Overview
The LTC7801EUFD#TRPBF, produced by Analog Devices Inc., is a high-performance step-down switching regulator DC/DC controller. It drives an all N-channel synchronous power MOSFET stage, enabling operation from input voltages up to 140V. This controller features a constant frequency current mode architecture with a phase-lockable frequency of up to 850kHz, making it highly versatile for various power management applications. The LTC7801 is designed to maximize efficiency with programmable gate drive voltage and integrated switch in the top gate driver, eliminating the need for an external bootstrap diode. It also includes an internal charge pump for 100% duty cycle operation and a low 40μA no-load quiescent current, which extends operating run time in battery-powered systems.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Input Voltage Range | Up to 140 | V |
| Output Voltage Range | 0.8V to 60V | V |
| Switching Frequency | Up to 850kHz | kHz |
| Gate Drive Voltage | 5V to 10V | V |
| No-Load Quiescent Current | 40μA | μA |
| Operating Junction Temperature Range | -40°C to 125°C (LTC7801I), -40°C to 150°C (LTC7801H) | °C |
| Reference Voltage | 0.8V | V |
Key Features
- Constant frequency current mode architecture with phase-lockable frequency up to 850kHz.
- Programmable gate drive voltage from 5V to 10V to support logic or standard-level FETs.
- Integrated switch in the top gate driver eliminates the need for an external bootstrap diode.
- Internal charge pump for 100% duty cycle operation.
- Low 40μA no-load quiescent current for extended battery life in battery-powered systems.
- OPTI-LOOP® compensation for optimized transient response over a wide range of output capacitance and ESR values.
- Precision 0.8V reference and power good output indicator.
- Output overvoltage protection and foldback current limiting for fault conditions.
- Regulator shutdown feature to prevent overheating in high input voltage applications.
Applications
The LTC7801EUFD#TRPBF is suitable for a variety of high-performance power management applications, including:
- Battery-powered systems where low quiescent current is crucial for extended battery life.
- High-input voltage applications requiring robust overvoltage protection and efficient power conversion.
- Systems needing precise voltage regulation and fast transient response, such as in industrial, automotive, and telecommunications equipment.
- Applications requiring high switching frequencies and phase-lockable operation, such as in power supplies for high-frequency devices.
Q & A
- What is the maximum input voltage for the LTC7801EUFD#TRPBF?
The LTC7801EUFD#TRPBF can operate from input voltages up to 140V.
- What is the range of the output voltage for this controller?
The output voltage can be programmed between 0.8V and 60V using external resistors.
- What is the switching frequency range of the LTC7801EUFD#TRPBF?
The switching frequency can be up to 850kHz and is phase-lockable.
- How does the LTC7801EUFD#TRPBF manage overvoltage conditions?
The controller features an overvoltage comparator that turns off the top MOSFET and turns on the bottom MOSFET until the overvoltage condition is cleared.
- What is the purpose of the OPTI-LOOP® compensation in the LTC7801EUFD#TRPBF?
OPTI-LOOP® compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values.
- How does the LTC7801EUFD#TRPBF handle foldback current limiting?
Foldback current limiting is activated when the output voltage falls to less than 70% of its nominal level, progressively lowering the peak current limit in proportion to the severity of the overcurrent or short-circuit condition.
- What is the regulator shutdown feature in the LTC7801EUFD#TRPBF?
The regulator shutdown feature prevents overheating in high input voltage applications by disabling the regulator if the EXTVCC LDO becomes disabled for an extended period.
- What is the operating junction temperature range for the LTC7801EUFD#TRPBF?
The operating junction temperature range is -40°C to 125°C for the LTC7801I and -40°C to 150°C for the LTC7801H.
- How does the LTC7801EUFD#TRPBF indicate power good status?
The power good output indicator is connected to an open drain of an internal N-channel MOSFET, which pulls the PGOOD pin low when the VFB pin voltage is not within ±10% of the 0.8V reference voltage.
- What is the no-load quiescent current of the LTC7801EUFD#TRPBF?
The no-load quiescent current is 40μA, which helps extend the operating run time in battery-powered systems.
