50mV 350 320 5 µA TC VREF 0 to 0.75mA output load 4.7 0.01 1.22 ±100 VDD1 - 1.0 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 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 VDD1 ±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