Overview
The LT4320/LT4320-1 from Analog Devices Inc. is an ideal diode bridge controller designed to drive four N-channel MOSFETs. This controller supports voltage rectification from DC to 600Hz typical, making it highly efficient for various power supply applications. By maximizing available voltage and reducing power dissipation, the LT4320 simplifies power supply design, eliminates thermal design problems, and reduces the need for costly heat sinks and large PC board areas. The internal charge pump of the LT4320 enables an all-NMOS design, eliminating the need for larger and more costly PMOS switches.
Key Specifications
| Parameter | Value |
|---|---|
| Operating Voltage Range | 9V to 72V |
| Operating Frequency | DC to 600Hz typical |
| Quiescent Current (I_Q) | 1.5mA (Typical) |
| Package Type | 8-Lead (3mm × 3mm) DFN, 8-Lead PDIP |
| Operating Junction Temperature Range | –40°C to 85°C (LT4320I), –40°C to 125°C (LT4320H), –55°C to 125°C (LT4320MP) |
| Absolute Maximum Ratings | –3V to 80V (IN1, IN2), –0.3V to 80V (OUTP, BG1, BG2, TG1, TG2) |
Key Features
- Maximizes power efficiency by reducing voltage drop and power dissipation.
- Eliminates thermal design problems and the need for costly heat sinks.
- Supports voltage rectification from DC to 600Hz typical.
- Internal charge pump supports an all-NMOS design, eliminating larger and more costly PMOS switches.
- Fast turn-off minimizes reverse current transients in case of power source failure or shorting.
Applications
- Security cameras.
- Terrestrial or airborne power distribution systems.
- Power-over-Ethernet (PoE) powered devices with secondary input.
- Polarity-agnostic power input systems.
- Diode bridge replacement in various power supply designs.
Q & A
- What is the primary function of the LT4320?
The LT4320 is an ideal diode bridge controller that drives four N-channel MOSFETs to support voltage rectification from DC to 600Hz typical.
- What are the key benefits of using the LT4320 in power supply designs?
The LT4320 maximizes available voltage, reduces power dissipation, eliminates thermal design problems, and reduces the need for costly heat sinks and large PC board areas.
- What is the operating voltage range of the LT4320?
The operating voltage range of the LT4320 is from 9V to 72V.
- What types of packages are available for the LT4320?
The LT4320 is available in 8-Lead (3mm × 3mm) DFN and 8-Lead PDIP packages.
- How does the LT4320 handle power source failures or shorting?
The LT4320 features a fast turn-off mechanism that minimizes reverse current transients in case of power source failure or shorting.
- What are some common applications of the LT4320?
The LT4320 is commonly used in security cameras, terrestrial or airborne power distribution systems, Power-over-Ethernet (PoE) powered devices, and as a diode bridge replacement.
- What should be done to protect the LT4320 from transient overvoltage events?
For applications that may encounter transient overvoltage events higher than the LT4320's absolute maximum rating, a unidirectional transient voltage suppressor (TVS) should be installed between the OUTP and OUTN pins as close as possible to the LT4320.
- What is the quiescent current (I_Q) of the LT4320?
The quiescent current (I_Q) of the LT4320 is typically 1.5mA.
- What are the temperature ranges for different versions of the LT4320?
The operating junction temperature range for the LT4320I is –40°C to 85°C, for the LT4320H it is –40°C to 125°C, and for the LT4320MP it is –55°C to 125°C.
- How does the internal charge pump of the LT4320 benefit the design?
The internal charge pump of the LT4320 supports an all-NMOS design, eliminating the need for larger and more costly PMOS switches.
