MAX127/MAX128 Multirange, 12-Bit Data Acquisition Systems (DAS)

Overview

The MAX127 and MAX128 are high-performance, multirange, 12-bit data acquisition systems (DAS) designed for precision analog-to-digital conversion applications. These devices operate on a single +5V power supply, making them ideal for low-power and portable systems. The MAX127/MAX128 integrate a high-speed track/hold amplifier, a 12-bit successive approximation analog-to-digital converter (ADC), and a flexible input multiplexer, enabling seamless data acquisition across multiple input ranges.

These components are particularly suited for applications requiring high accuracy and speed, such as industrial automation, medical instrumentation, and test equipment. The inclusion of an internal 4.096V reference or the option for an external reference provides designers with flexibility in system design.

Features

• Single +5V Supply Operation: Simplifies power supply design and reduces system complexity.
• 12-Bit Resolution: Provides high-precision analog-to-digital conversion with excellent linearity.
• Multirange Input Capability: Supports various input voltage ranges, including ±10V, ±5V, 0V to +10V, and 0V to +5V, enhancing versatility.
• 5MHz Bandwidth Track/Hold: Ensures accurate signal capture for high-frequency inputs.
• 8ksps Throughput Rate: Delivers fast conversion speeds for real-time data acquisition.
• Internal or External Reference: Features an onboard 4.096V reference or allows for an external reference for customized accuracy.
• Low Power Consumption: Optimized for energy-sensitive applications.
• Serial Interface: Compatible with SPI/QSPI/MICROWIRE for easy integration with microcontrollers and digital systems.

Applications

The MAX127/MAX128 are designed for a wide range of applications that require precise analog signal digitization. Key application areas include:

• Industrial Automation: Process control, sensor interfacing, and data logging.
• Medical Instrumentation: Patient monitoring, diagnostic equipment, and portable medical devices.
• Test and Measurement: Data acquisition systems, oscilloscopes, and signal analyzers.
• Automotive Systems: Engine control units (ECUs), battery management, and sensor monitoring.
• Consumer Electronics: Audio processing, instrumentation, and embedded control systems.

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (V_DD): +6V
• Analog Input Voltage Range: ±15V
• Reference Input Voltage (V_REF): V_DD + 0.3V
• Digital Input Voltage Range: -0.3V to V_DD + 0.3V
• Operating Temperature Range: -40°C to +85°C
• Storage Temperature Range: -65°C to +150°C

Key Performance Specifications

• Resolution: 12 bits
• Integral Nonlinearity (INL): ±1 LSB (max)
• Differential Nonlinearity (DNL): ±1 LSB (max)
• Signal-to-Noise Ratio (SNR): 72dB (typ)
• Total Harmonic Distortion (THD): -80dB (typ)
• Power Supply Rejection Ratio (PSRR): 70dB (typ)
• Conversion Time: 125µs (max)
• Power Consumption: 5mW (typ) during operation, 1µW (typ) in shutdown mode.

Package Information

The MAX127/MAX128 are available in multiple package options to accommodate various PCB layouts and assembly processes. The following packages are offered:

• 20-Pin PDIP (Plastic Dual In-Line Package): Suitable for through-hole mounting with a standard 0.3" row spacing.
• 20-Pin SOIC (Small Outline Integrated Circuit): Ideal for space-constrained applications with surface-mount technology (SMT) compatibility.
• 20-Pin SSOP (Shrink Small Outline Package): Provides a compact footprint for high-density PCB designs.

Pin Configuration

The pinout for the MAX127/MAX128 is as follows:

• Pin 1 (CH0): Analog Input Channel 0
• Pin 2 (CH1): Analog Input Channel 1
• Pin 3 (CH2): Analog Input Channel 2
• Pin 4 (CH3): Analog Input Channel 3
• Pin 5 (CH4): Analog Input Channel 4
• Pin 6 (CH5): Analog Input Channel 5
• Pin 7 (CH6): Analog Input Channel 6
• Pin 8 (CH7): Analog Input Channel 7
• Pin 9 (COM): Common Reference for Analog Inputs
• Pin 10 (REF): Reference Voltage Input/Output
• Pin 11 (V_DD): Positive Supply Voltage (+5V)
• Pin 12 (DGND): Digital Ground
• Pin 13 (CS): Chip Select (Active Low)
• Pin 14 (RD): Read Input (Active Low)
• Pin 15 (WR): Write Input (Active Low)
• Pin 16 (HBEN): High-Byte Enable
• Pin 17 (INT): Interrupt Output (Active Low)
• Pin 18 (SHDN): Shutdown Input (Active High)
• Pin 19 (AGND): Analog Ground
• Pin 20 (DB0): Data Bit 0 (LSB)

Conclusion

The MAX127/MAX128 are versatile, high-performance 12-bit data acquisition systems that combine precision, speed, and low power consumption in a compact form factor. With their multirange input capability, flexible reference options, and robust electrical characteristics, these devices are well-suited for a wide array of industrial, medical, and consumer applications. The availability of multiple package options further enhances their adaptability to diverse design requirements.