HT19LG-G

Telecom Overview

The HT19LG-G is an electronic line switch circuit designed to replace mechanical hook switches in telephone handsets and modems. It operates by switching the positive side of the telephone line using control inputs referenced to the negative line side. The device withstands 350V on the positive input in its off state and exhibits a maximum series resistance of 18Ω when active. It features current limiting determined by an external resistor connected between the CS and TP pins. The component utilizes three control inputs: HKS, LS, and DP, allowing for various switching configurations.

Telecom Feature Summary

• Supports high voltage operation with a 350V breakdown capability on the positive input side
• Provides low on-state resistance of 18Ω maximum for efficient line switching
• Includes programmable current limiting protection via an external sense resistor
• Features multiple control inputs including logic-level compatible LS and DP pins

Telecom Applications

• Telephone handset electronic hook switches
• Modem line interface circuits
• Fax machine line switching
• Answering machine line detection
• Remote meter reading equipment

Telecom Procurement Notes

Verify that the ordering suffix LG-G corresponds to the lead-free RoHS compliant package variant as specified in the official documentation. Confirm the package type matches the 8-Lead SOIC Narrow Body outline before integration. Ensure the supply chain source provides valid traceability for the Supertex or Microchip Technology manufacturing origin.

Telecom Selection Notes

Select this component for applications requiring direct replacement of mechanical hook switches in telecommunication interfaces. Ensure the design accommodates the 18Ω maximum switch resistance and the specific current limit settings derived from the external resistor value. Verify that the control logic levels align with the specified VIH and VIL thresholds for reliable switching operation.

Telecom Part Context

This part belongs to the HT19 family of electronic line switches originally developed by Supertex Inc., which has since been acquired by Microchip Technology. The device serves as a solid-state alternative to electromechanical relays or reed switches in legacy and modern telephony systems, offering reduced size and increased reliability.

Telecom Replacement Considerations

HT19LG

Telecom FAQ

How is the current limit for the HT19LG-G configured?

The current limit is determined by an external resistor connected between the CS (Current Sense) pin and the TP (Positive Output) pin.

What is the function of the DP pin?

The DP (Dial Pulse) pin is used to turn the hook switch off for pulse dialing operations; it is active low.

Can the HT19LG-G handle the full telephone line voltage in the off state?

Yes, in its off state, the device can withstand up to 350V on the positive input (TPG pin).