Product Overview
Dual-Supply ±12V Voltage Comparator LM311 Equivalent - Burroughs C311
Condition
Used component in good physical condition with normal wear consistent with age. No cracks or abnormal damage observed. Untested. Covered by our satisfaction guarantee. Sourced from a home workshop collection downsizing. AMD logo present on the package, indicating likely second-source manufacturing for Burroughs.
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Product Overview
Burroughs part number 1449-5543 is a 14-pin DIP voltage comparator identified internally as the C311. Engineering cross-reference documentation confirms it is functionally equivalent to the LM311 voltage comparator. This device was used in Burroughs business systems hardware, including the 9134 platform, where stable and predictable comparator performance was required.
The device operates on a dual-supply architecture requiring +12V on Pin 11 and -12V on Pin 6, with circuit ground on Pin 2. Differential analog inputs are provided at Pin 3 (non-inverting) and Pin 4 (inverting). Output is driven on Pin 9, with balance and strobe functionality available on Pins 7 and 8 for controlled hysteresis and feedback implementation.
Key Features
- Manufacturer: Burroughs
- Part Number: 1449-5543
- Internal Logic Mnemonic: C311
- Functional Equivalent: LM311 voltage comparator
- Package: 14-pin Dual In-Line Package (DIP)
- Supply Requirements: +12V (Pin 11), -12V (Pin 6)
- Ground Reference: Pin 2
- Inputs: Pin 3 non-inverting, Pin 4 inverting
- Output: Pin 9 logic output
- Balance Input: Pin 7
- Balance/Strobe Terminal: Pin 8
- Used in Burroughs 9134 system architecture
Applications
- Restoration of Burroughs 9134 hardware
- LM311 replacement in ±12V comparator circuits
- Industrial threshold detection circuits
- Zero-crossing detection systems
- Analog-to-digital interface conditioning
- Retrocomputing and mainframe peripheral repair
- Bench comparator prototyping with dual supplies
Frequently Asked Questions
Is this the same as an LM311?
Yes. Cross-reference documentation confirms functional equivalence to the commercial LM311 voltage comparator.
What supply voltages does it require?
This implementation requires +12V applied to Pin 11 and -12V applied to Pin 6, with circuit ground at Pin 2.
Where is the output pin?
The logic output is located on Pin 9.
What are Pins 7 and 8 used for?
Pin 7 is an isolated balance input. Pin 8 serves as a combined balance and strobe terminal and is typically tied to the output through a feedback resistor for stable hysteresis control.
Is this tested?
This unit is untested. It is covered by our satisfaction guarantee.
Burroughs systems were built for business environments where downtime was not tolerated. If you are maintaining legacy hardware or need a true dual-rail comparator with documented lineage, this one fits the era and the circuit.
