LM5010MHX/NOPB IC

Technical Specifications of LM5010MHX/NOPB

Datasheet	LM5010MHX/NOPB datasheet
Category	Integrated Circuits (ICs)
Family	PMIC – Voltage Regulators – DC DC Switching Regulators
Manufacturer	Texas Instruments
Series	–
Packaging	Tape & Reel (TR)
Part Status	Active
Function	Step-Down
Output Configuration	Positive
Topology	Buck
Output Type	Adjustable
Number of Outputs	1
Voltage – Input (Min)	8V
Voltage – Input (Max)	75V
Voltage – Output (Min/Fixed)	2.5V
Voltage – Output (Max)	70V
Current – Output	1A
Frequency – Switching	100kHz ~ 1MHz
Synchronous Rectifier	No
Operating Temperature	-40°C ~ 125°C (TJ)
Mounting Type	Surface Mount
Package / Case	14-TSSOP (0.173″, 4.40mm Width) Exposed Pad
Supplier Device Package	14-HTSSOP

Description of the LM5010

The step-down switching regulator LM5010 contains all the components necessary to build a low-cost, efficient buck bias regulator that can generate more than 1-A load current. This high-voltage regulator has an N-Channel Buck Switch and is available in thermally improved 10-pin WSON and 14-pin HTSSOP packages. Fast load transient response and easier circuit design are both benefits of the hysteretic regulation system, which does not require loop compensation. Because the input voltage and the ON-time have an inverse relationship, the operating frequency is unaffected by variations in the line and load. 1.25 A is the current threshold level for detecting valleys. Other characteristics include a maximum duty cycle limiter, thermal shutdown, gate drive under-voltage lockout, and VCC under-voltage lockout.

Features for the LM5010

• 8 to 75 volts is the input voltage range.
• 25 A is the valley’s current limit.
• The switching frequency may be greater than 1 MHz.
• N-Channel integrated buck switch
• A built-in startup regulator.
• Loop Compensation is not necessary.
• Ultra-Quick Transient Reaction.
• Operating Frequency Remains Stable Despite Variations in Load and Line.
• Limitation of the Maximum Duty Cycle During Startup.
• Varying Output Voltage
• 5-V Feedback Reference with Precision.
• Thermostatic shutdown
• Improved Heat Dissipation with Exposed Thermal Pad.

Applications

• High-Efficiency Point-of-Load (POL) Regulator
• Secondary High Voltage Post Regulator
• Automotive Systems

Overview

To create a low-cost, effective buck bias power converter, the LM5010 step-down switching regulator has all the necessary capabilities. This high-voltage regulator features a 75-V N-channel buck switch, is simple to use, and is offered in HTSSOP and thermally improved WSON packages. The regulator was developed based on a control strategy that uses an ON-time that is inversely proportional to VIN. No loop correction is needed with this control strategy.

Feature Description

All the features required to create a low-cost, effective buck bias power converter that can deliver more than 1 A to the load are included in the LM5010 step-down switching regulator. This high voltage regulator comes in thermally improved 10-pin WSON and 14-pin HTSSOP packages, has an N-Channel buck switch, and is simple to use. A constant ON-time control method, in which the ON-time varies inversely with VIN, underlies the operation of the regulator. As a result, the operating frequency remains largely stable despite load and input voltage changes. A switching frequency of between 100 kHz and 1 MHz is possible.

The hysteretic control has a very quick load transient response because it doesn’t need loop compensation. The buck switch is kept off until the high current level subsides thanks to the valley current limit detecting circuit, which has an internal setting of 1.25 A. The LM5010 can effectively regulate down greater voltages in a variety of applications. The new 42-V automotive power bus and 48-V telecom applications are well-suited for this regulator. A highly efficient intermediate bus converter followed by a point-of-load regulator can lead to high overall system efficiency.

● Control Circuit Overview

The output voltage feedback (FB) of the LM5010 buck DC-DC regulator is compared to an internal reference through a comparator and a one-shot ON timer in its control scheme (2.5 V). A programming resistor and the input voltage control how long the buck switch is activated if the FB voltage is lower than the reference (RON). When the switch turns off after the ON-time, it stays off for 265 ns or until the FB voltage drops below the reference, whichever comes first. After that, the buck switch activates for another ON-time interval. The OFF times are typically momentarily at a minimum of 265 ns when the load current increases abruptly. The OFF-time returns to its usual value after regulation has been established.

● Regulation Comparator

The voltage at the soft-start pin (2.5 V, +/- 2%) and the feedback voltage at FB are contrasted. When the voltage at FB drops below 2.5 V during normal operation (the output voltage is regulated), an ON-time period begins. During the ON-time, the buck switch remains on, raising the FB voltage above 2.5 V. Up until the FB voltage drops below 2.5 V after the ON-time period, the buck switch is off. Less than 5 nA over temperature is the bias current at the FB pin.

● Overvoltage Comparator

The FB feedback voltage is contrasted with a 2.9-V internal reference. The ON-time is instantly stopped if the voltage at FB increases above 2.9 V. If the output load or input voltage suddenly changes, this condition may develop. Until the voltage at FB drops below 2.5 V, the buck switch won’t activate again.

● N-Channel Buck Switch and Driver

The floating high-voltage gate driver and an N-Channel buck switch are included in the LM5010. The peak current via the buck switch cannot be greater than 3.5 A, and the average current cannot be greater than 3 A. Between BST and SW, the external bootstrap capacitor powers the gate driver circuit (C4). The inbuilt high voltage diode recharges C4 from VCC during each OFF-time, keeping the SW pin at about -1 V. The minimum OFF-time of 265 ns guarantees that the bootstrap capacitor will have enough time to recharge between each cycle. TI suggests a 0.022-F ceramic capacitor for C4.

● Thermal Shutdown

Operating the LM5010 should keep the junction temperature under 125°C. The controller enters a low-power reset mode by turning off the buck switch and the ON timer and grounding the soft-start pin if the junction temperature rises over that, which normally happens at 175°C. This function guard against unintentional device overheating that could lead to catastrophic failures. Normal operation returns until the junction temperature drops below 155°C (usual hysteresis = 20°C). At that point, the soft-start pin is released.

Layout

● Layout Guidelines

The comparators for regulation, overvoltage, and current limit in the LM5010 are extremely quick and react to brief noise pulses. As a result, layout factors are essential for the best performance. All the components must be as close as possible to their corresponding pins, and the layout must be as orderly and small as feasible. As little current as feasible should flow via the current loop created by D1, L1 (LIND), C2 (COUT), and the SGND and ISEN pins. A short and direct ground connection should be made between C2 (COUT) and C1 (CIN). If the LM5010’s internal heat dissipation is anticipated to result in high junction temperatures during normal operation, using the ground plane on the PC board can significantly aid heat dissipation.

The exposed pad on the bottom of the IC package can be soldered with a ground plane that extends from underneath the IC and connects to the exposed ground plane on the opposite side of the board using as many vias as possible. Internally, the exposed pad is attached to the IC substrate. When feasible, using large PC board traces at the pins can aid in cooling the IC.

The four no connect pins on the HTSSOP package may be linked to the ground plane to help dissipate heat from the package even though they are not electrically connected to any component of the IC. The junction temperature can be lowered by carefully situating the PC board inside the finished product and using any available air flow (forced or natural convection).

Conclusion

The LM5010 is made to work with an input power source that can deliver voltages between 8 and 75 volts. The input power supply needs to be well-regulated and able to provide the regulator with enough current during a peak load operation. To keep the converter stable, as in all applications, the power-supply source impedance must be low compared to the module input impedance.

You may get more information or purchase the LM5010MHX/NOPB by contacting us at ICRFQ, your trusted supplier of electronic components in China. We’ll ensure you receive the best products at the best possible rates.

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