EVALUATION KIT AVAILABLE
MAX1415/MAX1416
16-Bit, Low-Power, 2-Channel,
Sigma-Delta ADCs
General Description
The MAX1415/MAX1416 low-power, 2-channel, serial-
output analog-to-digital converters (ADCs) use a sigma-
delta 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 program-
mable 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.
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
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
CLOCK
GENERATOR
CLKIN
CLKOUT
BUFFER
AIN1+
AIN1-
AIN2+
AIN2-
BUFFER
S1 AND S2 ARE OPEN IN
BUFFERED MODE AND CLOSED
IN UNBUFFERED MODE
MUX
S1
S2
MAX1415
MAX1416
PGA
2nd-ORDER
SIGMA-DELTA
MODULATOR
DIGITAL
FILTER
V
DD
GND
REF+
REF-
SERIAL INTERFACE,
REGISTERS,
AND
CONTROL
CS
SCLK
DIN
DOUT
DRDY
RESET
QSPI is a trademark of Motorola, Inc.
MICROWIRE is a registered trademark of National Semiconductor Corp.
19-3163; Rev 3; 6/15
MAX1415/MAX1416
16-Bit, Low-Power, 2-Channel,
Sigma-Delta ADCs
Absolute Maximum Ratings
V
DD
to GND ............................................................-0.3V to +6V
All Other Pins to GND .............................. -0.3V to (V
DD
+ 0.3V)
Maximum Current Input into Any Pin .................................50mA
Continuous Power Dissipation (T
A
= +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
(V
DD
= 3V, V
GND
= 0V, V
REF+
= 1.225V, V
REF-
= GND, external f
CLKIN
= 2.4576MHz, CLKDIV bit = 0, C
REF+
to GND = 0.1μF, C
REF-
to GND = 0.1μF, T
A
= T
MIN
to T
MAX
, 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
Gain Drift
Bipolar Negative Full-Scale Error
Bipolar Negative Full-Scale Drift
(Note 2)
ANALOG INPUTS (AIN1+, AIN1-, AIN2+, AIN2-)
AIN Differential Input Voltage
Range (Note 7)
Unipolar input range
Bipolar input range
Unbuffered
Buffered
Unselected input channel
0
-V
REF
/ GAIN
GND -
30mV
GND +
50mV
V
REF
/
GAIN
V
REF
/
GAIN
V
DD
+
30mV
V
DD
-
1.5V
1
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
(Notes 2, 6)
After calibration
Gain = 1 to 4
Gain = 8 to 128
(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
16
(Tables 1, 3)
±0.0015
Bits
µV
%FSR
µV
µV/°C
µV
µV/°C
µV
µV/°C
µV
ppm of
FSR/°C
%FSR
µV/°C
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
AIN Absolute Input Voltage
Range (Note 8)
AIN DC Leakage Current
V
nA
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MAX1415/MAX1416
16-Bit, Low-Power, 2-Channel,
Sigma-Delta ADCs
Electrical Characteristics—MAX1415 (continued)
(V
DD
= 3V, V
GND
= 0V, V
REF+
= 1.225V, V
REF-
= GND, external f
CLKIN
= 2.4576MHz, CLKDIV bit = 0, C
REF+
to GND = 0.1μF, C
REF-
to GND = 0.1μF, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
PARAMETER
SYMBOL
Gain = 1
AIN Input Capacitance
Gain = 2
Gain = 4
Gain = 8 to 128
AIN Input Sampling Rate
f
s
Gain = 1 to 128
Gain = 1
Input Common-Mode Rejection
CMR
Gain = 2
Gain = 4
Gain = 8 to 128
Normal-Mode 50Hz Rejection
Normal-Mode 60Hz Rejection
Common-Mode 50Hz Rejection
Common-Mode 60Hz Rejection
EXTERNAL REFERENCE (REF+, REF-)
REF Differential Input Range
REF Absolute Input Voltage Range
REF Input Capacitance
REF Input Sampling Rate
f
s
Gain = 1 to 128
V
REF
(Note 9)
1.00
GND
10
f
CLKIN
/ 64
2.0
0.4
DIN,
CS, RESET
SCLK
250
500
±1
5
V
CLKINH
V
CLKINL
I
CLKIN
2.5
0.4
±10
DOUT and
DRDY,
I
SINK
= 100µA
CLKOUT, I
SINK
= 10µA
0.4
0.4
1.75
V
DD
V
V
pF
MHz
For filter notches of 25Hz, 50Hz,
±0.02 x f
NOTCH
For filter notches of 20Hz, 60Hz,
±0.02 x f
NOTCH
For filter notches of 25Hz, 50Hz,
±0.02 x f
NOTCH
For filter notches of 20Hz, 60Hz,
±0.02 x f
NOTCH
105
110
120
130
98
98
150
150
dB
dB
dB
dB
dB
CONDITIONS
MIN
TYP
34
38
45
60
f
CLKIN
/ 64
MHz
pF
MAX
UNITS
DIGITAL INPUTS (DIN, SCLK,
CS, RESET)
Input High Voltage
Input Low Voltage
Input Hysteresis
Input Current
Input Capacitance
CLKIN INPUT
CLKIN Input High Voltage
CLKIN Input Low Voltage
CLKIN Input Current
V
V
µA
V
IH
V
IL
V
HYST
I
IN
V
V
mV
µA
pF
DIGITAL OUTPUTS (DOUT,
DRDY,
CLKOUT)
Output-Voltage Low
V
OL
V
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MAX1415/MAX1416
16-Bit, Low-Power, 2-Channel,
Sigma-Delta ADCs
Electrical Characteristics—MAX1415 (continued)
(V
DD
= 3V, V
GND
= 0V, V
REF+
= 1.225V, V
REF-
= GND, external f
CLKIN
= 2.4576MHz, CLKDIV bit = 0, C
REF+
to GND = 0.1μF, C
REF-
to GND = 0.1μF, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
PARAMETER
Output-Voltage High
Tri-State Leakage Current
Tri-State Output Capacitance
SYSTEM CALIBRATION
Full-Scale Calibration Range
GAIN = selected PGA gain (1 to 128)
(Note 10)
GAIN = selected PGA gain (1 to 128)
(Note 10)
GAIN = selected PGA gain (1 to 128)
(Notes 10, 11)
-1.05 x
V
REF
/
GAIN
-1.05 x
V
REF
/
GAIN
0.8 x
V
REF
/
GAIN
2.7
Unbuffered, f
CLKIN
= 1MHz, gain = 1 to 128
Buffered, f
CLKIN
= 1MHz, gain = 1 to 128
Power-Supply Current (Note 12)
I
DD
Unbuffered,
f
CLKIN
= 2.4576MHz
Buffered,
f
CLKIN
= 2.4576MHz
Power-Supply Rejection Ratio
CLKIN Frequency
Duty Cycle
INTERNAL-CLOCK TIMING SPECIFICATIONS
MAX1415AE__,
f
CLK
= 1MHz (CLK = 0)
or 2.4576MHz (CLK = 1)
Internal-Clock Frequency
f
CLK
MAX1415C__,
f
CLK
= 1MHz (CLK = 0)
or 2.4576MHz (CLK = 1)
MAX1415E__,
f
CLK
= 1MHz (CLK = 0)
or 2.4576MHz (CLK = 1)
T
A
= -40°C to
+85°C
T
A
= 0°C to
+70°C
T
A
= -40°C to 0°C
T
A
= 0°C to +85°C
±4
PSRR
f
CLKIN
V
DD
= 2.7V to 3.6V
(Note 15)
400
40
Gain = 1 to 4
Gain = 8 to 128
Gain = 1 to 4
Gain = 8 to 128
(Note 14)
2500
60
1.05 x
V
REF
/
GAIN
1.05 x
V
REF
/
GAIN
2.1 x
V
REF
/
GAIN
3.6
0.40
0.725
0.55
0.55
0.825
1.0
8
µA
dB
kHz
%
mA
V
SYMBOL
V
OH
I
L
C
OUT
CONDITIONS
DOUT and
DRDY,
I
SOURCE
= 100µA
CLKOUT, I
SOURCE
= 10µA
DOUT only
DOUT only
9
MIN
V
DD
-0.6V
V
DD
-0.6V
±10
TYP
MAX
UNITS
V
µA
pF
Offset Calibration Range
V
Input Span
POWER REQUIREMENTS
Power-Supply Voltage
V
DD
V
V
Power-down mode (Note 13)
EXTERNAL-CLOCK TIMING SPECIFICATIONS
±4
±7
±4
%
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MAX1415/MAX1416
16-Bit, Low-Power, 2-Channel,
Sigma-Delta ADCs
Electrical Characteristics—MAX1415 (continued)
(V
DD
= 3V, V
GND
= 0V, V
REF+
= 1.225V, V
REF-
= GND, external f
CLKIN
= 2.4576MHz, CLKDIV bit = 0, C
REF+
to GND = 0.1μF, C
REF-
to GND = 0.1μF, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
PARAMETER
Typical Conversion-Time Variation
SYMBOL
∆t
CONV
CONDITIONS
t
CONV
= 1/ODR
MIN
TYP
±0.5
MAX
UNITS
%
Timing Characteristics—MAX1415
(Note 16) (Figures 8, 9)
PARAMETER
DRDY
High Time
Reset Pulse-Width Low
DRDY
Fall to
CS
Fall Setup Time
CS
Fall to SCLK Rise Setup Time
SCLK Fall to DOUT Valid Delay
SCLK Pulse-Width High
SCLK Pulse-Width Low
CS
Rise to SCLK Rise Hold Time
Bus Relinquish Time After SCLK
Rising Edge
SCLK Fall to
DRDY
Rise Delay
DIN to SCLK Setup Time
DIN to SCLK Hold Time
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
8
t
9
t
10
30
20
SYMBOL
CONDITIONS
MIN
f
CLKIN
100
0
120
0
100
100
0
100
100
100
500/
TYP
MAX
UNITS
s
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Electrical Characteristics—MAX1416
(V
DD
= 5V, V
GND
= 0V, V
REF+
= 2.5V, V
REF-
= GND, f
CLKIN
= 2.4576MHz, CLKDIV bit = 0, CREF+
to GND = 0.1μF, C
REF-
to GND =
0.1μF, T
A
= T
MIN
to T
MAX
, 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)
INL
Gain = 1, bipolar mode, unbuffered
After calibration
(Note 2)
After calibration
Gain = 1 to 4
Gain = 8 to 128
(Note 1)
0.5
(Note 1)
0.5
0.1
16
(Tables 1, 3)
±0.0015
Bits
µV
%FSR
µV
µV/°C
µV
µV/°C
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
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