LM5017MR - 100V 600mA Sync Buck Regulator | Texas Instruments
MPN: LM5017MR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.42 | $3.42 |
| 10 | $2.95 | $29.50 |
| 100 | $2.41 | $241.00 |
| 500 | $1.98 | $990.00 |
| 1,000 | $1.62 | $1,620.00 |
LM5017MR Overview
A buck (step-down) switching regulator is a DC-DC converter that efficiently reduces a higher DC rail to a lower DC rail by periodically switching an inductor-capacitor filter network. Buck regulators sit within the broader power management IC hierarchy of linear regulators -> voltage regulators -> DC-DC converters -> power management ICs -> integrated circuits. Compared with LDOs, buck regulators achieve much higher efficiency at large input-to-output differentials because they do not dissipate VIN-VOUT as heat; this makes the buck topology essential for 48V telecom rails, industrial 24V/36V/48V bus systems, and battery stacks where thermal dissipation would otherwise be impractical.
Key features of the LM5017MR include a wide 7.5V-100V input range, integrated 100V high-side and low-side switches that eliminate an external Schottky diode, and a precision enable/UVLO with adjustable threshold. The constant on-time control architecture requires no loop compensation, provides ultra-fast transient response, and maintains nearly constant operating frequency. Adjustable switching frequency up to 1MHz, intelligent peak current limit, and a precision 2% feedback reference round out the feature set. The HSOP EP package exposes the thermal pad for direct copper heat-sinking, critical at high input voltages where the high-side switch dissipation is non-trivial.
The constant on-time (COT) architecture uses a one-shot timer triggered by the feedback voltage falling below the internal reference, turning the high-side MOSFET on for a fixed on-time determined by VIN and a programming resistor. This produces a nearly constant frequency without the need for compensation components, dramatically simplifying PCB design and improving transient response compared with traditional voltage-mode or current-mode PWM controllers. The integrated 100V synchronous switches reduce BOM cost and PCB area, while the 1MHz maximum operating frequency enables small magnetic sizing. According to TI application notes, the LM5017 is also widely used in isolated Fly-Buck topologies for generating auxiliary rails in IGBT gate-drive and industrial PLC systems.
Typical applications include 48V telecom point-of-load conversion, industrial 24V/36V/48V bus regulation, automotive 12V/24V battery-powered systems, bias supplies for IGBT gate drivers, isolated Fly-Buck converters, and PoE (Power over Ethernet) PD regulation. The wide VIN range and integrated switches make it particularly attractive for distributed power systems where the input rail can vary from 18V to 80V during transients.
When designing with the LM5017MR, pay close attention to PCB layout: the RTN pin is the substrate ground and the exposed thermal pad must be soldered to a sufficiently large copper pour to keep junction temperature below the 125C operating lifetime de-rating. Use a low-ESR ceramic input capacitor rated for the full 100V input transient, and follow the datasheet's recommended inductor and feedback resistor values for the target output. The RT pin's on-time programming resistor sets frequency and must be selected based on VIN and VOUT.
This page synthesizes distributor pricing, drop-in alternatives including the LM5017MR/NOPB RoHS variant and same-package TI wide-Vin buck family members, and practical design notes not found in the standalone datasheet PDF.
Drop-in alternatives for LM5017MR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LM5017MR/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
LM5018MR/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
LM5019MR/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
LM5163MR/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
LM5164MR/NOPB
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LM5017MRX/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
LM5017MR Maximum Ratings & Electrical Characteristics
| Topology | Synchronous Buck (Step-Down) |
| Input Voltage Range | 7.5 V to 100 V |
| Output Voltage Range | 1.225 V to 90 V (adjustable) |
| Maximum Output Current | 600 mA |
| Peak Output Current Limit | 1.3 A (intelligent peak limit) |
| Switching Frequency | Adjustable up to 1 MHz (nearly constant via COT) |
| Feedback Reference Accuracy | 2% (precision internal reference) |
| Integrated Switches | 100 V high-side and low-side MOSFETs (no Schottky required) |
| Control Scheme | Constant On-Time (COT), no loop compensation required |
| Package | 8-Pin SO PowerPAD / HSOP EP (3.90 mm body) |
| Operating Temperature Range | -40 C to +125 C (junction) |
| Enable / UVLO | Adjustable undervoltage lockout with precision threshold |
| Transient Response | Ultra-fast (COT architecture) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (NOPB suffix denotes lead-free) |
LM5017MR Pin Configuration
| Pin 1 | RT — On-time programming resistor to VIN (sets switching on-time and frequency) |
| Pin 2 | EN/UVLO — Enable input and adjustable undervoltage lockout threshold |
| Pin 3 | VIN — Input supply voltage (7.5V to 100V) |
| Pin 4 | SW — Switch node - internally connected to high-side and low-side MOSFET drains/sources |
| Pin 5 | SW — Switch node (tied to pin 4 for higher current handling) |
| Pin 6 | BST — Bootstrap capacitor for high-side gate driver supply |
| Pin 7 | FB — Feedback voltage input to internal 1.225V reference |
| Pin 8 | RTN — Substrate ground (ground reference for all control circuits) |
Typical Applications
LM5017MR is suitable for 6 applications: 48V Telecom Point-of-Load Conversion, Industrial 24V/36V/48V Bus Regulation, Isolated Fly-Buck Converter for IGBT Gate Drivers, Automotive 12V/24V Battery-Powered Systems, Power over Ethernet (PoE) Powered Devices, Solar Microinverter Auxiliary Rail.
48V Telecom Point-of-Load Conversion
The LM5017MR's 7.5V-100V wide VIN range and integrated 100V synchronous MOSFETs make it ideal for stepping 48V telecom rails down to 3.3V, 5V, or 12V POL voltages for FPGAs, microcontrollers, and DSPs. The constant on-time (COT) control provides nearly constant switching frequency up to 1MHz with no loop compensation, drastically simplifying the bill of materials. According to TI LM3017 reference designs, the 600mA output capability serves most baseband and PHY interface power needs. The HSOP-8 EP package's exposed thermal pad handles the high-side switch dissipation at 48V input efficiently.
Recommended
Industrial 24V/36V/48V Bus Regulation
The LM5017MR is widely used in industrial automation, PLC, and motor-drive systems where 24V, 36V, or 48V bus voltages are standard. Its 100V absolute maximum input rating tolerates the inductive transients common on industrial bus wiring. The adjustable UVLO with precision enable threshold allows clean power-up sequencing in multi-rail systems. The COT architecture delivers ultra-fast transient response to sudden load steps from solenoid or relay actuation. TI's LM5017 reference designs document complete PCB layouts for these bus voltages.
Recommended
Isolated Fly-Buck Converter for IGBT Gate Drivers
The LM5017MR is one of the most popular converters for isolated Fly-Buck topologies that generate isolated auxiliary rails for IGBT gate drivers in motor drives, solar inverters, and UPS systems. The integrated switches and wide VIN range simplify the primary-side circuit, while the transformer's secondary winding provides galvanic isolation at low cost. TI's Fly-Buck reference designs document ±15V isolated outputs up to 200mA from a 24V-48V input rail, suitable for most IGBT gate driver bias needs.
Recommended
Automotive 12V/24V Battery-Powered Systems
The LM5017MR's wide VIN range covers automotive 12V cranking transients (down to 6V during engine cranking) and 24V truck/bus systems. For 12V lead-acid battery applications, the LM5017MR delivers 5V or 3.3V rails for body control modules, instrument clusters, and infotainment systems. The HSOP-8 EP package's automotive-qualified thermal performance and the wide temperature range (-40C to +125C junction) suit under-hood and cabin environments.
Recommended
Power over Ethernet (PoE) Powered Devices
The LM5017MR's 7.5V to 100V input range directly accommodates the 36V-57V PoE+ voltage applied at the PD input. Designers can use the LM5017MR to step the PoE rail to 5V or 3.3V for the PD's MCU, and an isolated Fly-Buck variant for high-side gate bias. The integrated 100V switches eliminate the need for transient voltage suppressors on the PoE input in many designs. TI's PoE reference designs use the LM5017 family for 13W PD applications.
Recommended
Solar Microinverter Auxiliary Rail
The LM5017MR can be used as an auxiliary bias supply in solar microinverter and string inverter designs. The wide VIN range accepts 24V-80V PV panel-side rails, and the integrated switches generate 12V or 15V rails for gate drivers and housekeeping circuits. The COT control's constant frequency keeps EMI predictable, simplifying CE/FCC compliance. The exposed thermal pad handles continuous operation in outdoor inverter enclosures at 70C ambient.
Recommended
Recommended Products Summary
Engineering reference data for LM5017MR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM5017MR/NOPB | LM5018MR/NOPB | LM5019MR/NOPB | LM5163MR/NOPB | LM5164MR/NOPB |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-Pin HSOP EP | 8-Pin HSOP EP - same | 8-Pin HSOP EP - same | 8-Pin HSOP EP - same | 8-Pin HSOP EP - same | 8-Pin HSOP EP - same |
| Input Voltage Range | 7.5 V to 100 V | 7.5 V to 100 V | 7.5 V to 100 V | 7.5 V to 100 V | 6 V to 100 V | 6 V to 100 V |
| Maximum Output Current | 600 mA | 600 mA | 300 mA | 100 mA | 500 mA | 1000 mA |
| Output Voltage Range | 1.225 V to 90 V | 1.225 V to 90 V | 1.225 V to 90 V | 1.225 V to 90 V | 0.8 V to 100 V | 0.8 V to 100 V |
| Maximum Switching Frequency | 1 MHz (COT) | 1 MHz (COT) | 1 MHz (COT) | 1 MHz (COT) | 1 MHz (adaptive COT) | 1 MHz (adaptive COT) |
| External Schottky Required | No (integrated sync switches) | No | No | No | No | No |
| Loop Compensation Required | No (COT control) | No | No | No | No | No |
| RoHS / Lead-Free | Non-RoHS (leaded LM5017MR) | RoHS-compliant | RoHS-compliant | RoHS-compliant | RoHS-compliant | RoHS-compliant |
Key Differentiators
- Highest output current at 100V VIN in SO PowerPAD-8 (vs LM5018MR/NOPB)
- 100V integrated synchronous MOSFETs vs older 100V buck families (vs LM5163MR/NOPB)
- Wide-Vin compatibility up to 100V in SO PowerPAD-8 (vs LM5164MR/NOPB)
Design Notes
Estimated: at VIN=48V, VOUT=5V, IOUT=600mA, power dissipation is (48-5)*0.6 = 25.8W - clearly the LM5017MR is not designed for this condition (designed for low-duty, sub-1W applications). At more realistic VIN=24V, VOUT=5V, IOUT=600mA, dissipation is ~11.4W and the HSOP-8 EP package cannot handle this either. The LM5017MR is intended for very low duty-cycle or low-power applications such as 24V->12V at 200mA (~2.4W), or 48V->3.3V at 100mA (~4.5W). Always size the exposed pad copper pour per the LM3017 PCB guidelines and derate on junction temperature above 100C ambient.
Place input ceramic capacitors as close to VIN and RTN as possible to minimize switching loop inductance. The exposed thermal pad must be soldered to a continuous ground pour with multiple thermal vias to the internal ground plane. Use a 4-layer PCB with dedicated ground plane for best EMI performance. Keep the feedback trace short and away from the SW node. The RT resistor should be placed close to the RT pin with the resistor-to-VIN connection routed cleanly to avoid noise coupling.
Do not confuse the LM5017 with the LM5163 - despite TI's 100% compatibility claim, pin 4 (RT programming) in the LM5017 connects to VIN while the LM5163's RT pin connects to GND. This pin-level difference requires PCB rework when migrating. Always use ceramic input capacitors rated for at least 100V with low ESR. Never leave the BST capacitor unpopulated - the high-side gate driver will not function without it. The FB trace must not cross noisy switching nodes.
Compliance Information
LM5017MR (base) is non-RoHS leaded terminal finish. Use LM5017MR/NOPB for RoHS-compliant lead-free designs. Not AEC-Q100 qualified; for automotive applications consider LM5017-Q1 equivalents if available. REACH compliant per TI product declaration. Conflict minerals declaration on file with TI.
