CA3260 Operational Amplifier Technical Summary

CA3260 Dual Operational Amplifier

Overview

The CA3260A and CA3260 are integrated circuit operational amplifiers that combine the advantages of both CMOS and bipolar transistors on a single monolithic chip. These devices represent the dual versions of the popular CA3160 series, offering enhanced performance characteristics for a wide range of applications.

The input stage utilizes gate-protected P-Channel MOSFET (PMOS) transistors, providing exceptional input impedance, minimal input current, and superior speed performance. This architecture allows the input terminals to handle common mode voltages that include the negative supply rail, making these amplifiers particularly suitable for single-supply applications.

Key Features

MOSFET Input Stage:
- Extremely high input impedance: 1.5 TΩ (1.5 × 10¹²Ω) typical
- Ultra-low input current:
  - 5pA typical at 15V operation
  - 2pA typical at 5V operation
Single Supply Operation: Ideal for battery-powered and single-supply applications
Extended Common Mode Range: Input terminals can swing 0.5V below the negative supply rail
CMOS Output Stage: Allows signal swing to either (or both) supply rails
Wide Operating Voltage Range: 5V to 16V single supply or ±2.5V to ±8V dual supplies

Applications

The CA3260 series operational amplifiers are versatile components suitable for numerous applications, including:

Ground referenced single supply amplifiers
Fast sample-hold amplifiers
Long duration timers and monostable multivibrators
Interface circuits with digital CMOS logic
High input impedance wideband amplifiers
Voltage followers (particularly useful for single supply D/A converters)
Voltage regulators with output control down to 0V
Wien bridge oscillators
Voltage controlled oscillators
Photo diode sensor amplifiers

Electrical Characteristics

Absolute Maximum Ratings

Supply Voltage (V⁺ to V^-): 16V
Differential Input Voltage: ±8V
Input Voltage Range: (V^- - 0.5V) to (V⁺ + 0.5V)
Output Short Circuit Duration: Continuous
Operating Temperature Range: -55°C to +125°C
Storage Temperature Range: -65°C to +150°C

Typical Performance Characteristics

Input Offset Voltage: 2mV typical
Input Bias Current: 5pA typical at 15V
Large Signal Voltage Gain: 100V/mV typical
Slew Rate: 10V/μs typical
Gain Bandwidth Product: 4MHz typical
Power Consumption: 6mW typical per amplifier at ±5V

Package Information

The CA3260 is available in several industry-standard packages:

8-Pin Plastic DIP (Dual-In-Line Package):
- Package Code: P
- Dimensions: 9.81mm × 6.35mm × 3.3mm
- Pin Pitch: 2.54mm
8-Pin SOIC (Small Outline Integrated Circuit):
- Package Code: M
- Dimensions: 4.9mm × 3.9mm × 1.25mm
- Pin Pitch: 1.27mm
8-Pin TSSOP (Thin Shrink Small Outline Package):
- Package Code: PW
- Dimensions: 3.0mm × 4.4mm × 1.0mm
- Pin Pitch: 0.65mm

Pin Configuration

The 8-pin configuration for the dual operational amplifier is as follows:

Pin 1: Output A
Pin 2: Inverting Input A
Pin 3: Non-Inverting Input A
Pin 4: V^- (Negative Supply)
Pin 5: Non-Inverting Input B
Pin 6: Inverting Input B
Pin 7: Output B
Pin 8: V⁺ (Positive Supply)

Design Considerations

Input Protection

The gate-protected PMOS input transistors provide inherent protection against electrostatic discharge (ESD) and input overvoltage conditions. However, for maximum reliability in harsh environments, additional external protection may be considered.

Power Supply Decoupling

For optimal performance, it is recommended to use 0.1μF ceramic capacitors placed as close as possible to the power supply pins. In high-frequency applications, additional bulk decoupling (10μF tantalum or electrolytic) may be beneficial.