A5350CA-T

Overview

The A5350CA-T is a low-current BiCMOS integrated circuit designed for ionization-type smoke detectors. It operates on a single 6.0 V to 12.0 V supply and features an internal oscillator that powers down the device for 1.66 seconds, sensing for only 10 ms to minimize standby power consumption. The IC supports interconnecting up to 125 units via its I/O pin. Key electrical parameters include a typical supply current of 5.0 µA at 9.0 V, a low-battery threshold of 7.5 V (adjustable), and horn output drive capabilities with a typical on-time of 160 ms during alarms. It is housed in a 16-pin DIP package.

Feature Summary

• Enables networking of up to 125 detectors for synchronized alarm signaling
• Incorporates active guard amplifiers on detector input pins to minimize surface leakage currents
• Features pulse testing capability for periodic low-battery voltage checks
• Includes internal reverse battery protection and power-on reset logic

Applications

• Ionization smoke detection systems
• Interconnected fire safety networks
• Battery-operated security sensors using alternative chamber types

Procurement Notes

Verify component status before procurement as this variant is classified as Not For New Design. Confirm availability through authorized channels as samples may be restricted. Ensure compliance with RoHS requirements for the lead-free suffix version. Contact Allegro MicroSystems sales representatives for specific purchasing options and obsolescence management strategies.

Selection Notes

Select this component for applications requiring ultra-low standby current to extend battery life in smoke detection devices. Consider the adjustable sensitivity and low-battery thresholds for custom chamber integration. Evaluate the 16-pin DIP packaging constraints against PCB layout requirements. Verify compatibility with external piezoelectric horns and LED indicators based on specified drive currents.

Part Context

The A5350CA-T belongs to the A5350 series of ionization smoke detector ICs from Allegro MicroSystems. It provides a complete solution for smoke sensing, including oscillator timing, comparator circuits, and alarm drivers. The series is designed to facilitate alignment and testing of finished detectors while maintaining minimal power consumption in standby mode.

Replacement Considerations

No direct replacement parts are listed in the provided documentation. The datasheet indicates the part is discontinued and not recommended for new designs. Existing designs should consult Allegro MicroSystems for potential legacy support or alternative product recommendations.

FAQ

How does the A5350CA-T manage power consumption?

It uses an internal oscillator to power down the device for 1.66 seconds and sense for only 10 ms, minimizing standby current.

What is the function of the GUARD1 and GUARD2 pins?

These pins provide active guard voltages to minimize surface leakage currents around the detector input pin.

Can the low-battery threshold be adjusted?

Yes, it can be externally adjusted by connecting a resistor between the LOW-V SET pin and either VDD or VSS.