General Description
The MAX1226/MAX1228/MAX1230 are serial 12-bit ana-
log-to-digital converters (ADCs) with an internal reference
and an internal temperature sensor. These devices fea-
ture on-chip FIFO, scan mode, internal clock mode, inter-
nal averaging, and AutoShutdownTM. The maximum
sampling rate is 300ksps using an external clock. The
MAX1230 has 16 input channels, the MAX1228 has 12
input channels, and the MAX1226 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 +5V supply and contain a 10MHz
SPITM/QSPITM/MICROWIRETM-compatible serial port.
The MAX1230 is available in 28-pin 5mm x 5mm QFN
with exposed pad and 24-pin QSOP packages. The
MAX1226/MAX1228 are only available in QSOP pack-
ages. All three devices are specified over the extended
-40°C to +85°C temperature range.
________________________Applications
System Supervision
Data-Acquisition Systems
Industrial Control Systems
Patient Monitoring
Data Logging
Instrumentation
Features
o Internal Temperature Sensor (±1°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 Over Temperature
o Scan Mode, Internal Averaging, and Internal Clock
o Low-Power Single +5V Operation
1.9mA at 300ksps
o Internal 4.096V Reference or External Differential
Reference
o 10MHz 3-Wire SPI/QSPI/MICROWIRE-Compatible
Interface
o Space-Saving 28-Pin 5mm x 5mm QFN Package
MAX1226/MAX1228/MAX1230
12-Bit 300ksps ADCs with FIFO,
Temp Sensor, Internal Reference
________________________________________________________________ Maxim Integrated Products
1
Pin Configurations
19-2852; Rev 1; 7/03
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.
EVALUATION KIT
AVAILABLE
Ordering Information
*Future product--contact factory for availability.
Ordering Information continued at end of data sheet.
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
AIN0
EOC
DOUT
DIN
CS
SCLK
V
DD
GND
REF+
MAX1226
QSOP
AIN1
AIN2
AIN5
AIN3
AIN4
REF-/AIN6
CNVST/AIN7
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
EOC
DOUT
DIN
CS
AIN3
AIN2
AIN1
AIN0
SCLK
V
DD
GND
REF+
AIN7
AIN6
AIN5
AIN4
12
11
9
10
CNVST/AIN11
REF-/AIN10
AIN9
AIN8
MAX1228
QSOP
TOP VIEW
PART
TEMP RANGE
PIN-PACKAGE
MAX1226ACEE-T*
0°C to +70°C
16 QSOP
MAX1226AEEE-T*
-40°C to +85°C
16 QSOP
Pin Configurations continued at end of data sheet.
AutoShutdown is a trademark of Maxim Integrated Products, Inc.
SPI/QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
MAX1226/MAX1228/MAX1230
12-Bit 300ksps ADCs with FIFO,
Temp Sensor, Internal Reference
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
DD
= +5V ±5%, f
SAMPLE
= 300kHz, f
SCLK
= 4.8MHz (50% duty cycle), V
REF
= 4.096V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Typical values are at T
A
= +25°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.
V
DD
to GND ..............................................................-0.3V to +6V
CS, SCLK, DIN, EOC, DOUT to GND.........-0.3V to (V
DD
+ 0.3V)
AIN0AIN13, 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 QFN 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
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC ACCURACY (Note 1)
Resolution
RES
12
Bits
Integral Nonlinearity
INL
±1.0
LSB
Differential Nonlinearity
DNL
No missing codes over temperature
±1.0
LSB
Offset Error
±0.5
±4.0
LSB
Gain Error
(Note 2)
±0.5
±4.0
LSB
Offset Error Temperature
Coefficient
±2
ppm/°C
FSR
Gain Temperature Coefficient
±0.8
ppm/°C
Channel-to-Channel Offset
Matching
±0.1
LSB
DYNAMIC SPECIFICATIONS (10kHz sine wave input, 4.096V
P-P
, 300ksps, f
SCLK
= 4.8MHz)
Signal-to-Noise Plus Distortion
SINAD
70
dB
Total Harmonic Distortion
THD
Up to the 5th harmonic
-82
dBc
Spurious-Free Dynamic Range
SFDR
80
dBc
Intermodulation Distortion
IMD
f
in1
= 9.9kHz, f
in2
= 10.2kHz
76
dBc
Full-Power Bandwidth
-3dB point
1
MHz
Full-Linear Bandwidth
S / (N + D) > 68dB
25
kHz
MAX1226/MAX1228/MAX1230
12-Bit 300ksps ADCs with FIFO,
Temp Sensor, Internal Reference
_______________________________________________________________________________________
3
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +5V ±5%, f
SAMPLE
= 300kHz, f
SCLK
= 4.8MHz (50% duty cycle), V
REF
= 4.096V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Typical values are at T
A
= +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
CONVERSION RATE
External reference
0.8
Power-Up Time
t
PU
Internal reference (Note 3)
65
µs
Acquisition Time
t
ACQ
0.6
µs
Internally clocked
3.5
Conversion Time
t
CONV
Externally clocked (Note 4)
2.7
µs
Externally clocked conversion
0.1
4.8
External Clock Frequency
f
SCLK
Data I/O
10
MHz
SCLK Duty Cycle
40
60
%
Aperture Delay
30
ns
Aperture Jitter
<50
ps
ANALOG INPUT
Unipolar
0
V
REF
Input Voltage Range
Bipolar (Note 5)
- V
RE F
/ 2
V
RE F
/ 2
V
Input Leakage Current
V
IN
= V
DD
±0.01
±1
µA
Input Capacitance
During acquisition time (Note 6)
24
pF
INTERNAL TEMPERATURE SENSOR
Grade A, T
A
= +25
°C
±0.3
Grade A =, T
A
= -20°C to +85°C
±0.5
±1
Grade A, T
A
= T
MIN
to T
MAX
±0.75
±1.5
Grade B, T
A
= +25
°C
±0.7
Measurement Error (Note 7)
Grade B, T
A
= T
MIN
to T
MAX
±1.2
±3.0
°C
Temperature Measurement Noise
0.1
°C
RMS
Temperature Resolution
1/8
°C
Power-Supply Rejection
0.3
°C/V
INTERNAL REFERENCE
REF Output Voltage
4.024
4.096
4.168
V
Grade A
±8
REF Temperature Coefficient
TC
REF
Grade B
±30
ppm/°C
Output Resistance
6.5
k
REF Output Noise
200
µV
RMS
REF Power-Supply Rejection
PSRR
-70
dB
EXTERNAL REFERENCE INPUT
REF- Input Voltage Range
V
REF-
0
500
mV
REF+ Input Voltage Range
V
REF+
1.0
V
DD
+ 50mV
V
V
REF+
= 4.096V, f
SAMPLE
= 300ksps
40
100
REF+ Input Current
I
REF+
V
REF+
= 4.096V, f
SAMPLE
= 0
±0.1
±5
µA
MAX1226/MAX1228/MAX1230
12-Bit 300ksps ADCs with FIFO,
Temp Sensor, Internal Reference
4
_______________________________________________________________________________________
Note 1: Tested at V
DD
= +5V, unipolar input mode.
Note 2: Offset nulled.
Note 3: Time for reference to power up and settle to within 1 LSB.
Note 4: Conversion time is defined as the number of clock cycles multiplied by the clock period; clock has 50% duty cycle.
Note 5: 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.
Note 6: See Figure 3 (Input Equivalent Circuit) and the Sampling Error vs. Source Impedance curve in the Typical Operating
Characterisitcs section.
Note 7: Fast automated test, excludes self-heating effects.
Note 8: Supply current is specified depending on whether an internal or external reference is used for voltage conversions.
Temperature measurements always use the internal reference.
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +5V ±5%, f
SAMPLE
= 300kHz, f
SCLK
= 4.8MHz (50% duty cycle), V
REF
= 4.096V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Typical values are at T
A
= +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DIGITAL INPUTS (SCLK, DIN,
CS, CNVST)
Input Voltage Low
V
IL
0.8
V
Input Voltage High
V
IH
2.0
V
Input Hysteresis
V
HYST
200
mV
Input Leakage Current
I
IN
V
IN
= 0 or V
DD
±0.01
±1.0
µA
Input Capacitance
C
IN
15
pF
DIGITAL OUTPUTS (DOUT,
EOC)
I
SINK
= 2mA
0.4
Output Voltage Low
V
OL
I
SINK
= 4mA
0.8
V
Output Voltage High
V
OH
I
SOURCE
= 1.5mA
V
DD
- 0.5
V
Tri-State Leakage Current
I
L
CS = V
DD
±0.05
±1
µA
Tri-State Output Capacitance
C
OUT
CS = V
DD
15
pF
POWER REQUIREMENTS
Supply Voltage
V
DD
4.75
5.25
V
During temp sense
2400
3100
f
SAMPLE
= 300ksps
1950
2300
f
SAMPLE
= 0, REF on
1000
1350
Internal
reference
Shutdown
0.2
5
During temp sense
1650
2300
f
SAMPLE
= 300ksps
1250
1500
Supply Current (Note 8)
I
DD
External
reference
Shutdown
0.2
5
µA
Power-Supply Rejection
PSR
V
DD
= 4.75V to 5.25V; full-scale input
±0.2
±1.2
mV
MAX1226/MAX1228/MAX1230
12-Bit 300ksps ADCs with FIFO,
Temp Sensor, Internal Reference
_______________________________________________________________________________________
5
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Externally clocked conversion
208
SCLK Clock Period
t
CP
Data I/O
100
ns
SCLK Duty Cycle
t
CH
40
60
%
SCLK Fall to DOUT Transition
t
DOT
C
LOAD
= 30pF
40
ns
CS Rise to DOUT Disable
t
DOD
C
LOAD
= 30pF
40
ns
CS Fall to DOUT Enable
t
DOE
C
LOAD
= 30pF
40
ns
DIN to SCLK Rise Setup
t
DS
40
ns
SCLK Rise to DIN Hold
t
DH
0
ns
CS to SCLK Rise Setup
t
CSS
40
ns
SCLK Rise to
CS Hold
t
CSH
0
ns
t
CSW
CKSEL = 00, CKSEL = 01 (temp sense)
40
ns
CNVST Pulse Width
CKSEL = 01 (voltage conversion)
1.4
µs
t
T S
Temp sense
55
Voltage conversion
7
CS or CNVST Rise to EOC
Low (Note 9)
t
R P
Reference power-up
65
µs
TIMING CHARACTERISTICS (Figure 1)
Note 9: This time is defined as the number of clock cycles needed for conversion multiplied by the clock period. If the internal refer-
ence needs to be powered up, the total time is additive. The internal reference is always used for temperature measurements.
-1.0
-0.4
-0.6
-0.8
-0.2
0
0.2
0.4
0.6
0.8
1.0
0
1024
2048
3072
4096
INTEGRAL NONLINEARITY
vs. OUTPUT CODE
MAX1226/28/30 toc01
OUTPUT CODE
INTEGRAL NONLINEARITY (LSB)
-1.0
-0.4
-0.6
-0.8
-0.2
0
0.2
0.4
0.6
0.8
1.0
0
1024
2048
3072
4096
DIFFERENTIAL NONLINEARITY
vs. OUTPUT CODE
MAX1226/28/30 toc02
OUTPUT CODE
DIFFERENTIAL NONLINEARITY (LSB)
SINAD vs. FREQUENCY
MAX1226/28/30 toc03
FREQUENCY (kHz)
SINAD AMPLITUDE (dB)
100
10
1
10
20
30
40
50
60
70
80
90
100
0
0.1
1000
Typical Operating Characteristics
(V
DD
= +5V, V
REF
= +4.096V, f
SCLK
= 4.8MHz, C
LOAD
= 30pF, T
A
= +25°C, unless otherwise noted.)
PDF 
ZIP