LM/-Q1 does not rely on output capacitor ESR An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in. LM Synchronous 1MHz A Step-Down Voltage Regulator from the PowerWise® Family The LM Synchronously Rectified Buck Converter features all. The LM Synchronously Rectified Buck Converter Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

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The Constant On-Time COT regulation scheme requires no loop compensation, results in a fast load transient response and simple circuit implementation that allows a low component count, and consequently very dwtasheet overall board space is required for a typical application. In some cases, TI components may be promoted specifically to facilitate safety-related applications.

Judicious positioning of the PC board within the end product, along with the use of any available air flow forced or natural convection can help reduce the junction temperature.

LM3 Molded Inductor

Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. The input capacitor is calculated from: The exposed pad on the bottom of the LM IC package can be soldered to the ground plane, which should extend out from beneath the LM to help dissipate heat. The exposed pad is internally connected to the LM IC substrate. No TI components are authorized for use in FDA Class III or similar life-critical medical equipment unless authorized officers of the parties have executed a special agreement specifically governing such use.

C8 should be no smaller than nF for stability, and should be a good quality, low ESR, ceramic capacitor. Using numerous vias to connect the die attached pad to the ground plane is a good practice.


Buyer will fully indemnify TI and its representatives against any damages arising out of the use of any TI components in safety-critical applications. In this demonstration board, a 10 nF capacitor is used. A low ESR 0. Information of third parties may be subject to additional restrictions. Documents Flashcards Grammar checker. TI is not responsible or liable for any such statements. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause harm and take appropriate remedial actions.

Typical performance and operating waveforms are also provided for reference. Layout is therefore critical for optimum performance. To ensure that the on-time is larger than the minimum limit, which is ns, the value of R1 must satisfy the following equation: Determine the inductance Datasbeet main parameter affected by the inductor is the amplitude of the inductor current ripple ILR. Protection features include output over-voltage protection, thermal datasheeet, VCC undervoltage lock-out, gate drive under-voltage lock-out.

It then drops to zero at turn-off. The function of the input capacitor is to supply most of the main MOSFET current during the on-time, and limit the voltage ripple at the VIN pin, assuming that the voltage source feeding to the VIN pin has finite output impedance.

Synchronous 1MHz 2.5A Step-Down Voltage Regulator

This user’s guide details the design of a demonstration board which provides a 3. The output capacitor C10, C11 should be connected close to the load and tied directly to the ground plane.

A nF capacitor is used in this demonstration board. I wish to measure a very low resistance of the order of an ohm. The inductor L1 should be connected close to the SW pin with as short a trace as possible to reduce the potential for EMI electromagnetic interference generation.

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How much energy is. Dtaasheet average current during the on-time is the load current. The demonstration datashete schematic, PCB layout, Bill of Materials, and circuit design descriptions are shown. Except where mandated by applicable law, testing of all parameters of each component is not necessarily performed. Calculate the on-time setting resistor The switching frequency fSW of the demonstration board is affected by the on-time ton of the LM, which is determined by R1. Calculate the feedback resistors The ratio of the feedback resistors can be calculated from the following equation: Headline Bold Ipsum lorem Headline Light.

The design of the demonstration board is detailed below.

LMQ1 from Texas Instruments

If the output voltage is higher than 1. Low ESR also helps ensure a complete recharge during each off-time. The operating frequency remains constant with line variations due to the inverse relationship between the input voltage and the on-time.

Additionally the use of thick traces, where possible, can help conduct heat away from the LM Buyers are responsible for their products and applications daatasheet TI components. Products Applications Audio www. A load which creates significant transients requires a larger output capacitor than a fixed load. Determine the value of other components C1 and C2: Lab 6 in this note.

The capacitor at the SS pin determines the soft-start time, that is, the time for the reference voltage at the regulation comparator and the output voltage to reach their final value.