G5125 Global Mixed-mode Technology Inc. Micro-Power Boost DC/DC Converter Features General Description The G5125 boost converter contains a 0.7Ω internal switch. The IC operates at constant frequency 1MHz, allowing the use of tiny, low cost and low height inductors and capacitors. The IC operates from a 2.7V to 5.5V supply voltage and can boost supply voltage up to 30V at the output. High inrush current at start-up is eliminated using the soft-start function. Constant frequency current mode PWM architecture results in low, predictable output noise. The G5125 includes cycle-by-cycle 850mA current limiting to maximum inductor current and over-temperature protection circuit. The G5125 is suitable for small or medium size LCD panel of high bias voltage with a constant current to provide PDAs, and other portable devices. The G5125 is available in SOT-23-5 package. Operating Voltage：2.7V ~ 5.5V High Operating Frequency：1MHz Shutdown Current：＜1μA High Output Voltage：Up to 30V Soft Start Function Cycle by Cycle Current Limiting SOT-23-5 Package Applications STN/OLED BIAS Personal Digital Assistants DSC Ordering Information ORDER NUMBER MARKING TEMP. RANGE PACKAGE (Pb free) G5125T11U 5125x -40°C to 85°C SOT-23-5 Note: T1: SOT-23-5 1 : Bonding Code U: Tape & Reel Pin Configuration Typical Application Circuit 10µH or 22µH G5125 LX 1 GND 2 5 CIN 4.7µF IN 4 3 GND SOT-23-5 500k R1 FB EN EN COUT 10µF LX IN G5125 G963 FB VOUT=15V VIN=2.7V to 5.5V 44k R2 TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 0.4 Jan 11, 2008 1 G5125 Global Mixed-mode Technology Inc. Absolute Maximum Ratings Continuous Power Dissipation (TA=25°C) SOT-23-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400mW Operating Temperature Range1 . . . . . -40°C to +85°C Junction Temperature . . . . . . . . . . . . . . . . . . . +150°C Storage Temperature . . . . . . . . . . . . -65°C to +150°C Reflow Temperature (soldering, 10sec) . . . . . . 260°C IN to GND. . . . . . . . . . . . . . . . . . . . . . . . . . .-0.3V to 7V LX to GND. . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 35V EN to GND. . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VIN FB to GND. . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VIN Thermal Resistance Junction to Ambient, (θJA) SOT-23-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240°C/W Note: 1. It is guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the -40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. Electrical Characteristics VIN=VEN=3.6V, TA = 25°C. PARAMETER Operating Input Voltage Quiescent Current Shutdown Supply Current VIH EN Input Level VIL CONDITIONS No Switching EN=0V MIN TYP MAX UNITS 2.7 --- --0.2 5.5 0.3 V mA --1.5 0 --- 1 --- µA V --- --- 0.8 V UVLORISING 2 2.25 2.5 V Oscillator Frequency Maximum Duty Cycle --85 1 90 ----- MHz % 1.225 --- 1.250 700 1.275 --- V mΩ --500 --850 10 1300 µA mA Trigger --- 120 --- °C Hysteresis ----- 20 0.5 ----- °C ms Feedback Regulation Voltage NMOS RDS-ON ILX=200mA LX Leakage Current Switching Current Limit EN=0, VLX=32V duty cycle=80% Over Temperature Soft Start TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 0.4 Jan 11, 2008 2 G5125 Global Mixed-mode Technology Inc. Pin Descriptions PIN Name 1 2 LX GND FUNCTION 3 4 FB EN Feedback Input. Enable Input. Drive EN high to turn on the regulator, drive it low to turn it off. 5 IN Power Input Pin. It must be bypassed with a low-ESR capacitor. Power Switching Output Ground Pin. Block Diagram IN CURRENT SENSE CURRENT LIMIT REFERENCE LX + CONTROL FB EN ON/OFF CONTROL GND TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 0.4 Jan 11, 2008 3 Global Mixed-mode Technology Inc. G5125 Operating Capacitor Selection The small size of ceramic capacitors makes them suitable for G5125 applications. X5R and X7R types are recommended because they retain their capacitance over wider voltage and temperature ranges than other types such as Y5V or Z5U. A minimum 10μF capacitor for output is required for most applications. Larger input/output capacitor minimizes input/output ripple. The G5125 step-up DC-DC converter operates from a 2.7V to 5.5V supply and converts up to 30V. The device includes an internal switching MOSFET with a 0.7Ω on-resistance and consumes 200μA of supply current. During startup, the G5125 limits the maximum on-time to limit initial battery inrush current. Adjust the output voltage by connecting a voltage divider from the output (VOUT) to FB. Select R1 and R2 (see application circuit) to set the voltage of FB (VFB) equaling 1.25V and VOUT may up to 30V. The G5125 built in a cycle-by-cycle 850mA current-limit function to maximum inductor current. The G5125 consumes 0.1μA when voltage of EN is Low. Diode Selection Schottky diodes, with their low forward voltage drop and fast reverse recovery, are the ideal choices for G5125 applications. The forward voltage drop of a Schottky diode represents the conduction losses in the diode, while the diode capacitance (CT or CD) represents the switching losses. For diode selection, both forward voltage drop and diode capacitance need to be considered. Schottky diodes with higher current ratings usually have lower forward voltage drop and large diode capacitance, which can cause significant switching losses at the 1MHz switching frequency of the G5125. Application Information Inductor Selection The inductor’s saturation current rating should be greater than the peak switching current. The large inductance prevents the large inductor’s current ripple to induce maximum current limit in on-time period and output voltage ripple can be reduced also. Inductor with low core losses and small DCR (cooper wire resistance) is recommended. TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 0.4 Jan 11, 2008 4 G5125 Global Mixed-mode Technology Inc. Package Information C D L E H θ1 e e1 A A2 A1 b SOT-23-5 (T1) Package Note: 1. Package body sizes exclude mold flash protrusions or gate burrs 2. Tolerance ±0.1000 mm (4mil) unless otherwise specified 3. Coplanarity: 0.1000mm 4. Dimension L is measured in gage plane MIN. DIMENSION IN MM NOM. MAX. MIN. DIMENSION IN INCH NOM. MAX. A A1 1.00 0.00 1.10 ----- 1.30 0.10 0.039 0.000 0.043 ----- 0.051 0.004 A2 b 0.70 0.35 0.80 0.40 0.90 0.50 0.028 0.014 0.031 0.016 0.035 0.020 C D E e e1 H L θ1 0.10 2.70 1.40 --------2.60 0.37 0.15 2.90 1.60 0.95 1.90 (TYP) 2.80 ------ 0.25 3.10 1.80 --------3.00 ----- 0.004 0.106 0.055 --------0.102 0.015 0.006 0.114 0.063 0.037 0.075 (TYP) 0.110 ----- 0.010 0.122 0.071 --------0.118 ----- 1° 5° 9° 1° 5° 9° SYMBOL Taping Specification PACKAGE Q’TY/REEL SOT-23-5 3,000 ea Feed Direction SOT-23-5 Package Orientation GMT Inc. does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and GMT Inc. reserves the right at any time without notice to change said circuitry and specifications. TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 0.4 Jan 11, 2008 5