General Description
The MAX1076/MAX1078 are low-power, high-speed, seri-
al-output, 10-bit, analog-to-digital converters (ADCs) that
operate at up to 1.8Msps and have an internal reference.
These devices feature true-differential inputs, offering bet-
ter noise immunity, distortion improvements, and a wider
dynamic range over single-ended inputs. A standard
SPITM/QSPITM/MICROWIRETM interface provides the clock
necessary for conversion. These devices easily interface
with standard digital signal processor (DSP) synchronous
serial interfaces.
The MAX1076/MAX1078 operate from a single +4.75V to
+5.25V supply voltage. The MAX1076/MAX1078 include
a 4.096V internal reference. The MAX1076 has a unipolar
analog input, while the MAX1078 has a bipolar analog
input. These devices feature a partial power-down mode
and a full power-down mode for use between conver-
sions, which lower the supply current to 2mA (typ) and
1A (max), respectively. Also featured is a separate
power-supply input (V
L
), which allows direct interfacing to
+1.8V to V
DD
digital logic. The fast conversion speed,
low-power dissipation, excellent AC performance, and DC
accuracy (0.5 LSB INL) make the MAX1076/MAX1078
ideal for industrial process control, motor control, and
base-station applications.
The MAX1076/MAX1078 come in a 12-pin TQFN pack-
age, and are available in the commercial (0C to +70C)
and extended (-40C to +85C) temperature ranges.
Applications
Data Acquisition
Communications
Bill Validation
Portable Instruments
Motor Control
Features
1.8Msps Sampling Rate
Only 50mW (typ) Power Dissipation
Only 1A (max) Shutdown Current
High-Speed, SPI-Compatible, 3-Wire Serial Interface
61dB S/(N + D) at 525kHz Input Frequency
Internal True-Differential Track/Hold (T/H)
Internal 4.096V Reference
No Pipeline Delays
Small 12-Pin TQFN Package
MAX1076/MAX1078
1.8Msps, Single-Supply, Low-Power, True-
Differential, 10-Bit ADCs with Internal Reference
________________________________________________________________ Maxim Integrated Products
1
12
AIN+
11
N.C.
10
SCLK
4
5
N.C.
6
GND
1
2
REF
3
9
8
7
RGND
CNVST
DOUT
V
L
MAX1076
MAX1078
AIN-
V
DD
TQFN
TOP VIEW
PART
TEMP RANGE
PIN-
PACKAGE
INPUT
MAX1076
CTC-T
0
C to +70
C
12 TQFN-12
Unipolar
MAX1076ETC-T
-40
C to +85
C
12 TQFN-12
Unipolar
MAX1078
CTC-T
0
C to +70
C
12 TQFN-12
Bipolar
MAX1078ETC-T
-40
C to +85
C
12 TQFN-12
Bipolar
Pin Configuration
Ordering Information
MAX1076
MAX1078
DOUT
AIN+
4.7F
10F
10F
+4.75V TO +5.25V
0.01F
0.01F
0.01F
+1.8V TO V
DD
AIN-
REF
V
DD
DIFFERENTIAL
INPUT
VOLTAGE
RGND
V
L
GND
CNVST
SCLK
C/DSP
+
-
Typical Operating Circuit
19-3291; Rev 0; 5/04
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.
SPI/QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
MAX1076/MAX1078
1.8Msps, Single-Supply, Low-Power, True-
Differential, 10-Bit ADCs with Internal Reference
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
DD
= +5V 5%, V
L
= V
DD
, f
SCLK
= 28.8MHz, 50% duty cycle, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25C.)
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
V
L
to GND ................-0.3V to the lower of (V
DD
+ 0.3V) and +6V
Digital Inputs
to GND .................-0.3V to the lower of (V
DD
+ 0.3V) and +6V
Digital Output
to GND ....................-0.3V to the lower of (V
L
+ 0.3V) and +6V
Analog Inputs and
REF to GND..........-0.3V to the lower of (V
DD
+ 0.3V) and +6V
RGND to GND .......................................................-0.3V to +0.3V
Maximum Current into Any Pin............................................50mA
Continuous Power Dissipation (T
A
= +70C)
12-Pin TQFN (derate 16.9mW/C above +70C) ......1349mW
Operating Temperature Ranges
MAX107_ CTC ...................................................0C to +70C
MAX107_ ETC.................................................-40C to +85C
Junction Temperature ......................................................+150C
Storage Temperature Range .............................-60C to +150C
Lead Temperature (soldering, 10s) .................................+300C
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC ACCURACY
Resolution
10
Bits
Relative Accuracy
INL
(Note 1)
0.5
LSB
Differential Nonlinearity
DNL
(Note 2)
0.5
LSB
Offset Error
2
LSB
Offset-Error Temperature
Coefficient
1
ppm/C
Gain Error
Offset nulled
2
LSB
Gain Temperature Coefficient
2
ppm/C
DYNAMIC SPECIFICATIONS
(f
IN
= 525kHz sine wave, V
IN
= V
REF
, unless otherwise noted.)
Signal-to-Noise Plus Distortion
SINAD
60
61
dB
Total Harmonic Distortion
THD
Up to the 5th harmonic
-80
-74
dB
Spurious-Free Dynamic Range
SFDR
-80
-74
dB
Intermodulation Distortion
IMD
f
IN1
= 250kHz, f
IN2
= 300kHz
-78
dB
Full-Power Bandwidth
-3dB point, small-signal method
20
MHz
Full-Linear Bandwidth
S/(N + D) > 56dB, single ended
2
MHz
CONVERSION RATE
Minimum Conversion Time
t
CONV
(Note 3)
0.556
s
Maximum Throughput Rate
1.8
Msps
M i ni m um Thr oug hp ut Rate
( N ote 4)
10
ksps
Track-and-Hold Acquisition Time
t
ACQ
(Note 5)
104
ns
Aperture Delay
5
ns
Aperture Jitter
(Note 6)
30
ps
External Clock Frequency
f
SCLK
28.8
MHz
MAX1076/MAX1078
1.8Msps, Single-Supply, Low-Power, True-
Differential, 10-Bit ADCs with Internal Reference
_______________________________________________________________________________________
3
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +5V 5%, V
L
= V
DD
, f
SCLK
= 28.8MHz, 50% duty cycle, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ANALOG INPUTS (AIN+, AIN-)
AIN+ - AIN-, MAX1076
0
V
REF
Differential Input Voltage Range
V
IN
AIN+ - AIN-, MAX1078
-V
REF
/ 2
+V
REF
/ 2
V
Absolute Input Voltage Range
0
V
DD
V
DC Leakage Current
1
A
Input Capacitance
Per input pin
16
pF
Input Current (Average)
Time averaged at maximum throughput rate
75
A
REFERENCE OUTPUT (REF)
REF Output Voltage Range
Static, T
A
= +25C
4.086
4.096
4.106
V
Voltage Temperature Coefficient
50
ppm/C
I
SOURCE
= 0 to 2mA
0.3
Load Regulation
I
SINK
= 0 to 200A
0.5
mV/mA
Line Regulation
V
DD
= 4.75V to 5.25V, static
0.5
mV/V
DIGITAL INPUTS (SCLK, CNVST)
Input-Voltage Low
VIL
0.3 x V
L
V
Input-Voltage High
VIH
0.7 x V
L
V
Input Leakage Current
I
IL
0.05
10
A
DIGITAL OUTPUT (DOUT)
Output Load Capacitance
C
OUT
For stated timing performance
30
pF
Output-Voltage Low
V
OL
I
SINK
= 5mA, V
L
1.8V
0.4
V
Output-Voltage High
V
OH
I
SOURCE
= 1mA, V
L
1.8V
V
L
- 0.5V V
Output Leakage Current
I
OL
Output high impedance
0.2
10
A
POWER REQUIREMENTS
Analog Supply Voltage
V
DD
4.75
5.25
V
Digital Supply Voltage
V
L
1.8
V
DD
V
Static, f
SCLK
= 28.8MHz
8
11
Static, no SCLK
5
7
Analog Supply Current,
Normal Mode
I
DD
Operational,
1.8Msps
10
13
mA
f
SCLK
= 28.8MHz
2
Analog Supply Current,
Partial Power-Down Mode
I
DD
No SCLK
2
mA
f
SCLK
= 28.8MHz
1
Analog Supply Current,
Full Power-Down Mode
I
DD
No SCLK
0.3
1
A
Operational, full-scale input at 1.8Msps
1
2.5
Static, f
SCLK
= 28.8MHz
0.4
1
Partial/full power-down mode,
f
SCLK
= 28.8MHz
0.2
0.5
mA
Digital Supply Current (Note 7)
Static, no SCLK (all modes)
0.1
1
A
Positive-Supply Rejection
PSR
V
DD
= 5V 5%, full-scale input
0.2
3.0
mV
MAX1076/MAX1078
1.8Msps, Single-Supply, Low-Power, True-
Differential, 10-Bit ADCs with Internal Reference
4
_______________________________________________________________________________________
Note 1:
Relative accuracy is the deviation of the analog value at any code from its theoretical value after the gain error and the offset
error have been nulled.
Note 2:
No missing codes over temperature.
Note 3:
Conversion time is defined as the number of clock cycles (16) multiplied by the clock period.
Note 4:
At sample rates below 10ksps, the input full-linear bandwidth is reduced to 5kHz.
Note 5:
The listed value of three SCLK cycles is given for full-speed continuous conversions. Acquisition time begins on the 14th ris-
ing edge of SCLK and terminates on the next falling edge of CNST. The IC idles in acquisition mode between conversions.
Note 6:
Undersampling at the maximum signal bandwidth requires the minimum jitter spec for SINAD performance.
Note 7:
Digital supply current is measured with the V
IH
level equal to V
L
, and the V
IL
level equal to GND.
TIMING CHARACTERISTICS
(V
DD
= +5V 5%, V
L
= V
DD
, f
SCLK
= 28.8MHz, 50% duty cycle, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
SCLK Pulse-Width High
t
CH
V
L
= 1.8V to V
DD
15.6
ns
SCLK Pulse-Width Low
t
CL
V
L
= 1.8V to V
DD
15.6
ns
C
L
= 30pF, V
L
= 4.75V to V
DD
14
C
L
= 30pF, V
L
= 2.7V to V
DD
17
SCLK Rise to DOUT Transition
t
DOUT
C
L
= 30pF, V
L
= 1.8V to V
DD
24
ns
DOUT Remains Valid After SCLK
t
DHOLD
V
L
= 1.8V to V
DD
4
ns
CNVST Fall to SCLK Fall
t
SETUP
V
L
= 1.8V to V
DD
10
ns
CNVST Pulse Width
t
CSW
V
L
= 1.8V to V
DD
20
ns
Power-Up Time; Full Power-Down
t
PWR-UP
2
ms
Restart Time; Partial Power-Down
t
RCV
16
Cycles
CNVST
SCLK
DOUT
t
DHOLD
t
DOUT
t
SETUP
t
CSW
t
CL
t
CH
Figure 1. Detailed Serial-Interface Timing
GND
6k
C
L
DOUT
DOUT
C
L
GND
V
L
a) HIGH-Z TO V
OH
, V
OL
TO V
OH
,
AND V
OH
TO HIGH-Z
b) HIGH-Z TO V
OL
, V
OH
TO V
OL
,
AND V
OL
TO HIGH-Z
6k
Figure 2. Load Circuits for Enable/Disable Times
MAX1076/MAX1078
1.8Msps, Single-Supply, Low-Power, True-
Differential, 10-Bit ADCs with Internal Reference
_______________________________________________________________________________________
5
Typical Operating Characteristics
(V
DD
= +5V, V
L
= V
DD
, f
SCLK
= 28.8MHz, f
SAMPLE
= 1.8Msps, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25C.)
INTEGRAL NONLINEARITY
vs. DIGITAL OUTPUT CODE (MAX1076)
MAX1076/78 toc01
DIGITAL OUTPUT CODE
INL (LSB)
756
512
256
-0.1
0
0.1
0.2
-0.2
0
1024
INTEGRAL NONLINEARITY
vs. DIGITAL OUTPUT CODE (MAX1078)
MAX1076/78 toc02
DIGITAL OUTPUT CODE
INL (LSB)
256
0
-256
-0.1
0
0.1
0.2
-0.2
-512
512
DIFFERENTIAL NONLINEARITY
vs. DIGITAL OUTPUT CODE (MAX1076)
MAX1076/78 toc03
DIGITAL OUTPUT CODE
INL (LSB)
756
512
256
-0.1
0
0.1
0.2
-0.2
0
1024
DIFFERENTIAL NONLINEARITY
vs. DIGITAL OUTPUT CODE (MAX1078)
MAX1076/78 toc04
DIGITAL OUTPUT CODE
INL (LSB)
256
0
-256
-0.1
0
0.1
0.2
-0.2
-512
512
OFFSET ERROR
vs. TEMPERATURE (MAX1076)
MAX1076/78 toc05
TEMPERATURE (C)
OFFSET ERROR (LSB)
60
35
10
-15
-0.25
0
0.25
0.50
-0.50
-40
85
OFFSET ERROR
vs. TEMPERATURE (MAX1078)
MAX1076/78 toc06
TEMPERATURE (C)
OFFSET ERROR (LSB)
60
35
10
-15
-0.25
0
0.25
0.50
-0.50
-40
85
GAIN ERROR
vs. TEMPERATURE (MAX1076)
MAX1076/78 toc07
TEMPERATURE (C)
GAIN ERROR (LSB)
60
35
-15
10
-0.75
-0.50
-0.25
0
0.25
0.50
0.75
1.00
-1.00
-40
85
GAIN ERROR
vs. TEMPERATURE (MAX1078)
MAX1076/78 toc08
TEMPERATURE (C)
GAIN ERROR (LSB)
60
35
-15
10
-0.75
-0.50
-0.25
0
0.25
0.50
0.75
1.00
-1.00
-40
85
DYNAMIC PERFORMANCE
vs. INPUT FREQUENCY (MAX1076)
MAX1076/78 toc09
ANALOG INPUT FREQUENCY (kHz)
DYNAMIC PERFORMANCE (dB)
400
300
200
61.1
61.2
61.3
61.4
61.5
61.6
61.0
100
500
SNR
SINAD
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