Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - DC/DC voltage regulator Holder MicroBump 10

VIN

BST

LM34919C

VCC

RON/SD

6V - 40V

Input

OUT

RTN

ISEN

SGND

SHUTDOWN

LM34919B

LM34919B-Q1

www.ti.com

SNVS623A –MAY 2010–REVISED FEBRUARY 2013

Ultra-Small 40-V 600-mA Constant On-Time Buck Switching Regulator

Check for Samples: LM34919B, LM34919B-Q1

FEATURES

• AEC-Q100 Grade 1 qualified (-40°c to 125°c)

TYPICAL APPLICATIONS

• Maximum switching frequency: 2.6 MHz

• Automotive Safety and Infotainment

=14V,V

=3.3V)

• High Efficiency Point-Of-Load (POL) Regulator

• Input Voltage Range: 6V to 40V

• Non-Isolated Telecommunication Buck

• Integrated N-Channel buck switch

Regulator

• Integrated start-up regulator

• Secondary High Voltage Post Regulator

• No loop compensation required

DESCRIPTION

• Ultra-Fast transient response

The LM34919B Step Down Switching Regulator

• Operating frequency remains constant with

features all of the functions needed to implement a

load current and input voltage

low cost, efficient, buck bias regulator capable of

• Maximum Duty Cycle Limited During Start-Up

supplying 0.6A to the load. This buck regulator

contains an N-Channel Buck Switch, and is available

• Adjustable output voltage

in a 10-Pin DSBGA package. The constant on-time

• Valley Current Limit At 0.64A

feedback regulation scheme requires no loop

• Precision internal reference

compensation, results in fast load transient response,

• Low bias current and simplifies circuit implementation. The operating

frequency remains constant with line and load

• Highly efficient operation

variations due to the inverse relationship between the

• Thermal shutdown

input voltage and the on-time. The valley current limit

• 10-Pin DSBGA Package

results in a smooth transition from constant voltage to

constant current mode when current limit is detected,

reducing the frequency and output voltage, without

the use of foldback. Additional features include: VCC

under-voltage lockout, thermal shutdown, gate drive

under-voltage lockout, and maximum duty cycle

limiter.

Basic Step Down Regulator

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
LM34919B LM34919B-Q1 www.ti.com SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 Ultra-Small 40-V 600-mA Constant On-Time Buck Switching Regulator Check for Samples: LM34919B, LM34919B-Q1 FEATURES 1 • • 2 • • • • • • • • • • • • • • AEC-Q100 Grade 1 qualified (-40°c to 125°c) Maximum switching frequency: 2.6 MHz (VIN=14V,Vo=3.
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LM34919B LM34919B-Q1 SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 www.ti.com Connection Diagram SW D3 BST C1 C3 VCC SGND B1 B3 SS RON/SD A1 A3 FB VIN D1 ISEN D2 A2 D3 D2 D1 C3 C1 B3 B1 A3 A2 A1 RTN Figure 1. Bump Side Figure 2. Top View PIN DESCRIPTIONS Pin No. Name A1 RON/SD A2 RTN A3 FB B1 SGND B3 SS C1 Description Application Information On-time control and shutdown An external resistor from VIN to this pin sets the buck switch on-time.
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LM34919B LM34919B-Q1 www.ti.com SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 Absolute Maximum Ratings (1) VIN to RTN 44V BST to RTN 52V SW to RTN (Steady State) -1.5V to 44V ESD Rating, Human Body Model (2) 2kV BST to VCC 44V BST to SW 14V VCC to RTN 14V SGND to RTN -0.3V to +0.3V SS, RON/SD to RTN -0.3V to 4V FB to RTN -0.
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LM34919B LM34919B-Q1 SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 www.ti.com Electrical Characteristics Specifications with standard type are for TJ = 25°C only; limits in boldface type apply over the full Operating Junction Temperature (TJ) range. 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.
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LM34919B LM34919B-Q1 www.ti.com SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 Electrical Characteristics (continued) Specifications with standard type are for TJ = 25°C only; limits in boldface type apply over the full Operating Junction Temperature (TJ) range. 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.
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LM34919B LM34919B-Q1 SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 www.ti.com Typical Performance Characteristics 6 Efficiency at 2.1 MHz, 3.3V Efficiency at 250 kHz, 3.3V Figure 3. Figure 4. Efficiency at 2.1 MHz, 5V VCC vs. VIN Figure 5. Figure 6. VCC vs. ICC ICC vs. Externally Applied VCC Figure 7. Figure 8.
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LM34919B LM34919B-Q1 www.ti.com SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 Typical Performance Characteristics (continued) ON-TIME vs. VIN and RON Voltage at the RON/SD Pin Figure 9. Figure 10. Operating Current into VIN Shutdown Current into VIN Figure 11. Figure 12. VCC UVLO at Vin vs. Temperature Gate Drive UVLO vs. Temperature Figure 13. Figure 14.
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LM34919B LM34919B-Q1 SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 www.ti.com Typical Performance Characteristics (continued) 8 VCC Voltage vs. Temperature VCC Output Impedance vs. Temperature Figure 15. Figure 16. VCC Current Limit vs. Temperature Reference Voltage vs. Temperature Figure 17. Figure 18. Soft-Start Current vs. Temperature On-Time vs. Temperature Figure 19. Figure 20.
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LM34919B LM34919B-Q1 www.ti.com SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 Typical Performance Characteristics (continued) Minimum Off-Time vs. Temperature Current Limit Threshold vs. Temperature Figure 21. Figure 22. Operating & Shutdown Current vs. Temperature RON Pin Shutdown Threshold vs. Temperature Figure 23. Figure 24.
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LM34919B LM34919B-Q1 SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 www.ti.com BLOCK DIAGRAM 6V to 40V Input VIN C1 GND LM34919C 7V SERIES REGULATOR VCC VCC UVLO C5 RON ON TIMER RON START FINISH RON/SD 0.8V OFF TIMER START FINISH BST Gate Drive SD UVLO 2.5V SS C3 10.5 PA VIN C4 LOGIC C6 LEVEL SHIFT Driver FB SW THERMAL SHUTDOWN REGULATION COMPARATOR VOUT D1 OVER- VOLTAGE 2.
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LM34919B LM34919B-Q1 www.ti.com SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 VIN 7.0V UVLO VCC SW Pin Inductor Current 2.5V SS Pin VOUT t1 t2 Figure 25. Start Up Sequence FUNCTIONAL DESCRIPTION The LM34919B Step Down Switching Regulator features all the functions needed to implement a low cost, efficient buck bias power converter capable of supplying at least 0.6A to the load. This high voltage regulator contains an N-Channel buck switch, is easy to implement, and is available in a DSBGA package.
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LM34919B LM34919B-Q1 SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 www.ti.com Control Circuit Overview The LM34919B buck DC-DC regulator employs a control scheme based on a comparator and a one-shot ontimer, with the output voltage feedback (FB) compared to an internal reference (2.5V). If the FB voltage is below the reference the buck switch is turned on for a time period determined by the input voltage and a programming resistor (RON).
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LM34919B LM34919B-Q1 www.ti.com SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 VCC C3 BST C4 L1 LM34919C D2 SW VOUT D1 ISEN R1 R3 SGND R2 C2 FB Figure 26. Self Biased Configuration Regulation Comparator The feedback voltage at FB is compared to the voltage at the Softstart pin (2.5V). In normal operation (the output voltage is regulated), an on-time period is initiated when the voltage at FB falls below 2.5V.
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LM34919B LM34919B-Q1 SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 www.ti.com VIN Input Voltage RON LM34919C RON/SD STOP RUN Figure 27. Shutdown Implementation Current Limit Current limit detection occurs during the off-time by monitoring the recirculating current through the free-wheeling diode (D1). Referring to the Block Diagram, when the buck switch is turned off the inductor current flows through the load, into SGND, through the sense resistor, out of ISEN and through D1.
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LM34919B LM34919B-Q1 www.ti.com SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 N-Channel Buck Switch and Driver The LM34919B integrates an N-Channel buck switch and associated floating high voltage gate driver. The peak current allowed through the buck switch is 1.5A, and the maximum allowed average current is 1A. The gate driver circuit works in conjunction with an external bootstrap capacitor and an internal high voltage diode. A 0.
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LM34919B LM34919B-Q1 SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 www.ti.com APPLICATIONS INFORMATION EXTERNAL COMPONENTS The procedure for calculating the external components is illustrated with the following design example. Referring to the Block Diagram, the circuit is to be configured for the following specifications: - VOUT = 3.3V - VIN = 6V to 24V - Minimum load current = 200 mA - Maximum load current = 600 mA - Switching Frequency = 1.
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LM34919B LM34919B-Q1 www.ti.com SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 A standard value 0.27Ω resistor is used for R3 to allow for tolerances. C2 should generally be no smaller than 3.3 µF, although that is dependent on the frequency and the desired output characteristics. C2 should be a low ESR good quality ceramic capacitor. Experimentation is usually necessary to determine the minimum value for C2, as the nature of the load may require a larger value.
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LM34919B LM34919B-Q1 SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 www.ti.com 6V - 24V Input VCC VIN C1 2.2 PF C5 0.1 PF C3 0.1 PF LM34919C BST RON C4 0.022 PF L1 8.2 PH 28 k: VOUT 3.3V SW RON/SD D1 SHUTDOWN C6 0.022 PF SS ISEN R1 787: FB RTN R2 2.49 k: SGND R3 0.27: C2 22 PF Figure 29. Example Circuit Figure 30. Efficiency (Circuit of Figure 29) Figure 31. Frequency vs.
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LM34919B LM34919B-Q1 www.ti.com SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 L1 SW VOUT LM34919C Cff R1 R3 FB R2 C2 Figure 32. Reduced Ripple Configuration b) Minimum ripple configuration: The circuit of Figure 33 provides minimum ripple at VOUT, determined primarily by C2’s characteristics and the inductor’s ripple current since R3 is removed. RA and CA are chosen to generate a sawtooth waveform at their junction, and that voltage is AC-coupled to the FB pin via CB.
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LM34919B LM34919B-Q1 SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 www.ti.com L1 SW LM34919C R1 R3 FB VOUT R2 C2 Figure 34. Alternate Minimum Output Ripple Configuration Minimum Load Current The LM34919B requires a minimum load current of 1 mA. If the load current falls below that level, the bootstrap capacitor (C4) may discharge during the long off-time, and the circuit will either shutdown, or cycle on and off at a low frequency.
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LM34919B LM34919B-Q1 www.ti.com SNVS623A – MAY 2010 – REVISED FEBRUARY 2013 REVISION HISTORY Changes from Original (February 2013) to Revision A • Page Changed layout of National Data Sheet to TI format ..........................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE MATERIALS INFORMATION www.ti.com 14-Mar-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) LM34919BQTL/NOPB DSBGA YPA 10 250 178.0 8.4 LM34919BQTLX/NOPB DSBGA YPA 10 3000 178.0 LM34919BTL/NOPB DSBGA YPA 10 250 178.0 LM34919BTLX/NOPB DSBGA YPA 10 3000 178.0 1.85 2.08 0.76 4.0 8.0 Q1 8.4 1.85 2.08 0.76 4.0 8.0 Q1 8.4 1.85 2.08 0.
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PACKAGE MATERIALS INFORMATION www.ti.com 14-Mar-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM34919BQTL/NOPB DSBGA YPA 10 250 210.0 185.0 35.0 LM34919BQTLX/NOPB DSBGA YPA 10 3000 210.0 185.0 35.0 LM34919BTL/NOPB DSBGA YPA 10 250 210.0 185.0 35.0 LM34919BTLX/NOPB DSBGA YPA 10 3000 210.0 185.0 35.
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MECHANICAL DATA YPA0010 0.600 ±0.075 D E TLP10XXX (Rev D) D: Max = 2.012 mm, Min =1.951 mm E: Max = 1.779 mm, Min =1.718 mm 4215069/A NOTES: A. All linear dimensions are in millimeters. Dimensioning and tolerancing per ASME Y14.5M-1994. B. This drawing is subject to change without notice. www.ti.
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