G5111 Global Mixed-mode Technology Inc. Micro-power Step-Up DC/DC Converters in SOT23-5 Features General Description Configurable Output Voltage Up to 28V 20A Quiescent Current <1A Shutdown Current <1A Shutdown Pin Current Supply Range from 2.5V to 6.5V Low VDS(on): 250mV (ISW=300mA) Tiny SOT23-5 Package The G5111 boost converter is designed for small/ medium size LCD panel of high bias voltage. Applications Furthermore, the 350mA current limit, 500ns fixed minimum off-time and tiny SOT23-5 package facilitates the use of smaller inductor and other surface-mount components to minimize the PCB size in those space-conscious applications. Due to a typical 20A quiescent current and 2.5V~ 6.5V supply voltage range, it is suitable for battery powered portable applications. Such as PDAs and Handheld Computers. When the IC sets to shutdown mode, it only consumes less than 1A. STN/TFT LCD Bias Personal Digital Assistants (PDAs) Handheld Computers Digital Still Cameras Cellular Phones WebPad White LED Driver Local 3V to 5V Conversion To control the IC, no other external current is needed for the shutdown pin. It typically consumes less than 1A of full supply range. Ordering Information PART TEMP. RANGE PINPACKAGE TOP MARK SOT23-5 SOT23-5 51xx 52xx G5111 T11 -40C ~ +85C G5111 T12 -40C ~ +85C Pin Configuration SW 1 Typical Application Circuit 5 VCC 10H GND 2 G5111 T11 G963 VCC 4 FB 3 SW SHDN 1M G5111 SOT23-5 SHDN SHDN 1 VCC 2 20V 12mA VIN 2.5V to 4.2V 5 FB 4 SW 4.7F 1F FB GND 62k G5111 T12 G963 GND 3 SOT23-5 TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Oct 02, 2002 1 G5111 Global Mixed-mode Technology Inc. Absolute Maximum Ratings Junction Temperature ........................................+125C Storage Temperature......................... -65C to +150C Lead Temperature (Soldering, 10 sec)...............+300C SW to GND.........................................-0.3V to +30V FB to GND............... .............................-0.3V to VCC VCC, SHDN to GND.....................................-0.3V to +7V Operating Temperature Range (Note 1) ..-40C to +85C Stress beyond those listed under "Absolute Maximum Rating" may cause permanent damage to the device. Electrical Characteristics (VCC = 3.6V, V SHDN = 3.6V, TA = 25C) PARAMETER CONDITIONS MIN Input Voltage Range TYP 2.5 Not Switching V SHDN = 0V Quiescent Current FB Comparator Trip Point Output Voltage Line Regulation FB Pin Bias Current (Note 2) Switch Off Time Switch VDS(ON) Switch Current Limit 1.18 2.5V<VIN<6.5V VFB = 1.2V VFB > 1V VFB < 0.6V ISW = 300mA 300 SHDN Pin Current 20 0.1 1.2 -0.05 30 500 1.6 250 350 0.1 MAX UNITS 6.5 30 1 1.22 350 400 V A A V %/V nA ns s mV mA 1 A 80 0.9 SHDN Input Voltage High V SHDN Input Voltage Low Switch Leakage Current Switch Off, VSW = 28V 0.01 0.25 V 5 A Note 1: The G5111 are guaranteed to meet performance specifications from 0C to 85C. Specifications over the -40C to 85C operating temperature range are assured by design, characterization and correlation with statistical process controls. Note 2: Bias current flows into the FB pin. Block Diagram L1 VIN VOUT C2 C1 BIAS VOUT R1 FB + SW SHDN VCC SHUTDOWN LOGIC PUMP CONTROL OC DRIVER COMP ERROR COMP en_sw + R2 1.2V T OFF PULSE CONTROL VREF GND TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Oct 02, 2002 2 G5111 Global Mixed-mode Technology Inc. Typical Performance Characteristics (VCC=+3.6V, V SHDN =+3.6V, L=10H, TA=25C, unless otherwise noted.) Output Voltage vs. Load Current 21 20.5 20.5 Output Voltage (V) Output Voltage (V) Output Voltage vs. Input Voltage 21 IOUT=1mA 20 IOUT=10mA 19.5 VIN=2.7V 20 VIN=4.2V 19.5 19 19 2.5 3 3.5 4 4.5 5 1 5.5 2 3 5 6 7 8 9 10 Quiescent Current vs. Temperature Efficiency vs. Load Current 50 90 Quiescent Current (A) VIN=4.2V 85 80 Efficiency (%) 4 Load Current (mA) Input Voltage (V) VIN=3.6V 75 70 VIN=2.7V 65 60 40 VIN=4.2V 30 20 VIN=2.7V 55 10 50 0.1 1 10 -20 100 0 40 60 80 100 Feedback Voltage vs. Temperature Vds_on vs. Temperature 1.22 Feedback Voltage (V) 500 Switch Vds_on (mV) 20 Temperature (C) Load Current (mA) 400 VIN=2.7V 300 200 VIN=4.2V 100 1.21 VIN=2.7V 1.2 1.19 VIN=4.2V 1.18 -20 0 20 40 60 80 -20 100 Temperature (C) 0 20 40 60 80 100 Temperature (C) TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Oct 02, 2002 3 G5111 Global Mixed-mode Technology Inc. Typical Performance Characteristics (Continued) FB Bias Current vs. Temperature Switch Current Limit vs. Temperature 450 VIN=2.7V Peak Current (mA) Feedback Bias Current (nA) 30 25 20 VIN=4.2V 400 VIN=4.2V 350 VIN=2.7V 300 250 15 -20 0 20 40 60 80 -20 100 0 20 40 60 80 100 Temperature (C) Temperature (C) Line Transient Load Transient TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Oct 02, 2002 4 G5111 Global Mixed-mode Technology Inc. Pin Description PIN NAME FUNCTION 4 3 SW GND Switch Pin. The drain of the internal NMOS power switch. Connect this pin to inductor. Ground. Feedback Pin. Set the output voltage by selecting values for R1 and R2 (see Block Diagram): 3 5 FB 4 1 SHDN 5 2 VCC T11 T12 1 2 R1 = R2 VOUT -1 1 .2 Active-Low Shutdown Pin. Tie this pin to logic-high to enable the device or tied it to logic-low to turn this device off. Input Supply Pin. Bypass this pin with a capacitor as close to the device as possible. Function Description Where VD = 0.4V (Schottky diode voltage), ILIM = 350mA and tOFF = 500ns. A larger value can be used to lightly increase the available output current, but limit it to about twice the calculating value. When too large of an inductor will increase the output voltage ripple without providing much additional output current. In varying VIN condition such as battery power applications, use the minimum VIN value in the above equation. A smaller value can be used to give smaller physical size, but the inductor current overshoot will be occurs (see Current Limit Overshoot section). The G5111 is a boost converter with a NMOS switch embedded (refer to Block Diagram). The boost cycle is getting started when FB pin voltage drop below 1.2V as the NMOS switch turns on. During the switch on period, the inductor current ramps up until 350mA current limit is reached. Then turns the switch off, while the inductor current flows through external schottky diode, and ramps down to zero. During the switch off period, the inductor current charges output capacitor and the output voltage is boosted up. This pumping mechanism continues cycle by cycle until the FB pin voltage exceed 1.2V and entering the none switching mode. In this mode, the G5111 consumes as low as 20uA typically to save battery power. Inductor Selection--SEPIC Regulator For a SEPIC regulator using the G5111, the approximate inductance value can be calculated by below formula. As for the boost inductor selection, a larger or smaller value can be used. Applications Information L=2 Choosing an Inductor There are several recommended inductors that work well with the G5111 in Table 1. Use the equations and recommendations in the next few sections to find the proper inductance value for your design. PART VALUE((H) MAX DCR () 4.7 10 22 4.7 10 4.7 10 4.7 10 22 0.26 0.30 0.92 0.11 0.18 0.16 0.20 0.09 0.16 0.37 VENDOR Murata www.murata.com IPEAK = ILIM + Sumida www.sumida.com VIN(MAX) - VSAT x 100ns L Where VSAT = 0.25V (switch saturation voltage). When the systems with high input voltages and uses smaller inductance value, the current overshoot will be most apparent. This overshoot can be useful as it helps increase the amount of available output current. To use small inductance value for systems design, the current limit overshoot can be quite high. Even if it is internally current limited to 350mA, the power switch of the G5111 can operate larger currents without any problem, but the total efficiency will suffer. The IPEAK is keep below 500mA for the G5111 will be obtained best performance. Coilcraft www.coilcraft.com Inductor Selection--Boost Regulator The appropriate inductance value for the boost regulator application may be calculated from the following equation. Select a standard inductor close to this value. L= x tOFF Current Limit Overshoot The G5111 use a constant off-time control scheme, the power switch is turned off after the 350mA current limit is reached. When the current limit is reached and when the switch actually turns off, there is a 100ns delay time. During this time, the inductor current exceeds the current limit by a small amount. The formula below can calculate the peak inductor current. Table 1. Recommended Inductors LQH3C4R7 LQH3C100 LQH3C220 CD43-4R7 CD43-100 CDRH4D18-4R7 CDRH4D18-100 DO1608-472 DO1608-103 DO1608-223 VOUT + VD ILIM VOUT-VIN(MIN)+VD x tOFF ILIM TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Oct 02, 2002 5 G5111 Global Mixed-mode Technology Inc. Capacitor Selection Low ESR (Equivalent Series Resistance) capacitors should be used at the output to minimize the output ripple voltage and the peak-to-peak transient voltage. Multilayer ceramic capacitors (MLCC) are the best choice, as they have a very low ESR and are available in very small packages. Their small size makes them a good match with the G5111's SOT-23 package. If solid tantalum capacitors (like the AVX TPS, Sprague 593D families) or OS-CON capacitors are used, they will occupy more volume than a ceramic ones and the higher ESR increases the output ripple voltage. Notice that use a capacitor with a sufficient voltage rating. A low ESR surface-mount ceramic capacitors also make a good selection for the input bypass capacitor, which should be placed as close as possible to the G5111. A 4.7F input capacitor is sufficient for most applications. recommended. Many different manufacturers make equivalent parts, but make sure that the component is rated to operate at least 0.35A. To achieve high efficiency, the average current rating of the Schottky diodes should be greater than the peak switching current. Choose a reverse breakdown voltage greater than the output voltage. Lowering Output Voltage Ripple The G5111 supplies energy to the load in bursts by ramping up the inductor current, then delivering that current to the load. To use low ESR capacitors will help minimize the output ripple voltage, but proper selection of the inductor and the output capacitor also plays a big role. If a larger inductance value or a smaller capacitance value is used, the output ripple voltage will increase because the capacitor will be slightly overcharged each burst cycle. To reduce the output ripple, increase the output capacitance value or add a 10pF feed-forward capacitor in the feedback network of the G5111 (see the circuits in the Typical Applications section). To add this small, inexpensive 10pF capacitor will greatly reduce the output voltage ripple. Diode Selection For most G5111 applications, the high switching frequency requires a high-speed rectifier Schottky diodes, such as the Motorola MBR0530 (0.5A, 30V) with their low forward voltage drop and fast switching speed, are Typical Applications Boost Converter L1 4.7H SEPIC Converter 5V 50mA VIN 2.5V to 4.2V VCC VCC SW G5111 SHDN GND D1 3.3V 60mA VIN 2.5V to 4.2V SW L2 10H R1 390k C1 4.7F C3 1F L1 10H D1 R1 470k G5111 C2 22F SHDN FB C1 4.7F R2 120k GND C2 22F FB R2 270k L1,L2:MURATA LQH3C100K24 D1:MOTOROLA MBR0520 L1:MURATA LQH3C4R7M24 D1:MOTOROLA MBR0520 TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Oct 02, 2002 6 G5111 Global Mixed-mode Technology Inc. White LED Driver L1 10H/0.5A D1 VBAT 2.5V~5.5V MBR0530 C1 4.7F C2 1F SW VCC D2(Optional) 27V G5111 ON/OFF Control FB SHDN GND R2 120k_1% R3 VBIAS(+3.3V) R1 30_1% 308k_1% PWM Dim R4 660k_1% Dimming Ratio>50:1 Drive 2~8 White LEDs PWM Dimming Control VH=3.3V VL=0V Freq=160~240Hz TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Oct 02, 2002 7 G5111 Global Mixed-mode Technology Inc. Package Information C D L E H 1 e1 e A A2 A1 b Note: 1. 2. 3. 4. Package body sizes exclude mold flash protrusions or gate burrs Tolerance 0.1000 mm (4mil) unless otherwise specified Coplanarity: 0.1000mm Dimension L is measured in gage plane SYMBOLS A A1 A2 b C D E e e1 H L 1 DIMENSIONS IN MILLIMETERS MIN NOM MAX 1.00 0.00 0.70 0.35 0.10 2.70 1.40 --------2.60 0.37 1 1.10 ----0.80 0.40 0.15 2.90 1.60 1.90(TYP) 0.95 2.80 -----5 1.30 0.10 0.90 0.50 0.25 3.10 1.80 --------3.00 ----9 Taping Specification Feed Direction SOT23-5 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: 1.1 Oct 02, 2002 8