MAX17645
RECOMMENDED FOR NEW DESIGNS4.5V to 36V, 1A, High-Efficiency, Synchronous Step-Down DC-DC Converter
High-Efficiency, High-Voltage, Synchronous Step-Down DC-DC Converter with Integrated MOSFETs
- Part Models
- 4
- 1ku List Price
- Starting From $0.62
Overview
- 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
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.
Applications
- Factory Automation
- Aftermarket Market Automation
- General Point of Load
Documentation
Data Sheet 1
Video 1
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.
| Part Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| MAX17645BATA+ | LFCSP | ||
| MAX17645BATA+T | LFCSP | ||
| MAX17645DATA+ | LFCSP | ||
| MAX17645DATA+T | LFCSP |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Apr 20, 2026 - 2571D PIN/ERRATA |
||
| MAX17645BATA+ | PRODUCTION | |
| MAX17645BATA+T | PRODUCTION | |
| MAX17645DATA+ | PRODUCTION | |
| MAX17645DATA+T | PRODUCTION | |
|
Jul 5, 2023 - 2377 ASSEMBLY |
||
| MAX17645BATA+ | PRODUCTION | |
| MAX17645BATA+T | PRODUCTION | |
| MAX17645DATA+ | PRODUCTION | |
| MAX17645DATA+T | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
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Evaluation Kits
Evaluation Kit for the MAX17645 in 5V Output Voltage Application
Resources
Evaluation Kit for the MAX17645 in 5V Output Voltage Application
Resources
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