19-5962; Rev 1; 9/11
KIT
ATION
EVALU
BLE
AVAILA
12-Bit, 300ksps ADCs with Differential
Track/Hold, and Internal Reference
General Description
The MAX11634–MAX11637 are serial 12-bit analog-to-
digital converters (ADCs) with an internal reference and
true differential track/hold. These devices feature on-chip
FIFO, scan mode, internal clock mode, internal averag-
ing, and AutoShutdown™. The maximum sampling rate is
300ksps using an external clock. The MAX11636/
MAX11637 have 8 input channels and the MAX11634/
MAX11635 have 4 input channels. These four devices
operate from either a +3V supply or a +5V supply, and
contain a 10MHz SPI™-/QSPI™-/MICROWIRE™-compati-
ble serial port.
The MAX11634–MAX11637 are available in a 16-pin
QSOP package. All four devices are specified over the
extended -40°C to +85°C temperature range.
Features
o
Analog Multiplexer with True Differential Track/Hold
8-/4-Channel Single-Ended
4-/2-Channel True Differential
Unipolar or Bipolar Inputs
o
Single Supply
2.7V to 3.6V (MAX11635/MAX11637)
4.75V to 5.25V (MAX11634/MAX11636)
o
External Reference: 1V to V
DD
o
16-Entry First-In/First-Out (FIFO)
o
Scan Mode, Internal Averaging, and Internal Clock
o
Accuracy: ±1 LSB INL, ±1 LSB DNL, No Missing
Codes Over Temperature
o
10MHz 3-Wire SPI-/QSPI-/MICROWIRE-Compatible
Interface
o
Small 16-Pin QSOP Package
MAX11634–MAX11637
Applications
System Supervision
Data-Acquisition Systems
Industrial Control Systems
Patient Monitoring
Data Logging
Instrumentation
Ordering Information/Selector Guide
PART
MAX11634EEE+T
MAX11635EEE+T
MAX11636EEE+T
MAX11637EEE+T
NUMBER OF INPUTS
4 Single-Ended/
2 Differential
4 Single-Ended/
2 Differential
8 Single-Ended/
4 Differential
8 Single-Ended/
4 Differential
SUPPLY VOLTAGE (V)
4.75 to 5.25
2.7 to 3.6
4.75 to 5.25
2.7 to 3.6
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
16 QSOP
16 QSOP
16 QSOP
16 QSOP
+Denotes
a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
AutoShutdown is a trademark of Maxim Integrated Products, Inc.
SPI/QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
________________________________________________________________
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 Differential
Track/Hold, and Internal Reference
MAX11634–MAX11637
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–AIN5, REF-/AIN6,
CNVST/AIN7,
REF+ to GND.........................................-0.3V to (V
DD
+ 0.3V)
Maximum Current into any Pin ............................................50mA
Continuous Power Dissipation (T
A
= +70°C)
QSOP (single-layer board)
(derate 8.3mW/°C above +70°C) .................................667mW
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.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
QSOP
Junction-to-Ambient Thermal Resistance (θ
JA
)...............105°C/W
Junction-to-Case Thermal Resistance (θ
JC
)......................37°C/W
Note 1:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to
www.maxim-ic.com/thermal-tutorial.
ELECTRICAL CHARACTERISTICS
(V
DD
= 2.7V to 3.6V (MAX11635/MAX11637), V
DD
= 4.75V to 5.25V (MAX11634/MAX11636), f
SAMPLE
= 300kHz, f
SCLK
= 4.8MHz
(external clock, 50% duty cycle), V
REF
= 2.5V (MAX11635/MAX11637), V
REF
= 4.096V (MAX11634/MAX11636) T
A
= T
MIN
to T
MAX
,
unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 2)
PARAMETER
DC ACCURACY (Note 3)
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, 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
MAX11635/MAX11637
MAX11634/MAX11636
Up to the 5th
harmonic
MAX11635/MAX11637
MAX11634/MAX11636
71
73
-80
-88
81
89
76
1
100
dB
dBc
dBc
dBc
MHz
kHz
(Note 4)
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
MAX11635/MAX11637
MAX11634/MAX11636
f
IN1
= 29.9kHz, f
IN2
= 30.2kHz
-3dB point
S/(N + D) > 68dB
2
_______________________________________________________________________________________
12-Bit, 300ksps ADCs with Differential
Track/Hold, and Internal Reference
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= 2.7V to 3.6V (MAX11635/MAX11637), V
DD
= 4.75V to 5.25V (MAX11634/MAX11636), f
SAMPLE
= 300kHz, f
SCLK
= 4.8MHz
(external clock, 50% duty cycle), V
REF
= 2.5V (MAX11635/MAX11637), V
REF
= 4.096V (MAX11634/MAX11636) T
A
= T
MIN
to T
MAX
,
unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 2)
PARAMETER
CONVERSION RATE
Power-Up Time
Acquisition Time
Conversion Time
External Clock Frequency
Aperture Delay
Aperture Jitter
ANALOG INPUT
Input Voltage Range
Input Leakage Current
Input Capacitance
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
V
REF-
V
REF+
V
REF+
= 2.5V (MAX11635/MAX11637),
V
REF+
= 4.096V (MAX11634/MAX11636),
f
SAMPLE
= 300ksps
V
REF+
= 2.5V (MAX11635/MAX11637),
V
REF+
= 4.096V (MAX11634/MAX11636),
f
SAMPLE
= 0
MAX11634/MAX11636
MAX11635/MAX11637
MAX11634/MAX11636
MAX11635/MAX11637
2.0
V
DD
x 0.7
200
0
1.0
40
500
V
DD
+ 50mV
100
µA
±0.1
±5
mV
V
PSRR
TC
REF
MAX11634/MAX11636
MAX11635/MAX11637
MAX11634/MAX11636
MAX11635/MAX11637
4.024
2.48
4.096
2.50
±20
±30
6.5
200
-70
4.168
2.52
V
ppm/°C
k
µV
RMS
dB
Unipolar
Bipolar (Note 7)
V
IN
= V
DD
During acquisition time (Note 8)
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 6)
Externally clocked conversion
Data I/O
30
< 50
2.7
0.1
4.8
10
External reference
Internal reference (Note 5)
0.6
3.5
0.8
65
µs
µs
µs
MHz
ns
ps
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX11634–MAX11637
REF+ Input Current
I
REF+
DIGITAL INPUTS (SCLK, DIN,
CS, CNVST
(Note 9)
Input Voltage Low
Input Voltage High
Input Hysteresis
V
IL
V
IH
V
HYST
0.8
V
DD
x 0.3
V
V
mV
_______________________________________________________________________________________
3
12-Bit, 300ksps ADCs with Differential
Track/Hold, and Internal Reference
MAX11634–MAX11637
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= 2.7V to 3.6V (MAX11635/MAX11637), V
DD
= 4.75V to 5.25V (MAX11634/MAX11636), f
SAMPLE
= 300kHz, f
SCLK
= 4.8MHz
(external clock, 50% duty cycle), V
REF
= 2.5V (MAX11635/MAX11637), V
REF
= 4.096V (MAX11634/MAX11636) T
A
= T
MIN
to T
MAX
,
unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 2)
PARAMETER
Input Leakage Current
Input Capacitance
DIGITAL OUTPUTS (DOUT,
EOC)
Output Voltage Low
Output Voltage High
Three-State Leakage Current
Three-State Output Capacitance
POWER REQUIREMENTS
Supply Voltage
V
DD
MAX11634/MAX11636
MAX11635/MAX11637
Internal
reference
I
DD
External
reference
Internal
reference
I
DD
External
reference
Power-Supply Rejection
PSR
f
SAMPLE
= 300ksps
f
SAMPLE
= 0, REF on
Shutdown
f
SAMPLE
= 300ksps
Shutdown
f
SAMPLE
= 300ksps
f
SAMPLE
= 0, REF on
Shutdown
f
SAMPLE
= 300ksps
Shutdown
4.75
2.7
1750
1000
0.2
1050
0.2
2300
1050
0.2
1500
0.2
±0.2
±0.2
5.25
3.6
2000
1200
5
1200
5
2550
1350
5
1700
5
±1
±1.4
mV
µA
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
I
IN
C
IN
CONDITIONS
V
IN
= 0V or V
DD
MIN
TYP
±0.01
15
MAX
±1.0
UNITS
µA
pF
MAX11635/MAX11637
Supply Current (Note 10)
MAX11634/MAX11636
Supply Current (Note 10)
V
DD
= 2.7V to 3.6V, full-scale input
V
DD
= 4.75V to 5.25V, full-scale input
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Limits at T
A
= -40°C are guaranteed by design and not production tested.
Tested at V
DD
= 3V (MAX11635/MAX11637); V
DD
= 5V (MAX11634/MAX11636), 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.
Note 8:
See Figure 3 (Equivalent Input Circuit) and the Sampling Error vs. Source Impedance curve in the
Typical Operating
Characteristics
section.
Note 9:
When
CNVST
is configured as a digital input, do not apply a voltage between V
IL
and V
IH
.
Note 10:
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 Differential
Track/Hold, and Internal Reference
MAX11634–MAX11637
TIMING CHARACTERISTICS (Figure 1)
PARAMETER
SCLK Clock Period
SCLK Pulse-Width High
SCLK Pulse-Width Low
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
CS
Low to SCLK Setup
CS
High to SCLK Setup
CS
High After SCLK Hold
CS
Low After SCLK Hold
CNVST
Pulse-Width Low
CS
or
CNVST
Rise to
EOC
Low (Note 11)
SYMBOL
t
CP
t
CH
t
CL
t
DOT
t
DOD
t
DOE
t
DS
t
DH
t
CSS0
t
CSS1
t
CSH1
t
CSH0
t
CSPW
CKSEL = 00
CKSEL = 01
Voltage conversion
Reference power-up
C
LOAD
= 30pF
C
LOAD
= 30pF
C
LOAD
= 30pF
40
0
40
40
0
0
40
1.4
7
65
4
Data I/O
CONDITIONS
Externally clocked conversion
MIN
208
100
40
40
40
40
40
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
µs
ns
µs
µs
Note 11:
This time is defined as the number of clock cycles needed for conversion multiplied by the clock period. If the internal
reference needs to be powered up, the total time is additive. The internal reference is always used for temperature
measurements.
Typical Operating Characteristics
(V
DD
= 3V, V
REF
= 2.5V, f
SCLK
= 4.8MHz, C
LOAD
= 30pF, T
A
= +25°C for MAX11635/MAX11637, unless otherwise noted. V
DD
= 5V,
V
REF
= 4.096V, f
SCLK
= 4.8MHz, C
LOAD
= 30pF, T
A
= +25°C for MAX11634/MAX11636, unless otherwise noted.)
INTEGRAL NONLINEARITY
vs. OUTPUT CODE
MAX11634 toc01
INTEGRAL NONLINEARITY
vs. OUTPUT CODE
MAX11634 toc02
DIFFERENTIAL NONLINEARITY
vs. OUTPUT CODE
0.8
0.6
0.4
DNL (LSB)
0.2
0
-0.2
-0.4
-0.6
MAX11634 toc03
1.0
0.8
0.6
0.4
INL (LSB)
1.0
0.8
0.6
0.4
INL (LSB)
0.2
0
-0.2
-0.4
1.0
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0
1024
2048
3072
4096
OUTPUT CODE (DECIMAL)
MAX11634/MAX11636
f
SAMPLE
= 300ksps
-0.6
-0.8
-1.0
0
1024
MAX11635/MAX11637
f
SAMPLE
= 300ksps
2048
3072
4096
OUTPUT CODE (DECIMAL)
-0.8
-1.0
0
1024
MAX11634/MAX11636
f
SAMPLE
= 300ksps
2048
3072
4096
OUTPUT CODE (DECIMAL)
_______________________________________________________________________________________
5
