Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - DC/DC voltage regulator Boost TSSOP 8

DGK

OUT

3 2

TPS61085

3.3 Hm

2.3 V to 6 V

10 F

16 V

1 F

16 V

FREQ

GND

COMP

100 nF

51 k

COMP

1.1 nF

COMP

158 kΩ

18.2 kΩ

2* 10 µF

25 V

12 V/300 mA

PMEG2010AEH

TPS61085

www.ti.com

SLVS859A –JUNE 2008–REVISED APRIL 2012

650 kHz/1.2 MHz, 18.5 V STEP-UP DC-DC CONVERTER

Check for Samples: TPS61085

FEATURES

• 2.3 V to 6 V Input Voltage Range APPLICATIONS

• 18.5 V Boost Converter With 2.0 A Switch

• Handheld Devices

Current

• GPS Receiver

• 650 kHz/1.2 MHz Selectable Switching

• Digital Still Camera

Frequency

• Portable Applications

• Adjustable Soft-Start

• DSL Modem

• Thermal Shutdown

• PCMCIA Card

• Undervoltage Lockout

• TFT LCD Bias Supply

• 8-Pin MSOP Package

• 8-Pin TSSOP Package

DESCRIPTION

The TPS61085 is a high frequency, high efficiency DC to DC converter with an integrated 2.0 A, 0.13 Ω power

switch capable of providing an output voltage up to 18.5 V. The selectable frequency of 650 kHz or 1.2 MHz

allows the use of small external inductors and capacitors and provides fast transient response. The external

compensation allows optimizing the application for specific conditions. A capacitor connected to the soft-start pin

minimizes inrush current at startup.

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.

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 (26 pages)

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DGK TPS61085 PW www.ti.com SLVS859A – JUNE 2008 – REVISED APRIL 2012 650 kHz/1.2 MHz, 18.5 V STEP-UP DC-DC CONVERTER Check for Samples: TPS61085 FEATURES 1 • • • • • • • • 2.3 V to 6 V Input Voltage Range 18.5 V Boost Converter With 2.0 A Switch Current 650 kHz/1.
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TPS61085 SLVS859A – JUNE 2008 – REVISED APRIL 2012 www.ti.com 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. ORDERING INFORMATION (1) (1) (2) (2) TA ORDERING PACKAGE –40 to 85°C TPS61085DGK MSOP-8 (DGK) PACKAGE MARKING PMKI –40 to 85°C TPS61085PW TSSOP-8 (PW) 61085 The DGK and PW packages are available taped and reeled.
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TPS61085 www.ti.com SLVS859A – JUNE 2008 – REVISED APRIL 2012 ELECTRICAL CHARACTERISTICS VIN = 3.3 V, EN = VIN, VS = 12 V, TA = –40°C to 85°C, typical values are at TA = 25°C (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT 6 V 70 100 μA 1 μA V SUPPLY VIN Input voltage range IQ Operating quiescent current into IN Device not switching, VFB = 1.3 V ISDVIN Shutdown current into IN EN = GND UVLO Undervoltage lockout threshold VIN falling 2.2 VIN rising 2.
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TPS61085 SLVS859A – JUNE 2008 – REVISED APRIL 2012 www.ti.com PIN ASSIGNMENT DGK, PW PACKAGES (TOP VIEW) COMP 1 8 SS FB 2 7 FREQ EN 3 6 IN PGND 4 5 SW 8-PIN 4.9mm x 3mm x 1.1mm MSOP (DGK) 8-PIN 6.4mm x 3mm x 1.2mm TSSOP (PW) PIN FUNCTIONS PIN NAME NO. I/O DESCRIPTION COMP 1 I/O FB 2 I Feedback pin EN 3 I Shutdown control input.
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TPS61085 www.ti.com SLVS859A – JUNE 2008 – REVISED APRIL 2012 MAXIMUM LOAD CURRENT vs INPUT VOLTAGE MAXIMUM LOAD CURRENT vs INPUT VOLTAGE 1.6 1.6 fS = 1.2 MHz fS = 1.2 MHz 1.4 1.4 VOUT = 9 V 1.2 IOUT − Output Current (A) IOUT − Output Current (A) 1.2 VOUT = 9 V VOUT = 12 V 1 0.8 0.6 0.4 VOUT = 12 V 1 0.8 0.6 0.4 VOUT = 15 V 0.2 0.2 VOUT = 15 V VOUT = 18.5 V 0 2.5 3.0 3.5 VOUT = 18.5 V 4.0 4.5 5.0 VIN − Input Voltage (V) 5.5 0 2.5 6.0 3.0 3.5 4.0 4.5 5.
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TPS61085 SLVS859A – JUNE 2008 – REVISED APRIL 2012 www.ti.com PWM SWITCHING DISCONTINUOUS CONDUCTION MODE PWM SWITCHING CONTINUOUS CONDUCTION MODE VSW 5 V/div VSW 5 V/div VS_AC 50 mV/div VS_AC 50 mV/div VIN = 3.3 V VS = 12 V/1 mA fS = 1.2 MHz IL 1 A/div VIN = 3.3 V VS = 12 V/300 mA fS = 1.2 MHz IL 200 mA/div 200 ns/div 200 ns/div Figure 5. Figure 6. LOAD TRANSIENT RESPONSE HIGH FREQUENCY (1.2 MHz) LOAD TRANSIENT RESPONSE LOW FREQUENCY (650 kHz) COUT = 20 µF L = 3.
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TPS61085 www.ti.com SLVS859A – JUNE 2008 – REVISED APRIL 2012 SUPPLY CURRENT vs SUPPLY VOLTAGE SOFT-START 2 1.8 EN 5 V/div Switching fS = 1.2 MHz L = 3.3 µH ICC - Supply Current - mA 1.6 VIN = 3.3 V VS = 12 V/300 mA VS 5 V/div CSS = 100 nF IL 1 A/div 1.4 1.2 1 0.8 Switching fS = 650 kHz L = 6.8 µH 0.6 0.4 Not Switching 0.2 2 ms/div 0 2 FREQUENCY vs LOAD CURRENT FREQUENCY vs SUPPLY VOLTAGE 5.5 6 1400 1200 FREQ = VIN L = 3.3 µH fS - Frequency - kHz 1200 fS - Frequency - kHz 3.5 4 4.
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TPS61085 SLVS859A – JUNE 2008 – REVISED APRIL 2012 www.ti.com DETAILED DESCRIPTION VIN VS EN SS IN SW FREQ Current limit and Soft Start tOFF Generator Bias Vref = 1.238V UVLO Thermal Shutdown tON PWM Generator Gate Driver of Power Transistor COMP GM Amplifier FB V ref PGND Figure 13. Block Diagram The boost converter is designed for output voltages up to 18.5 V with a switch peak current limit of 2.0 A minimum.
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TPS61085 www.ti.com SLVS859A – JUNE 2008 – REVISED APRIL 2012 Design Procedure The first step in the design procedure is to verify that the maximum possible output current of the boost converter supports the specific application requirements. A simple approach is to estimate the converter efficiency, by taking the efficiency numbers from the provided efficiency curves or to use a worst case assumption for the expected efficiency, e.g. 90%. 1. Duty cycle, D: D = 1- VIN ×h VS (1) 2.
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TPS61085 SLVS859A – JUNE 2008 – REVISED APRIL 2012 www.ti.com Inductor Selection The TPS61085 is designed to work with a wide range of inductors. The main parameter for the inductor selection is the saturation current of the inductor which should be higher than the peak switch current as calculated in the Design Procedure section with additional margin to cover for heavy load transients.
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TPS61085 www.ti.com SLVS859A – JUNE 2008 – REVISED APRIL 2012 Usually a Schottky diode with 2 A maximum average rectified forward current rating is sufficient for most applications. The Schottky rectifier can be selected with lower forward current capability depending on the output current Iout but has to be able to dissipate the power. The dissipated power, PD , is the average rectified forward current times the diode forward voltage, Vforward .
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TPS61085 SLVS859A – JUNE 2008 – REVISED APRIL 2012 www.ti.com Table 3. Recommended Compensation Network Values at High/Low Frequency FREQUENCY L VS 15 V High (1.2 MHz) 3.3 µH 12 V 9V 15 V Low (650 kHz) 6.8 µH 12 V 9V VIN ± 20% RCOMP CCOMP Used IOUT 5V 82 kΩ 1.1 nF 0.7A 3.3 V 75 kΩ 1.6 nF 0.5A 5V 51 kΩ 1.1 nF 0.9A 3.3 V 47 kΩ 1.6 nF 0.6A 5V 30 kΩ 1.1 nF 1.2A 3.3 V 27 kΩ 1.6 nF 0.8A 5V 43 kΩ 2.2 nF 0.7A 3.3 V 39 kΩ 3.3 nF 0.5A 5V 27 kΩ 2.2 nF 0.9A 3.
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TPS61085 www.ti.com SLVS859A – JUNE 2008 – REVISED APRIL 2012 Frequency Select Pin (FREQ) The frequency select pin FREQ allows to set the switching frequency of the device to 650 kHz (FREQ = low) or 1.2 MHz (FREQ = high). Higher switching frequency improves load transient response but reduces slightly the efficiency. The other benefits of higher switching frequency are a lower output ripple voltage. The use of the 1.2 MHz switching frequency is recommended unless light load efficiency is a major concern.
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TPS61085 SLVS859A – JUNE 2008 – REVISED APRIL 2012 www.ti.com L 6.8 µH VIN 3.3 V ±20% 6 CIN 10 µF 16 V CBY 1 µF 16 V SW IN 3 5 D PMEG2010AEH R1 158 kΩ 2 EN VS 12 V/600 mA max FB R2 18.2 kΩ 1 7 FREQ COUT 2* 10 µF 25 V COMP 4 RCOMP 24 kΩ 8 GND SS CCOMP 3.3 nF CSS TPS61085 100 nF Figure 15. Typical Application, 3.3 V to 12 V (fS = 650 kHz) L 3.3 µH VIN 3.
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TPS61085 www.ti.com SLVS859A – JUNE 2008 – REVISED APRIL 2012 L 6.8 µH VIN 3.3 V ±20% 6 CIN 10 µF 16 V CBY 1 µF 16 V SW IN 3 D PMEG2010AEH 5 R1 113 kΩ 2 EN VS 9 V/800 mA max FB R2 18 kΩ 1 7 FREQ COUT 2* 10 µF 25 V COMP 4 RCOMP 13 kΩ 8 GND SS CCOMP 3.3 nF CSS TPS61085 100 nF Figure 17. Typical Application, 3.3 V to 9 V (fS = 650 kHz) RISO 10 kΩ L 6.8 µH VIN 3.
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TPS61085 SLVS859A – JUNE 2008 – REVISED APRIL 2012 www.ti.com TFT LCD Application Circuit VGL -7 V/ 20 mA T1 BC857B -VS C4 100nF/ 50V D2 BAT54S C3 100 nF 50 V C2 R8 7 kΩ 470 nF 25 V C1 1µF/ 35V D3 BAT54S D1 BZX84C7V5 D4 BAT54S C6 470 nF 50 V D5 BAT54S C5 100 nF 50 V D6 BAT54S VGH 20 V/20 mA T2 BC850B 3* VS R10 13 kΩ C8 2*VS 1 µF 35 V C7 470 nF 50 V D8 BZX84C 20V D7 BAT54S L 3.3µH VIN 3.
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TPS61085 www.ti.com SLVS859A – JUNE 2008 – REVISED APRIL 2012 L 6.8 µH optional CBY 1 µF/ 16 V VIN 5 V ± 20% 5 6 3 DZ BZX84C 18 V COUT 2* 10 µF/ 25 V EN 2 FB 7 PWM 100 Hz to 500 Hz VS 500 mA 3S3P wLED LW E67C SW IN CIN 10 µF/ 16 V D SL22 4 FREQ COMP SS PGND RLIMIT 110 Ω 1 8 TPS61085 RSENSE 15 Ω RCOMP 24 kΩ CCOMP 3.3 nF CSS 100 nF Figure 21. Simple Application (3.
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TPS61085 SLVS859A – JUNE 2008 – REVISED APRIL 2012 www.ti.com REVISION HISTORY Changes from Original (June 2008) to Revision A Page • Changed the circuit illustration value of CCOMP From: 1.6 nF To: 1.1 nF .............................................................................. 1 • Deleted Lead Temperature from the Abs Max table .............................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com 11-Apr-2013 (4) Multiple Top-Side Markings will be inside parentheses. Only one Top-Side 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 Top-Side Marking for that device. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided.
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PACKAGE MATERIALS INFORMATION www.ti.com 26-Jan-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing TPS61085DGKR VSSOP DGK 8 TPS61085DGKT VSSOP DGK TPS61085PWR TSSOP PW SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 2500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 8 250 180.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 8 2000 330.0 12.4 7.0 3.6 1.6 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 26-Jan-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TPS61085DGKR VSSOP DGK 8 2500 367.0 367.0 35.0 TPS61085DGKT VSSOP DGK 8 250 210.0 185.0 35.0 TPS61085PWR TSSOP PW 8 2000 367.0 367.0 35.
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