Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - DC/DC voltage regulator Holder HTSSOP 14

VIN

BST

LM2695

VCC

RON/SD

8V - 30V

Input

OUT

RTN

ISEN

SGND

SHUTDOWN

LM2695

www.ti.com

SNVS413A –JANUARY 2006–REVISED APRIL 2013

LM2695 High Voltage (30V, 1.25A) Step Down Switching Regulator

Check for Samples: LM2695

FEATURES

DESCRIPTION

The LM2695 Step Down Switching Regulator features

• Integrated 33V, N-Channel Buck Switch

all of the functions needed to implement a low cost,

• Integrated Start-Up Regulator

efficient, buck bias regulator capable of supplying

• Input Voltage Range: 8V to 30V

1.25A to the load. This buck regulator contains a 33V

N-Channel Buck Switch, and is available in the

• No Loop Compensation Required

thermally enhanced WSON-10 and HTSSOP-14

• Ultra-Fast Transient Response

packages. The hysteretic regulation scheme requires

• Operating Frequency Remains Constant with

no loop compensation, results in fast load transient

Load Current and Input Voltage

response, and simplifies circuit implementation. The

operating frequency remains constant with line and

• Maximum Duty Cycle Limited During Start-Up

load variations due to the inverse relationship

• Adjustable Output Voltage

between the input voltage and the on-time. The

• Valley Current Limit At 1.25A

current limit detection is set at 1.25A. Additional

features include: VCC under-voltage lockout, thermal

• Precision Internal Reference

shutdown, gate drive under-voltage lockout, and

• Low Bias Current

maximum duty cycle limiter.

• Highly Efficient Operation

• Thermal Shutdown

PACKAGE

• 10-Pin WSON (4 mm x 4 mm)

TYPICAL APPLICATIONS

• 14-Pin HTSSOP

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

• Exposed Thermal Pad For Improved Heat

• Non-Isolated Telecommunication Buck

Dissipation

Regulator

• Secondary High Voltage Post Regulator

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 (21 pages)

PAGE 1
LM2695 www.ti.com SNVS413A – JANUARY 2006 – REVISED APRIL 2013 LM2695 High Voltage (30V, 1.25A) Step Down Switching Regulator Check for Samples: LM2695 FEATURES DESCRIPTION • • • • • • The LM2695 Step Down Switching Regulator features all of the functions needed to implement a low cost, efficient, buck bias regulator capable of supplying 1.25A to the load. This buck regulator contains a 33V N-Channel Buck Switch, and is available in the thermally enhanced WSON-10 and HTSSOP-14 packages.
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LM2695 SNVS413A – JANUARY 2006 – REVISED APRIL 2013 www.ti.com Connection Diagram 1 2 3 4 5 6 7 NC NC SW VIN BST VCC ISEN RON/SD SGND SS RTN FB NC NC 14 1 13 2 12 3 11 4 10 5 SW VIN BST VCC ISEN RON/SD SGND SS RTN FB 10 9 8 7 6 9 8 Figure 1. 14-Lead HTSSOP (Top View) See PWP0014A Package Figure 2.
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LM2695 www.ti.com SNVS413A – JANUARY 2006 – REVISED APRIL 2013 Absolute Maximum Ratings (1) (2) (3) VIN to RTN 33V BST to RTN 47V SW to RTN (Steady State) ESD Rating (4) -1.5V Human Body Model 2kV BST to VCC 33V VIN to SW 33V BST to SW 14V VCC to RTN 14V SGND to RTN -0.3V to +0.3V Current out of ISEN See Text SS to RTN -0.3V to 4V All Other Inputs to RTN -0.
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LM2695 SNVS413A – JANUARY 2006 – REVISED APRIL 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 ensured 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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LM2695 www.ti.com SNVS413A – JANUARY 2006 – REVISED APRIL 2013 Typical Performance Characteristics 7.0 7.5 RON = 400k 6.0 FS = 150 kHz ON-TIME (Ps) VCC (V) 7.0 FS = 45 kHz 6.5 FS = 750 kHz 6.0 5.0 4.0 RON = 200k 3.0 RON = 100k 2.0 5.5 1.0 RON = 44.2k 0 5.0 6.5 7.0 7.5 8.0 8.5 9.0 10 0 20 30 VIN (V) VIN (V) Figure 3. VCC vs VIN Figure 4.
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LM2695 SNVS413A – JANUARY 2006 – REVISED APRIL 2013 www.ti.com Functional Description The LM2695 Step Down Switching Regulator features all the functions needed to implement a low cost, efficient buck bias power converter capable of supplying 1.25A to the load. This high voltage regulator contains a 33V NChannel buck switch, is easy to implement, and is available in the thermally enhanced WSON-10 and HTSSOP14 packages.
PAGE 7
LM2695 www.ti.com SNVS413A – JANUARY 2006 – REVISED APRIL 2013 Output voltage regulation is based on ripple voltage at the feedback input, requiring a minimum amount of ESR for the output capacitor C2. The LM2695 requires a minimum of 25 mV of ripple voltage at the FB pin. In cases where the capacitor’s ESR is insufficient additional series resistance may be required (R3 in Typical Application Circuit and Block Diagram).
PAGE 8
LM2695 SNVS413A – JANUARY 2006 – REVISED APRIL 2013 www.ti.com Start-Up Regulator, VCC The start-up regulator is integral to the LM2695. The input pin (VIN) can be connected directly to line voltage up to 30V, with transient capability to 33V. The VCC output regulates at 7.0V, and is current limited at 9.7 mA. Upon power up, the regulator sources current into the external capacitor at VCC (C3). When the voltage on the VCC pin reaches the under-voltage lockout threshold of 5.
PAGE 9
LM2695 www.ti.com SNVS413A – JANUARY 2006 – REVISED APRIL 2013 See Figure 4. The inverse relationship with VIN results in a nearly constant frequency as VIN is varied. To set a specific continuous conduction mode switching frequency (FS), the RON resistor is determined from the following: RON = VOUT FS x 1.3 x 10-10 (6) In high frequency applicatons the minimum value for tON is limited by the maximum duty cycle required for regulation and the minimum off-time of (250 ns, ±15%).
PAGE 10
LM2695 SNVS413A – JANUARY 2006 – REVISED APRIL 2013 www.ti.com IPK 'I IOCL Inductor Current 1.25A IO Normal Operation Load Current Increases Current Limited Figure 8. Inductor Current - Current Limit Operation The current limit threshold can be increased by connecting an external resistor between SGND and ISEN. The external resistor will typically be less than 1Ω. The peak current out of SW and ISEN must not exceed 2A. The average current out of SW must be less than 1.5A.
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LM2695 www.ti.com SNVS413A – JANUARY 2006 – REVISED APRIL 2013 APPLICATIONS INFORMATION EXTERNAL COMPONENTS The following guidelines can be used to select the external components. R1 and R2: The ratio of these resistors is calculated from: R1/R2 = (VOUT/2.5V) - 1 (9) R1 and R2 should be chosen from standard value resistors in the range of 1.0 kΩ - 10 kΩ which satisfy the above ratio. RON: The minimum value for RON is calculated from: RON t 200 ns x VIN(MAX) 1.
PAGE 12
LM2695 SNVS413A – JANUARY 2006 – REVISED APRIL 2013 www.ti.com If the capacitor used for C2 does not have sufficient ESR, R3 is added in series as shown in Typical Application Circuit and Block Diagram. Generally R3 is less than 1Ω. C2 should generally be no smaller than 3.3 µF, although that is dependent on the frequency and the allowable ripple amplitude at VOUT1. Experimentation is usually necessary to determine the minimum value for C2, as the nature of the load may require a larger value.
PAGE 13
LM2695 www.ti.com SNVS413A – JANUARY 2006 – REVISED APRIL 2013 If it is expected that the internal dissipation of the LM2695 will produce excessive junction temperatures during normal operation, good use of the PC board’s ground plane can help considerably to dissipate heat.
PAGE 14
LM2695 SNVS413A – JANUARY 2006 – REVISED APRIL 2013 www.ti.com REVISION HISTORY Changes from Original (April 2013) to Revision A • 14 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.com 14-Feb-2014 Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties.
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PACKAGE MATERIALS INFORMATION www.ti.com 23-Sep-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) LM2695MHX/NOPB HTSSOP PWP 14 2500 330.0 12.4 LM2695SD/NOPB WSON DPR 10 1000 178.0 LM2695SDX/NOPB WSON DPR 10 4500 330.0 6.95 8.3 1.6 8.0 12.0 Q1 12.4 4.3 4.3 1.3 8.0 12.0 Q1 12.4 4.3 4.3 1.3 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 23-Sep-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM2695MHX/NOPB HTSSOP PWP 14 2500 367.0 367.0 35.0 LM2695SD/NOPB WSON DPR 10 1000 210.0 185.0 35.0 LM2695SDX/NOPB WSON DPR 10 4500 367.0 367.0 35.
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MECHANICAL DATA PWP0014A MXA14A (Rev A) www.ti.
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MECHANICAL DATA DPR0010A SDC10A (Rev A) www.ti.
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