STI34061

STI34061 1.2A, 1.5MHz Synchronous Buck Converter in SOT Package GENERAL DESCRIPTION FEATURES The STI34061 is a 1.5MHz constant frequency, current mode PWM buck converter. The device integrates a main switch and a synchronous MOSFET for high efficiency without an external Schottky diode. It is ideal for powering portable equipment that runs from a single cell Lithium-Ion (Li+) battery. The output voltage can be regulated as low as 0.6V. This device offers two operation modes, PWM control and PFM Mode switching control, which allows a high efficiency over the wider range of the load. ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ APPLICATIONS ⚫ ⚫ ⚫ ⚫ Up to 93% Efficiency 2.5V to 5.5V Input Voltage Range Output Voltage as Low as 0.6V 1.5MHz Constant Frequency Operation 1.2A Output Current No Schottky Diode Required Low Quiescent Current: 50µA Slope Compensated Current Mode Control for Excellent Line and Load Transient Response Thermal Fault Protection Inrush Current Limit and Soft Start SOT23-5 Package General Purpose PoL supply Set Top Box PDA/MID/PAD Digital Still and Video Cameras TYPICAL APPILCATION VIN 4 VIN LX 3 CIN 10µF L 2.2µH VOUT=1.2V R1 100kΩ 1 EN FB 5 COUT GND 2 R2 10µF 100kΩ Figure 1. Basic Application Circuit TMI and SUNTO are the brands of TOLL microelectronic . STI34061 V1.1 2018.09 www.toll-semi.com www.suntosemi.com 1 STI34061 ABSOLUTE MAXIMUM RATINGS (Note 1) Parameter Value Unit Input Supply Voltages -0.3~6.5 V LX Voltages -0.3~6.5 V EN, FB Voltage -0.3~6.5 V Storage Temperature Range -65~150 °C Junction Temperature (Note 2) -40~150 °C Power Dissipation 600 mW Lead Temperature Soldering,10Sec 260 °C PIN CONFIGURATION SOT23-5 Top Mark: T50XXX (T50: Device Code, XXX: Inside Code) www.toll-semi.com 2 Part Number Package Top mark Quantity/ Reel STI34061 SOT23-5 T50XXX 3000 www.suntosemi.com TMI and SUNTO are the brands of TOLL microelectronic. STI34061 V1.1 2018.09 STI34061 PIN FUNCTIONS Pin Name 1 EN 2 GND 3 LX 4 VIN 5 FB Function Chip Enable Pin. Drive EN above 1.5V to turn on the part. Drive EN below 0.3V to turn it off. Do not leave EN floating. Ground Pin Power Switch Output. It is the switch node connection to Inductor. Power Supply Input. Must be closely decoupled to GND with a 4.7µF or greater ceramic capacitor. Output Voltage Feedback Pin. ESD RATING Items Description Value Unit VESD Human Body Model for all pins ±2000 V JEDEC specification JS-001 RECOMMENDED OPERATING CONDITIONS Items Description Voltage Range IN 2.5 5.5 V TA Operating Temperature Range -40 85 °C TMI and SUNTO are the brands of TOLL microelectronic . STI34061 V1.1 2018.09 Min Max www.toll-semi.com Unit www.suntosemi.com 3 STI34061 ELECTRICAL CHARACTERISTICS (Note 3) (VIN=VEN=3.6V, VOUT=1.8V, TA = 25°C, unless otherwise noted.) Parameter Test Conditions Min Input Voltage Range Typ 2.5 UVLO Threshold Max Unit 5.5 V 2.1 Quiescent Current VEN=2.0V, IOUT=0， VFB=VREF*105% Shutdown Current VEN =0V Regulated Feedback Voltage TA = 25°C 0.582 V 50 130 µA 1 10 µA 0.600 0.618 V Reference Voltage Line Regulation VIN = 2.5V to 6.0V 0.04 0.40 %/V Output Voltage Line Regulation VIN = 2.5V to 6.0V 0.04 0.4 % Output Voltage Load Regulation 0.5 % VOUT=100% 1.5 MHz VOUT=0V 400 kHz On Resistance of PMOS ILX=100mA 0.32 Ω On Resistance of NMOS ILX=-100mA 0.21 Ω Oscillation Frequency Peak Current Limit VIN=5V, VOUT=1.2V, L=4.7μH/2A 1.5 A EN Input Low Level 0.30 EN Input High Level 1.5 EN Leakage Current LX Leakage Current VEN=0V, VIN=VLX=5V V V ±0.01 ±1.0 µA ±0.01 ±1.0 µA Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: TJ is calculated from the ambient temperature TA and power dissipation PD according to the following formula: TJ = TA + (PD) x (250°C/W). Note 3: 100% production test at +25°C. Specifications over the temperature range are guaranteed by design and characterization. www.toll-semi.com 4 www.suntosemi.com TMI and SUNTO are the brands of TOLL microelectronic. STI34061 V1.1 2018.09 STI34061 FUNCTION DESCRIPTION The STI34061 is a high performance 1.2A, 1.5MHz monolithic buck converter. The STI34061 requires only three external power components (Cin, Cout and L). The adjustable version can be programmed with external feedback to any voltage, ranging from 0.6V to the input voltage. At dropout, the converter duty cycle increases to 100% and the output voltage tracks the input voltage minus the Rdson drop of the high-side MOSFET. The internal error amplifier and compensation provides excellent transient response, load, and line regulation. Soft start function prevents input inrush current and output overshoot during start up. FUNCTIONAL BLOCK DIAGRAM Figure 2. STI34061 Block Diagram TMI and SUNTO are the brands of TOLL microelectronic . STI34061 V1.1 2018.09 www.toll-semi.com www.suntosemi.com 5 STI34061 APPLICATION INFORMATION Setting the Output Voltage Figure 1 shows the basic application circuit for the STI34061. The STI34061 can be externally programmed. Resistors R1 and R2 in Figure 1 program the output to regulate at a voltage higher than 0.6V. The external resistor sets the output voltage according to the following equation: VOUT = 0.6  (1 + R1 ) R2 R1 = (VOUT / 0.6 − 1)  R2 Inductor Selection For most designs, the STI34061 operates with inductors of 2.2µH to 10µH. Low inductance values are physically smaller but require faster switching, which results in some efficiency loss. The inductor value can be derived from the following equation: L= VOUT  (VIN − VOUT ) VIN  I L  f OSC Where I L is inductor Ripple Current. Large value inductors result in lower ripple current and small value inductors result in high ripple current. For optimum voltage-positioning load transients, choose an inductor with DC series resistance in the 50mΩ to 150mΩ range. Input Capacitor Selection The input capacitor reduces the surge current drawn from the input and switching noise from the device. The input capacitor impedance at the switching frequency should be less than input source impedance to prevent high frequency switching current passing to the input. A low ESR input capacitor sized for maximum RMS current must be used. Ceramic capacitors with X5R or X7R dielectrics are highly recommended because of their low ESR and small temperature coefficients. A 4.7µF ceramic capacitor for most applications is sufficient. A large value may be used for improved input voltage filtering. Output Capacitor Selection The output capacitor is required to keep the output voltage ripple small and to ensure regulation loop stability. The output capacitor must have low impedance at the switching frequency. Ceramic capacitors with X5R or X7R dielectrics are recommended due to their low ESR and high ripple current ratings. The output ripple VOUT is determined by: VOUT   VOUT  (V IN − VOUT )  1    ESR + V IN  f OSC  L 8  f osc  C 3   A 10µF ceramic can satisfy most applications. www.toll-semi.com 6 www.suntosemi.com TMI and SUNTO are the brands of TOLL microelectronic. STI34061 V1.1 2018.09 STI34061 Layout Consideration When laying out the printed circuit board, the Following checking should be used to ensure proper operation of the STI34061. Check the following in your layout: 1.The power traces, consisting of the GND trace, the LX trace and the VIN trace should be kept short, direct and wide. 2.Does the (+) plates of Cin connect to Vin as closely as possible. This capacitor provides the AC current to the internal power MOSFETs. 3.Keep the switching node, LX, away from the sensitive VOUT node. 4.Keep the (-) plates of Cin and Cout as close as possible TMI and SUNTO are the brands of TOLL microelectronic . STI34061 V1.1 2018.09 www.toll-semi.com www.suntosemi.com 7 STI34061 PACKAGE INFORMATION SOT23-5 Unit: mm Symbol Dimensions In Millimeters Min Max L 2.82 3.02 B 1.50 C Symbol Dimensions In Millimeters Min Max E1 0.85 1.05 1.70 a 0.35 0.50 0.90 1.30 c 0.10 0.20 L1 2.60 3.00 b 0.35 0.55 E 1.80 2.00 F 0 0.15 Note: 1) All dimensions are in millimeters. 2) Package length does not include mold flash, protrusion or gate burr. 3) Package width does not include inter lead flash or protrusion. 4) Lead popularity (bottom of leads after forming) shall be 0.10 millimeters max. 5) Pin 1 is lower left pin when reading top mark from left to right. www.toll-semi.com 8 www.suntosemi.com TMI and SUNTO are the brands of TOLL microelectronic. STI34061 V1.1 2018.09 STI34061 TAPE AND REEL INFORMATION TAPE DIMENSIONS: REEL DIMENSIONS: Note: 1) All Dimensions are in Millimeter 2) Quantity of Units per Reel is 3000 3) MSL level is level 3. TMI and SUNTO are the brands of TOLL microelectronic . STI34061 V1.1 2018.09 www.toll-semi.com www.suntosemi.com 9