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MAX127, MAX127A

Multirange, +5V, 12-Bit DAS with 2-Wire Serial Interface

First 2-Wire 12-Bit, 8-Channel, Serial ADCs Have +/-17V Fault-Protected Inputs

Product Details

Key Features

Parametric specs for Precision ADCs (< 5Msps)
Resolution (bits) (ADC) 12
# Input Channels 8
Conv. Rate (ksps) (max) 8
Data Bus I2C
ADC Architecture SAR
Diff/S.E. Input S.E. Only
Internal VREF (V) (nominal) 4.096
External VREF (V) (min) 2.4
External VREF (V) (max) 4.18
Unipolar VIN (V) (max) 10
Bipolar VIN (±V) (max) 10
INL (±LSB) 1
Package/Pins PDIP/24
SSOP/28
Budgetary
Price (See Notes)
15.52
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Simplified Block Diagram

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Parameters

Parametric specs for Precision ADCs (<u><</u> 5Msps)
Resolution (bits) (ADC) 12
# Input Channels 8
Conv. Rate (ksps) (max) 8
Data Bus I2C
ADC Architecture SAR
Diff/S.E. Input S.E. Only
Internal VREF (V) (nominal) 4.096
External VREF (V) (min) 2.4
External VREF (V) (max) 4.18
Unipolar VIN (V) (max) 10
Bipolar VIN (±V) (max) 10
INL (±LSB) 1
Package/Pins PDIP/24
SSOP/28
Budgetary
Price (See Notes)
15.52

Key Features

  • 12-Bit Resolution, 1/2 LSB Linearity
  • +5V Single-Supply Operation
  • I2C-Compatible, 2-Wire Serial Interface
  • Four Software-Selectable Input Ranges
    • MAX127: 0 to +10V, 0 to +5V, ±10V, ±5V
    • MAX128: 0 to +VREF, 0 to +VREF/2, ±VREF, ±VREF/2
  • 8 Analog Input Channels
  • 8ksps 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

Applications/Uses

  • Battery-Powered Applications
  • Data Acquisition
  • Industrial Control Systems
  • Robotics

Description

The MAX127/MAX128 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 may 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 MAX127; and ±VREF, ±VREF/2, 0 to +VREF, 0 to +VREF/2 for the MAX128. 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, an 8ksps throughput rate, and the option of an internal 4.096V or external reference.

The MAX127/MAX128 feature a 2-wire, I2C-compatible serial interface that allows communication among multiple devices using SDA and SCL lines.

A hardware shutdown input (SHDN) and two software-programmable power-down modes (standby and full power-down) are provided for low-current shutdown between conversions. In standby mode, the reference buffer remains active, eliminating startup delays.

The MAX127/MAX128 are available in 24-pin narrow PDIP or space-saving 28-pin SSOP packages.

Simplified Block Diagram

MAX127, MAX127A, MAX127B, MAX128, MAX128A, MAX128B: Typical Operating Circuit MAX127, MAX127A, MAX127B, MAX128, MAX128A, MAX128B: Typical Operating Circuit Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .