TPS61087 Actual Size 3 mm x 3 mm www.ti.com SLVS821C – MAY 2008 – REVISED JULY 2013 650 kHz/1.2 MHz, 18.5 V STEP-UP DC-DC CONVERTER WITH 3.2 A SWITCH Check for Samples: TPS61087 FEATURES 1 • • • • • • • APPLICATIONS 2.5 V to 6 V Input Voltage Range 18.5 V Boost Converter With 3.2 A Switch Current 650 kHz/1.
TPS61087 SLVS821C – MAY 2008 – REVISED JULY 2013 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 PACKAGE MARKING –40 to 85°C TPS61087DRC QFN-10 (DRC) PMOQ TPS61087DSC QFN-10 (DSC) PMWI The DRC package is available taped and reeled.
TPS61087 www.ti.com SLVS821C – MAY 2008 – REVISED JULY 2013 ELECTRICAL CHARACTERISTICS VIN = 5 V, EN = VIN, VS = 15 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 75 100 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 VUVLO Under-voltage lockout threshold VIN falling 2.4 VIN rising 2.
TPS61087 SLVS821C – MAY 2008 – REVISED JULY 2013 www.ti.com PIN ASSIGNMENT DRC, DSC PACKAGE (TOP VIEW) COMP SS FB EN FREQ Thermal Pad IN AGND SW PGND SW 10-PIN 3mm x 3mm x 1mm QFN PIN FUNCTIONS PIN NAME NO. I/O DESCRIPTION COMP 1 I/O FB 2 I Feedback pin 3 I Shutdown control input.
TPS61087 www.ti.com SLVS821C – MAY 2008 – REVISED JULY 2013 TYPICAL CHARACTERISTICS MAXIMUM LOAD CURRENT vs INPUT VOLTAGE MAXIMUM LOAD CURRENT vs INPUT VOLTAGE 3.0 3.0 fS = 1.2 Mhz 2.5 VOUT = 9 V 2.0 VOUT = 12 V 1.5 VOUT = 15 V 1.0 VOUT = 18.5 V 0.5 IOUT - Maximum Load Current - A IOUT - Maximum Load Current - A fS = 650 kHz 2.5 2.0 VOUT = 9 V VOUT = 12 V 1.5 1.0 VOUT = 18.5 V 0.5 VOUT = 15 V 0.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 0.0 2.5 6.
TPS61087 SLVS821C – MAY 2008 – REVISED JULY 2013 www.ti.com TYPICAL CHARACTERISTICS (continued) PWM SWITCHING DISCONTINUOUS CONDUCTION MODE PWM SWITCHING CONTINUOUS CONDUCTION MODE VSW 10 V/div VSW 10 V/div VS_AC 50 mV/div VS_AC 50 mV/div VIN = 5 V VS = 15 V/2 mA FREQ = VIN Il 1 A/div VIN = 5 V VS = 15 V/500 mA FREQ = VIN IL 500 mA/div 200 ns/div Figure 6. 200 ns/div Figure 5. LOAD TRANSIENT RESPONSE HIGH FREQUENCY (1.
TPS61087 www.ti.com SLVS821C – MAY 2008 – REVISED JULY 2013 TYPICAL CHARACTERISTICS (continued) SUPPLY CURRENT vs SUPPLY VOLTAGE SOFT-START 2.0 ICC - Supply Current - mA EN 5 V/div VIN = 5 V VS = 15 V/500 mA VS 5 V/div CSS = 100 nF IL 1 A/div 1.8 SWITCHING fS = 1.2 Mhz 1.6 L = 3.3 mH 1.4 SWITCHING fS = 650 kHz 1.2 L = 6.8 mH 1.0 0.8 0.6 0.4 0.2 2 ms/div NOT SWITCHING 0 2.5 3.0 3.5 4.0 4.5 5.0 VCC - Supply Voltage - V Figure 9. Figure 10.
TPS61087 SLVS821C – MAY 2008 – REVISED JULY 2013 www.ti.com DETAILED DESCRIPTION VIN VS EN SS IN SW FREQ SW Current limit and Soft Start tOFF Generator AGND Bias Vref = 1.238V UVLO Thermal Shutdown tON PWM Generator Gate Driver of Power Transistor COMP GM Amplifier FB Vref 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 3.2 A minimum.
TPS61087 www.ti.com SLVS821C – MAY 2008 – REVISED JULY 2013 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.
TPS61087 SLVS821C – MAY 2008 – REVISED JULY 2013 www.ti.com Inductor Selection The TPS61087 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.
TPS61087 www.ti.com SLVS821C – MAY 2008 – REVISED JULY 2013 Rectifier Diode Selection To achieve high efficiency a Schottky type should be used for the rectifier diode. The reverse voltage rating should be higher than the maximum output voltage of the converter.
TPS61087 SLVS821C – MAY 2008 – REVISED JULY 2013 www.ti.com Table 3. Recommended Compensation Network Values at High/Low Frequency FREQUENCY L VS 15 V 3.3 μH High (1.2 MHz) 12 V 9V 15 V 6.8 μH Low (650 kHz) 12 V 9V VIN ± 20% RCOMP CCOMP 5V 100 kΩ 820 pF 3.3 V 91 kΩ 1.2 nF 5V 68 kΩ 820 pF 3.3 V 68 kΩ 1.2 nF 5V 39 kΩ 820 pF 3.3 V 39 kΩ 1.2 nF 5V 51 kΩ 1.5 nF 3.3 V 47 kΩ 2.7 nF 5V 33 kΩ 1.5 nF 3.3 V 33 kΩ 2.7 nF 5V 18 kΩ 1.5 nF 3.3 V 18 kΩ 2.
TPS61087 www.ti.com SLVS821C – MAY 2008 – REVISED JULY 2013 ΔVC_ESR can be neglected in many cases since ceramic capacitors provide low ESR. 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 a 1.
TPS61087 SLVS821C – MAY 2008 – REVISED JULY 2013 www.ti.com APPLICATION INFORMATION L 3.3 µH VIN 5 V ± 20% Cin 2* 10 µF 16 V 8 Cby 1 µF 16 V 3 9 4 5 IN SW EN SW FREQ FB AGND COMP PGND SS VS 15 V/900 mA max. D SL22 6 R1 200 kΩ 7 Cout 4* 10 µF 25 V 2 R2 18 kΩ 1 Rcomp 100 kΩ 10 Css 100 nF TPS61087 Ccomp 820 pF Figure 14. Typical Application, 5 V to 15 V (fS = 1.2 MHz) L 6.
TPS61087 www.ti.com SLVS821C – MAY 2008 – REVISED JULY 2013 L 3.3 µH VIN 3.3 V ± 20% Cin 2* 10 µF 16 V 8 Cby 1 µF 16 V 3 9 4 5 IN SW EN SW FREQ FB COMP AGND PGND SS D SL22 6 VS 9 V/950 mA max. R1 110 kΩ 7 Cout 4* 10 µF 25 V 2 R2 18 kΩ 1 Rcomp 39 kΩ 10 Css 100 nF TPS61087 Ccomp 1.2 nF Figure 16. Typical Application, 3.3 V to 9 V (fS = 1.2 MHz) L 6.8 µH VIN 3.
TPS61087 SLVS821C – MAY 2008 – REVISED JULY 2013 www.ti.com Riso 10 kW L 6.8 µH VIN 5 V ± 20% Cby 1 µF/16 V 8 Cin 2* 10 µF/ 16 V 3 SW EN 9 FREQ 4 Enable SW IN FB AGND COMP PGND SS 5 VS 15 V/300 mA BC857C D SL22 6 Ciso 1 µF/ 25 V 7 R1 200 kΩ 2 Cout 4*10 µF/ 25 V R2 18 kΩ 1 Rcomp 51 kΩ 10 TPS61087 Css 100 nF Ccomp 1.5 nF Figure 18. Typical Application with External Load Disconnect Switch L 6.
TPS61087 www.ti.com SLVS821C – MAY 2008 – REVISED JULY 2013 TFT LCD APPLICATION T2 BC850B 3·Vs VGL -7 V/20 mA T1 BC857B R8 6.8 kΩ C13 1 µF/ 35 V C16 470 nF/ 50 V -Vs C14 470 nF/ 25 V D4 BAV99 C15 470 nF/ 50 V D3 BAV99 C18 470 nF/ 50 V R10 13 kΩ 2·Vs C17 470 nF/ 50 V D2 BAV99 D8 BZX84C7V5 Vgh 26.5 V/20 mA C20 1 µF/ 35 V C19 470 nF/ 50 V D9 BZX84C27V L 3.
TPS61087 SLVS821C – MAY 2008 – REVISED JULY 2013 www.ti.com WHITE LED APPLICATIONS L 6.8 µH optional VIN 5 V ± 20% Cin 2* 10 µF/ 16 V Cby 1 µF/ 16 V 6 8 3 9 4 5 IN SW EN SW D SL22 Dz BZX84C 18 V VS 500 mA 3S3P wLED LW E67C 7 Cout 4* 10 µF/ 25 V 2 FREQ FB AGND COMP PGND SS Rlimit 110 Ω 1 Rcomp 51 kΩ 10 TPS61087 Css 100 nF Rsense 15 Ω Ccomp 1.5 nF Figure 21. Simple Application (5 V input voltage) (fS = 650 kHz) for wLED Supply (3S3P) (with optional clamping Zener diode) L 6.
TPS61087 www.ti.com SLVS821C – MAY 2008 – REVISED JULY 2013 L 6.8 µH optional VIN 5 V ± 20% Cin 2* 10 µF/ 16 V Cby 1 µF/ 16 V 6 8 3 9 4 5 IN SW EN SW D SL22 Dz BZX84C 18 V VS 500 mA 3S3P wLED LW E67C 7 2 FREQ FB AGND COMP PGND SS TPS61087 R1 180 kΩ Rlimit 110 Ω 1 10 Css 100 nF Rcomp 51 kΩ Ccomp 1.5 nF Cout 4* 10 µF/ 25 V Rsense 15 Ω R2 127 kΩ Analog Brightness Control 3.3 V ~ wLED off 0 V ~ lLED = 30 mA (each string) PWM Signal Can be used swinging from 0 V to 3.3 V Figure 23.
PACKAGE OPTION ADDENDUM www.ti.
PACKAGE OPTION ADDENDUM www.ti.com 10-Jun-2014 (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided.
PACKAGE MATERIALS INFORMATION www.ti.com 13-May-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) W Pin1 (mm) Quadrant TPS61087DRCR SON DRC 10 3000 330.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 TPS61087DRCR SON DRC 10 3000 330.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 TPS61087DRCT SON DRC 10 250 180.0 12.4 3.3 3.3 1.1 8.0 12.
PACKAGE MATERIALS INFORMATION www.ti.com 13-May-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TPS61087DRCR SON DRC 10 3000 367.0 367.0 35.0 TPS61087DRCR SON DRC 10 3000 367.0 367.0 35.0 TPS61087DRCT SON DRC 10 250 210.0 185.0 35.0 TPS61087DRCT SON DRC 10 250 210.0 185.0 35.0 TPS61087DSCR WSON DSC 10 3000 367.0 367.0 35.0 TPS61087DSCT WSON DSC 10 250 210.0 185.0 35.
IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.