Document
MAX1415/MAX1416
EVALUATION KIT AVAILABLE
16-Bit, Low-Power, 2-Channel, Sigma-Delta ADCs
General Description
The MAX1415/MAX1416 low-power, 2-channel, serialoutput analog-to-digital converters (ADCs) use a sigmadelta modulator with a digital filter to achieve 16-bit resolution with no missing codes. These ADCs are pin-compatible upgrades to the MX7705/AD7705. The MAX1415/MAX1416 feature an internal oscillator (1MHz or 2.4576MHz), an on-chip input buffer, and a programmable gain amplifier (PGA). The devices offer an SPI-/ QSPI™-/MICROWIRE®-compatible serial interface.
The MAX1415/MAX1416 are available in 16-pin PDIP, SO, and TSSOP packages.
Applications
●● Industrial Instruments ●● Weigh Scales ●● Strain-Gauge Measurements ●● Loop-Powered Systems ●● Flow and Gas Meters ●● Medical Instrumentation ●● Pressure Transducers ●● Thermocouple Measurements ●● RTD Measurements
Ordering Information continued at end of data sheet.
Functional Diagram
Benefits and Features
●● Improve Measurement Quality with Excellent DC Accuracy • 16-Bit Sigma-Delta ADC with Two Fully-Differential Input Channels • 0.0015% INL (max) with No Missing Codes
●● Minimize Power Consumption with Low-Power Dissipation • 1.2mW (max) 3V supply • 2μA (typ) Power-Down Current
●● Lower System Cost with Integrated Functionality • PGA with 1 to 128 Programmable Gain • Optional Input Buffers • > 98dB 50Hz/60Hz Rejection
●● Increase System Accuracy with Built-in Self Calibration • On-Demand Offset and Gain Self-Calibration and System Calibration • User-Programmable Offset and Gain Registers
●● Flexible Single-Supply Options • 2.7V to 3.6V (MAX1415) • 4.75V to 5.25V (MAX1416)
●● Pin Compatible Upgrades for MX7705/AD7705
AIN1+ AIN1AIN2+ AIN2-
REF+ REF-
BUFFER
MAX1415 MAX1416
CLOCK GENERATOR
MUX
S1 S2
2nd-ORDER PGA SIGMA-DELTA
MODULATOR
DIGITAL FILTER
BUFFER
S1 AND S2 ARE OPEN IN BUFFERED MODE AND CLOSED
IN UNBUFFERED MODE
SERIAL INTERFACE, REGISTERS, AND CONTROL
QSPI is a trademark of Motorola, Inc. MICROWIRE is a registered trademark of National Semiconductor Corp.
CLKIN CLKOUT
VDD GND
CS SCLK DIN DOUT DRDY RESET
19-3163; Rev 3; 6/15
MAX1415/MAX1416
16-Bit, Low-Power, 2-Channel, Sigma-Delta ADCs
Absolute Maximum Ratings
VDD to GND.............................................................-0.3V to +6V All Other Pins to GND............................... -0.3V to (VDD + 0.3V) Maximum Current Input into Any Pin..................................50mA Continuous Power Dissipation (TA = +70°C) 16-Pin PDIP (derate 10.5mW/°C above +70°C)..........842mW 16-Pin TSSOP (derate 9.4mW/°C above +70°C).........755mW 16-Pin Wide SO (derate 9.5mW/°C above +70°C)......762mW
Operating Temperature Range............................ -40°C to +85°C Storage Temperature Range............................. -60°C to +150°C Junction Temperature.......................................................+150°C Lead Temperature (soldering, 10s).................................. +300°C Soldering Temperature (reflow)........................................+260°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—MAX1415
(VDD = 3V, VGND = 0V, VREF+ = 1.225V, VREF- = GND, external fCLKIN = 2.4576MHz, CLKDIV bit = 0, CREF+ to GND = 0.1μF, CREFto GND = 0.1μF, TA = TMIN to TMAX, unless otherwise noted.)
PARAMETER DC ACCURACY Resolution (No Missing Codes) Output Noise Integral Nonlinearity Unipolar Offset Error Unipolar Offset Drift Bipolar Zero Error
Bipolar Zero Drift (Note 2)
Positive Full-Scale Error Full-Scale Drift Gain Error
SYMBOL
CONDITIONS
INL Gain = 1, bipolar mode, unbuffered After calibration (Note 2) After calibration Gain = 1 to 4 Gain = 8 to 128 After calibration (Notes 2, 4) After calibration
Gain Drift
(Notes 2, 6)
Bipolar Negative Full-Scale Error
After calibration
Bipolar Negative Full-Scale Drift (Note 2)
Gain = 1 to 4 Gain = 8 to 128
ANALOG INPUTS (AIN1+, AIN1-, AIN2+, AIN2-)
AIN Differential Input Voltage Range (Note 7)
Unipolar input range Bipolar input range
AIN Absolute Input Voltage Range (Note 8)
AIN DC Leakage Current
Unbuffered
Buffered Unselected input channel
MIN TYP MAX UNITS
16 (Tables 1, 3) ±0.0015 (Note 1) 0.5 (Note 1) 0.5 0.1 (Notes 1, 3) 0.5 (Notes 1, 5)
0.5
±0.003 1 0.6
Bits µV %FSR µV µV/°C µV
µV/°C
µV µV/°C
µV ppm of FSR/°C %FSR
µV/°C
0
-VREF / GAIN
GND 30mV
GND + 50mV
VREF / GAIN
VREF / GAIN
VDD + 30mV
VDD 1.5V
1
V
V nA
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MAX1415/MAX1416
16-Bit, Low-Power, 2-Channel, Sigma-Delta ADCs
Electrical Characteristics—MAX1415 (continued)
(VDD = 3V, VGND = 0V, VREF+ = 1.225V, VREF- = GND, external.