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General Description
The MAX157/MAX159 low-power, 10-bit analog-to-digi-
tal converters (ADCs) are available in 8-pin µMAX and
DIP packages. Both devices operate with a single
+2.7V to +5.25V supply and feature a 7.4µs succes-
sive-approximation ADC, automatic power-down, fast
wake-up (2.5µs), an on-chip clock, and a high-speed,
3-wire serial interface.
Power consumption is only 3.2mW (V
DD
= +3.6V) at the
maximum sampling rate of 108ksps. At slower through-
put rates, the 0.2µA automatic shutdown further
reduces power consumption.
The MAX157 provides 2-channel, single-ended opera-
tion and accepts input signals from 0 to V
REF
. The
MAX159 accepts pseudo-differential inputs ranging
from 0 to V
REF
. An external clock accesses data
through the 3-wire serial interface, which is SPITM,
QSPITM, and MICROWIRETM compatible.
Excellent dynamic performance and low power, com-
bined with ease of use and a small package size, make
these converters ideal for battery-powered and data
acquisition applications, or for other circuits with
demanding power-consumption and space require-
ments. For pin-compatible 12-bit upgrades, see the
MAX144/MAX145 data sheet.
Applications
Battery-Powered Systems
Instrumentation
Portable Data Logging
Test Equipment
Isolated Data Acquisition
Medical Instruments
Process-Control Monitoring
System Supervision
Features
o
Single-Supply Operation (+2.7V to +5.25V)
o
Two Single-Ended Channels (MAX157)
Single Pseudo-Differential Channel (MAX159)
o
Low Power
0.9mA (at 108ksps, +3V)
100µA (at 10ksps, +3V)
10µA (at 1ksps, +3V)
<0.2µA (power-down mode)
o
Internal Track/Hold
o
108ksps Sampling Rate
o
SPI/QSPI/MICROWIRE-Compatible 3-Wire
Serial Interface
o
Space-Saving 8-Pin µMAX Package
o
Pin-Compatible 12-Bit Upgrades Available
MAX157/MAX159
+2.7V, Low-Power, 2-Channel,
108ksps, Serial 10-Bit ADCs in 8-Pin µMAX
________________________________________________________________
Maxim Integrated Products
1
CS/SHDN
REF
GND
1
2
8
7
SCLK
DOUT
( ) ARE FOR MAX159 ONLY.
CH0 (CH+)
CH1 (CH-)
V
DD
µ
MAX/DIP
TOP VIEW
3
4
6
5
MAX157
MAX159
19-1388; Rev 0; 11/98
Pin Configuration
Ordering Information
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
*
Contact factory for availability.
±1
8 CERDIP*
-55°C to +125°C
MAX159BMJA
±0.5
8 CERDIP*
-55°C to +125°C
MAX159AMJA
±1
8 Plastic DIP
-40°C to +85°C
MAX159BEPA
±0.5
8 Plastic DIP
-40°C to +85°C
MAX159AEPA
±1
8 µMAX
-40°C to +85°C
MAX159BEUA
±1
±0.5
±1
±0.5
±1
±0.5
±1
±0.5
±1
±0.5
±0.5
±1
±0.5
±1
±0.5
INL
(LSB)
8 CERDIP*
8 CERDIP*
8 Plastic DIP
-40°C to +85°C
-55°C to +125°C
-55°C to +125°C
MAX157BMJA
MAX157AMJA
MAX157BEPA
8 Plastic DIP
8 µMAX
-40°C to +85°C
-40°C to +85°C
MAX157AEPA
MAX157BEUA
8 µMAX
8 Plastic DIP
0°C to +70°C
-40°C to +85°C
MAX159AEUA
MAX159BCPA
8 Plastic DIP
8 µMAX
8 µMAX
0°C to +70°C
0°C to +70°C
0°C to +70°C
MAX159ACPA
MAX159BCUA
MAX159
ACUA
8 µMAX
8 Plastic DIP
0°C to +70°C
-40°C to +85°C
MAX157AEUA
MAX157BCPA
8 Plastic DIP
8 µMAX
8 µMAX
PIN-
PACKAGE
TEMP.
RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
MAX157ACPA
MAX157BCUA
MAX157
ACUA
PART
MAX157/MAX159
+2.7V, Low-Power, 2-Channel,
108ksps, Serial 10-Bit ADCs in 8-Pin µMAX
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
DD
= +2.7V to +5.25V, V
REF
= 2.5V, 0.1µF capacitor at REF, f
SCLK
= 2.17MHz, 16 clocks/conversion cycle (108ksps),
CH- = GND for MAX159, 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
CH0, CH1 (CH+, CH-) to GND...................-0.3V to (V
DD
+ 0.3V)
REF to GND ................................................-0.3V to (V
DD
+ 0.3V)
Digital Inputs to GND ...............................................-0.3V to +6V
DOUT to GND.............................................-0.3V to (V
DD
+ 0.3V)
DOUT Sink Current ............................................................ 25mA
Continuous Power Dissipation (T
A
= +70°C)
µMAX (derate 4.1mW/°C above +70°C) ......................330mW
Plastic DIP (derate 9.09mW/°C above +70°C) ............727mW
CERDIP (derate 8.00mW/°C above +70°C) .................640mW
Operating Temperature Ranges
MAX157/MAX159_C_A .......................................0°C to +70°C
MAX157/MAX159_E_A ....................................-40°C to +85°C
MAX157/MAX159_MJA................................. -55°C to +125°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°C
DC ACCURACY
(Note 1)
DYNAMIC SPECIFICATIONS
(f
IN
(sine wave) = 10kHz, V
IN
= 2.5Vp-p, 108ksps, external f
SCLK
= 2.17MHz, CH- = GND for MAX159)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
Gain Error (Note 3)
±2
LSB
Offset Error
±2
LSB
Differential Nonlinearity
DNL
±0.5
LSB
±1
Gain Temperature Coefficient
±0.8
ppm/°C
Channel-to-Channel Offset
Matching
±0.02
LSB
Channel-to-Channel Gain
Matching
±0.02
LSB
Resolution
RES
10
Bits
Relative Accuracy (Note 2)
INL
±0.5
LSB
Signal-to-Noise Ratio plus
Distortion
SINAD
66
dB
Total Harmonic Distortion
(including 5th-order harmonic)
THD
-70
dB
Spurious-Free Dynamic Range
SFDR
70
dB
Channel-to-Channel Crosstalk
-75
dB
Small-Signal Bandwidth
2.25
MHz
Full-Power Bandwidth
1.0
MHz
CONDITIONS
No missing codes over temperature
MAX15_B
External reference, V
REF
= 2.5V
f
IN
= 65kHz, V
IN
= 2.5Vp-p (Note 4)
-3dB rolloff
MAX15_A
MHz
+2.7V, Low-Power, 2-Channel,
108ksps, Serial 10-Bit ADCs in 8-Pin µMAX
_______________________________________________________________________________________
3
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.7V to +5.25V, V
REF
= 2.5V, 0.1µF capacitor at REF, f
SCLK
= 2.17MHz, 16 clocks/conversion cycle (108ksps),
CH- = GND for MAX159, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
CONVERSION RATE
0.5
I
SINK
= 16mA
Three-State Output Capacitance
15
pF
C
OUT
CS/SHDN = V
DD
(Note 8)
Output High Voltage
V
DD
- 0.5
V
V
OH
Output Low Voltage
0.4
V
V
OL
I
SINK
= 5mA
I
SOURCE
= 0.5mA
Input Capacitance
15
pF
C
IN
Input Leakage Current
±1
µA
I
IN
V
IN
= 0 or V
DD
(Note 8)
Input Hysteresis
0.2
V
V
HYS
V
V
3.0
V
DD
> 3.6V
Input Low Voltage
0.8
V
IL
Input High Voltage
2.0
V
IH
V
DD
3.6V
Shutdown REF Input Current
0.01
10
µA
Input Resistance
18
25
k
Input Current
100
140
µA
V
REF
= 2.5V
Input Voltage Range (Note 7)
0 V
DD
+ 50mV
V
V
REF
Analog Input Voltage Range
(Note 6)
0
V
REF
V
V
IN
Input Capacitance
16
µA
C
IN
Multiplexer Leakage Current
±0.01 ±1
µA
On/off-leakage current, V
IN
= 0 to V
DD
Aperture Delay
25
ns
Aperture Jitter
<50
ps
Serial Clock Frequency
0.1
2.17
f
SCLK
0
5
MHz
External clock mode
Internal clock mode, for data transfer only
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
7.4
µs
Conversion Time (Note 5)
t
CONV
5 7
T/H Acquisition Time
t
ACQ
2.5
µs
CONDITIONS
External clock, f
SCLK
= 2.17MHz, 16 clock
cycles per conversion
Internal clock
Three-State Output Leakage
Current
±10
µA
CS/SHDN = V
DD
CONVERSION RATE
ANALOG INPUTS
EXTERNAL REFERENCE
DIGITAL INPUTS (
CS
/SHDN, SCLK) AND DIGITAL OUTPUT (DOUT)
MAX157/MAX159
MAX157/MAX159
+2.7V, Low-Power, 2-Channel,
108ksps, Serial 10-Bit ADCs in 8-Pin µMAX
4
_______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.7V to +5.25V, V
REF
= 2.5V, 0.1µF capacitor at REF, f
SCLK
= 2.17MHz, 16 clocks/conversion cycle (108ksps),
CH- = GND for MAX159, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
TIMING CHARACTERISTICS (Figure 7)
(V
DD
= +2.7V to +5.25V, V
REF
= 2.5V, 0.1µF capacitor at REF, f
SCLK
= 2.17MHz, 16 clocks/conversion cycle (108ksps),
CH- = GND for MAX159, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
Note 1:
Tested at V
DD
= +2.7V.
Note 2:
Relative accuracy is the deviation of the analog value at any code from its theoretical value after full-scale range has been
calibrated.
Note 3:
Offset nulled.
Note 4:
The on channel is grounded; the sine wave is applied to off channel (MAX157 only).
Note 5:
Conversion time is defined as the number of clock cycles times the clock period; clock has 50% duty cycle.
Note 6:
The common-mode range for the analog inputs is from GND to V
DD
(MAX159 only).
Note 7:
ADC performance is limited by the converter's noise floor, typically 300µVp-p.
Note 8:
Guaranteed by design. Not subject to production testing.
Note 9:
Measured as V
FS
(2.7V) - V
FS
(5.25V).
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
0
5
SCLK Clock Frequency
f
SCLK
0.1
2.17
MHz
SCLK Fall to Output Data Valid
t
DO
20
120
ns
215
CS/SHDN Fall to Output Enable
Wake-Up Time
t
WAKE
2.5
µs
t
DV
120
ns
CS/SHDN Rise to Output
Disable
t
TR
120
ns
SCLK Pulse Width High
t
CH
50
ns
CONDITIONS
Internal clock, SCLK for data transfer only
(Note 8)
Internal clock, SCLK for data transfer only
External clock
C
L
= 100pF
External clock
C
L
= 100pF (Figure 1)
C
L
= 100pF (Figure 1)
ns
SCLK to CS/SHDN Setup
t
SCLKS
60
CS/SHDN Pulse Width
t
CS
60
ns
215
SCLK Pulse Width Low
t
CL
50
ns
Internal clock, SCLK for data transfer only
(Note 8)
External clock
POWER REQUIREMENTS
Power-Supply Rejection
(Note 9)
PSR
±0.15
mV
V
DD
= 2.7V to 5.25V, full-scale input
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
Positive Supply Voltage
V
DD
+2.7
+5.25
V
CONDITIONS
Positive Supply Current
I
DD
0.9
2.0
mA
Operating mode
Positive Supply Current
I
DD
0.2
5
µA
Shutdown, CS/SHDN = GND
POWER REQUIREMENTS
MAX157/MAX159
+2.7V, Low-Power, 2-Channel,
108ksps, Serial 10-Bit ADCs in 8-Pin µMAX
_______________________________________________________________________________________
5
500
700
900
1100
1300
1500
2.5
3.0
3.5
4.0
4.5
5.0
5.5
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX157/159 toc01
V
DD
(V)
SUPPLY CURRENT (
µ
A)
V
REF
= V
DD
R
L
=
C
L
= 50pF
CODE = 1010101000
500
750
1000
1250
1500
-60
-20
0
-40
20 40 60 80 100 120 140
SUPPLY CURRENT
vs. TEMPERATURE
MAX157/159 toc02
TEMPERATURE (°C)
SUPPLY CURRENT (
µ
A)
V
REF
= V
DD
R
L
=
C
L
= 50pF
CODE = 1010101000
10,000
0.1
0.1
1
100
1k
10k
10
100k
SUPPLY CURRENT
vs. SAMPLING RATE
1
MAX157/159 toc03
SAMPLING RATE (sps)
SUPPLY CURRENT (
µ
A)
100
10
1000
V
REF
= V
DD
CODE = 1010101000
C
L
= 50pF
0
400
200
600
800
1000
2.5
3.0
3.5
4.0
4.5
5.0
5.5
SHUTDOWN CURRENT
vs. SUPPLY VOLTAGE
MAX157/159 toc04
V
DD
(V)
SHUTDOWN CURRENT (nA)
V
REF
= V
DD
0
0.05
0.10
0.15
0.20
-60
-10
40
90
-35
15
65
140
115
OFFSET ERROR vs. TEMPERATURE
MAX157/159 toc07
TEMPERATURE (°C)
OFFSET ERROR (LSB)
0
200
400
600
800
1000
-60
20 40
-20
0
-40
60 80 100 120 140
SHUTDOWN CURRENT
vs. TEMPERATURE
MAX157/159 toc05
TEMPERATURE (°C)
SHUTDOWN CURRENT (nA)
V
REF
= V
DD
0
0.05
0.10
0.15
0.20
2.5
3.0
3.5
4.0
4.5
5.0
5.5
OFFSET ERROR vs. SUPPLY VOLTAGE
MAX157/159 toc06
V
DD
(V)
OFFSET ERROR (LSB)
Typical Operating Characteristics
(V
DD
= +3.0V, V
REF
= 2.5V, 0.1µF capacitor at REF, f
SCLK
= 2.17MHz, 16 clocks/conversion cycle (108ksps); CH- = GND for
MAX159; T
A
= +25°C, unless otherwise noted.)
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