G5114/G5116/G5118 Global Mixed-mode Technology Inc. High Efficiency, Constant Current Output for 8 Series LEDs Driver Features General Description Driving Up to 8 LEDs Auto Trigger/Release OVP Function (G5114/G5118) Input Voltage Range: 1.7V ~ 6.5V Precise Dimming Control Using PWM Signal 50µA No Switching Current Internal 30V Switch With 0.8Ω Rds(on) Soft Start Function Included Up to 85% Efficiency The G5114/G5116/G5118 are high efficiency boost converters with constant current output that drives up to 8 white LEDs. The continuous LED current is set with the FB pin regulated voltage across an external sense resistor (Rs) connected from that pin to ground. A dimming PWM waveform to SHDN pin controls LED average current proportional to its duty makes the brightness of LEDs also proportional to the duty. Low FB regulation voltage and low switch turned on resistance result in high converting efficiency from wide battery voltage range to high LED series voltage. Applications White LED Backlight Display for PDA Pocket PC Smart Phones Handheld Devices Cellular Phones An over-voltage protection prevents device damage while LEDs is open. It is easy to release protection state by just put the load path closed. Ordering Information ORDER NUMBER ORDER NUMBER (Pb free) MARKING TEMP. RANGE PACKAGE G5114T1U G5114T1Uf 5114X -40°C ~ +85°C SOT-23-5 G5116T1U G5118P8U G5116T1Uf G5118P8Uf 5116X G5118 -40°C ~ +85°C -40°C ~ +85°C SOT-23-5 MSOP-8 Pin Configuration SW 1 GND 2 Typical Application Circuit 5 VCC G5114 4 OVP FB 3 VOUT VIN SW 1 GND 2 5 VCC 4.7µF/ 6.3V SW C1 C2 1µF/ 35V 8 LEDs OVP G5118 G5116 PWM Dimming Waveform 4 SHDN FB 3 D1 L1 VIN 2.7V to 4.2V SOT-23-5 FB SHDN GND RS SOT-23-5 VCC 1 8 SW 7 AGND PGND 2 G5118 6 FB N.C. 3 OVP 4 5 SHDN MSOP-8L TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Sep 13, 2004 1 G5114/G5116/G5118 Global Mixed-mode Technology Inc. Absolute Maximum Ratings SW, OVP to GND……….……..…….…..….-0.3V to +35V VCC, SHDN to GND.….......................…...-0.3V to +7V FB to GND.....................….......................…-0.3V to VCC Operating Temperature.….……………...…-40°C to 85°C Junction Temperature.......................…...................125°C Storage Temperature………....……....…..–65°C to 150°C Reflow Temperature (soldering, 10sec)……….....260°C Stress beyond those listed under “Absolute Maximum Rating” may cause permanent damage to the device. Electrical Characteristics (VCC=V SHDN =3.6V, TA=25°C, unless specified) PARAMETER CONDITION MIN Input Voltage Range TYP MAX UNIT V 1.7 --- 6.5 G5114/G5118, Trigger 28 29 30 V G5114/G5118, Release --- --- 25 V OV Pin Input Current G5114/G5118, Vovp = 28V --- 10 15 µA Quiescent Current VFB = 0.3V V SHDN = 0V --- 50 100 µA OV Protection Threshold FB Comparator Trip Point --- 2.4 3 µA 242 250 258 mV ns Switch Off Time VFB = 0V --- 400 --- Switch RDS(ON) ISW = 150mA --- 0.8 1.2 Ω Switch Leakage Current Switch Off, VSW = 30V --- 0.1 5 µA Switch Current Limit 320 400 480 mA SHDN Pin Voltage High 0.9 --- --- V SHDN Pin Voltage Low --- --- 0.25 V Note.1:The G5114/G5116/G5118 are guaranteed to meet performance specifications from 0°C~85°C. Specifications over the -40°C~85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. Block Diagram L1 D1 VOUT VIN C2 C1 SHDN VCC BIAS * SW SHUTDOWN LOGIC OVP** CTRL VOUT LED Series FB + PUMP CONTROL OC DRIVER COMP ERROR COMP en_sw + R2 0.25V TOFF PULSE CONTROL VREF GND * SHDN pin only availiable for G5116/G5118 ** OVP pin only availiable for G5114/G5118 TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Sep 13, 2004 2 G5114/G5116/G5118 Global Mixed-mode Technology Inc. Typical Performance Characteristics (VCC = +3.6V, V SHDN = +3.6V, L=10µH, TA=25°C, unless otherwise noted) Efficiency vs. Output Current Efficiency vs. Input Voltage 90 90 VIN=4.2V 80 VIN-3.6V 75 VIN=2.7V 70 65 IO=20mA 85 Efficiency (%) Efficiency (%) 85 80 75 70 65 6LEDs, CO=1µF 60 6LEDs, CO=1µF 60 0 5 10 15 20 25 1.5 2 2.5 3.5 4 4.5 5 5.5 6 SW RDS_on vs. Temperature 1.5 1.25 1.25 SW RDS_on ( Ω) SW RDS_on ( Ω) SW RDS_on vs. Input Voltage 1.5 1 0.75 0.5 0.25 1 0.75 0.5 0.25 0 0 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 -40 -20 Input Voltage (V) 0 20 40 60 80 100 Temperature (°C) Current Limit vs. Input Voltage Current Limit vs. Temperature 500 600 500 400 Current Limit (mA) Current Limit (mA) 3 Input Voltage (V) Load Current (mA) 300 200 100 400 300 200 100 0 0 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 -40 6.5 Input Voltage (V) -20 0 20 40 60 80 100 Temperature (°C) TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Sep 13, 2004 3 G5114/G5116/G5118 Global Mixed-mode Technology Inc. Typical Performance Characteristics (Continued) OVP Trigger Threshold vs. Input Voltage OVP Trigger Threshold vs. Temperature 35 OVP Trigger Threshold (V) OVP Trigger Threshold (V) 31 30 29 28 27 34 33 32 31 30 29 28 27 26 25 26 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 -40 6.5 -20 0 20 40 60 80 100 Input Voltage (V) Temperature (°C) OVP Release Threshold vs. Input Voltage OVP Release Threshold vs. Temperature 30 OVP Release Threshold (V) OVP Release Threshold (V) 24 23.5 23 22.5 22 29 28 27 26 25 24 23 22 21 20 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 -40 -20 0 LED Current vs. Input Voltage 40 60 80 100 LED Current vs. Duty Cycle 30 25 CO=0.1µF 6LEDs 25 6LEDs 20 20 LED Current (mA) LED Current (mA) 20 Temperature (°C) Input Voltage (V) CO=1µF 15 10 CO=0.1µF 15 10 CO=1µF 5 5 0 0 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 0 10 20 30 40 50 60 70 80 90 100 Duty Cycle (%) Input Voltage (V) TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Sep 13, 2004 4 Global Mixed-mode Technology Inc. G5114/G5116/G5118 Typical Performance Characteristics (Continued) PWM Dimming Efficiency vs. Output Current 90 Efficiency (%) 85 VIN=4.2V 80 75 VIN=3.0V VIN=3.6V 70 65 8LEDs, CO=1µF 60 0 5 10 15 20 25 Load Current (mA) G5118 Inrush Current Waveform OVP Waveform TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Sep 13, 2004 5 Global Mixed-mode Technology Inc. G5114/G5116/G5118 Pin Description PIN NAME G5114 G5116 G5118 SOT-23-5 SOT-23-5 MSOP-8 1 1 8 SW 2 2 2 3 3 6 PGND AGND FB 4 5 SHDN 4 OVP 1 VCC 4 5 5 7 FUNCTION Switch Pin. The drain of the internal NMOS power switch. Connect this pin to inductor. Power Ground Pin. Analog Ground Pin. Feedback Pin. Active Low Shutdown Pin. Tie this pin to logical high to enable the device or tied it to logical low to turn this device off. Internal 1.5MΩ pulled high. Over Voltage Protection Sense Pin. Input Supply Pin. Bypass this pin with a capacitor as close to the device as possible. Function Description Applications Information Operation The G5114/G5116/G5118 are boost converters with NMOS switch embedded. They operate in a PFM scheme with constant peak current control. The operation frequency is up to 1MHz and is determined by the current limit, inductor value, input voltage and minimum off time. The boost cycle is started when FB pin voltage drop below 0.25V as the NMOS switch turns on. During the switch on period, the inductor current ramps up until 400mA 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 provides for load current and also charges output capacitor. It makes the LED current higher and results in larger voltage drop on sense resistor Rs. The cycle stop when FB pin voltage is above 0.25V. Inductor Selection The PFM peak current control scheme of the G5114/ G5116/G5118 is inherently stable. The inductor value does not affect the stability of the regulator. The selected inductor must have a saturation current that meets the maximum peak current of the converter. Another important inductor parameter is the DC resistance. The lower DC resistance has the higher the efficiency of the converter. The current limit function acts as an inherent soft start by controlling the inrush current. Output Capacitor Selection For better output voltage filtering, a low ESR output capacitor is recommended. Ceramic capacitors have a low ESR value, but depending on the application, tantalum capacitors can be used. The selection of the output capacitor value directly influences the output voltage ripple of the converter which also influences line regulation. The larger output voltage ripple, the larger line regulation, which means that the LED current changes if the input voltage changes. If a certain change in LED current gives a noticeable change in LED brightness, depends on the LED manufacturer and on the application. Applications requiring good line regulation ±1%/V (TYP) must use output capacitor values ±1µF. Table 1. Recommended Inductors PART LQH32CN100K1 VALUE(µH) MAX DCR (Ω) VENDOR 10 0.39 MURATA 1 PWM Dimming To control the brightness of the LEDs, use a low frequency PWM waveform to turn G5116/G5118 on for duty 0%~100%. How bright the LEDs at 100% duty are determined by sense resistor Rs. Overvoltage Protection (OVP) OVP is designed to prevent the damage of internal NMOS switch in case the increased impedance of the LED load (include the LED opened). Once the device detects over voltage at the output, the internal NMOS switch is kept off until the output voltage drops below 25V. 972AS-100M 10 0.48 TOKO 960AW-100M 10 0.18 TOKO TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Sep 13, 2004 6 Global Mixed-mode Technology Inc. Table 2. Recommended Output Capacitors PART VALUE (µF) VOLTAGE RATING (V) VENDOR UMK212BJ104MG 0.1 50 Tayo Yuden GMK316BJ105KL 1 35 Tayo Yuden GMK316F475ZG 4.7 35 Tayo Yuden Setting The LED Current The Converter regulates the LED current by regulating the voltage across the current sense resistor (RS). The voltage across the sense resistor is regulated to the internal reference voltage of V(FB)=250mV. The LED Current can be calculated: ILED = Input Capacitor Selection For good input voltage filtering the capacitor value can be increased. Low ESR ceramic capacitors are recommended. A 4.7µF ceramic input capacitor is sufficient for most applications. Table 3. Recommended Input Capacitors PART VALUE (µF) VOLTATE RATING (V) 1 10 Tayo Yuden JMK212BJ475MG 4.7 6.3 Tayo Yuden JMK212BJ106MG 10 6.3 Tayo Yuden Table 4. Recommended Diodes REVERSE VOLTAGE (V) VENDOR MBR0530 30 On Semiconductor = 0.25V RS Layout considerations In all switching power supplies the layout is an important step in the design, especially at high peak currents and switching frequencies. If the layout is not carefully done, the regulator might show noise problems and duty cycle jitter. The input capacitor should be placed as close as possible to the input pin for good input voltage filtering. The inductor and diode must be placed as close as possible to the switch pin to minimize noise coupling into other circuits. Since the feedback pin and network is a high impedance circuit, the feedback network should be routed away from the inductor. Diode Selection To achieve high efficiency a Schottky diode must be used. The current rating of the diode must meet the peak current rating of the converter. Schottky diodes, with their low forward voltage drop and fast switching speed, are best match for the G5114/G5116/G5118. PART VFB RS The current programming method is used when the brightness of the LEDs is fixed or control by a PWM signal applied to the SHDN pin. When using a PWM signal on the SHDN pin, the LED brightness is only dependent on the PWM duty cycle, independent of the PWM frequency or amplitude, which simplifies the systems. VENDOR LMK212BJ105MG G5114/G5116/G5118 TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Sep 13, 2004 7 G5114/G5116/G5118 Global Mixed-mode Technology Inc. Package Information C D L E H θ1 e1 e A A2 A1 b SOT-23-5 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 SYMBOL MIN DIMENSIONS IN MILLIMETER NOM MAX A A1 1.00 0.00 1.10 ----- 1.30 0.10 A2 b C D E e 0.70 0.35 0.10 2.70 1.40 ----- 0.80 0.40 0.15 2.90 1.60 1.90(TYP) 0.90 0.50 0.25 3.10 1.80 ----- e1 H L θ1 ----2.60 0.37 0.95 2.80 ------ ----3.00 ----- 1º 5º 9º TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Sep 13, 2004 8 G5114/G5116/G5118 Global Mixed-mode Technology Inc. C E1 E L D θ 12° (4X) A2 y e A A1 b MSOP-8 Package Note: 1. Package body sizes exclude mold flash and gate burrs 2. Dimension L is measured in gage plane 3. Tolerance 0.10mm unless otherwise specified 4. Controlling dimension is millimeter converted inch dimensions are not necessarily exact. 5. Followed from JEDEC MO-137 SYMBOL A A1 A2 b C D E E1 e L y θ MIN. DIMENSION IN MM NOM. MAX. MIN. DIMENSION IN INCH NOM. MAX. 0.81 0.00 0.76 0.28 0.13 2.90 4.80 2.90 ----0.40 ----0º 1.02 ----0.86 0.30 0.15 3.00 4.90 3.00 0.65 0.53 --------- 1.22 0.20 0.97 0.38 0.23 3.10 5.00 3.10 ----0.66 0.10 6º 0.032 0.000 0.030 0.011 0.005 0.114 0.189 0.114 ----0.016 ----0º 0.040 ----0.034 0.012 0.006 0.118 0.193 0.118 0.026 0.021 --------- 0.048 0.008 0.038 0.015 0.009 0.122 0.197 0.122 ----0.026 0.004 6º Taping Specification Feed Direction SOT-23-5 Package Orientation Feed Direction Typical MSOP Package Orientation PACKAGE Q’TY/BY REEL SOT-23-5 MSOP-8 3,000 ea 2,500 ea 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 Sep 13, 2004 9