ST1S30 3 A, 1.5 MHz PWM step-down switching regulator with synchronous rectification Features ■ 1.5 MHz fixed frequency PWM with current control mode ■ 3 A output current capability ■ Typical efficiency: > 90% ■ 2 % DC output voltage tolerance ■ Two versions available: power good or inhibit ■ Integrated output over-voltage protection ■ Non switching quiescent current: (typ) 1.5 mA over temperature range ■ RDSon (typ) 100 mΩ ■ Utilizes tiny capacitors and inductors ■ Operating junction temp. -25 °C to 125 °C ■ Available in DFN8 (4 x 4 mm) exposed pad DFN8 (4 x 4 mm) Description The ST1S30 is a step-down DC-DC converter optimized for powering low output voltage applications. It supplies a current in excess of 3 A over an input voltage range from 2.7 V to 6 V. A high PWM switching frequency (1.5 MHz) allows the use of tiny surface-mount components. Table 1. Moreover, since the required synchronous rectifier is integrated, the number of the external components is reduced to minimum: a resistor divider, an inductor and two capacitors. The Power Good function continuously monitors the output voltage. An open drain Power Good flag is released when the output voltage is within regulation. In addition, 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 thermally protected and the output current limited to prevent damages due to accidental short circuit. The ST1S30 is available in the DFN8 (4 x 4 mm) package. Device summary Order codes ST1S30PUR Package (1) Note PG version DFN8 (4 x 4 mm) ST1S30IPUR INHIBIT version 1. Available on request. September 2010 Doc ID 17927 Rev 1 1/11 www.st.com 11 Contents ST1S30 Contents 1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5 Typical application circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2/11 Doc ID 17927 Rev 1 ST1S30 Diagram 1 Diagram Figure 1. Schematic diagram (*) Only for ST1S30I (**) Only for ST1S30 Doc ID 17927 Rev 1 3/11 Pin configuration 2 ST1S30 Pin configuration Figure 2. Pin connections (top view) ST1S30PUR ST1S30IPUR !-V Table 2. Pin n° Symbol 1 FB 2 GND 3 SW 6 7 8 4/11 Pin description Name and function Feedback voltage System ground Switching pin VIN_SW Power supply for the MOSFET switch VIN_A Power supply for analog circuit INH/PG Inhibit (INH) for ST1S30IPUR or Power Good (PG) for ST1S30PUR Exposed pad GND 4, 5 NC To be connected to PCB ground plane for optimal electrical and thermal performance Not internally connected. Can be connected to GND or left floating Doc ID 17927 Rev 1 ST1S30 3 Maximum ratings Maximum ratings Table 3. Note: Absolute maximum ratings Symbol Parameter Value Unit VIN_SW Positive power supply voltage -0.3 to 7 V VIN_A Positive power supply voltage -0.3 to 7 V VINH Inhibit voltage (I version) -0.3 to VI + 0.3 V SWITCH voltage Max. voltage of output pin -0.3 to 7 V VFB Feedback voltage -0.3 to 3 V PG Power Good open drain -0.3 to 7 V TJ Max junction temperature -40 to 150 °C TSTG Storage temperature range -65 to 150 °C TLEAD Lead temperature (soldering) 10 sec 260 °C Absolute maximum ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied. Table 4. Thermal data Symbol Parameter Value Unit RthJC Thermal resistance junction-case 10 °C/W RthJA Thermal resistance junction-ambient 40 °C/W Value Unit Table 5. Symbol ESD performance Parameter Test conditions ESD ESD protection voltage HBM 2 kV ESD ESD protection voltage MM 500 V Doc ID 17927 Rev 1 5/11 Electrical characteristics 4 ST1S30 Electrical characteristics Refer to Figure 3 application circuit VIN_SW = VIN_A = 5 V, VO = 1.2 V, C1 = 10 µF, C2 = 22 µF, L1 = 2.2 µH, TJ = -25 to 125 °C (unless otherwise specified. Typical values are referred to 25 °C) Table 6. Symbol Electrical characteristics for ST1S30 Parameter Test conditions Min. Typ. Max. Unit 784 800 816 mV 600 nA 5.5 V FB Feedback voltage IFB VFB pin bias current VI Input voltage IO = 10 mA to 3 A Under voltage lock out threshold VI Rising 2.3 V Hysteresis 150 mV Overvoltage protection threshold VO rising Overvoltage protection hysteresis VO falling 5 % Overvoltage clamping current VO = 1.2 V 300 mA VINH > 1.2 V, not switching 1.5 UVLO 2.7 1.05 VO 1.1 VO V OVP IOVP 2.5 IQ Quiescent current IO Output current VI = 2.7 to 5.5 V (1) %VO/ΔVI Output line regulation VI = 2.7 V to 5.5 V, IO = 100 mA (1) 0.16 %VO/ ΔVI %VO/ΔIO Output load regulation IO = 10 mA to 3 A (1) 0.2 % PWM switching frequency VFB = 0.65 V PWMfS DMAX 1 VINH < 0.0 V, T = - 30 °C to 85 °C Maximum duty cycle 3 mA A 1.2 1.5 80 87 % 0.92 VO V Power good output threshold PG 1.8 MHz Power good output voltage low ISINK = 6 mA open drain output RDSON-N NMOS switch on resistance ISW = 750 mA 0.1 Ω RDSON-P PMOS switch on resistance ISW = 750 mA 0.1 Ω Switching current limitation (1) 3.7 IO = 10 mA to 100 mA, VO = 3.3 V 65 ISWL ν TSHDN THYS Efficiency (1) 0.4 4.4 5.1 V A % IO = 100 mA to 3 A, VO = 3.3 V 85 Thermal shutdown 150 °C Thermal shutdown hysteresis 20 °C %VO/ΔIO Load transient response IO = 100 mA to 1 A, TA = 25 °C tR = tF ≥ 200 ns (1) -10 +10 %VO %VO/ΔIO Short circuit removal response IO = 10 mA to IO = short, TA = 25 °C (1) -10 +10 %VO 1. Guaranteed by design, but not tested in production. 6/11 Doc ID 17927 Rev 1 ST1S30 Electrical characteristics Refer to Figure 4 application circuit VIN_SW = VIN_A = VINH = 5 V, VO = 1.2 V, C1 = 10 µF, C2 = 22, C3 = 1 µF, L1 = 2.2 µH, TJ = -25 to 125 °C (unless otherwise specified. Typical values are referred to 25 °C) Table 7. Symbol Electrical characteristics for ST1S30I Parameter Test conditions FB Feedback voltage IFB VFB pin bias current VI Minimum input voltage IO = 10 mA to 2 A Overvoltage protection threshold VO rising Overvoltage protection hysteresis VO falling Min. Typ. Max. Unit 784 800 816 mV 600 nA 2.7 V 1.05 VO 1.1 VO V OVP IQ Quiescent current IO Output current VINH 5 VINH > 1.2 V, not switching 1.5 VINH < 0.0 V, T = - 30 °C to 85 °C Inhibit threshold VI = 2.7 to 5.5 V (1) 2.5 mA 1 µA 3 Device ON, VI = 2.7 to 5.5 V 1.3 Device ON, VI = 2.7 to 5 V 1.2 A V Device OFF IINH % 0.4 Inhibit pin current 2 µA %VO/ ΔVI %VO/ΔVI Output line regulation VI = 2.7 V to 5.5 V, IO = 100 mA (1) 0.16 %VO/ΔIO Output load regulation IO = 10 mA to 2 A (1) 0.2 0.6 %VO/ ΔIO PWM switching frequency VFB = 0.65 V 1.2 1.5 1.8 MHz 80 87 % PWMfS DMAX Maximum duty cycle RDSON-N NMOS switch on resistance ISW = 750 mA 0.1 Ω RDSON-P PMOS switch on resistance ISW = 750 mA 0.1 Ω Switching current limitation (1) 3.7 IO = 10 mA to 100 mA, VO = 3.3 V 65 ISWL ν TSHDN THYS Efficiency (1) 4.4 5.1 A % IO = 100 mA to 3 A, VO = 3.3 V 85 Thermal shutdown 150 °C Thermal shutdown hysteresis 20 °C %VO/ΔIO Load transient response IO = 100 mA to 1 A, TA = 25 °C tR = tF ≥ 200 ns (1) -10 +10 %VO %VO/ΔIO Short circuit removal response IO = 10 mA to IO = short, TA = 25 °C (1) -10 +10 %VO 1. Guaranteed by design, but not tested in production. Doc ID 17927 Rev 1 7/11 Typical application circuits ST1S30 5 Typical application circuits Figure 3. Application circuit fot VOUT > 1.2 V Figure 4. Application circuit for 0.8 V < VOUT < 1.2 V Note: These typical application circuits are provided to help designing the external components. However, we recommend to thoroughly validate any circuit solution in the real application environment conditions. 8/11 Doc ID 17927 Rev 1 ST1S30 6 Package mechanical data Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. ECOPACK® is an ST trademark. Table 8. DFN8 (4x4) mechanical data mm. Dim. Min. Typ. Max. A 0.80 0.90 1.00 A1 0 0.02 0.05 A3 0.20 b 0.23 0.30 0.38 D 3.90 4.00 4.10 D2 2.82 3.00 3.23 E 3.90 4.00 4.10 E2 2.05 2.20 2.30 e L Figure 5. 0.80 0.40 0.50 0.60 DFN8 (4x4) mechanical dimensions " Doc ID 17927 Rev 1 9/11 Revision history 7 ST1S30 Revision history Table 9. 10/11 Document revision history Date Revision 09-Sep-2010 1 Changes First release Doc ID 17927 Rev 1 ST1S30 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. 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