19-5246; Rev 0; 4/10
20-Bit, Single-Channel, Ultra-Low-Power,
Delta-Sigma ADC with 2-Wire Serial Interface
General Description
The MAX11208 is an ultra-low-power (< 300FA active
current), high-resolution, serial-output ADC. This device
provides the highest resolution per unit power in the
industry and is optimized for applications that require
very high dynamic range with low power, such as sen-
sors on a 4mA to 20mA industrial control loop. The
MAX11208 provides a high-accuracy internal oscillator
that requires no external components.
When used with the specified data rates, the internal
digital filter provides more than 80dB rejection of 50Hz or
60Hz line noise. The MAX11208 provides a simple 2-wire
serial interface in the space-saving, 10-pin
FMAX
M
pack-
age. The MAX11208 operates over the -40NC to +85NC
temperature range.
Features
S
20-Bit_Full-Scale_Resolution
20-Bit_Noise-Free_Resolution_at_13.75sps_
19-Bit_Noise-Free_Resolution_at_120sps
S
720nV
RMS
_Noise_(MAX11208B)
S
3ppm_INL
S
No_Missing_Codes
S
Ultra-Low_Power_Dissipation
Operating_Mode_Current_Drain_<_300µA_(max)_
Sleep_Mode_Current_Drain_<_0.1µA
S
2.7V_to_3.6V_Analog_Supply_Voltage_Range
S
1.7V_to_3.6V_Digital_and_I/O_Supply_Voltage_Range
S
Fully_Differential_Signal_Inputs
S
Fully_Differential_Reference_Inputs
S
Internal_System_Clock
2.4576MHz_(MAX11208A)_
2.2528MHz_(MAX11208B)
S
External_Clock
S
Serial_2-Wire_Interface_(Clock_Input_and_Data_
Output)
S
On-Demand_Offset_and_Gain_Self-Calibration
S
-40°C_to_+85°C_Operating_Temperature_Range
S
±2kV_ESD_Protection
S
Lead(Pb)-Free_and_RoHS-Compliant_µMAX_
Package
MAX11208
Applications
Sensor Measurement (Temperature and
Pressure)
Portable Instrumentation
Battery Applications
Weigh Scales
Ordering Information
PART
MAX11208AEUB+
MAX11208BEUB+
PIN-PACKAGE
10
FMAX
10
FMAX
OUTPUT_RATE_
(sps)
120
13.75
Note:
All devices are specified over the -40NC to +85NC oper-
ating temperature range.
+Denotes
a lead(Pb)-free/RoHS-compliant package.
Selector Guide
RESOLUTION
(BITS)
24
20
18
16
4-WIRE_SPI,_16-PIN_QSOP,_
PROGRAMMABLE_GAIN
MAX11210
MAX11206
MAX11209
MAX11213
4-WIRE_SPI,
16-PIN_QSOP
MAX11200
MAX11207
MAX11211
MAX11203
2-WIRE_SERIAL,
10-PIN_µMAX
MAX11201 (with buffers)
MAX11202 (without buffers)
MAX11208
MAX11212
MAX11205
µMAX is a registered trademark of Maxim Integrated Products, Inc.
________________________________________________________________ _Maxim
Integrated Products_
_ 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
20-Bit, Single-Channel, Ultra-Low-Power,
Delta-Sigma ADC with 2-Wire Serial Interface
MAX11208
ABSOLUTE_MAXIMUM_RATINGS
Any Pin to GND ....................................................-0.3V to +3.9V
AVDD to GND.......................................................-0.3V to +3.9V
DVDD to GND ......................................................-0.3V to +3.9V
Analog Inputs (AINP, AINN, REFP, REFN)
to GND ............................................. -0.3V to (V
AVDD
+ 0.3V)
Digital Inputs and Digital Outputs
to GND ............................................. -0.3V to (V
DVDD
+ 0.3V)
ESD
HB
(AVDD, AINP, AINN, REFP, REFN, DVDD, CLK,
CS,
SCLK,
RDY/DOUT,
GND) ................................
Q2kV
(Note 1)
Continuous Power Dissipation (T
A
= +70NC)
10-Pin
FMAX
(derate 5.6mW/NC above +70NC) ..........444mW
Operating Temperature Range .......................... -40NC to +85NC
Junction Temperature .....................................................+150NC
Storage Temperature Range............................ -55NC to +150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
Note_1:
Human Body Model to specification MIL-STD-883 Method 3015.7.
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
(V
AVDD
= +3.6V, V
DVDD
= +1.8V, V
REFP
- V
REFN
= V
AVDD
; internal clock, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values
are at T
A
= +25NC under normal conditions, unless otherwise noted.)
PARAMETER
ADC_PERFORMANCE
Noise-Free Resolution (Notes 2, 3)
Thermal Noise (Notes 2, 3)
Integral Nonlinearity
Zero Error
Zero Drift
Full-Scale Error
Full-Scale Error Drift
Power-Supply Rejection
ANALOG_INPUTS/REFERENCE_INPUTS
DC rejection
Common-Mode Rejection
Normal-Mode 50Hz Rejection
Normal-Mode 60Hz Rejection
Common-Mode Voltage Range
Low input voltage
Absolute Input Voltage
High input voltage
DC Input Leakage
AIN Dynamic Input Current
Sleep mode (Note 2)
CMR
NMR
50
NMR
60
50Hz/60Hz rejection, MAX11208A
50Hz/60Hz rejection, MAX11208B
MAX11208B (Note 6)
MAX11208B (Note 6)
90
90
144
65
73
GND
GND -
30mV
V
AVDD
+
30mV
±1
5
80.5
87
V
AVDD
dB
dB
V
123
dB
AVDD DC rejection
DVDD DC Rejection
70
90
After calibration, V
REFP
- V
REFN
= 2.5V
(Note 5)
-30
NFR
VN
INL
V
OFF
MAX11208A
MAX11208B
MAX11208A
MAX11208B
(Note 4)
After calibration, V
REFP
- V
REFN
= 2.5V
-10
-13
1
50
3
0.05
80
100
+30
19
20
2.1
0.72
+10
+13
Bits
FV
RMS
ppmFSR
ppmFSR
nV/NC
ppmFSR
ppmFSR/
NC
dB
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
FA
FA
2_ _ _______________________________________________________________________________________
20-Bit, Single-Channel, Ultra-Low-Power,
Delta-Sigma ADC with 2-Wire Serial Interface
ELECTRICAL_CHARACTERISTICS_(continued)
(V
AVDD
= +3.6V, V
DVDD
= +1.8V, V
REFP
- V
REFN
= V
AVDD
; internal clock, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values
are at T
A
= +25NC under normal conditions, unless otherwise noted.)
PARAMETER
REF Dynamic Input Current
AIN Input Capacitance
REF Input Capacitance
AIN Voltage Range
REF Voltage Range
Input Sampling Rate
REF Sampling Rate
LOGIC_INPUTS_(SCLK,_CLK)
Input Current
Input Low Voltage
Input High Voltage
Input Hysteresis
External Clock
LOGIC_OUTPUTS_(RDY/DOUT)
Output Low Level
Output High Level
Floating State Leakage Current
Floating State Output
Capacitance
POWER_REQUIREMENTS
Analog Supply Voltage
Digital Supply Voltage
Total Operating Current
DVDD Operating Current
AVDD Operating Current
AVDD Sleep Current
DVDD Sleep Current
2-WIRE_SERIAL-INTERFACE_TIMING_CHARACTERISTICS
SCLK Frequency
SCLK Pulse Width Low
SCLK Pulse Width High
SCLK Rising Edge to Data Valid
Transition Time
f
SCLK
t
1
t
2
t
3
60/40 duty cycle 5MHz clock
40/60 duty cycle 5MHz clock
80
80
40
5
MHz
ns
ns
ns
AVDD
DVDD
(AVDD + DVDD)
2.7
1.7
230
45
185
0.4
0.35
3.6
3.6
300
60
245
2
2
V
V
FA
FA
FA
FA
FA
V
IL
V
IH
V
HYS
MAX11208A
MAX11208B
V
OL
V
OH
I
OL
= 1mA, also tested for V
DVDD
= 3.6V
I
OH
= 1mA, also tested for V
DVDD
= 3.6V
Output leakage current
0.9 x
V
DVDD
Q10
9
0.7 x
V
DVDD
200
2.4576
2.2528
0.4
Input leakage current
Q1
0.3 x
V
DVDD
FA
V
V
mV
MHz
f
S
MAX11208A
MAX11208B
MAX11208A
MAX11208B
246
225
246
225
V
AINP
- V
AINN
-V
REF
SYMBOL
CONDITIONS
MIN
TYP
7.5
10
15
+V
REF
V
AVDD
MAX
UNITS
FA
pF
pF
V
V
kHz
kHz
MAX11208
V
V
FA
pF
________________________________________________________________________________________ _ 3
20-Bit, Single-Channel, Ultra-Low-Power,
Delta-Sigma ADC with 2-Wire Serial Interface
MAX11208
ELECTRICAL_CHARACTERISTICS_(continued)
(V
AVDD
= +3.6V, V
DVDD
= +1.8V, V
REFP
- V
REFN
= V
AVDD
; internal clock, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values
are at T
A
= +25NC under normal conditions, unless otherwise noted.)
PARAMETER
SCLK Rising Edge Data Hold
Time
RDY/DOUT
Fall to SCLK Rising
Edge
Next Data Update Time; No Read
Allowed
Data Conversion Time
Data Ready Time After Calibration
Starts (CAL + CNV)
SCLK High After
RDY/DOUT
Goes
Low to Activate Sleep Mode
Time from
RDY/DOUT
Low to
SCLK High for Sleep-Mode
Activation
Data Ready Time After Wake-Up
from Sleep Mode
Data Ready Time After Calibration
from Sleep-Mode Wake-Up (CAL
+ CNV)
Note_2:
Note_3:
Note_4:
Note_5:
Note_6:
SYMBOL
t
4
t
5
t
6
t
7
t
8
t
9
t
10
t
11
t
12
MAX11208A
MAX11208B
MAX11208A
MAX11208B
MAX11208A
MAX11208B
MAX11208A
MAX11208B
MAX11208A
MAX11208B
MAX11208A
MAX11208B
MAX11208A
MAX11208B
0
0
0
0
8.6
73
208.4
256.2
CONDITIONS
Allows for positive edge data read
MIN
3
0
155
169
8.6
73
208.3
256.1
8.6
73
8.6
73
TYP
MAX
UNITS
ns
ns
Fs
ms
ms
ms
ms
ms
ms
These specifications are not fully tested and are guaranteed by design and/or characterization.
V
AINP
= V
AINN
.
ppmFSR is parts per million of full-scale range.
Positive full-scale error includes zero-scale errors.
The MAX11208A has no normal-mode rejection at 50Hz or 60Hz.
4_ _ _______________________________________________________________________________________
20-Bit, Single-Channel, Ultra-Low-Power,
Delta-Sigma ADC with 2-Wire Serial Interface
Typical Operating Characteristics
(V
AVDD
= 3.6V, V
DVDD
= 1.8V, V
REFP
- V
REFN
= AVDD; internal clock; T
A
= T
MIN
to T
MAX
, unless otherwise specified. Typical values
are at T
A
= +25NC.)
ANALOG ACTIVE CURRENT
vs. AVDD VOLTAGE (MAX11208A)
MAX11208 toc01
MAX11208
ANALOG ACTIVE CURRENT
vs. AVDD VOLTAGE (MAX11208B)
MAX11208 toc02
ANALOG SLEEP CURRENT vs. AVDD
VOLTAGE (MAX11208A/MAX11208B)
V
DVDD
= 1.8V
0.8
CURRENT (µA)
0.6
0.4
0.2
T
A
= +25°C
0
T
A
= +85°C
T
A
= -45°C
MAX11208 toc03
240
V
DVDD
= 1.8V
220
200
CURRENT (µA)
180
160
140
120
100
2.70
2.85
3.00
3.15
3.30
3.45
T
A
= +85°C
T
A
= +25°C
T
A
= -45°C
240
V
DVDD
= 1.8V
220
200
CURRENT (µA)
180
160
140
120
100
T
A
= +85°C
T
A
= +25°C
T
A
= -45°C
1.0
3.60
2.70
2.85
3.00
3.15
3.30
3.45
3.60
2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6
AVDD VOLTAGE (V)
AVDD VOLTAGE (V)
AVDD VOLTAGE (V)
ACTIVE SUPPLY CURRENT
vs. TEMPERATURE (MAX11208A)
MAX11208 toc04
ACTIVE SUPPLY CURRENT
vs. TEMPERATURE (MAX11208B)
MAX11208 toc05
SLEEP CURRENT vs. TEMPERATURE
(MAX11208A/MAX11208B)
V
AVDD
= 3.6V
V
DVDD
= 1.8V
MAX11208 toc06
300
250
200
150
100
V
DVDD
= 1.8V
50
0
-45
-25
-5
15
35
55
75
300
250
TOTAL
CURRENT (µA)
200
V
AVDD
= 3.6V
150
100
50
0
V
DVDD
= 1.8V
1.0
0.8
CURRENT (µA)
0.6
0.4
0.2
0
V
DVDD
TOTAL
TOTAL
V
AVDD
= 3.6V
CURRENT (µA)
V
AVDD
95
-45
-25
-5
15
35
55
75
95
-45
-25
-5
15
35
55
75
95
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
DIGITAL ACTIVE CURRENT
vs. DVDD VOLTAGE
MAX11208 toc07
DIGITAL SLEEP CURRENT vs. DVDD
VOLTAGE (MAX11208A/MAX11208B)
MAX11208 toc08
INTERNAL OSCILLATOR FREQUENCY
vs. TEMPERATURE
V
DVDD
= 1.8V
V
AVDD
= 3.0V
MAX11208 toc09
130
120
110
CURRENT (µA)
100
90
80
70
60
50
40
V
AVDD
= 3.6V
T
A
= +85°C, +25°C, -45°C
3.0
V
AVDD
= 3.6V
2.5
2.0
1.5
1.0
T
A
= +85°C
0.5
0
T
A
= -45°C
T
A
= +25°C
2.6
2.5
FREQUENCY (MHz)
2.4
2.3
2.2
2.1
2.0
MAX11208B
MAX11208A
MAX11208B
1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6
DVDD VOLTAGE (V)
CURRENT (µA)
MAX11208A
1.7 1.9 2.1 2.3 2.5 2.7 2.9 3.1 3.3 3.5
DVDD VOLTAGE (V)
-45
-25
-5
15
35
55
75
95
TEMPERATURE (°C)
________________________________________________________________________________________ _ 5
嵌入式系统
