ICL7134 - 14-Bit Multiplying Digital-to-Analog Converter (DAC)

Overview

The ICL7134 is a high-precision, four-quadrant multiplying digital-to-analog converter (DAC) that combines thin-film resistor technology with advanced CMOS circuitry. This integrated circuit features an on-chip PROM-controlled correction circuit that enables true 14-bit performance without requiring external adjustments. The device is designed for applications demanding high accuracy and stability, offering exceptional linearity and low temperature coefficients.

With its microprocessor-compatible interface and double-buffered inputs, the ICL7134 simplifies system integration while maintaining precision performance. The four-quadrant multiplication capability makes it suitable for a wide range of analog signal processing applications.

Key Features

• 14-bit linearity (0.003% Full Scale Range)
• No gain adjustment required due to on-chip PROM correction
• Microprocessor-compatible interface with double-buffered inputs
• Bipolar operation without additional adjustments or external resistors
• Excellent temperature stability with low linearity and gain temperature coefficients
• Low power consumption for energy-sensitive applications
• Full four-quadrant multiplication capability
• Military-grade versions available (883B processed)

Applications

The ICL7134 is suitable for a wide range of precision analog applications, including:

• Automated test equipment (ATE)
• Process control systems
• Precision instrumentation
• Digital signal processing systems
• Programmable gain amplifiers
• Analog waveform generation
• Military and aerospace systems
• Medical instrumentation
• Audio processing equipment

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (V+ to V-): ±18V
• Digital Input Voltage: -0.3V to V+ +0.3V
• Reference Input Voltage: ±V Supply
• Power Dissipation: 500mW
• Operating Temperature Range:
  • Commercial: 0°C to +70°C
  • Industrial: -25°C to +85°C
  • Military: -55°C to +125°C
• Storage Temperature Range: -65°C to +150°C

DC Characteristics (TA = +25°C, V+ = +15V, V- = -15V unless otherwise specified)

• Resolution: 14 bits
• Integral Nonlinearity (INL): ±1 LSB max (0.003% FSR)
• Differential Nonlinearity (DNL): ±0.5 LSB max
• Gain Error: ±0.05% FSR max after correction
• Gain Temperature Coefficient: ±5 ppm/°C typ
• Zero-Scale Error: ±1 mV max
• Power Supply Rejection Ratio (PSRR): 80 dB min
• Reference Input Resistance: 10 kΩ typ
• Reference Input Current: ±100 nA max
• Output Leakage Current: ±10 nA max
• Power Consumption: 100 mW typ

AC Characteristics

• Settling Time to ±0.003% FSR: 10 μs typ
• Glitch Impulse: 10 nV-s typ
• Digital Feedthrough: ±0.5 LSB max
• Digital Input Capacitance: 10 pF typ

Functional Description

The ICL7134 architecture consists of several key functional blocks:

Digital Interface

The double-buffered input structure allows simultaneous update of multiple DACs while maintaining data integrity. The interface includes:

• 14-bit parallel data input
• Chip select (CS) input
• Write (WR) control input
• Load DAC (LDAC) control for synchronous updates

DAC Core

The multiplying DAC core uses precision thin-film resistors and CMOS switches to achieve high accuracy. The four-quadrant architecture allows both positive and negative reference voltages and output currents.

Correction Circuitry

The on-chip PROM stores calibration coefficients that automatically compensate for gain and linearity errors, eliminating the need for manual adjustments.

Package Information

Available Packages

• 28-pin Plastic Dual In-line Package (PDIP)
• 28-pin Ceramic Dual In-line Package (CERDIP)
• 28-pin Small Outline Integrated Circuit (SOIC)
• 28-pin Leadless Chip Carrier (LCC)

Package Dimensions (28-pin PDIP)

• Overall Length: 36.32 mm max
• Overall Width: 13.97 mm max
• Lead Pitch: 2.54 mm
• Body Thickness: 4.57 mm max

Pin Configuration

The 28-pin package includes the following key pins:

• Pins 1-14: Data Inputs (D13-D0)
• Pin 15: Chip Select (CS)
• Pin 16: Write Input (WR)
• Pin 17: Load DAC (LDAC)
• Pin 18: Reference Input (REF)
• Pin 19: Analog Output (IOUT)
• Pin 20: Feedback Resistor (RFB)
• Pins 21-22: Power Supply (V+, V-)
• Pin 23: Ground (GND)
• Pins 24-28: Additional Control and Status Pins

Design Considerations

Reference Voltage Selection

The ICL7134 accepts reference voltages from -10V to +10V, allowing flexible system design. For optimal performance:

• Use a low-noise, stable reference source
• Consider temperature coefficients when selecting reference components
• Bypass reference inputs with 0.1 μF capacitors

Layout Guidelines

To maintain the device's high performance:

• Use a ground plane to minimize noise
• Keep analog and digital traces separated
• Minimize lead lengths for critical analog paths
• Use proper power supply decoupling (0.1 μF ceramic + 10 μF tantalum per supply)

Thermal Considerations

While the ICL7134 has low power dissipation, in high-temperature environments:

• Ensure adequate airflow
• Consider using thermal vias for surface-mount packages
• Monitor junction temperature in critical applications

Ordering Information

The ICL7134