19-2851; Rev 7; 4/12
KIT
ATION
EVALU
BLE
AVAILA
12-Bit 300ksps ADCs with FIFO,
Temp Sensor, Internal Reference
Features
o
Internal Temperature Sensor (±0.7°C Accuracy)
o
16-Entry First-In/First-Out (FIFO)
o
Analog Multiplexer with True Differential
Track/Hold
16-, 12-, 8-Channel Single Ended
8-, 6-, 4-Channel True Differential
(Unipolar or Bipolar)
o
Accuracy: ±1 LSB INL, ±1 LSB DNL, No Missing
Codes Overtemperature
o
Scan Mode, Internal Averaging, and Internal Clock
o
Low-Power Single +3V Operation
1mA at 300ksps
o
Internal 2.5V Reference or External Differential
Reference
o
10MHz 3-Wire SPI-/QSPI-/MICROWIRE-Compatible
Interface
o
Space-Saving 28-Pin 5mm x 5mm TQFN Package
General Description
The MAX1227/MAX1229/MAX1231 are serial 12-bit ana-
log-to-digital converters (ADCs) with an internal reference
and an internal temperature sensor. These devices fea-
ture an on-chip FIFO, scan mode, internal clock mode,
internal averaging, and AutoShutdown™. The maximum
sampling rate is 300ksps using an external clock. The
MAX1231 has 16 input channels, the MAX1229 has 12
input channels, and the MAX1227 has 8 input channels.
All input channels are configurable for single-ended or
differential inputs in unipolar or bipolar mode. All three
devices operate from a +3V supply and contain a 10MHz
SPI™-/QSPI™-/MICROWIRE™-compatible serial port.
The MAX1231 is available in 28-pin 5mm x 5mm TQFN
with exposed pad and 24-pin QSOP packages. The
MAX1227/MAX1229 are only available in QSOP pack-
ages. All three devices are specified over the extended
-40°C to +85°C temperature range.
MAX1227/MAX1229/MAX1231
________________________Applications
System Supervision
Data-Acquisition Systems
Industrial Control Systems
Patient Monitoring
Data Logging
Instrumentation
AutoShutdown is a trademark of Maxim Integrated Products, Inc.
SPI/QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
Ordering Information
PART
MAX1227BCEE+
MAX1227BEEE+
MAX1229BCEP+
MAX1229BEEP+
TEMP RANGE
0°C to +70°C
-40°C to +85°C
0°C to +70°C
-40°C to +85°C
PIN-PACKAGE
16 QSOP
16 QSOP
20 QSOP
20 QSOP
Ordering Information continued at end of data sheet.
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed pad (TQFN only). Connect to GND.
Pin Configurations
+
TOP VIEW
AIN0 1
AIN1 2
AIN2 3
AIN3 4
AIN4 5
AIN5 6
REF-/AIN6 7
CNVST/AIN7 8
AIN0 1
20 EOC
19 DOUT
18 DIN
17 CS
+
16 EOC
15 DOUT
AIN1 2
AIN2 3
AIN3 4
14 DIN
MAX1227
AIN4 5
13 CS
AIN5 6
12 SCLK
AIN6 7
11 V
DD
10 GND
9
REF+
AIN8 9
AIN9 10
AIN7 8
MAX1229
16 SCLK
15 V
DD
14 GND
13 REF+
12 CNVST/AIN11
11 REF-/AIN10
QSOP
Pin Configurations continued at end of data sheet.
QSOP
________________________________________________________________
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.
12-Bit 300ksps ADCs with FIFO,
Temp Sensor, Internal Reference
MAX1227/MAX1229/MAX1231
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND ..............................................................-0.3V to +6V
CS,
SCLK, DIN,
EOC,
DOUT to GND.........-0.3V to (V
DD
+ 0.3V)
AIN0–AIN13, REF-/AIN_,
CNVST/AIN_,
REF+ to GND.........................................-0.3V to (V
DD
+ 0.3V)
Maximum Current into Any Pin............................................50mA
Continuous Power Dissipation (T
A
= +70°C)
16-Pin QSOP (derate 8.3mW/°C above +70°C)...........667mW
20-Pin QSOP (derate 9.1mW/°C above +70°C)...........727mW
24-Pin QSOP (derate 9.5mW/°C above +70°C)...........762mW
28-Pin TQFN 5mm x 5mm
(derate 20.8mW/°C above +70°C) ........................1667mW
Operating Temperature Ranges
MAX12__C__.......................................................0°C to +70°C
MAX12__E__ ....................................................-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
(V
DD
= +2.7V to +3.6V, f
SAMPLE
= 300kHz, f
SCLK
= 4.8MHz (50% duty cycle), V
REF
= 2.5V, T
A
= T
MIN
to T
MAX
, unless otherwise
noted. Typical values are at T
A
= +25°C.)
PARAMETER
DC ACCURACY (NOTE 1)
Resolution
Integral Nonlinearity
Differential Nonlinearity
Offset Error
Gain Error
Offset Error Temperature
Coefficient
Gain Temperature Coefficient
Channel-to-Channel Offset
Matching
DYNAMIC SPECIFICATIONS (30kHz sine wave input, 2.5V
P-P
, 300ksps, f
SCLK
= 4.8MHz)
Signal-to-Noise Plus Distortion
Total Harmonic Distortion
Spurious-Free Dynamic Range
Intermodulation Distortion
Full-Power Bandwidth
Full-Linear Bandwidth
SINAD
THD
SFDR
IMD
f
IN1
= 29.9kHz, f
IN2
= 30.2kHz
-3dB point
S/(N + D) > 68dB
Up to the 5th harmonic
71
-80
81
76
1
100
dB
dBc
dBc
dBc
MHz
kHz
(Note 2)
RES
INL
DNL
No missing codes over temperature
±0.5
±0.5
±2
±0.8
±0.1
12
±1.0
±1.0
±4.0
±4.0
Bits
LSB
LSB
LSB
LSB
ppm/°C
FSR
ppm/°C
LSB
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
12-Bit 300ksps ADCs with FIFO,
Temp Sensor, Internal Reference
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.7V to +3.6V, f
SAMPLE
= 300kHz, f
SCLK
= 4.8MHz (50% duty cycle), V
REF
= 2.5V, T
A
= T
MIN
to T
MAX
, unless otherwise
noted. Typical values are at T
A
= +25°C.)
PARAMETER
CONVERSION RATE
Power-Up Time
Acquisition Time
Conversion Time
External Clock Frequency
SCLK Duty Cycle
Aperture Delay
Aperture Jitter
ANALOG INPUT
Input Voltage Range
Input Leakage Current
Input Capacitance
INTERNAL TEMPERATURE SENSOR
Measurement Error (Note 7)
Temperature Measurement Noise
Temperature Resolution
Power-Supply Rejection
INTERNAL REFERENCE
REF Output Voltage
REF Temperature Coefficient
Output Resistance
REF Output Noise
REF Power-Supply Rejection
EXTERNAL REFERENCE INPUT
REF- Input Voltage Range
REF+ Input Voltage Range
REF+ Input Current
V
REF-
V
REF+
I
REF+
V
REF+
= 2.5V, f
SAMPLE
= 300ksps
V
REF+
= 2.5V, f
SAMPLE
= 0
0
1.0
40
±0.1
500
V
DD
+ 50mV
100
±5
mV
V
µA
PSRR
TC
REF
2.48
2.50
±30
6.5
200
-70
2.52
V
ppm/°C
kΩ
µV
RMS
dB
T
A
= +25°C
T
A
= T
MIN
to T
MAX
±0.7
±1.2
0.4
1/8
0.3
±2.5
°C
°C
RMS
°C
°C/V
Unipolar
Bipolar (Note 5)
V
IN
= V
DD
During acquisition time (Note 6)
0
-V
REF
/2
±0.01
24
V
REF
V
REF
/2
±1
V
µA
pF
t
PU
t
ACQ
t
CONV
f
SCLK
Internally clocked
Externally clocked (Note 4)
Externally clocked conversion
Data I/O
40
30
<50
2.7
0.1
4.8
10
60
3.5
External reference
Internal reference (Note 3)
0.8
65
0.6
µs
µs
µs
MHz
%
ns
ps
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX1227/MAX1229/MAX1231
_______________________________________________________________________________________
3
12-Bit 300ksps ADCs with FIFO,
Temp Sensor, Internal Reference
MAX1227/MAX1229/MAX1231
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.7V to +3.6V, f
SAMPLE
= 300kHz, f
SCLK
= 4.8MHz (50% duty cycle), V
REF
= 2.5V, T
A
= T
MIN
to T
MAX
, unless otherwise
noted. Typical values are at T
A
= +25°C.)
PARAMETER
Input Voltage Low
Input Voltage High
Input Hysteresis
Input Leakage Current
Input Capacitance
DIGITAL OUTPUTS (DOUT,
EOC)
Output Voltage Low
Output Voltage High
Tri-State Leakage Current
Tri-State Output Capacitance
POWER REQUIREMENTS
Supply Voltage
V
DD
During temp sense
Internal
reference
Supply Current (Note 9)
I
DD
External
reference
Power-Supply Rejection
PSR
f
SAMPLE
= 300ksps
f
SAMPLE
= 0, REF on
Shutdown
During temp sense
f
SAMPLE
= 300ksps
Shutdown
V
DD
= 2.7V to 3.6V; full-scale input
2.7
2400
1750
1000
0.2
1550
1050
0.2
±0.2
3.6
2700
2000
1200
5
2000
1200
5
±1
mV
µA
V
V
OL
V
OH
I
L
C
OUT
I
SINK
= 2mA
I
SINK
= 4mA
I
SOURCE
= 1.5mA
CS
= V
DD
CS
= V
DD
V
DD
- 0.5
±0.05
15
±1
0.4
0.8
V
V
µA
pF
SYMBOL
V
IL
V
IH
V
HYST
I
IN
C
IN
V
IN
= 0 or V
DD
V
DD
x 0.7
200
±0.01
15
±1.0
CONDITIONS
MIN
TYP
MAX
V
DD
x 0.3
UNITS
V
V
mV
µA
pF
DIGITAL INPUTS (SCLK, DIN,
CS, CNVST)
(Note 8)
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
Note 9:
Tested at V
DD
= +2.7V, unipolar input mode.
Offset nulled.
Time for reference to power up and settle to within 1 LSB.
Conversion time is defined as the number of clock cycles multiplied by the clock period; clock has 50% duty cycle.
The operational input voltage range for each individual input of a differentially configured pair is from GND to V
DD
. The
operational input voltage difference is from -V
REF
/2 to +V
REF
/2.
See Figure 3 (Input Equivalent Circuit) and the Typical Operating Curve in the
Sampling Error vs. Source Impedance
sec-
tion.
Fast automated test, excludes self-heating effects.
When CNVST is configured as a digital input, do not apply a voltage between V
IL
and V
IN
.
Supply current is specified depending on whether an internal or external reference is used for voltage conversions.
Temperature measurements always use the internal reference.
4
_______________________________________________________________________________________
12-Bit 300ksps ADCs with FIFO,
Temp Sensor, Internal Reference
MAX1227/MAX1229/MAX1231
TIMING CHARACTERISTICS (Figure 1)
PARAMETER
SCLK Clock Period
SCLK Duty Cycle
SCLK Fall to DOUT Transition
CS
Rise to DOUT Disable
CS
Fall to DOUT Enable
DIN to SCLK Rise Setup
SCLK Rise to DIN Hold
C
S
Rise-to-SCLK Rise Setup Time
CS Fall-to-SCLK Hold Time
CNVST
Pulse Width
CS
or
CNVST
Rise to
EOC
Low (Note 10)
SYMBOL
t
CP
t
CH
t
DOT
t
DOD
t
DOE
t
DS
t
DH
t
CSS1
T
CSH0
t
CSW
t
TS
CKSEL = 00, CKSEL = 01 (temp sense)
CKSEL = 01 (voltage conversion)
Temp sense
Voltage conversion
Reference power-up
0
40
0
40
1.4
55
7
65
µs
C
LOAD
= 30pF
C
LOAD
= 30pF
C
LOAD
= 30pF
Data I/O
CONDITIONS
Externally clocked conversion
MIN
208
100
40
60
40
40
40
40
TYP
MAX
UNITS
ns
%
ns
ns
ns
ns
ns
ns
ns
ns
µs
Note 10:
This time is defined as the number of clock cycles needed for conversion multiplied by the clock period. If the internal ref
erence needs to be powered up, the total time is additive. The internal reference is always used for temperature measure
ments.
Typical Operating Characteristics
(V
DD
= +3V, V
REF
= +2.5V, f
SCLK
= 4.8MHz, C
LOAD
= 30pF, T
A
= +25°C, unless otherwise noted.)
INTEGRAL NONLINEARITY
vs. OUTPUT CODE
MAX1227/29/31 toc01
DIFFERENTIAL NONLINEARITY
vs. OUTPUT CODE
MAX1227/29/31 toc02
SINAD vs. FREQUENCY
90
80
AMPLITUDE (dB)
70
60
50
40
30
20
10
0
MAX1227/29/31 toc03
1.0
0.8
INTEGRAL NONLINEARITY (LSB)
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0
1024
2048
OUTPUT CODE
3072
1.0
0.8
DIFFERENTIAL NONLINEARITY (LSB)
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
100
4096
-1.0
0
1024
2048
OUTPUT CODE
3072
4096
0.1
1
10
FREQUENCY (kHz)
100
1000
_______________________________________________________________________________________
5
微控制器 MCU
