FAN5336 tm 1.5MHz Boost Regulator with 33V Integrated FET Switch Features Description ■ 1.5MHz Switching Frequency The FAN5336 is a high-efficiency, low-noise, fixed-frequency PWM, current-mode, DC-DC boost regulator. It is designed for small LCD bias supply and white LED backlight supply applications. Depending on the application, a FAN5336 regulator can output up to 33V at up to 50mA output current. With output voltage up to 21V, the output current can be up to 100mA. FAN5336 can be used for power conversion as low as 9V output voltage. ■ Low Noise ■ Adjustable Output Voltage ■ Up to 1.5A Peak Switch Current ■ Low Shutdown Current: <1µA ■ Cycle-by-Cycle Current Limit ■ Over-Voltage Protection at the Feedback Pin ■ Fixed-Frequency PWM Operation A current-mode control loop has a fast transient response that provides excellent load regulation within 0.2% of output voltage. The FAN5336 switches at fixed 1.5MHz frequency, allowing the use of small, low-cost external components. Constant frequency switching results in low input noise and small output capacitors. FAN5336 provides cycle-by-cycle current limiting up to 1.5A peak current. ■ Soft-Start Capability ■ Internal Compensation ■ Thermal Shutdown ■ Excellent Load Regulation: 0.2% ■ Low Ripple ■ 6-Lead 3x3mm MLP The FAN5336 may be used to drive a serial flash LED with up to 100mA current at 21V for a maximum of 400ms on-time and 10% duty cycle. Applications ■ Portable Displays ■ Mobile Phone / Smart Phone LED Backlights A low-EMI mode reduces interference and radiated electromagnetic energy caused by the ringing of the inductor. ■ Display Bias ■ PDA, DVD, Camcorder Backlights Additional features include thermal shutdown, over-voltage protection, cycle-by-cycle current limit, low ripple, and soft-start support. ■ Pager and Cordless Phone Displays ■ Portable Medical Diagnostic Equipment ■ Remote Controls The device is available in a 3x3mm 6-lead MLP, 0.8mm thickness package. ■ MP3 or PMP or DSC Players ■ Serial Flash LED Drivers Application Diagram D1 L1 VIN VOUT 6.8µH CIN 10µF SW 6 1 V IN 2 3 ON OFF COUT P1 GND SHDN CF R1 4.7µF 180pF NC 5 FB 4 R2 Figure 1. Typical Application Diagram © 2004 Fairchild Semiconductor Corporation FAN5336 Rev. 1.0.1 www.fairchildsemi.com FAN5336 — 1.5MHz Boost Regulator with 33V Integrated FET Switch April 2007 Part Number Package Temperature Range Pb-Free Packing Method FAN5336MPX 6-Lead 3x3mm MLP -40°C to +85°C Yes Tape and Reel 6-Lead 3x3mm UMLP -40°C to +85°C Yes Tape and Reel FAN5336UMPX Pin Assignments VIN 1 6 SW GND 2 5 NC SHDN 3 4 FB P1 Figure 2. 6-Lead, 3x3mm MLP (Top View) Pin Descriptions Pin # Name P1 GND 1 VIN 2 GND 3 SHDN 4 FB Feedback Pin. Feedback node that connects to an external voltage divider. 5 NC No Connect. 6 SW Switching Node. © 2004 Fairchild Semiconductor Corporation FAN5336 Rev. 1.0.1 Description Analog and Power Ground. P1 must be soldered to the PCB ground. Input Voltage Pin. Ground. Shutdown Control Pin. Logic HIGH enables, logic LOW disables the device. www.fairchildsemi.com 2 FAN5336 — 1.5MHz Boost Regulator with 33V Integrated FET Switch Ordering Information Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. Symbols VIN Parameter Min. VIN to GND Max. Unit 6.0 V FB, SHDN to GND -0.3 VIN + 0.3 V SW to GND -0.3 35 V TL Lead Soldering Temperature (10 seconds) 300 °C TJ Junction Temperature 150 °C TSTG Storage Temperature ΘJA Thermal Resistance ESD Electrostatic Discharge Protection Level(1) -55 HBM 2 CDM 1 150 °C 265 °C/W kV Note: 1. Using EIA/JESD22A114B (Human Body Model) and EIA/JESD22C101-A (Charge Device Model). Recommended Operating Conditions The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend exceeding them or designing to absolute maximum ratings. Symbols VIN VOUT TA COUT Parameter Min. Input Voltage Typ. 2.7 Output Voltage 9 Ambient Operating Temperature -40 2.2(2) Output Capacitance 25 Max. Unit 5.5 V 33 V 85 °C 10 µF Note: 2. This load capacitance value is required for loop stability. Tolerance, temperature variation, and voltage dependency of the capacitance must be considered. Typically a 4.7µF ceramic capacitor is required to achieve the specified value at VOUT = 33V. © 2004 Fairchild Semiconductor Corporation FAN5336 Rev. 1.0.1 www.fairchildsemi.com 3 FAN5336 — 1.5MHz Boost Regulator with 33V Integrated FET Switch Absolute Maximum Ratings VIN = 2.7 to 5.5V, VSHDN = VIN, and TA = -40°C to +85°C. Typical values are at TA = 25°C and VIN = 3.6V unless otherwise noted. Parameter Conditions Min. Typ. Max. Units +3 % 1.8 A Refer to the Test Circuit in Figure 3. Output Voltage Accuracy VIN = 3.6V -3 Switch Current Limit VIN = 3.2V 1.1 1.5 VOUT = 21V ±5%, VIN ≥ 3.0V 75 Load Current VOUT = 21V ±5%, VIN ≥ 3.2V, TON < 0.4s, TOFF > 3.6s 100 Switch On-Resistance VIN = 3.6V 0.4 No Switching, VFB ≥ 1.27V 0.7 Switching 6.5 VSHDN = 0V 0.1 Quiescent Current OFF Mode Current Device ON Shutdown Threshold mA mA 3.0 µA 1.5 Device OFF V 0.5 Shutdown Pin Bias Current VSHDN = 0V or VSHDN = 5.5V Feedback Voltage (VREF) ILoad = 0mA, VIN = 3.6V at 25°C 1.205 Feedback Pin Bias Current Feedback Voltage Line Regulation(3) Ω 3.0V < VIN < 5.5V, ILOAD = 0mA 1 10 nA 1.230 1.255 V 1 10 nA 0.4 1.5 %/V 1.85 MHz Switching Frequency 1.15 1.50 Maximum Duty Cycle 87 93 Start-up Turn-on Time VIN = 3.0V, IOUT = 75mA 3.0 Load Regulation VIN = 3.6V, 1mA < ILoad <100mA 0.2 Switch Leakage Current No Switching, VIN = 5.5V % 5.0 ms 1 µA % Note: ΔV OUT 1 3.The line regulation is calculated based on ------------------ × -------------- . ΔV IN V OUT Test Circuit VIN BAT54 L 2.7V to 5.5V VOUT 6.8µH CIN 10µF IN 3 ON OFF GND SHDN CF SW 6 1 V 2 COUT P1 R1 160k R2 10k 4.7µF 180pF NC 5 FB 4 Figure 3. Test Circuit © 2004 Fairchild Semiconductor Corporation FAN5336 Rev. 1.0.1 www.fairchildsemi.com 4 FAN5336 — 1.5MHz Boost Regulator with 33V Integrated FET Switch Electrical Characteristics VIN=3.6V, VOUT=21V, TA=25°C, CIN=10µF, COUT=4.7µF, L=6.8µH, CF=180pF, R1=160kΩ, R2=10kΩ unless otherwise noted. Load Regulation 21.5 Output Voltage (V) Efficiency (%) Efficiency vs. Load Current 90 85 80 75 70 65 60 55 50 45 40 Vin=2.7V Vin=3.6V 21.3 21.1 20.9 Vin=2.7V 20.7 Vin=3.6V Vin=5.5V 10 20 30 40 50 60 70 80 90 Vin=5.5V 20.5 100 10 Load Current (mA) 20 30 40 50 60 70 80 90 100 Load Current (mA) Figure 4. Efficiency vs. Load Current Figure 5. Load Regulation Output Voltage(V) Line Regulation at No Load 22 21.8 21.6 21.4 21.2 21 20.8 20.6 20.4 20.2 20 2.5 3 3.5 4 4.5 5 5.5 Battery Voltage(V) Figure 6. Line Regulation at No Load Figure 7. 100mA Load Current Operation Figure 8. Start-up Response Figure 9. Load Transient Response © 2004 Fairchild Semiconductor Corporation FAN5336 Rev. 1.0.1 www.fairchildsemi.com 5 FAN5336 — 1.5MHz Boost Regulator with 33V Integrated FET Switch Typical Performance Characteristics FAN5336 — 1.5MHz Boost Regulator with 33V Integrated FET Switch Block Diagram VIN SHDN 3 SW 6 1 Shutdown Circuitry FB + Comp - 1.15 x VREF Thermal Shutdown FB 4 Error Amp + R + Comp - R Ramp Generator Q R Current Limit Comparator - Driver n S + Oscillator + Amp Reference 0.03 Soft-Start 5 NC 2 GND Figure 10. Block Diagram Circuit Description The FAN5336 is a pulse-width modulated (PWM) current-mode boost converter. The FAN5336 improves the performance of battery-powered equipment by significantly minimizing the spectral distribution of noise at the input caused by the switching action of the regulator. To facilitate effective noise filtering, the switching frequency was chosen to be high, 1.5MHz. An internal soft-start circuit minimizes in-rush currents. The timing of the soft-start circuit was chosen to reach 95% of the nominal output voltage within 5ms following an enable command when VIN = 2.7V, VOUT = 21V, ILOAD = 35mA and COUT (EFFECTIVE) = 4.7µF. comparator consists of the sum of two components: the amplified control signal received from the 30mΩ current sense resistor and the ramp generator voltage derived from the oscillator. The oscillator sets the latch and the latch turns on the FET switch. Under normal operating conditions, the PWM comparator resets the latch and turns off the FET, terminating the pulse. Since the comparator input contains information about the output voltage and the control loop is arranged to form a negative feedback loop, the value of the peak inductor current is adjusted to maintain regulation. Every time the latch is reset, the FET is turned off and the current flow through the switch is terminated. The latch can be reset by other events as well, such as overcurrent and over-voltage conditions. Over-current condition is monitored by the current-limit comparator, which resets the latch and turns off the switch within each clock cycle. An over-voltage condition at the feedback (FB) pin is detected by a fast comparator limiting the duty cycle in a similar manner to over-current monitoring. The device architecture is a current-mode controller with an internal sense resistor connected in series with the Nchannel switch. The voltage at the feedback pin tracks the output voltage at the cathode of the external Schottky diode (shown in the test circuit in Figure 3). The error amplifier amplifies the difference between the feedback voltage and the internal bandgap reference. The amplified error voltage serves as a reference voltage to the PWM comparator. The inverting input of the PWM © 2004 Fairchild Semiconductor Corporation FAN5336 Rev. 1.0.1 www.fairchildsemi.com 6 Setting the Output Voltage Table 3: Recommended Capacitors Cap. Value Vendor Part Number The internal feedback voltage reference (VREF) is 1.23V (typical). The output voltage is divided by a resistor divider, R1 and R2 to the FB pin. The output voltage is calculated by: V OUT R 1⎞ ⎛ = V REF ⎜⎜ 1 + -------⎟⎟ R2 ⎝ ⎠ 10µF Murata GRM31CR70J106KA01B 4.7µF Murata GRM32RR61E475KC31B A feedforward capacitor (CF ) is required for stability. The recommended value is around 180pF. EQ 1 Diode Selection The external diode used for rectification is usually a Schottky diode. Its average forward current should exceed the load current and its reverse voltage maximum ratings should exceed the voltage at the output of the converter. A barrier Schottky diode, such as BAT54, is preferred due to its low reverse current over the temperature range. The maximum output current depends on the output voltage settings. Table 1 provides the recommended voltage for several steady-state configurations: Table 1: Recommended Voltages ILOAD Max. R1 (kΩ) for VOUT (V) (mA) R2 = 10kΩ VIN Range (V) 9 50 63.2 2.7 to 5.5 9 170 63.2 2.9 to 4.7 12 125 87.5 2.7 to 5.5 21 75 160 3.6 to 5.5 33 50 258 4.0 to 5.5 33 10 258 2.7 to 5.5 Care should be taken to avoid any short circuit of VOUT to GND, even with the IC disabled, since the diode can be instantly damaged by the excessive current. Flash LED Driver The FAN5336 may be used to drive a serial flash LED with up to 100mA current at 21V for a maximum of 400ms on-time and 10% duty cycle. Inductor Selection Thermal Shutdown The inductor parameters directly related to device performance are saturation current and DC resistance. The FAN5336 operates with a typical inductor value of 6.8µH. The lower the DC resistance, the higher the efficiency. Balancing inductor size, cost, and overall efficiency allows optimum choice. When the die temperature exceeds 150°C, a reset occurs and remains in effect until the die cools to 130°C, when the circuit is allowed to restart. PCB Layout Recommendations The inherently high peak currents and switching frequency of power supplies require careful PCB layout design. For best results, use wide traces for high-current paths and place the input capacitor, the inductor, and the output capacitor as close as possible to the integrated circuit terminals. The resistor divider that sets the output voltage should be routed away from the inductor to avoid RF coupling. A four-layer PCB, with at least one ground plane connected to Pin 2 of the IC, is recommended. The ground plane acts as an electromagnetic shield to reduce EMI and parasitic coupling between components. The inductor saturation current should be rated around 1.5A, which is the threshold of the internal current limit circuit. This limit is reached only during the start-up and with heavy load conditions. When this occurs, the converter can shift into discontinuous conduction mode due to the automatic turn-off of the switching transistor, resulting in higher ripple and reduced efficiency. Table 2: Recommended Inductors Inductor Value Vendor Part Number 6.8µH 6.8µH TDK SLF7028T6R8M1R3 Murata LQS66C6R8M04 Comment Lower Profile Higher Efficiency Capacitors Selection For best performance, low-ESR input and output capacitors are required. Ceramic capacitors of CIN = 10µF and COUT = 4.7µF, placed as close as possible to the IC pins, are recommended for the lower input and output ripple. The output capacitor voltage rating should be selected according to the VOUT setting. © 2004 Fairchild Semiconductor Corporation FAN5336 Rev. 1.0.1 Figure 11. Recommended PCB Layout www.fairchildsemi.com 7 FAN5336 — 1.5MHz Boost Regulator with 33V Integrated FET Switch Applications Information FAN5336 — 1.5MHz Boost Regulator with 33V Integrated FET Switch Mechanical Dimensions Dimensions are in millimeters unless otherwise noted. Figure 12. 6-Lead 3x3 Molded Leadless Package (MLP) © 2004 Fairchild Semiconductor Corporation FAN5336 Rev. 1.0.1 www.fairchildsemi.com 8 Dimensions are in millimeters unless otherwise noted. 2.45 3.0 0.15 C 6 A 2X 4 B 2.10 1.65 3.50 3.0 (0.70) 1 0.15 C 0.95 TYP 3 0.65 TYP 2X 0.6 MAX 0.10 C 0.08 C (0.20) 0.05 0.00 C SEATING PLANE 2.00 PIN #1 IDENT 3 1 0.45 0.20 1.21 0.2 MIN 4 6 0.95 1.90 0.30~0.45 0.10 C A B C 0.05 A. CONFORMS TO JEDEC REGISTRATION MO-229, VARIATION VEEA, DATED 8/2003, EXCEPT THICKNESS B. DIMENSIONS ARE IN MILLIMETERS. C. DIMENSIONS AND TOLERANCES PER ASME Y14.5M, 1994 D. FILENAME AND REVISION: UMLP06Arev1 Figure 12. 6-Lead 3x3 Ultrathin Molded Leadless Package (UMLP) © 2004 Fairchild Semiconductor Corporation FAN5336 Rev. 1.0.1 www.fairchildsemi.com 9 FAN5336 — 1.5MHz Boost Regulator with 33V Integrated FET Switch Mechanical Dimensions FAN5336 — 1.5MHz Boost Regulator with 33V Integrated FET Switch © 2004 Fairchild Semiconductor Corporation FAN5336 Rev. 1.0.1 www.fairchildsemi.com 10