LM2751SDX-A

LM2751 www.ti.com SNVS299B – APRIL 2005 – REVISED MAY 2013 LM2751 Regulated 2X, 1.5X Switched Capacitor White LED Driver Check for Samples: LM2751 FEATURES APPLICATIONS • • • • • • • 1 2 • • • • • • Regulated Output Options: 4.5V, 5.0V Output Voltage Regulated Within 3% Peak Efficiency Over 90% 150mA (4.5V) or 80mA (5.0V) Output Current Capability Input Voltage Range: 2.8V to 5.5V Low Input and Output Voltage Ripple TON fMAX = DMIN ÷ TON (2) (3) The minimum recommended PWM frequency is 100Hz. Frequencies below this may be visibly noticeable as flicker or blinking. The maximum recommended PWM frequency is 1kHz. Frequencies above this may cause noise in the audible range. THERMAL PROTECTION When the junction temperature exceeds 150°C (typ.), internal thermal protection circuitry disables the device. This feature protects the LM2751 from damage due to excessive power dissipation. The device will recover and operate normally when the junction temperature falls below 140°C (typ.). It is important to have good thermal conduction with a proper layout to reduce thermal resistance. POWER EFFICIENCY Charge-Pump efficiency is derived in the following two ideal equations (supply current and other losses are neglected for simplicity): IIN = G x IOUT E = (VOUT x IOUT) ÷ (VIN x IIN) = VOUT ÷ (G x VIN) (4) (5) In the equations, G represents the charge pump gain. Efficiency is at its highest as G x VIN approaches VOUT. Refer to the efficiency graph in the Typical Performance Characteristics for the detailed efficiency data. POWER DISSIPATION The power dissipation (PDISSIPATION) and junction temperature (TJ) can be approximated with the equations below. PIN is the product of the input current and input voltage, POUT is the power consumed by the load connected to the output, TAis the ambient temperature, and θJA is the junction-to-ambient thermal resistance for the 10-pin SON package. VIN is the input voltage to the LM2751, VVOUT is the voltage at the output of the device, and IOUT is the total current supplied to the load connected to VOUT. PDISSIPATION = PIN - POUT = (VIN × IIN) − (VVOUT × IOUT) TJ = TA + (PDISSIPATION × θJA) (6) (7) (8) The junction temperature rating takes precedence over the ambient temperature rating. The LM2751 may be operated outside the ambient temperature rating, so long as the junction temperature of the device does not exceed the maximum operating rating of 115°C. The maximum ambient temperature rating must be derated in applications where high power dissipation and/or poor thermal resistance causes the junction temperature to exceed 115°C. 12 Submit Documentation Feedback Copyright © 2005–2013, Texas Instruments Incorporated Product Folder Links: LM2751 LM2751 www.ti.com SNVS299B – APRIL 2005 – REVISED MAY 2013 REVISION HISTORY Changes from Revision A (May 2013) to Revision B • Page Changed layout of National Data Sheet to TI format .......................................................................................................... 12 Submit Documentation Feedback Copyright © 2005–2013, Texas Instruments Incorporated Product Folder Links: LM2751 13 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) LM2751SD-B/NOPB ACTIVE WSON DSC 10 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 85 L146B (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of