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LM22673-ADJ

VIN

BOOT

GND

VIN

VOUT

IADJ

LM22673

www.ti.com

SNVS586N –SEPTEMBER 2008–REVISED APRIL 2013

LM22673/LM22673-Q1 42V, 3A SIMPLE SWITCHER®, Step-Down Voltage Regulator with

Features

Check for Samples: LM22673

FEATURES

DESCRIPTION

The LM22673 switching regulator provides all of the

• Wide Input Voltage Range: 4.5V to 42V

functions necessary to implement an efficient high

• Internally Compensated Voltage Mode Control

voltage step-down (buck) regulator using a minimum

• Stable with Low ESR Ceramic Capacitors

of external components. This easy to use regulator

incorporates a 42V N-channel MOSFET switch

• 120 mΩ N-Channel MOSFET PFM Package

capable of providing up to 3A of load current.

• 100 mΩ N-Channel MOSFET SO PowerPAD

Excellent line and load regulation along with high

Package

efficiency (>90%) are featured. Voltage mode control

• Output Voltage Options:

offers short minimum on-time, allowing the widest

ratio between input and output voltages. Internal loop

– ADJ (Outputs as Low as 1.285V)

compensation means that the user is free from the

– 5.0 (Output Fixed to 5V)

tedious task of calculating the loop compensation

• ±1.5% Feedback Reference Accuracy

components. Fixed 5V output and adjustable output

voltage options are available. A switching frequency

• Switching Frequency of 500 kHz

of 500 kHz allows for small external components and

• -40°C to 125°C Operating Junction

good transient response. An adjustable soft-start

Temperature Range

feature is provided through the selection of a single

• Adjustable Soft-Start

external capacitor. In addition, the switch current limit

can be programmed with a single external resistor,

• Adjustable Current Limit

allowing solution optimization. The LM22673 also has

• Integrated Boot-Strap Diode

built in thermal shutdown, and current limiting to

• Fully Webench

Enabled

protect against accidental overloads.

• LM22673-Q1 is an Automotive Grade Product

The LM22673 is a member of Texas Instruments'

that is AEC-Q100 Grade 1 Qualified (-40°C to

SIMPLE SWITCHER® family. The SIMPLE

+125°C Junction Temperature)

SWITCHER® concept provides for an easy to use

complete design using a minimum number of external

PACKAGE

components and the TI WEBENCH

design tool. TI's

WEBENCH

tool includes features such as external

• SO PowerPAD (Exposed Pad)

component calculation, electrical simulation, thermal

• PFM (Exposed Pad)

simulation, and Build-It boards for easy design-in.

APPLICATIONS

Simplified Application Schematic

• Industrial Control

• Telecom and Datacom Systems

• Embedded Systems

• Conversions from Standard 24V, 12V and 5V

Input Rails

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 (27 pages)

PAGE 1
LM22673 www.ti.com SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 LM22673/LM22673-Q1 42V, 3A SIMPLE SWITCHER®, Step-Down Voltage Regulator with Features Check for Samples: LM22673 FEATURES DESCRIPTION • • • • • The LM22673 switching regulator provides all of the functions necessary to implement an efficient high voltage step-down (buck) regulator using a minimum of external components. This easy to use regulator incorporates a 42V N-channel MOSFET switch capable of providing up to 3A of load current.
PAGE 2
LM22673 SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 www.ti.com Connection Diagram BOOT 1 8 SW NC 2 7 VIN IADJ 3 6 GND FB 4 5 SS Exposed Pad Connect to GND Figure 1. 8-Lead Plastic SO PowerPAD Package Package Number DDA0008B 7 SS 6 FB 5 IADJ 4 GND 3 BOOT 2 VIN 1 SW Exposed Pad Connect to GND Figure 2.
PAGE 3
LM22673 www.ti.com SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 Absolute Maximum Ratings (1) (2) VIN to GND 43V SS, IADJ Pin Voltage -0.5V to 7V SW to GND (3) -5V to VIN Boot Pin Voltage VSW + 7V FB Pin Voltage -0.5V to 7V Power Dissipation Internally Limited Junction Temperature 150°C For soldering specifications, refer to the following document: www.ti.
PAGE 4
LM22673 SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 www.ti.com Electrical Characteristics Limits in standard type are for TJ = 25°C only; limits in boldface type apply over the junction temperature (TJ) range of -40°C to +125°C. Minimum and Maximum limits are ensured through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TA = TJ = 25°C, and are provided for reference purposes only. Unless otherwise specified: VIN = 12V.
PAGE 5
LM22673 www.ti.com SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 Typical Performance Characteristics Unless otherwise specified the following conditions apply: Vin = 12V, TJ = 25°C. Efficiency vs IOUT and VIN VOUT = 3.3V Current Limit vs Temperature Figure 3. Figure 4. Normalized Switching Frequency vs Temperature Feedback Bias Current vs Temperature Figure 5. Figure 6. Normalized Feedback Voltage vs Temperature 1.5 Normalized RDS(ON) vs Temperature NORMALIZED RDS(ON) 1.4 PFM Package 1.3 1.
PAGE 6
LM22673 SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 www.ti.com Typical Performance Characteristics (continued) Unless otherwise specified the following conditions apply: Vin = 12V, TJ = 25°C. Normalized Feedback Voltage vs Input Voltage Soft-start Current vs Temperature Figure 9. Figure 10. Current Limit vs IADJ Resistor Figure 11.
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LM22673 www.ti.com SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 SIMPLIFIED BLOCK DIAGRAM VIN VIN BOOT Vcc INT REG, EN, UVLO ILimit IADJ PWM Cmp. FB TYPE III COMP + + - LOGIC Error Amp. VOUT SW OSC 1.285V & Soft-start SS GND Figure 12. Simplified Block Diagram Detailed Operating Description The LM22673 incorporates a voltage mode constant frequency PWM architecture. In addition, input voltage feedforward is used to stabilize the loop gain against variations in input voltage.
PAGE 8
LM22673 SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 www.ti.com Duty-Cycle Limits Ideally the regulator would control the duty cycle over the full range of zero to one. However due to inherent delays in the circuitry, there are limits on both the maximum and minimum duty cycles that can be reliably controlled. This in turn places limits on the maximum and minimum input and output voltages that can be converted by the LM22673.
PAGE 9
LM22673 www.ti.com SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 Where Vsc is the value of output voltage during the overload and Fsw is the normal switching frequency. If the input voltage should exceed this value, while in foldback mode, the regulator and/or the diode may be damaged. It is important to note that the voltages in these equations are measured at the inductor. Normal trace and wiring resistance will cause the voltage at the inductor to be higher than that at a remote load.
PAGE 10
LM22673 SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 www.ti.com Soft-Start The soft-start feature allows the regulator to gradually reach steady-state operation, thus reducing start-up stresses. The internal soft-start feature brings the output voltage up in about 500 µs. This time can be extended by using an external capacitor connected to the SS pin. Values in the range of 100 nF to 1 µF are recommended.
PAGE 11
LM22673 www.ti.com SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 COMPENSATOR GAIN (dB) 40 -ADJ -5.0 35 30 25 20 15 10 5 0 100 1k 10k 100k 1M FREQUENCY (Hz) 10M Figure 15. Compensator Gain In general, hand calculations or simulations can only aid in selecting good power stage components. Good design practice dictates that load and line transient testing should be done to verify the stability of the application. Also, Bode plot measurements should be made to determine stability margins.
PAGE 12
LM22673 SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 www.ti.com (9) where Fsw is the switching frequency and Vin should be taken at its maximum value, for the given application. The above formula provides a guide to select the value of the inductor L; the nearest standard value will then be used in the circuit.
PAGE 13
LM22673 www.ti.com SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 OUTPUT CAPACITOR The output capacitor is responsible for filtering the output voltage and supplying load current during transients. Capacitor selection depends on application conditions as well as ripple and transient requirements. Best performance is achieved with a parallel combination of ceramic capacitors and a low ESR SP™ or POSCAP™ type.
PAGE 14
LM22673 SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 www.ti.com A maximum value of 10 kΩ is recommended for the sum of RFBB and RFBT to maintain good output voltage accuracy for the -ADJ option. A maximum of 2 kΩ is recommended for the -5.0 option. For the -5.0 option, the total internal divider resistance is typically 9.93 kΩ.
PAGE 15
LM22673 www.ti.com SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 Thermal Considerations The components with the highest power dissipation are the power diode and the power MOSFET internal to the LM22673 regulator. The easiest method to determine the power dissipation within the LM22673 is to measure the total conversion losses then subtract the power losses in the diode and inductor. The total conversion loss is the difference between the input power and the output power.
PAGE 16
LM22673 SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 www.ti.
PAGE 17
LM22673 www.ti.com SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 PCB Layout Example for SO PowerPAD Package RFBB 2.55 k: VIN 5.5V to 35V VIN FB LM22673-ADJ SS C2 22 PF + C1 2.2 PF IADJ C6 4.7 PF BOOT GND VOUT C3 10 nF RFBT 7.32 k: L1 10 PH SW D1 60V 5A C4 120 PF + VOUT -5V Figure 19.
PAGE 18
LM22673 SNVS586N – SEPTEMBER 2008 – REVISED APRIL 2013 www.ti.com REVISION HISTORY Changes from Revision M (April 2013) to Revision N • 18 Page Changed layout of National Data Sheet to TI format ..........................................................................................................
PAGE 19
PACKAGE OPTION ADDENDUM www.ti.com 23-Feb-2014 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (°C) Device Marking (4/5) LM22673MR-5.0/NOPB ACTIVE SO PowerPAD DDA 8 95 Green (RoHS & no Sb/Br) SN | CU SN Level-3-260C-168 HR -40 to 125 L22673 5.
PAGE 20
PACKAGE OPTION ADDENDUM www.ti.com Orderable Device 23-Feb-2014 Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (°C) Device Marking (4/5) LM22673TJ-ADJ/NOPB ACTIVE TO-263 NDR 7 1000 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LM22673 TJ-ADJ LM22673TJE-5.0/NOPB ACTIVE TO-263 NDR 7 250 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LM22673 TJ-5.
PAGE 21
PACKAGE OPTION ADDENDUM www.ti.com 23-Feb-2014 In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
PAGE 22
PACKAGE MATERIALS INFORMATION www.ti.com 29-May-2013 TAPE AND REEL INFORMATION *All dimensions are nominal 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 LM22673MRE-5.0/NOPB SO Power PAD DDA 8 250 178.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LM22673MRE-ADJ/NOPB SO Power PAD DDA 8 250 178.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LM22673MRX-5.0/NOPB SO Power PAD DDA 8 2500 330.0 12.4 6.5 5.4 2.
PAGE 23
PACKAGE MATERIALS INFORMATION www.ti.com 29-May-2013 Device Package Package Pins Type Drawing B Power PAD LM22673QTJ-5.0/NOPB SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant TO-263 NDR 7 1000 330.0 24.4 10.6 15.4 2.45 12.0 24.0 Q2 LM22673QTJ-ADJ/NOPB TO-263 NDR 7 1000 330.0 24.4 10.6 15.4 2.45 12.0 24.0 Q2 LM22673QTJE-5.0/NOPB TO-263 NDR 7 250 178.0 24.4 10.6 15.4 2.45 12.0 24.
PAGE 24
PACKAGE MATERIALS INFORMATION www.ti.com 29-May-2013 Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM22673QMRX-5.0/NOPB SO PowerPAD DDA 8 2500 367.0 367.0 35.0 LM22673QMRX-ADJ/NOP B SO PowerPAD DDA 8 2500 367.0 367.0 35.0 LM22673QTJ-5.0/NOPB TO-263 NDR 7 1000 367.0 367.0 35.0 LM22673QTJ-ADJ/NOPB TO-263 NDR 7 1000 367.0 367.0 35.0 LM22673QTJE-5.0/NOPB TO-263 NDR 7 250 210.0 185.0 35.
PAGE 25
MECHANICAL DATA NDR0007A BOTTOM SIDE OF PACKAGE TOP SIDE OF PACKAGE TJ7A (Rev D) www.ti.
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MECHANICAL DATA DDA0008B MRA08B (Rev B) www.ti.
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