WD1042E-5/TR

WD1042 WD1042 1.5MHz, 1.0A, Step-down DC-DC Converter Http//:www.sh-willsemi.com Descriptions The WD1042 is a high efficiency, synchronous step down DC-DC converter optimized for battery powered portable applications. It supports up to 1.0A output current. With a wide input voltage range of 2.5V to 5.5V, the device supports applications powered by single Li-ion battery with extended voltage range, two and SOT-23-5L three alkaline cell, 3.3V and 5V input voltage range. The WD1042 operates at 1.5MHz fixed switching frequency with Pulse-Width-Modulation (PWM) and enters FB VIN 5 4 Pulse-Skipping-Modulation (PSM) operation at light load current to maintain high efficiency over the entire load current range. 1 2 3 The switching frequency is internally set at 1.5MHz, EN GND SW allowing the use of tiny surface mount inductor and input/output capacitors. Low output voltage is easily supported with the 0.6V feedback reference voltage. Pin configuration (Top view) The WD1042 is available in SOT-23-5L package. Standard product is Pb-free and Halogen-free. 1042 DEYW Features ⚫ Input voltage range : 2.5~5.5V ⚫ Continue output current : 1.0A ⚫ Switching frequency : 1.5MHz (Typ.) ⚫ Efficiency : Up to 92% ⚫ Feedback reference voltage : 0.6V ⚫ 100% duty cycle for low dropout operation Y = Year code ⚫ Adjustable Output Voltage W = Week code 1042 = Device code DE = Special code Marking Applications ⚫ IPC ⚫ PADs ⚫ STBs ⚫ DSCs Will Semiconductor Ltd. Device Package Shipping WD1042E-5/TR SOT-23-5L 3000/Reel&Tape Order information 1 Feb,2018 - Rev. 1.0 WD1042 Typical Applications L1: 2.2uH Vin:2.5-5.5V VIN Cin 10uF SW WD1042 EN R1 120K C1 22pF Cout 22uF FB R2 60K GND Fig1 Schematic Diagram Pin Descriptions Pin Name Pin Number Pin Description EN 1 Enable Control. Pull high to turn on. Do not leave it floating GND 2 Ground pin. SW 3 Inductor pin. VIN 4 Input pin. Decouple this pin to GND with at least 10 uF ceramic Cap. FB 5 Feedback pin. Connected to the feedback resistor for adjustable version or VOUT for fix output version Block Diagram VIN U.V.L.O SW Currrent Limit & Feedback PWM Comp. Logic Buffer Driver U.V.L.O Comp. Ramp Wave Generator GND PWM\PSM Selector EN Control Logic Verf 0.6V With Soft Start Error Amp. FB Vref 0.6V Phase Compesation OTP Will Semiconductor Ltd. 2 Feb,2018 - Rev. 1.0 WD1042 Absolute Maximum Ratings Parameter Symbol Value Unit VIN -0.3～6.0 V EN, FB pin voltage range - -0.3～VIN V SW pin voltage range (DC) - -0.3～VIN V PD 0.5 W RθJA 250 oC/W Junction temperature TJ 150 oC Lead temperature(Soldering, 10s) TL 260 oC Operating ambient temperature Topr -40 ~ 85 oC Storage temperature Tstg -55 ~ 150 oC HBM 4000 V CDM 2000 V VIN pin voltage range Power Dissipation – SOT-23-5L (Note 1) Junction to Ambient Thermal Resistance – SOT-23-5L (Note 1) ESD Ratings These are stress ratings only. Stresses exceeding the range specified under “Absolute Maximum Ratings” may cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability. Note 1: Surface mounted on FR-4 Board using 1 square inch pad size, dual side, 1oz copper Will Semiconductor Ltd. 3 Feb,2018 - Rev. 1.0 WD1042 Electronics Characteristics (Ta=25oC, VIN=3.6V, VEN=VIN, unless otherwise noted) Parameter Input Voltage Range VIN Under Voltage Lockout Threshold Standby Supply Current Shutdown Supply Current Feedback reference Voltage Line Regulation Symbol Conditions Min. VIN VUVLO IQ ISHDN VFB △LINE Typ. 2.5 Max. Units 5.5 V Rising 2.4 Falling 2.3 VFB = 105%, IOUT = 0A 40 VEN = 0V 0.2 1 uA 0.60 0.612 V Vin=Vout(nom)+1 V 0mA≤IOUT≤250MA 0.588 2.5 V uA VIN = 2.5V to 5.5V 0.15 %/V Inductor Limit Current ILIM VIN = 3.6V, VOUT = 90%*VOUT 1.95 A Oscillator Frequency fOSC VFB or VOUT in regulation 1.5 MHz RDS(ON) of P-Channel FET RPFET ISW = 100mA 250 mΩ RDS(ON) of N-Channel FET RNFET ISW = −100mA 100 mΩ Feedback Leakage Current IFB SW Leakage Current ILSW EN Rising Threshold VENH EN falling Threshold VENL EN Leakage Current IEN VIN = 5.5V, VSW = 0V or 5.5V ±30 nA ±1 uA 1.4 V VIN = 5.5V, VEN = 0V or VIN 0.4 V 1 uA Max Duty Cycle 100 % Soft Start Time 700 uS 6.0 V 5.9 V 155 oC 30 oC Input OVP Shutdown VOVP Over Temperature Protection TOTP Rising Falling 5.6 OTP Hysteresis Will Semiconductor Ltd. 4 Feb,2018 - Rev. 1.0 WD1042 100 100 80 80 Efficiency(%) Efficiency(%) Typical Characteristics (Ta=25oC, VIN=3.6V, unless otherwise noted) 60 40 VOUT=1.8V VIN=2.7V VIN=3.6V VIN=5.5V 20 0 0 200 400 600 800 60 40 VOUT=0.6V VIN=2.7V VIN=3.6V VIN=5.5V 20 0 1000 0 200 Output Current(mA) 400 600 800 1000 Output Current(mA) 1.88 0.63 0.62 1.84 0.61 1.80 Vout(V) VOUT(V) 0.60 1.76 1.72 0.59 0.58 0.57 1.68 VOUT=1.8V 1.64 VIN=3.6V 0 100 200 VIN=2.7V VIN=3.6V 0.55 VIN=5.5V 1.60 VOUT=0.6V 0.56 VIN=2.7V 300 400 500 600 700 800 900 0.54 1000 VIN=5.5V 0 100 200 Output Current (mA) 300 400 500 600 700 800 900 1000 Output Current (mA) 1.89 0.62 1.86 0.61 1.83 Vout(V) Vout(V) 1.80 1.77 1.74 1.71 1.65 -50 0.59 VOUT=0.6V,IOUT=0mA VOUT=1.8V,IOUT=0mA 0.58 VIN=2.7V 1.68 0.60 VIN=2.7V VIN=3.6V VIN=3.6V VIN=5.5V VIN=5.5V -25 0 25 50 75 100 0.57 -50 125 o 0 25 50 75 100 125 o Temperature ( C) Will Semiconductor Ltd. -25 Temperature ( C) 5 Feb,2018 - Rev. 1.0 WD1042 0.10 0.09 1.65 Shutdown Current(uA) Oscillator Frequency(MHz) 1.70 1.60 1.55 1.50 1.45 1.40 VOUT=1.8V IOUT=1000mA 1.35 1.30 2.5 3.0 3.5 4.0 4.5 5.0 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 EN=0V 0.00 2.5 5.5 3.0 3.5 Input Voltage (V) Oscillator Frequency(MHz) Quiescent Current(uA) 5.0 5.5 1.8 59 58 57 56 55 54 52 2.5 4.5 Input Voltage (V) 60 53 4.0 EN=3.0V VOUT=1.8V 3.0 3.5 4.0 4.5 5.0 1.7 1.6 1.5 1.4 1.3 VOUT=1.8V,IOUT=1000mA VIN=2.7V VIN=3.6V VIN=5.5V 1.2 -50 5.5 -25 0 25 50 75 100 125 o Input Voltage (V) Temperature ( C) Oscillator Frequency(MHz) 1.8 1.7 1.6 1.5 1.4 VOUT=0.6V,IOUT=1000mA 1.3 VIN=2.7V VIN=3.6V VIN=5.5V 1.2 -50 -25 0 25 50 75 100 125 o Temperature ( C) Will Semiconductor Ltd. 6 Feb,2018 - Rev. 1.0 WD1042 VIN=3.6V, VO=1.8V，EN=3.6V , IO=1A, EN On VIN=3.6V, VO=1.8V，EN=3.6V , IO=1A, EN Off Load Transient Response Load Transient Response VIN=5V,VO=1.8V,EN=3.6V,IO=1mA-1A Ripple : VIN=5V, VO=1.8V，EN=3.6V Will Semiconductor Ltd. IO=1A VIN=5V,VO=0.6V,EN=5V,IO=1mA-1A VIN=3.6V, VO=1.8V，EN=3.6V 7 VOUT short Feb,2018 - Rev. 1.0 WD1042 Operation Informations goes into shutdown. In this mode, the high-side and low-side MOSFET are turned off. PWM Control Mode . The WD1042 step-down converter operates with typically 1.5MHz fixed-frequency pulse width Dropout Operation modulation (PWM) at moderate to heavy load The device starts to enter 100% duty-cycle mode currents. Both the main P-channel MOSFET and once the input voltage comes close to the nominal synchronous N-channel MOSFET switches are output voltage. In order to maintain the output internal. During PWM operation, the converter uses voltage, the main switch is turned on 100% for one a current-mode control scheme to achieve good line or more cycles. The output voltage will then be and load transient response. At the beginning of determined by the input voltage minus the voltage each clock cycle initiated by the clock signal, the drop across the P-channel MOSFET and the main switch is turned on. The current flows from the inductor. input capacitor via the main switch through the inductor to the output capacitor and load. During this phase, the current ramps up until the PWM Shutdown Mode comparator trips and the control logic turn off the Drive EN to GND to place the WD1042 in shutdown switch. prevents mode. In shutdown mode, the reference, control shoot-through current, the synchronous switch is After a dead time, which circuit, main switch, and synchronous switch turn off turned on and the inductor current ramps down. The and the output becomes high impedance. Input current flows from the inductor and the output current falls to 0.1μA (Typ.) during shutdown mode. capacitor to the load. It returns back to the inductor through the synchronous switch. Over Temperature Protection (OTP) The next cycle is initiated by the clock signal again As soon as the junction temperature (TJ) exceeds turning off the synchronous switch and turning on 165oC the main switch. shutdown. In this mode, the high-side and low-side (Typ.), the device goes into thermal MOSFET are turned off. Pulse Skipping Mode (PSM) At light loads, the inductor current may reach zero or reverse on each pulse. The synchronous switch is turned off by the current reversal comparator, IRCMP, and the switch voltage will ring. This is discontinuous mode operation, and is normal behavior for the switching regulator. At very light loads, the WD1042 will automatically skip pulses in pulse skipping mode (PSM) operation to maintain output regulation. Short-Circuit Protection When the output is shorted to ground, the device Will Semiconductor Ltd. 8 Feb,2018 - Rev. 1.0 WD1042 Application Informations External component selection for the application circuit depends on the load current requirements. I LPK = I LOAD ( MAX ) + I L 2 Inductor Core Selection Certain tradeoffs between different performance Different core materials and shapes will change the parameters can also be made. size/current and price/current relationship of an inductor. Toroid or shielded pot cores in ferrite or Output Voltage Setting The output voltage can be calculated as: VOUT R1   = 0.6  1 +   R2  permalloy materials are small and don’t radiate much energy, but generally cost more than powdered iron core inductors with similar electrical characteristics. The choice of which style inductor to use often depends more on the price vs. size requirements and any radiated field EMI The external resistive divider is connected to the requirements than on what the WD1042 requires to output. To minimize the current through the operate. feedback divider network, R1 should be larger than 100kΩ. The sum of R1 and R2 should not exceed 1 MΩ, to keep the network robust against noise. An external feed forward capacitor CFWD, is required for optimum load transient response. The value of CFWD should be in the range between 22pF and 33pF. Route the FB line away from noise sources, such as the inductor or the SW line. Inductor Selection The WD1042 high switching frequency allows the use of a physically small inductor. The inductor ripple current is determined by  V  V I L = OUT 1 − OUT  ( f )( L)  VIN  Input Capacitor Selection Capacitor ESR is a major contributor to input ripple in high-frequency DC-DC converters. Ordinary aluminum electrolytic capacitors have high ESR and should be avoided. Low-ESR tantalum or polymer capacitors are better and provide a compact solution for space constrained surface mount designs. Ceramic capacitors have the lowest overall ESR. The input filter capacitor reduces peak currents and noise at the input voltage source. Connect a low ESR bulk capacitor (2.2μF to 10μF) to the input. Select this bulk capacitor to meet the input ripple requirements and voltage rating rather than capacitance value. Use the following equation to calculate the maximum RMS input current: Where △IL is the peak-to-peak inductor ripple I RMS = current and f is the switching frequency. The inductor peak-to-peak current ripple is typically set to be 40% of the maximum dc load current. Using this guideline and solving for L, L=  VOUT  VOUT 1 −  f (40% I LOAD ( MAX ) )  VIN  It is important to ensure that the inductor is capable of handling the maximum peak inductor current, ILPK, determined by Will Semiconductor Ltd. I OUT VOUT  (VIN − VOUT ) VIN Output Capacitor Selection Ceramic capacitors with low-ESR values have the lowest output voltage ripple and are recommended. At nominal load current, the device operates in PWM mode, and the RMS ripple current is calculated as: 9 Feb,2018 - Rev. 1.0 WD1042 4. VOUT VIN 1 = VOUT   L f 2 3 1− I RMSCout Place the feedback resistors as close as possible to the FB pin to prevent noise pickup. 5. FB, At nominal load current, the device operates in PWM mode, and the overall output voltage ripple is the sum of the voltage spike caused by the output Avoid routing high impedance traces, such as near the high current traces and components or near the switch node (SW). 6. If high impedance traces are routed near high current and/or the SW node, place a ground capacitor ESR plus the voltage ripple caused by plane shield between the traces. charging and discharging the output capacitor: VOUT  VIN  1 V = VOUT   + ESR  L f 8  C  f OUT   1− At light load currents, the converter operates in pulse skipping mode, and the output voltage ripple is dependent on the capacitor and inductor values. Larger output capacitor and inductor values minimize the voltage ripple in PSM operation and tighten dc output accuracy in PSM operation. PC Board Layout Considerations WD1042 PCB Suggest Layout (Demo) A good circuit board layout aids in extracting the most performance from the WD1042. Poor circuit layout degrades electromagnetic the output interference ripple and (EMI) the or electromagnetic compatibility (EMC) performance. The evaluation board layout is optimized for the WD1042. Use this layout for best performance. If this layout needs changing, use the following guidelines: 1. Use separate analog and power ground planes. Connect the sensitive analog circuitry (such as voltage divider components) to analog ground; connect the power components (such as input and output bypass capacitors) to power ground. Connect the two ground planes together near the load to reduce the effects of voltage dropped on circuit board traces. Locate CIN as close to the VIN pin as possible, and use separate input bypass capacitors for the analog. 2. Route the high current path from CIN, through L, to the SW and PGND pins as short as possible. 3. Keep high current traces as short and as wide as possible. Will Semiconductor Ltd. 10 Feb,2018 - Rev. 1.0 WD1042 PACKAGE OUTLINE DIMENSIONS SOT-23-5L D θ b K L M E E1 (Ⅰ) (Ⅱ) c e e1 A A1 SIDE VIEW A2 TOP VIEW SIDE VIEW Symbol Dimensions in Millimeters Min. Typ. Max. A - - 1.45 A1 0.00 - 0.15 A2 0.90 1.10 1.30 b 0.30 0.40 0.50 c 0.10 - 0.21 D 2.72 2.92 3.12 E 2.60 2.80 3.00 E1 1.40 1.60 1.80 e 0.95 BSC e1 1.90 BSC L 0.30 0.45 0.60 M 0.10 0.15 0.25 K 0.00 - 0.25 θ 0° - 8° Will Semiconductor Ltd. 11 Feb,2018 - Rev. 1.0 WD1042 TAPE AND REEL INFORMATION Reel Dimensions RD Reel Dimensions Tape Dimensions W P1 Quadrant Assignments For PIN1 Orientation In Tape Q1 Q2 Q1 Q2 Q3 Q4 Q3 Q4 RD Reel Dimension W Overall width of the carrier tape P1 Pitch between successive cavity centers Pin1 Pin1 Quadrant Will Semiconductor Ltd. User Direction of Feed 7inch 13inch 1 8mm 12mm 16mm 2mm 4mm 8mm Q1 Q2 Q3 12 Q4 Feb,2018 - Rev. 1.0