Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - DC/DC voltage regulator Holder HTSSOP 16

BST

COMP

RAMP

VCC

VIN

OUT

GND

LM5575

VIN

VOUT

SYNC

LM5575

www.ti.com

SNVS471G –JANUARY 2007–REVISED APRIL 2013

LM5575/LM5575Q SIMPLE SWITCHER® 75V, 1.5A Step-Down Switching Regulator

Check for Samples: LM5575

FEATURES

DESCRIPTION

The LM5575 is an easy to use SIMPLE SWITCHER®

• LM5575Q is an Automotive Grade Product that

buck regulator which allows design engineers to

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

design and optimize a robust power supply using a

125°C Operating Junction Temperature)

minimum set of components. Operating with an input

• Integrated 75V, 330mΩ N-channel MOSFET

voltage range of 6 - 75V, the LM5575 delivers 1.5A of

continuous output current with an integrated 330mΩ

• Ultra-wide Input Voltage Range from 6V to 75V

N-Channel MOSFET. The regulator utilizes an

• Adjustable Output Voltage as Low as 1.225V

Emulated Current Mode architecture which provides

• 1.5% Feedback Reference Accuracy

inherent line regulation, tight load transient response,

• Operating Frequency Adjustable Between

and ease of loop compensation without the usual

limitation of low-duty cycles associated with current

50kHz and 500kHz with Single Resistor

mode regulators. The operating frequency is

• Master or Slave Frequency Synchronization

adjustable from 50kHz to 500kHz to allow

• Adjustable Soft-Start

optimization of size and efficiency. To reduce EMI, a

• Emulated Current Mode Control Architecture frequency synchronization pin allows multiple IC’s

from the LM(2)557x family to self-synchronize or to

• Wide Bandwidth Error Amplifier

synchronize to an external clock. The LM5575

• Built-in Protection

ensures robustness with cycle-by-cycle current limit,

• Automotive Grade Product Datasheet that is

short-circuit protection, thermal shut-down, and

remote shut-down. The device is available in a power

AEC-Q100 Grade 0 Qualified is Available Upon

enhanced HTSSOP-16 package featuring an

Request.

exposed die attach pad for thermal dissipation. The

– (−40°C to + 150°C Operating Junction

LM5575 is supported by the full suite of WEBENCH

Temperature)

On-Line design tools.

APPLICATIONS

PACKAGE

• Automotive

• HTSSOP-16EP (Exposed Pad)

• Industrial

Simplified Application Schematic

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.

2WEBENCH is a registered trademark of Texas Instruments.

3All other 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 (28 pages)

PAGE 1
LM5575 www.ti.com SNVS471G – JANUARY 2007 – REVISED APRIL 2013 LM5575/LM5575Q SIMPLE SWITCHER® 75V, 1.5A Step-Down Switching Regulator Check for Samples: LM5575 FEATURES DESCRIPTION • The LM5575 is an easy to use SIMPLE SWITCHER® buck regulator which allows design engineers to design and optimize a robust power supply using a minimum set of components. Operating with an input voltage range of 6 - 75V, the LM5575 delivers 1.5A of continuous output current with an integrated 330mΩ N-Channel MOSFET.
PAGE 2
LM5575 SNVS471G – JANUARY 2007 – REVISED APRIL 2013 www.ti.com Connection Diagram 1 VCC BST SD PRE VIN SW 2 3 4 5 6 7 8 SYNC IS COMP PGND FB OUT RT SS RAMP AGND 16 15 14 13 12 11 10 9 Figure 1. Top View 16-Lead HTSSOP PIN DESCRIPTIONS 2 Pin(s) Name 1 VCC 2 Description Application Information Output of the bias regulator Vcc tracks Vin up to 9V. Beyond 9V, Vcc is regulated to 7 Volts. A 0.1uF to 1uF ceramic decoupling capacitor is required. An external voltage (7.
PAGE 3
LM5575 www.ti.com SNVS471G – JANUARY 2007 – REVISED APRIL 2013 PIN DESCRIPTIONS (continued) Pin(s) Name 15 PRE Pre-charge assist for the bootstrap capacitor Description This open drain output can be connected to SW pin to aid charging the bootstrap capacitor during very light load conditions or in applications where the output may be pre-charged before the LM5575 is enabled. An internal pre-charge MOSFET is turned on for 250ns each cycle just prior to the on-time interval of the buck switch.
PAGE 4
LM5575 SNVS471G – JANUARY 2007 – REVISED APRIL 2013 www.ti.com Electrical Characteristics Specifications with standard typeface are for TJ = 25°C, and those with boldface type apply over full Operating Junction Temperature range. VIN = 48V, RT = 32.4kΩ unless otherwise stated. (1) Symbol Parameter Conditions Min Typ Max Units 6.85 7.15 7.
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LM5575 www.ti.com SNVS471G – JANUARY 2007 – REVISED APRIL 2013 Electrical Characteristics (continued) Specifications with standard typeface are for TJ = 25°C, and those with boldface type apply over full Operating Junction Temperature range. VIN = 48V, RT = 32.4kΩ unless otherwise stated.(1) Symbol Parameter Conditions Min Typ Max 1.207 1.225 1.
PAGE 6
LM5575 SNVS471G – JANUARY 2007 – REVISED APRIL 2013 www.ti.com Typical Performance Characteristics Oscillator Frequency vs Temperature FOSC = 200kHz Oscillator Frequency vs RT NORMALIZED OSCILLATOR FREQUENCY OSCILLATOR FREQUENCY (kHz) 1000 100 10 1 10 100 1.010 1.005 1.000 0.995 0.990 -50 -25 0 25 50 75 100 125 o 1000 TEMPERATURE ( C) RT (k:) Figure 2. Figure 3. Soft Start Current vs Temperature VCC vs ICC VIN = 12V 8 6 1.05 VCC (V) NORMALIZED SOFTSTART CURRENT 1.10 1.
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LM5575 www.ti.com SNVS471G – JANUARY 2007 – REVISED APRIL 2013 Typical Performance Characteristics (continued) Demoboard Efficiency vs IOUT and VIN 100 90 EFFICIENCY (%) 80 70 60 50 VIN = 24V VIN = 7V VIN = 48V 40 30 VIN = 75V 20 10 0 0.25 0.5 0.75 1 1.25 1.5 IOUT (A) Figure 8.
PAGE 8
LM5575 SNVS471G – JANUARY 2007 – REVISED APRIL 2013 www.ti.com TYPICAL APPLICATION CIRCUIT AND BLOCK DIAGRAM VIN 7V ± 75V C1 1.0 VIN 3 C2 1.0 5 PA R1 OPEN LM5575 7V REGULATOR 1.225V 2 SD STANDBY VCC SHUTDOWN 0.7V SD C12 OPEN R2 OPEN 10 SS BST UVLO C7 0.022 DRIVER S Q 1.225V 16 VIN DIS CLK 10 PA C4 0.01 C8 0.47 THERMAL SHUTDOWN UVLO 1 R Q LEVEL SHIFT PWM 0.7V PRE 15 C_LIMIT 6 FB C6 open C5 0.01 R4 49.
PAGE 9
LM5575 www.ti.com SNVS471G – JANUARY 2007 – REVISED APRIL 2013 An auxiliary supply voltage can be applied to the Vcc pin to reduce the IC power dissipation. If the auxiliary voltage is greater than 7.3V, the internal regulator will essentially shut off, reducing the IC power dissipation. The Vcc regulator series pass transistor includes a diode between Vcc and Vin that should not be forward biased in normal operation. Therefore the auxiliary Vcc voltage should never exceed the Vin voltage.
PAGE 10
LM5575 SNVS471G – JANUARY 2007 – REVISED APRIL 2013 www.ti.com LM5575 SYNC SW SYNC AGND CLK SW 500 ns Figure 11. Sync from External Clock LM5575 SYNC LM5575 SYNC UP TO 5 TOTAL DEVICES Figure 12. Sync from Multiple Devices Multiple LM5575 devices can be synchronized together simply by connecting the SYNC pins together. In this configuration all of the devices will be synchronized to the highest frequency device. The diagram in Figure 13 illustrates the SYNC input/output features of the LM5575.
PAGE 11
LM5575 www.ti.com SNVS471G – JANUARY 2007 – REVISED APRIL 2013 Error Amplifier and PWM Comparator The internal high gain error amplifier generates an error signal proportional to the difference between the regulated output voltage and an internal precision reference (1.225V). The output of the error amplifier is connected to the COMP pin allowing the user to provide loop compensation components, generally a type II network, as illustrated in Figure 9.
PAGE 12
LM5575 SNVS471G – JANUARY 2007 – REVISED APRIL 2013 www.ti.com Proper selection of the RAMP capacitor depends upon the selected value of the output inductor. The value of CRAMP can be selected from: CRAMP = L x 10-5, where L is the value of the output inductor in Henrys. With this value, the scale factor of the emulated current ramp will be approximately equal to the scale factor of the DC level sample and hold (1.0 V / A).
PAGE 13
LM5575 www.ti.com SNVS471G – JANUARY 2007 – REVISED APRIL 2013 Soft-Start The soft-start feature allows the regulator to gradually reach the initial steady state operating point, thus reducing start-up stresses and surges. The internal soft-start current source, set to 10µA, gradually increases the voltage of an external soft-start capacitor connected to the SS pin. The soft-start capacitor voltage is connected to the reference input of the error amplifier.
PAGE 14
LM5575 SNVS471G – JANUARY 2007 – REVISED APRIL 2013 www.ti.com L1 Current IPK+ IRIPPLE IO IPK- 1/Fs 0 mA Figure 16. Inductor Current Waveform To keep the circuit in continuous conduction mode (CCM), the maximum ripple current IRIPPLE should be less than twice the minimum load current, or 0.4Ap-p. Using this value of ripple current, the value of inductor (L1) is calculated using the following: L1 = VOUT x (VIN(max) ± VOUT) IRIPPLE x FS x VIN(max) (6) 5V x (75V ± 5V) L1 = = 39 PH 0.
PAGE 15
LM5575 www.ti.com SNVS471G – JANUARY 2007 – REVISED APRIL 2013 The forward voltage drop has a significant impact on the conversion efficiency, especially for applications with a low output voltage. “Rated” current for diodes vary widely from various manufacturers. The worst case is to assume a short circuit load condition. In this case the diode will carry the output current almost continuously. For the LM5575 this current can be as high as 2.1A.
PAGE 16
LM5575 SNVS471G – JANUARY 2007 – REVISED APRIL 2013 www.ti.com Capacitor C12 provides filtering for the divider. The voltage at the SD pin should never exceed 8V, when using an external set-point divider it may be necessary to clamp the SD pin at high input voltage conditions. The reference design utilizes the full range of the LM5575 (6V to 75V); therefore these components can be omitted. With the SD pin open circuit the LM5575 responds once the Vcc UVLO threshold is satisfied.
PAGE 17
LM5575 www.ti.com SNVS471G – JANUARY 2007 – REVISED APRIL 2013 Components R4 and C5 configure the error amplifier as a type II configuration which has a pole at DC and a zero at fZ = 1 / (2πR4C5). The error amplifier zero cancels the modulator pole leaving a single pole response at the crossover frequency of the loop gain. A single pole response at the crossover frequency yields a very stable loop with 90 degrees of phase margin.
PAGE 18
LM5575 SNVS471G – JANUARY 2007 – REVISED APRIL 2013 www.ti.com If a network analyzer is available, the modulator gain can be measured and the error amplifier gain can be configured for the desired loop transfer function. If a network analyzer is not available, the error amplifier compensation components can be designed with the guidelines given. Step load transient tests can be performed to verify acceptable performance. The step load goal is minimum overshoot with a damped response.
PAGE 19
LM5575 www.ti.com SNVS471G – JANUARY 2007 – REVISED APRIL 2013 PCB LAYOUT AND THERMAL CONSIDERATIONS The circuit in Figure 9 serves as both a block diagram of the LM5575 and a typical application board schematic for the LM5575. In a buck regulator there are two loops where currents are switched very fast. The first loop starts from the input capacitors, to the regulator VIN pin, to the regulator SW pin, to the inductor then out to the load.
PAGE 20
LM5575 SNVS471G – JANUARY 2007 – REVISED APRIL 2013 www.ti.com Table 1. 5V, 1.5A Demo Board Bill of Materials ITEM 20 PART NUMBER DESCRIPTION VALUE C 1 C3225X7R2A105M CAPACITOR, CER, TDK C 2 C3225X7R2A105M CAPACITOR, CER, TDK C 3 C0805A471K1GAC CAPACITOR, CER, KEMET 470p, 100V C 4 C2012X7R2A103K CAPACITOR, CER, TDK 0.01µ, 100V C 5 C2012X7R2A103K CAPACITOR, CER, TDK 0.01µ, 100V C 6 OPEN NOT USED C 7 C2012X7R2A223K CAPACITOR, CER, TDK 0.
PAGE 21
LM5575 www.ti.com SNVS471G – JANUARY 2007 – REVISED APRIL 2013 PCB Layout Figure 22. Component Side Figure 23. Solder Side Figure 24.
PAGE 22
LM5575 SNVS471G – JANUARY 2007 – REVISED APRIL 2013 www.ti.com REVISION HISTORY Changes from Revision F (April 2013) to Revision G • 22 Page Changed layout of National Data Sheet to TI format ..........................................................................................................
PAGE 23
PACKAGE OPTION ADDENDUM www.ti.
PAGE 24
PACKAGE OPTION ADDENDUM www.ti.com (4) 1-Nov-2013 There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device.
PAGE 25
PACKAGE MATERIALS INFORMATION www.ti.com 8-Apr-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) LM5575MHX HTSSOP PWP 16 2500 330.0 12.4 B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 6.95 8.3 1.6 8.0 12.0 Q1 LM5575MHX/NOPB HTSSOP PWP 16 2500 330.0 12.4 6.95 8.3 1.6 8.0 12.0 Q1 LM5575Q0MHX/NOPB HTSSOP PWP 16 2500 330.0 12.4 6.95 8.3 1.6 8.0 12.
PAGE 26
PACKAGE MATERIALS INFORMATION www.ti.com 8-Apr-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM5575MHX HTSSOP PWP 16 2500 367.0 367.0 35.0 LM5575MHX/NOPB HTSSOP PWP 16 2500 367.0 367.0 35.0 LM5575Q0MHX/NOPB HTSSOP PWP 16 2500 367.0 367.0 35.0 LM5575QMHX/NOPB HTSSOP PWP 16 2500 367.0 367.0 35.
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MECHANICAL DATA PWP0016A MXA16A (Rev A) www.ti.
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