Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - DC/DC voltage regulator Holder TSOT 23 6

GND

SHDN

LM2840/1/2-ADJL

VOUT

VIN

BOOT

OUT

LM2841, LM2842

www.ti.com

SNVS540H –MARCH 2009–REVISED APRIL 2013

LM2840/LM2841/LM2842/ LM2840-Q1/LM2841-Q1/LM2842-Q1 100/300/600 mA 42V Input

Step-Down DC/DC Regulator in Thin SOT

Check for Samples: LM2841, LM2842

FEATURES

DESCRIPTION

The LM2840, LM2841 and LM2842 are PWM DC/DC

• LM2840Q, LM2841-Q1 and LM2842-Q1 are

buck (step-down) regulators. With a wide input range

Automotive Grade Products that are AEC-Q100

from 4.5V-42V, they are suitable for a wide range of

Grade 1 Qualified (-40°C to +125°C Operating

applications such as power conditioning from

Junction Temperature)

unregulated sources. They feature a low R

DSON

(0.9Ω

• Input Voltage Range of 4.5V to 42V

typical) internal switch for maximum efficiency (85%

typical). Operating frequency is fixed at 550 kHz (X

• Output Current Options of 100 mA, 300 mA

version) and 1.25 MHz (Y version) allowing the use of

and 600 mA

small external components while still being able to

• Feedback Pin Voltage of 0.765V

have low output voltage ripple. Soft-start can be

• 550 kHz (X) or 1.25 MHz (Y) Switching

implemented using the shutdown pin with an external

Frequency

RC circuit allowing the user to tailor the soft-start time

to a specific application.

• Low Shutdown I

, 16 µA Typical

The LM2840 is optimized for up to 100 mA, the

• Short Circuit Protected

LM2841 for 300 mA and the LM2842 is optimized for

• Internally Compensated

up to 600 mA load currents. They all have a 0.765V

• Soft-Start Circuitry

nominal feedback voltage.

• Small Overall Solution Size (SOT-6L Package)

Additional features include: thermal shutdown, V

under-voltage lockout, and gate drive under-voltage

APPLICATIONS

lockout. The LM2840, LM2841 and LM2842 are

available in a low profile SOT-6L package.

• Battery Powered Equipment

• Industrial Distributed Power Applications

• Portable Media Players

• Portable Hand Held Instruments

Typical Application Circuit

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (20 pages)

PAGE 1
LM2841, LM2842 www.ti.com SNVS540H – MARCH 2009 – REVISED APRIL 2013 LM2840/LM2841/LM2842/ LM2840-Q1/LM2841-Q1/LM2842-Q1 100/300/600 mA 42V Input Step-Down DC/DC Regulator in Thin SOT Check for Samples: LM2841, LM2842 FEATURES DESCRIPTION • The LM2840, LM2841 and LM2842 are PWM DC/DC buck (step-down) regulators. With a wide input range from 4.5V-42V, they are suitable for a wide range of applications such as power conditioning from unregulated sources. They feature a low RDSON (0.
PAGE 2
LM2841, LM2842 SNVS540H – MARCH 2009 – REVISED APRIL 2013 www.ti.com Connection Diagram Top View LM2840/1/2 CB 1 GND 2 FB 3 PIN 1 ID 6 SW 5 VIN 4 SHDN Figure 1. SOT 6 Lead See Package Number DDC (R-PDSO-G6) PIN DESCRIPTIONS Pin Name 1 CB 2 GND 3 FB 4 SHDN Function SW FET gate bias voltage. Connect CBOOT cap between CB and SW. Ground connection. Feedback pin: Set feedback voltage divider ratio with VOUT = VFB (1+(R1/R2)).
PAGE 3
LM2841, LM2842 www.ti.com SNVS540H – MARCH 2009 – REVISED APRIL 2013 Absolute Maximum Ratings (1) (2) VIN -0.3V to +45V SHDN -0.3V to (VIN+0.3V) <45V SW Voltage -0.3V to +45V CB Voltage above SW Voltage 7V FB Voltage -0.3V to +5V Maximum Junction Temperature 150°C Power Dissipation (3) Internally Limited Lead Temperature 300°C Vapor Phase (60 sec.) 215°C Infrared (15 sec.
PAGE 4
LM2841, LM2842 SNVS540H – MARCH 2009 – REVISED APRIL 2013 www.ti.com Electrical Characteristics (continued) Specifications in standard type face are for TJ = 25°C and those with boldface type apply over the full Operating Temperature Range ( TJ = −40°C to +125°C). Minimum and Maximum limits are specified through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TJ = +25°C, and are provided for reference purposes only.
PAGE 5
LM2841, LM2842 www.ti.com SNVS540H – MARCH 2009 – REVISED APRIL 2013 Typical Performance Characteristics Efficiency vs. Load Current (LM2842X, VOUT = 3.3V) Efficiency vs. Load Current (LM2841X, VOUT = 3.3V) 100 100 VIN = 12V VIN = 12V 80 VIN = 36V 60 VIN = 36V EFFICIENCY (%) EFFICIENCY (%) 80 VIN = 24V 40 60 VIN = 24V 40 20 20 0 0.0 0.1 0.2 0.3 0.4 0.5 0 0.0 0.6 0.1 0.2 0.3 LOAD CURRENT (A) LOAD CURRENT (A) Figure 2. Figure 3. Efficiency vs.
PAGE 6
LM2841, LM2842 SNVS540H – MARCH 2009 – REVISED APRIL 2013 www.ti.com Typical Performance Characteristics (continued) Switch Current Limit vs. SHDN Pin Voltage (Soft-start Implementation, LM2842) SHDN Pin Current vs. SHDN Pin Voltage SWITCH CURRENT LIMIT (A) 1.2 1.0 0.9 0.7 0.6 0.4 1.1 1.7 2.3 2.8 3.4 4.0 SHDN PIN VOLTAGE (V) Figure 8. Figure 9. Switching Node and Output Voltage Waveforms Load Transient Waveforms VIN = 12V, VOUT = 3.
PAGE 7
LM2841, LM2842 www.ti.com SNVS540H – MARCH 2009 – REVISED APRIL 2013 BLOCK DIAGRAM CB + OSC SET FB + PWM Comp Error Amp + Bandgap Soft Start VIN Max Duty Cycle Limit + RESET Inductor Current Measurement DC LIMIT BUCK DRIVE FET Driver SW UVLO TSD UVLO Comp Thermal Shutdown BG Voltage Regulator GND SHDN Figure 13. Block Diagram OPERATION PROTECTION The LM2840/1/2 has dedicated protection circuitry running during normal operation to protect the IC.
PAGE 8
LM2841, LM2842 SNVS540H – MARCH 2009 – REVISED APRIL 2013 www.ti.com INPUT CAPACITOR A low ESR ceramic capacitor (CIN) is needed between the VIN pin and GND pin. This capacitor prevents large voltage transients from appearing at the input. Use a 2.2 µF-10 µF value with X5R or X7R dielectric. Depending on construction, a ceramic capacitor’s value can decrease up to 50% of its nominal value when rated voltage is applied.
PAGE 9
LM2841, LM2842 www.ti.com SNVS540H – MARCH 2009 – REVISED APRIL 2013 SCHOTTKY DIODE The breakdown voltage rating of the diode (D1) is preferred to be 25% higher than the maximum input voltage. The current rating for the diode should be equal to the maximum output current for best reliability in most applications. In cases where the duty cycle is greater than 50%, the average diode current is lower.
PAGE 10
LM2841, LM2842 SNVS540H – MARCH 2009 – REVISED APRIL 2013 www.ti.com CBOOT LM2840/1/2-ADJL 7V to 42V IN SHDN SW GND FB 5V OUT 0.15 PF D1 MA2YD26 CB VIN L1 15 PH R1 5.62k CIN 2.2 PF R2 1.02k COUT 47 PF Figure 15. Application Circuit, 5V Output CBOOT LM2840/1/2-ADJL 15V to 42V IN VIN CB SHDN SW GND FB L1 47 PH 12V OUT 0.15 PF D1 MA2YD26 R1 14.7k R2 1k CIN 2.2 PF COUT 22 PF Figure 16.
PAGE 11
LM2841, LM2842 www.ti.com SNVS540H – MARCH 2009 – REVISED APRIL 2013 REVISION HISTORY Changes from Revision G (April 2013) to Revision H • Page Changed layout of National Data Sheet to TI format ..........................................................................................................
PAGE 12
PACKAGE OPTION ADDENDUM www.ti.
PAGE 13
PACKAGE OPTION ADDENDUM www.ti.
PAGE 14
PACKAGE OPTION ADDENDUM www.ti.com 14-Feb-2014 (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided.
PAGE 15
PACKAGE MATERIALS INFORMATION www.ti.com 13-Feb-2014 TAPE AND REEL INFORMATION *All dimensions are nominal Device LM2840XMK-ADJL/NOPB LM2840XMKX-ADJL/NOP B Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 SOT DDC 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LM2840XQMK/NOPB SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.
PAGE 16
PACKAGE MATERIALS INFORMATION www.ti.com 13-Feb-2014 Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant LM2841YQMKX/NOPB SOT DDC 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LM2842XMK-ADJL/NOPB SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 SOT DDC 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LM2842XQMK/NOPB SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.
PAGE 17
PACKAGE MATERIALS INFORMATION www.ti.com 13-Feb-2014 Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) B LM2840YQMK/NOPB SOT DDC 6 1000 210.0 185.0 35.0 LM2840YQMKX/NOPB SOT DDC 6 3000 210.0 185.0 35.0 LM2841XMK-ADJL/NOPB SOT DDC 6 1000 210.0 185.0 35.0 SOT DDC 6 3000 210.0 185.0 35.0 LM2841XMKX-ADJL/NOP B LM2841XQMK/NOPB SOT DDC 6 1000 210.0 185.0 35.0 LM2841XQMKX/NOPB SOT DDC 6 3000 210.0 185.0 35.
PAGE 18
PAGE 19
PAGE 20
IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.