MAX1270BCAI Datasheet, PDF (1/20 Pages) Maxim Integrated Products – Multirange, +5V, 8-Channel, Serial 12-Bit ADCs

19-4782; Rev 2; 9/04
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Multirange, +5V, 8-Channel,
Serial 12-Bit ADCs
General Description
The MAX1270/MAX1271 are multirange, 12-bit data-
acquisition 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; ±V_REF, ±V_REF/2, 0 to
V_REF, 0 to V_REF/2 for the MAX1271. This range switch-
ing 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 fea-
tures include a 5MHz bandwidth track/hold, software-
selectable internal/external clock, 110ksps throughput
rate, and internal 4.096V or external reference operation.
The MAX1270/MAX1271 serial interface directly
connects to SPI™/QSPI™ and MICROWIRE™ devices
without external logic.
A hardware shutdown input (SHDN) and two software-
programmable power-down modes, standby (STBYPD)
or full power-down (FULLPD), are provided for low-cur-
rent shutdown between conversions. In standby mode,
the reference buffer remains active, eliminating startup
delays.
The MAX1270/MAX1271 are available in 24-pin narrow
PDIP or space-saving 28-pin SSOP packages.
Applications
Industrial Control Systems
Data-Acquisition Systems
Battery-Powered
Instruments
Automatic Testing
Robotics
Medical Instruments
Ordering Information
PART
TEMP RANGE PIN-PACKAGE
INL
(LSB)
MAX1270ACNG 0°C to +70°C 24 Narrow PDIP
MAX1270BCNG 0°C to +70°C 24 Narrow PDIP
±0.5
±1
MAX1270ACAI 0°C to +70°C 28 SSOP
±0.5
MAX1270BCAI 0°C to +70°C 28 SSOP
±1
Ordering Information continued at end of data sheet.
Features
♦ 12-Bit Resolution, 0.5 LSB Linearity
♦ +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 V_REF, 0 to V_REF/2, ±V_REF,
±V_REF/2
♦ Eight Analog Input Channels
♦ 110ksps Sampling Rate
♦ ±16.5V Overvoltage-Tolerant Input Multiplexer
♦ Internal 4.096V or External Reference
♦ Two Power-Down Modes
♦ Internal or External Clock
♦ 24-Pin Narrow PDIP or 28-Pin SSOP Packages
Typical Operating Circuit
+5V
0.1µF
V_DD
ANALOG
INPUTS
SHDN
CH0
CH1
CH2
CH3 ^MAX1270
CH4 ^MAX1271
CH5
CH6
CH7
REF
REFADJ
CS
SCLK
DIN
DOUT
SSTRB
4.7µF
0.01µF
DGND AGND
MC68HCXX
I/O
SCK
MOSI
MISO
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 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
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