Product Details
Key Features
Applications/Uses
Simplified Block Diagram
Technical Docs
Data Sheet | 4.5V to 36V, 1A, High-Efficiency, Synchronous Step-Down DC-DC Converter | Jun 24, 2022 |
Support & Training
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Sampling:
Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.
Key Features
- Reduces External Components and Total Cost
- No Schottky—Synchronous Operation
- Internal Control Loop Compensation
- Internal Soft-Start
- All Ceramic Capacitors, Ultra-Compact Layout
- Reduces Number of DC-DC Regulators to Stock
- Wide 4.5V to 36V Input Voltage Range
- Adjustable Output from 0.9V up to 89% of VIN
- Delivers Up to 1A Load Current
- High Efficiency
- 90% Full-Load Efficiency (VIN = 24V, VOUT = 5V, IOUT = 1A)
- 2.2μA (typ) Shutdown Current
- High Light-Load Efficiency with PFM Mode (MAX17645D)
- Flexible Design
- Programmable EN/UVLO Threshold
- Monotonic Startup into Prebiased Output
- Open-Drain Output (Actiive-Low RESET) for Output Status Monitoring
- Robust Operation
- Built-In Hiccup Mode Overload Protection
- Overtemperature Protection
- CISPR32 Class B Compliant
- Wide -40°C to +125°C Ambient Operating Temperature/-40°C to +150°C Junction Temperature
Applications/Uses
- Factory Automation
- Aftermarket Market Automation
- General Point of Load
Description
The MAX17645 is a high-efficiency, high voltage, synchronous step-down DC-DC converter with integrated MOSFETs, operates over a 4.5V to 36V input. It can deliver up to 1A load current. The MAX17645 operates at 650kHz switching frequency. The MAX17645B operates in pulse-width modulation (PWM) mode at all loads. The MAX17645D operates in pulse-frequency modulation (PFM) mode at light loads. The output voltage is programmable from 0.9V up to 89% of VIN. Built-in control loop compensation across the output voltage range eliminates the need for external compensation components. The feedback voltage regulation accuracy over -40°C to +125°C is ±1.1%.
The device features a peak-current-mode control architecture. In this architecture, while operating in PWM mode the part sets the duty cycle using a transconductance error amplifier, a PWM comparator, a high-side current-sense amplifier, and a slope-compensation generator. At each rising edge of the clock, the high-side MOSFET turns on and remains on until either the appropriate or maximum duty cycle is reached, or the peak current limit is detected. During the high-side MOSFET’s on-time, the inductor current ramps up. During the rest of the switching cycle, the high-side MOSFET remains off and the low-side MOSFET remains on, inductor current ramps down. An appropriate dead time is implemented between the high-side and low-side state transitions to avoid cross conduction.
A fixed soft-start time of 3.15ms (typ) allows users to reduce input inrush current. The device also features an enable/undervoltage lockout pin (EN/UVLO) that allows the user to turn on the part at the desired input-voltage level. An open-drain active-low RESET feature provides a power-good signal to the system upon achieving successful regulation of the output voltage.
Simplified Block Diagram
Technical Docs
Data Sheet | 4.5V to 36V, 1A, High-Efficiency, Synchronous Step-Down DC-DC Converter | Jun 24, 2022 |
Support & Training
Search our knowledge base for answers to your technical questions.
Filtered SearchOur dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .
Sampling:
Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.