Overview
The LT4295HUFD#TRPBF, produced by Analog Devices Inc., is an IEEE 802.3af/at/bt-compliant powered device (PD) interface controller that also integrates a switching regulator controller. This device supports both flyback and forward isolated power supply topologies, making it versatile for various power-over-ethernet (PoE) applications. It is designed to facilitate easy migration from LTPoE++ PDs to IEEE 802.3bt PDs and is pin-compatible with the LT4276A/B/C series. The LT4295 features an on-chip detection signature resistor, thermal protection, slope compensation, and other advanced power management functionalities.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Operating Voltage at VPORT Pin | 40 | 60 | V | ||
| VPORT Detection Signature Range | 1.5 | 10 | V | ||
| VPORT Classification Signature Range | 12.5 | 21 | V | ||
| VMARK VPORT Mark Event Range | After 1st Classification Event | 5.6 | 10 | V | |
| Reset Threshold | 2.6 | 5.6 | V | ||
| Hot Swap Turn-On Voltage | 35 | 37 | V | ||
| Gate Outputs PG, SG Output High Level | I = –1mA | VCC – 0.1 | V | ||
| Gate Outputs PG, SG Output Low Level | I = 1mA | 1 | V | ||
| Package Type | 28-Lead QFN (4mm × 5mm) | ||||
| Operating Temperature Range | –40°C | 125°C |
Key Features
- IEEE 802.3af/at/bt compliance for PoE applications.
- Supports both flyback and forward isolated power supply topologies, including No-Opto feedback for flyback topology.
- Pin-compatible with LT4276A/B/C series for easy migration.
- On-chip detection signature resistor, thermal protection, and slope compensation.
- Utilizes an external, low RDS(on) N-channel hot swap MOSFET and supports LT4320/LT4321 ideal diode bridges for enhanced power delivery efficiency.
- Auxiliary input voltages can be accurately sensed with a simple resistor divider connected to the AUX pin.
- Programmable frequency adjustment via ROSC pin and adjustable soft-start timing via SFST pin.
Applications
The LT4295HUFD#TRPBF is suitable for a variety of power-over-ethernet (PoE) applications, including but not limited to:
- Network devices such as switches, routers, and access points.
- IP phones and video conferencing equipment.
- Wireless access points and base stations.
- Security cameras and surveillance systems.
- Industrial control systems and IoT devices.
Q & A
- What is the operating voltage range of the LT4295HUFD#TRPBF?
The operating voltage range at the VPORT pin is from 40V to 60V. - Is the LT4295HUFD#TRPBF compatible with previous models?
Yes, it is pin-compatible with the LT4276A/B/C series. - What power supply topologies does the LT4295HUFD#TRPBF support?
The device supports both flyback and forward isolated power supply topologies. - How does the LT4295HUFD#TRPBF handle thermal protection?
The device includes on-chip thermal protection. - Can the LT4295HUFD#TRPBF be used in high-temperature environments?
The operating temperature range is from –40°C to 125°C. - What is the package type of the LT4295HUFD#TRPBF?
The device comes in a 28-Lead QFN (4mm × 5mm) package. - How does the LT4295HUFD#TRPBF support power delivery efficiency?
It utilizes an external, low RDS(on) N-channel hot swap MOSFET and supports LT4320/LT4321 ideal diode bridges. - Can the LT4295HUFD#TRPBF be used in industrial control systems?
Yes, it is suitable for industrial control systems and IoT devices. - How is the frequency adjustment done on the LT4295HUFD#TRPBF?
The frequency can be adjusted via the ROSC pin. - What is the purpose of the AUX pin on the LT4295HUFD#TRPBF?
The AUX pin allows for accurate sensing of auxiliary input voltages using a simple resistor divider.
