HMC475ST89

Overview

The HMC475ST89 is a silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) gain block amplifier designed for cellular and CATV applications. It operates across a frequency range of 0 Hz to 4.5 GHz. The device provides a typical gain of 21.5 dB and an output IP3 of +35 dBm at 850 MHz. It requires a single positive supply voltage between 8 V and 12 V, drawing a supply current of 110 mA. Key performance metrics include a noise figure of 3.8 dB and a P1dB compression point of 22 dBm. The component is housed in a surface-mount SOT-89 package.

Feature Summary

• Utilizes SiGe HBT technology for high-performance RF amplification
• Provides high linearity with +35 dBm output IP3 at 850 MHz
• Operates from a single positive supply voltage
• Suitable for wideband applications up to 4.5 GHz

Applications

• Cellular infrastructure systems
• CATV signal distribution networks
• Wideband RF front-end modules
• Test and measurement equipment

Procurement Notes

Verify the specific suffix (e.g., ST89E) against official Analog Devices discontinuance notices, as this component family has been subject to end-of-life declarations. Confirm that the requested part number matches the exact package and electrical specifications required for your design, as legacy components may have limited availability or require qualification for new production runs.

Selection Notes

Select this component when a wide bandwidth extending to 4.5 GHz is required alongside high linearity. The SiGe HBT process offers a balance of gain and noise performance suitable for general-purpose RF amplification. Ensure the power supply can deliver the required 110 mA current and that the thermal management supports the power dissipation within the SOT-89 package constraints.

Part Context

The HMC475 belongs to the Hittite Microwave (HMC) product line acquired by Analog Devices. It is classified as a gain block amplifier, distinct from low-noise amplifiers or power amplifiers. This specific model represents a discontinued item within the broader portfolio of RF integrated circuits previously manufactured under the Hittite brand name.

Replacement Considerations

• HMC475ST89E