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LM5000

www.ti.com

SNVS176D –MAY 2004–REVISED MARCH 2007

LM5000 High Voltage Switch Mode Regulator

Check for Samples: LM5000

FEATURES

DESCRIPTION

The LM5000 is a monolithic integrated circuit

• 80V Internal Switch

specifically designed and optimized for flyback, boost

• Operating Input Voltage Range of 3.1V to 40V

or forward power converter applications. The internal

• Pin Selectable Operating Frequency

power switch is rated for a maximum of 80V, with a

current limit set to 2A. Protecting the power switch

– 300kHz/700kHz (-3)

are current limit and thermal shutdown circuits. The

– 600kHz/1.3MHz (-6)

current mode control scheme provides excellent

• Adjustable Output Voltage

rejection of line transients and cycle-by-cycle current

limiting. An external compensation pin and the built-in

• External Compensation

slope compensation allow the user to optimize the

• Input Undervoltage Lockout

frequency compensation. Other distinctive features

• Softstart

include softstart to reduce stresses during start-up

and an external shutdown pin for remote ON/OFF

• Current Limit

control. There are two operating frequency ranges

• Over Temperature Protection

available. The LM5000-3 is pin selectable for either

• External Shutdown

300kHz (FS Grounded) or 700kHz (FS Open). The

• Small 16-Lead TSSOP or 16-Lead WSON

LM5000-6 is pin selectable for either 600kHz (FS

Grounded) or 1.3MHz (FS Open). The device is

Package

available in a low profile 16-lead TSSOP package or

a thermally enhanced 16-lead WSON package.

APPLICATIONS

• Flyback Regulator

• Forward Regulator

• Boost Regulator

• DSL Modems

• Distributed Power Converters

Typical Application Circuit

Figure 1. LM5000 Flyback Converter

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 (24 pages)

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LM5000 www.ti.com SNVS176D – MAY 2004 – REVISED MARCH 2007 LM5000 High Voltage Switch Mode Regulator Check for Samples: LM5000 FEATURES DESCRIPTION • • • The LM5000 is a monolithic integrated circuit specifically designed and optimized for flyback, boost or forward power converter applications. The internal power switch is rated for a maximum of 80V, with a current limit set to 2A. Protecting the power switch are current limit and thermal shutdown circuits.
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LM5000 SNVS176D – MAY 2004 – REVISED MARCH 2007 www.ti.com Connection Diagram Figure 2. Top View PIN DESCRIPTIONS 2 Pin Name 1 COMP Function Compensation network connection. Connected to the output of the voltage error amplifier. The RC compenstion network should be connected from this pin to AGND. An additional 100pF high frequency capacitor to AGND is recommended. 2 FB 3 SHDN Output voltage feedback input. Shutdown control input, Open = enable, Ground = disable.
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LM5000 www.ti.com SNVS176D – MAY 2004 – REVISED MARCH 2007 These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. Absolute Maximum Ratings (1) (2) VIN -0.3V to 40V SW Voltage -0.3V to 80V FB Voltage -0.3V to 5V COMP Voltage -0.3V to 3V All Other Pins -0.
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LM5000 SNVS176D – MAY 2004 – REVISED MARCH 2007 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) Unless otherwise specified. VIN = 12V and IL = 0A, unless otherwise specified. Symbol BV Parameter Output Switch Breakdown Voltage Conditions Min (1) TJ = 25°C, ISW = 0.1µA 80 TJ = -40°C to + 125°C, ISW = 0.
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LM5000 www.ti.com SNVS176D – MAY 2004 – REVISED MARCH 2007 Typical Performance Characteristics Iq (non-switching) vs VIN @ fSW = 300kHz Iq (non-switching) vs VIN @ fSW = 700kHz 3.000 3.000 2.800 2.800 2.600 2.600 2.400 -40oC 2.200 2.000 Iq (mA) Iq (mA) 2.400 25oC 1.800 125oC 2.000 25oC 1.800 125oC 1.600 1.600 1.400 1.400 1.200 1.200 1.000 1.000 0 10 5 15 20 25 35 30 40 -40oC 2.200 0 5 10 15 VIN (V) Figure 3.
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LM5000 SNVS176D – MAY 2004 – REVISED MARCH 2007 www.ti.com Typical Performance Characteristics (continued) Current Limit vs Temperature Current Limit vs VIN 2 2 1.95 1.95 1.9 1.85 CURRENT LIMIT (A) CURRENT LIMIT (A) 1.9 1.8 1.75 1.7 1.65 1.85 1.8 1.75 1.7 1.65 1.6 1.6 1.55 1.55 1.5 -40 -20 1.5 0 20 40 60 80 100 120 0 5 10 15 TEMPERATURE (oC) Figure 9. 25 30 35 40 Figure 10. fSW vs. VIN @ FS = Low (-3) fSW vs.
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LM5000 www.ti.com SNVS176D – MAY 2004 – REVISED MARCH 2007 Typical Performance Characteristics (continued) fSW vs. Temperature @ FS = OPEN (-6) 640 1.38 620 1.34 600 1.30 fSW (kHz) fSW (kHz) fSW vs. Temperature @ FS = Low (-6) 580 1.26 560 1.22 540 1.18 520 -40 -20 0 20 40 60 80 1.14 -40 100 120 -20 TEMPERATURE (oC) 0 40 60 80 100 120 TEMPERATURE (oC) Figure 15. Figure 16. Error Amp. Transconductance vs Temp.
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LM5000 SNVS176D – MAY 2004 – REVISED MARCH 2007 www.ti.com Typical Application Diagrams Figure 19. 300 kHz operation, 48V output Figure 20.
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LM5000 www.ti.
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LM5000 SNVS176D – MAY 2004 – REVISED MARCH 2007 www.ti.com BOOST REGULATOR OPERATION The LM5000 utilizes a PWM control scheme to regulate the output voltage over all load conditions. The operation can best be understood referring to the block diagram and Figure 21. At the start of each cycle, the oscillator sets the driver logic and turns on the NMOS power device conducting current through the inductor, cycle 1 of Figure 21 (a).
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LM5000 www.ti.com SNVS176D – MAY 2004 – REVISED MARCH 2007 The second cycle is shown in Figure 21 (b). During this cycle, the transistor is open and the diode is forward biased. The energy stored in the inductor is transferred to the load and output capacitor. The ratio of these two cycles determines the output voltage.
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LM5000 SNVS176D – MAY 2004 – REVISED MARCH 2007 www.ti.com To keep a current programmed control converter stable above duty cycles of 50%, the inductor must meet certain criteria. The inductor, along with input and output voltage, will determine the slope of the current through the inductor (see Figure 22 (a)). If the slope of the inductor current is too great, the circuit will be unstable above duty cycles of 50%. The LM5000 provides a compensation pin (COMP) to customize the voltage loop feedback.
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LM5000 www.ti.com SNVS176D – MAY 2004 – REVISED MARCH 2007 OUTPUT CAPACITOR SELECTION The choice of output capacitors is somewhat more arbitrary. It is recommended that low ESR (Equivalent Series Resistance, denoted RESR) capacitors be used such as ceramic, polymer electrolytic, or low ESR tantalum. Higher ESR capacitors may be used but will require more compensation which will be explained later on in the section.
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LM5000 SNVS176D – MAY 2004 – REVISED MARCH 2007 www.ti.com Now RC can be chosen with the selected value for CC. Check to make sure that the pole fPC is still in the 10Hz to 100Hz range, change each value slightly if needed to ensure both component values are in the recommended range. After checking the design at the end of this section, these values can be changed a little more to optimize performance if desired.
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LM5000 www.ti.com SNVS176D – MAY 2004 – REVISED MARCH 2007 In certain circuits, there exists a voltage spike, VLL, superimposed on top of the steady-state voltage . Usually, this voltage spike is caused by the transformer leakage inductance and/or the output rectifier recovery time. To “clamp” the voltage at the switch from exceeding its maximum value, a transient suppressor in series with a diode is inserted across the transformer primary.
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LM5000 SNVS176D – MAY 2004 – REVISED MARCH 2007 www.ti.com Figure 23.
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LM5000 www.ti.com SNVS176D – MAY 2004 – REVISED MARCH 2007 ITEM PART NUMBER DESCRIPTION VALUE C 1 C4532X7R2A105MT Capacitor, CER, TDK 1µ, 100V C 2 C4532X7R2A105MT Capacitor, CER, TDK 1µ, 100V C 3 C1206C224K5RAC Capacitor, CER, KEMET 0.22µ, 50V C 4 C1206C104K5RAC Capacitor, CER, KEMET 0.1µ, 50V C 5 C1206C104K5RAC Capacitor, CER, KEMET 0.1µ, 50V C 6 C1206C101K1GAC Capacitor, CER, KEMET 100p, 100V C 7 C1206C104K5RAC Capacitor, CER, KEMET 0.
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PACKAGE OPTION ADDENDUM www.ti.
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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.
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PACKAGE MATERIALS INFORMATION www.ti.com 11-Oct-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing LM5000-3MTCX TSSOP LM5000-3MTCX/NOPB LM5000SD-3/NOPB SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant PW 16 2500 330.0 12.4 6.95 8.3 1.6 8.0 12.0 Q1 TSSOP PW 16 2500 330.0 12.4 6.95 8.3 1.6 8.0 12.0 Q1 WSON NHQ 16 1000 178.0 12.4 5.3 5.3 1.3 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 11-Oct-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM5000-3MTCX TSSOP PW 16 2500 367.0 367.0 35.0 LM5000-3MTCX/NOPB TSSOP PW 16 2500 367.0 367.0 35.0 LM5000SD-3/NOPB WSON NHQ 16 1000 210.0 185.0 35.0 LM5000SD-6/NOPB WSON NHQ 16 1000 210.0 185.0 35.0 LM5000SDX-3/NOPB WSON NHQ 16 4500 367.0 367.0 35.0 LM5000SDX-6/NOPB WSON NHQ 16 4500 367.0 367.
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MECHANICAL DATA NHQ0016A SDA16A (Rev A) www.ti.
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