19-4782; Rev 2; 9/04
KIT
ATION
EVALU
ILABLE
AVA
Multirange, +5V, 8-Channel,
Serial 12-Bit ADCs
Features
The MAX1270/MAX1271 are multirange, 12-bit dataacquisition systems (DAS) that require only a single
+5V supply for operation, yet accept signals at their
analog inputs that can span above the power-supply
rail and below ground. These systems provide eight
analog input channels that are independently software
programmable for a variety of ranges: ±10V, ±5V, 0 to
+10V, 0 to +5V for the MAX1270; ±VREF, ±VREF/2, 0 to
VREF, 0 to VREF/2 for the MAX1271. This range switching increases the effective dynamic range to 14 bits and
provides the flexibility to interface 4–20mA, ±12V, and
±15V powered sensors directly to a single +5V system.
In addition, these converters are fault protected to
±16.5V; a fault condition on any channel will not affect
the conversion result of the selected channel. Other features include a 5MHz bandwidth track/hold, softwareselectable internal/external clock, 110ksps throughput
rate, and internal 4.096V or external reference operation.
♦ 12-Bit Resolution, 0.5 LSB Linearity
The MAX1270/MAX1271 serial interface directly
connects to SPI™/QSPI™ and MICROWIRE™ devices
without external logic.
A hardware shutdown input (SHDN) and two softwareprogrammable power-down modes, standby (STBYPD)
or full power-down (FULLPD), are provided for low-current shutdown between conversions. In standby mode,
the reference buffer remains active, eliminating startup
delays.
♦ Internal or External Clock
♦ +5V Single-Supply Operation
♦ SPI/QSPI and MICROWIRE-Compatible
3-Wire Interface
♦ Four Software-Selectable Input Ranges
MAX1270: 0 to +10V, 0 to +5V, ±10V, ±5V
MAX1271: 0 to VREF, 0 to VREF/2, ±VREF,
±VREF/2
♦ Eight Analog Input Channels
♦ 110ksps Sampling Rate
♦ ±16.5V Overvoltage-Tolerant Input Multiplexer
♦ Internal 4.096V or External Reference
♦ Two Power-Down Modes
♦ 24-Pin Narrow PDIP or 28-Pin SSOP Packages
Typical Operating Circuit
+5V
0.1µF
The MAX1270/MAX1271 are available in 24-pin narrow
PDIP or space-saving 28-pin SSOP packages.
VDD
Applications
SHDN
Industrial Control Systems Automatic Testing
Data-Acquisition Systems Robotics
Battery-Powered
Medical Instruments
Instruments
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CH7
ANALOG
INPUTS
MAX1270
MAX1271
MC68HCXX
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
INL
(LSB)
MAX1270ACNG
0°C to +70°C
24 Narrow PDIP
±0.5
MAX1270BCNG
0°C to +70°C
24 Narrow PDIP
0°C to +70°C
28 SSOP
I/O
SCK
MOSI
MISO
±1
MAX1270ACAI
CS
SCLK
DIN
DOUT
SSTRB
MAX1270BCAI
0°C to +70°C 28 SSOP
Ordering Information continued at end of data sheet.
REF
REFADJ
4.7µF
0.01µF
DGND
AGND
±0.5
±1
Pin Configurations appear at end of data sheet.
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
________________________________________________________________ Maxim Integrated Products
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.
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MAX1270/MAX1271
General Description
