Datasheet

ManualsBrandsSTMICROELECTRONICS ManualsPMICsPMIC - DC/DC voltage regulator Holder DFN 6

March 2008 Rev 6 1/16

ST1S03

1.5 A, 1.5 MHz adjustable,

step-down switching regulator

Features

■ Step-down current mode PWM (1.5 MHz)

DC-DC converter

■ 2 % DC output voltage tolerance

■ Internal soft start for START-UP current

limitation and power on delay of 50-100 µs

■ Typical efficiency: > 70 % over all operating

conditions

■ 1.5 A output current capability

■ Not switching quiescent current: max 2.5 mA

over temperature range

■ Switch V

: max 350 mV @ I

= 750 mA

■ Uses tiny capacitors and inductors

■ Available in DFN 3x3 mm exposed pad

Description

The ST1S03 is a step down DC-DC converter

optimized for powering low-voltage digital core in

HDD applications and, generally, to replace the

high current linear solution when the power

dissipation may cause an high heating of the

application environment. It provides up to 1.5 A

over an input voltage range of 3 V to 16 V. An high

switching frequency (1.5 MHz) allows the use of

tiny surface-mount components: as well as the

resistor divider to set the output voltage value,

only an inductor, a schottky diode and two

capacitors are required. Besides, a low output

ripple is guaranteed by the current mode PWM

topology and by the use of low ESR SMD ceramic

capacitors. The device is thermal protected and

current limited to prevent damages due to

accidental short circuit. The ST1S03 is available

in DFN6.

DFN6D (3x3mm)

Table 1. Device summary

Order code Packaging Package

ST1S03PU ST1S03PUR DFN6D (3x3 mm)

www.st.com

Summary of content (16 pages)

PAGE 1
ST1S03 1.5 A, 1.5 MHz adjustable, step-down switching regulator Features ■ Step-down current mode PWM (1.5 MHz) DC-DC converter ■ 2 % DC output voltage tolerance ■ Internal soft start for START-UP current limitation and power on delay of 50-100 µs ■ Typical efficiency: > 70 % over all operating conditions DFN6D (3x3mm) ■ 1.5 A output current capability ■ Not switching quiescent current: max 2.
PAGE 2
Contents ST1S03 Contents 1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5 Application notes . . . . . . . . . . .
PAGE 3
ST1S03 Diagram 1 Diagram Figure 1.
PAGE 4
Pin configuration ST1S03 2 Pin configuration Figure 2. Pin connections (top view) Table 2. Pin description Pin n° Symbol 1 VFB Voltage of feedback 2 GND System ground 3 SW 4 VIN_SW 5 VIN_A Power supply for the analog circuit 6 N.C.
PAGE 5
ST1S03 Maximum ratings 3 Maximum ratings Table 3. Absolute maximum ratings Symbol Parameter Value Unit VIN_SW Positive power supply voltage -0.3 to 16 V VIN_A Positive power supply voltage -0.3 to 16 V Max voltage of output pin -0.3 to 16 V SWITCH voltage VFB Feedback voltage 2.5 V IVFB Common mode input voltage ±1 mA Max junction temperature 150 °C -25 to 150 °C 300 °C TJ TSTG Storage temperature range TLEAD Lead temperature (Soldering) 10 Sec.
PAGE 6
Electrical characteristics ST1S03 4 Electrical characteristics Table 5. Electrical characteristics (VIN_SW = VIN_A = 5 V, CI = 4.7 µF, CO = 22 µF, L1 = 3.3 µH, TJ = 0 to 125 °C, unless otherwise specified. Typical values are referred to 25 °C) Symbol Parameter Test conditions FB Feedback voltage IFB VFB pin bias current IQ Quiescent current No Switching IO Output current VIN = 3V to 16V IMIN IO = 100mA Minimum output current Min. Typ. Max. Unit 784 800 816 mV 600 nA 2.
PAGE 7
ST1S03 5 Application notes Application notes The ST1S03 is an adjustable current mode PWM step-down DC-DC converter with internal 1.5 A power switch, packaged in 6-lead DFN 3x3 mm. It’s a complete 1.5 A switching regulator with its internal compensation eliminating additional component. The constant frequency, current mode, PWM architecture and stable operation with ceramic capacitors results in low, predictable output ripple.
PAGE 8
Typical application 6 Typical application Figure 3.
PAGE 9
ST1S03 Typical performance characteristics 7 Typical performance characteristics Figure 4. (L1 = 3.3 µH, CI = 4.7 µF, CO = 22 µF, unless otherwise specified) Load voltage feedback vs temp. Figure 5. Voltage feedback vs temperature Figure 6. Line output voltage regulation vs temperature Figure 7. Figure 8. Voltage feedback vs output current Figure 9.
PAGE 10
Typical performance characteristics ST1S03 Figure 10. Quiescent current vs temperature Figure 11. Quiescent current vs input voltage Figure 12. Minimum operating voltage vs output voltage Figure 13. Efficiency vs temperature Figure 14. Efficiency vs output current Figure 15.
PAGE 11
ST1S03 Typical performance characteristics Figure 16. Switch RDS-ON vs temperature Figure 17. Switch current limitation vs temperature Figure 18. Load transient response Figure 19. Load transient response VCC=5V, IO=100mA to 780mA, CI=4.7µF, CO=22µF, L=3.3µH, TON=38µs, TJ=25°C VCC=5V, IO=200mA to 1.2A, CI=4.7µF, CO=22µF, L=3.3µH, TON=38µs, TJ=25°C Figure 20. Start-Up transient Figure 21.
PAGE 12
Package mechanical data 8 ST1S03 Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK® packages. These packages have a lead-free second level interconnect. The category of second Level Interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are available at: www.
PAGE 13
ST1S03 Package mechanical data DFN6D (3x3 mm) mechanical data mm. inch. Dim. Min. A 0.80 A1 0 A3 0.02 Max. Min. 1.00 0.031 0.05 0 0.20 b 0.23 D 2.90 D2 2.23 E 2.90 E2 1.50 e L Typ. 3.00 3.00 0.40 Max. 0.039 0.001 0.002 0.008 0.45 0.009 3.10 0.114 2.50 0.088 3.10 0.114 1.75 0.059 0.95 0.30 Typ. 0.018 0.118 0.122 0.098 0.118 0.122 0.069 0.037 0.50 0.012 0.016 0.
PAGE 14
Package mechanical data ST1S03 Tape & Reel QFNxx/DFNxx (3x3) Mechanical Data mm. inch. Dim. Min. Typ. A Min. Typ. 330 13.2 Max. 12.992 C 12.8 D 20.2 0.795 N 60 2.362 T 14/16 Max. 0.504 0.519 18.4 0.724 Ao 3.3 0.130 Bo 3.3 0.130 Ko 1.1 0.043 Po 4 0.157 P 8 0.
PAGE 15
ST1S03 Revision history 9 Revision history Table 6. Document revision history Date Revision Changes 11-Nov-2004 1 First Release. 08-Feb-2005 2 Maturity Change. 03-Mar-2005 3 Mistake on Figure 1, TJ is changed 125 ==> 150°C on Table 3. 13-Jul-2005 4 Add new package SO-8 exposed pad. 29-Mar-2007 5 Package SO-8 removed. 07-Mar-2008 6 Removed: package mechanical data DFN6.
PAGE 16
ST1S03 Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale.