19-3163; Rev 1; 12/05
KIT
ATION
EVALU
BLE
AVAILA
16-Bit, Low-Power, 2-Channel,
Sigma-Delta ADCs
General Description
Features
♦
16-Bit Sigma-Delta ADCs
♦
Two Fully Differential Input Channels
♦
0.0015% Integral Nonlinearity with No Missing
Codes
♦
Internal Analog Input Buffers
♦
Programmable Gain Amplifier (PGA) from 1 to 128
♦
Internal Oscillator (2.4576MHz or 1MHz)
♦
Single 2.7V to 3.6V (MAX1415) or 4.75V to 5.25V
(MAX1416) Supply
♦
Low Power
1mW max, 3V Supply
2µA (typ) Power-Down Current
♦
SPI™-/QSPI™-/MICROWIRE™-Compatible 3-Wire
Serial Interface
♦
Pin Compatible with MX7705/AD7705
♦
16-Pin PDIP, SO, and TSSOP Packages
MAX1415/MAX1416
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 requires a single 2.7V to 3.6V supply, and
the MAX1416 requires a single 4.75V to 5.25V supply.
The operating supply current is 400µA (max) with a 3V
supply. Power-down mode reduces the supply current to
2µA (typ). When operating with a supply of 3V, the power
dissipation is less than 1.44mW, making the MAX1415
ideal for battery-powered applications.
Self-calibration and system calibration allow the
MAX1415/MAX1416 to correct for gain and offset errors.
Excellent DC performance (±0.0015% FSR INL) and low
noise (700nV in unbuffered mode) make the MAX1415/
MAX1416 ideal for measuring low-frequency signals with
a wide dynamic range. These devices accept fully differ-
ential bipolar/unipolar inputs. An internal input buffer
allows for input signals with high source impedances. An
on-chip digital filter, with a programmable cutoff and out-
put data rate, processes the output of the sigma-delta
modulator. The first notch frequency of the digital filter is
chosen to provide 150dB rejection of common-mode
50Hz or 60Hz noise and 98dB rejection of normal-mode
50Hz or 60Hz noise. A PGA and digital filtering allow sig-
nals to be directly acquired with little or no signal-condi-
tioning requirements.
The MAX1415/MAX1416 are available in 16-pin PDIP,
SO, and TSSOP packages.
Ordering Information
PART
MAX1415ENE*
MAX1415EWE*
MAX1415EUE
TEMP
RANGE
PIN-
PACKAGE
V
DD
(V)
3
3
3
3
3
3
3
3
PKG
CODE
P16-1
W16-1
U16-1
P16-1
W16-1
U16-1
P16-1
W16-1
-45°C to +85°C 16 PDIP
-45°C to +85°C 16 Wide SO
-45°C to +85°C 16 TSSOP
MAX1415AENE* -45°C to +85°C 16 PDIP
MAX1415AEWE* -45°C to +85°C 16 Wide SO
MAX1415AEUE* -45°C to +85°C 16 TSSOP
MAX1415CNE*
MAX1415CWE*
0°C to +70°C 16 PDIP
0°C to +70°C 16 Wide SO
Applications
Industrial Instruments
Weigh Scales
Strain-Gauge Measurements
Loop-Powered Systems
Flow and Gas Meters
Medical Instrumentation
Pressure Transducers
Thermocouple Measurements
RTD Measurements
SPI/QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
MAX1415CUE*
0°C to +70°C 16 TSSOP
3
U16-1
*Future
product—contact factory for availability.
Ordering Information continued at end of data sheet.
Pin Configuration
TOP VIEW
SCLK 1
CLKIN 2
CLKOUT 3
CS 4
RESET 5
AIN2+ 6
AIN1+ 7
AIN1- 8
16 GND
15 V
DD
14 DIN
MAX1415
MAX1416
13 DOUT
12 DRDY
11 AIN2-
10 REF-
9
REF+
PDIP/SO/TSSOP
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
16-Bit, Low-Power, 2-Channel,
Sigma-Delta ADCs
MAX1415/MAX1416
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
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, GND = 0, 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-)
Unipolar input range
AIN Differential Input Voltage
Range (Note 7)
Bipolar input range
Unbuffered
AIN Absolute Input Voltage
Range (Note 8)
Buffered
AIN DC Leakage Current
Unselected input channel
0
-V
REF
/
GAIN
GND -
30mV
GND +
50mV
V
REF
/
GAIN
V
V
REF
/
GAIN
V
DD
+
30mV
V
V
DD
-
1.5V
1
nA
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
2
_______________________________________________________________________________________
16-Bit, Low-Power, 2-Channel,
Sigma-Delta ADCs
ELECTRICAL CHARACTERISTICS—MAX1415 (continued)
(V
DD
= 3V, GND = 0, 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
DOUT and
DRDY,
I
SINK
= 100µA
CLKOUT, I
SINK
= 10µA
2.5
0.4
±10
0.4
0.4
1.75
V
DD
V
V
pF
MHz
For filter notches of 25Hz, 50Hz,
±0.02 ×
f
NOTCH
For filter notches of 20Hz, 60Hz,
±0.02 ×
f
NOTCH
For filter notches of 25Hz, 50Hz,
±0.02 ×
f
NOTCH
For filter notches of 20Hz, 60Hz,
±0.02 ×
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
MAX1415/MAX1416
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
_______________________________________________________________________________________
3
16-Bit, Low-Power, 2-Channel,
Sigma-Delta ADCs
MAX1415/MAX1416
ELECTRICAL CHARACTERISTICS—MAX1415 (continued)
(V
DD
= 3V, GND = 0, 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
CONDITIONS
DOUT and
DRDY,
I
SOURCE
= 100µA
Output-Voltage High
V
OH
CLKOUT, I
SOURCE
= 10µA
Tri-State Leakage Current
Tri-State Output Capacitance
SYSTEM CALIBRATION
Full-Scale Calibration Range
GAIN = selected PGA gain (1 to 128)
(Note 10)
-1.05
×
V
REF
/
GAIN
-1.05
×
V
REF
/
GAIN
0.8
×
V
REF
/
GAIN
1.05
×
V
REF
/
GAIN
1.05
×
V
REF
/
GAIN
2.1
×
V
REF
/
GAIN
V
I
L
C
OUT
DOUT only
DOUT only
9
MIN
V
DD
-
0.6V
V
V
DD
-
0.6V
±10
µA
pF
TYP
MAX
UNITS
Offset Calibration Range
GAIN = selected PGA gain (1 to 128)
(Note 10)
V
Input Span
POWER REQUIREMENTS
Power-Supply Voltage
V
DD
GAIN = selected PGA gain (1 to 128)
(Notes 10, 11)
V
2.7
Unbuffered, f
CLKIN
= 1MHz, gain = 1 to 128
Buffered, f
CLKIN
= 1MHz, gain = 1 to 128
Unbuffered,
f
CLKIN
= 2.4576MHz
Buffered,
f
CLKIN
= 2.4576MHz
Gain = 1 to 4
Gain = 8 to 128
Gain = 1 to 4
Gain = 8 to 128
(Note 14)
400
40
3.6
0.40
0.725
0.55
0.55
0.825
1.0
8
V
Power-Supply Current (Note 12)
I
DD
mA
Power-down mode (Note 13)
Power-Supply Rejection Ratio
CLKIN Frequency
Duty Cycle
INTERNAL-CLOCK TIMING SPECIFICATIONS
MAX1415AE__,
f
CLK
= 1MHz (CLK = 0)
or 2.4576MHz (CLK = 1)
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
PSRR
f
CLKIN
V
DD
= 2.7V to 3.6V
(Note 15)
EXTERNAL-CLOCK TIMING SPECIFICATIONS
µA
dB
2500
60
kHz
%
±4
Internal-Clock Frequency
f
CLK
T
A
= 0°C to
+70°C
T
A
= -40°C to 0°C
T
A
= 0°C to +85°C
±4
%
±7
±4
4
_______________________________________________________________________________________
16-Bit, Low-Power, 2-Channel,
Sigma-Delta ADCs
ELECTRICAL CHARACTERISTICS—MAX1415 (continued)
(V
DD
= 3V, GND = 0, 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
%
MAX1415/MAX1416
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
500/
f
CLKIN
100
0
120
0
100
100
0
100
100
100
TYP
MAX
UNITS
s
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ELECTRICAL CHARACTERISTICS—MAX1416
(V
DD
= 5V, GND = 0, V
REF+
= 2.5V, V
REF-
= GND, 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)
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
_______________________________________________________________________________________
5