MA6001

MA6001 MPOWER | Alldatasheet

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Dual 1.5A 1.5MHz Synchronous Buck Converter  GENERAL DESCRIPTION The MA6001 is a dual high-efficiency Pulse-Width-Modulated (PWM) step-down DC-DC converter. It is capable of delivering 1. 5A output current over a wide input voltage range from 2.5V to 5.5V, the MA6001 is ideally suited for portable electronic devices that are powered from 1-cell Li-ion battery or from other power sources within the range such as cellular phones, PDAs and other handheld devices. Two operational modes are available: PWM/Low-Dropout auto-switch and shutdown modes. Internal synchronous rectifier with low R DS(ON) dramatically reduces conduction loss at PWM mode. No external Schottky diode is required in practical application. The MA6001 enters Low-Dropout mode when no rmal PWM cannot provide regulated output voltage by continuously turning on the upper PMOS. The MA6001 enter shutdown mode and consumes less than 0.1μA when EN pin is pulled low. The switching ripple is easily smoothed-out by small package filtering elements due to a fixed operation frequency of 1.5MHz. This along with small TDFN-12L (3x3) package provides small PCB area application. Other features include soft start, lower internal reference voltage with 2% accuracy, over temperature protection, and over current protection.  FEATURES - 2.5V to 5.5V input voltage range - Output Adjustable from 0.6V to VIN - 170/130mΩ Internal Power MOSFET Switch - Stable with Low ESR Output Ceramic Capacitors - Up to 95% Efficiency - Less than 1μA Shutdown Current - 1.5Mhz Switching Frequency - Thermal Shutdown Protection - Current limit and short circuit protections. - Available in TDFN-12L 3x3 Pb-Free Package - Build-in soft start function

 BLOCK DIAGRAM FB1 EN1 VIN1 LX1 GND1Over-Temperature and Short-Circuit Protection FB Soft-Star 0.6V Icomp Isense AMP OSC SLOPE COMP PWM LOGIC NON-OVERLAP CONTROL RESET SET Enable Logic FB2 EN2 VIN2 LX2 GND2Over-Temperature and Short-Circuit Protection FB Soft-Star 0.6V Icomp Isense AMP OSC SLOPE COMP PWM LOGIC NON-OVERLAP CONTROL RESET SET Enable Logic  PIN ASSIGNMENT The package of MA6001 is TDFN-12L (3×3); the pin assignment is given by: GND EN2 NC2 FB2 GND1 LX1 VIN1EN1 NC1 FB1 GND2 LX2 VIN2 (Top View) TDFN-12L (3 x 3) Name Description VIN2 Power Input of Channel 2. LX2 Pin for Switching of Channel 2. GND1,2 Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation. FB1 Feedback of Channel 1. NC1, NC2 No Connection Pin. EN1 Chip Enable of Channel 1 (Active High). VEN1 ≦ VIN1. VIN1 Power Input of Channel 1. LX1 Pin for Switching of Channel 1. FB2 Feedback of Channel 2. EN2 Chip Enable of Channel 2 (Active High). VEN2 ≦ VIN2.

 ORDER/MARKING INFORMATION Order Information Top Marking  ABSOLUTE MAXIMUM RATINGS (at TA=25°C) Characteristics Symbol Rating Unit Supply Input Voltage V IN1/ VIN2 -0.3 to 7 V EN1, FB1, LX1, EN2, FB2 and LX2 Pin Voltage -0.3 to V IN + 0.3 V Power Dissipation, PD @ TA = 25°C PD 1.66 W Lead Temperature (Soldering, 10 sec.) 260 °C Storage Temperature Range T ST -65 to 150 °C Junction Temperature T J 150 °C Thermal Resistance from Junction to case θJC 8.2 °C/W Thermal Resistance from Junction to ambient θJA 60 °C/W Note: θJA is measured with the PCB copper area of approximately 1 in2(Multi-layer). That need connect to exposed pad.  RECOMMENDED OPERATING CONDITIONS Characteristics Symbol Rating Unit Supply Input Voltage V IN 2.5 to 5.5 V Junction Temperature Range T J -40 to 125 °C Ambient Temperature Range T A -40 to 85 °C Note: The device is not guaranteed to function outside its operating conditions.

 ELECTRICAL CHARACTERISTICS (VIN = 5V, VEN = 5V, VOUT = 3.3V, TA=25°C) Characteristics Symbol Conditions Min Typ Max Units Channel 1 and Channel 2 Input Voltage Range V IN 2.5 - 5.5 V Input UVLO UVLO I OUT=0A 1.8 2.2 2.5 V Input OVLO OVLO I OUT=0A - 6.0 - V Quiescent Current (per channel) IQ I OUT=0mA, VFB=1V - 250 350 μA Shutdown Current ISD VEN1= VEN2=0V - 0.1 1 μA Feedback Voltage V FB 0.588 0.600 0.612 V Load Regulation 0A < I OUT<1.5A - 0.6 - % Line Regulation 2.5V<V IN<5.5V - 0.3 - %/V FB Input Current I FB VFB = VIN -50 - 50 nA P-Switch RDS(ON) R DS(ON)_P IOUT= 500mA - 0.17 - Ω N-Switch RDS(ON) (Note1) R DS(ON)_N IOUT= 500mA (Note) - 0.13 - Ω Low Side Discharger - 60 - Ω P-Channel Current Limit I LIM_P 1.7 2.2 - A EN High-Level Input Voltage V EN_H 1.5 - - V EN Low-Level Input Voltage V EN_L - - 0.4 V Oscillator Frequency f OSC LX Pin 1.1 1.5 1.9 MHz Maximum Duty Cycle VFB=0.5V 100 - - % Thermal Shutdown Temperature TSD - 155 - °C Thermal Shutdown Hysteresis TSH - 30 - °C Note: Guarantee by design.

 APPLICATION CIRCUIT ˰1.7V≦VOUT≦4.4 V˱ 1.8V/1.5A GND2 OFF ON GND1 FB1 LX1 EN1 VOUT1 VIN1 200K 100K 10μF 2.2μHVIN2 10μF VIN LX2 FB2 EN2 OFF ON 3.3V/1.5A VOUT2 450k 100K 10μF 2.2μH 10μF 22P 22P option option 300K~50KRang:R4R2, )R4 R3(1VV),R2 R1(1VV FB2OUT2FB1OUT1 +×=+×= ˰1.0V≦VOUT≦1.6V˱ 1.5V/1.5A GND2 OFF ON GND1 FB1 LX1 EN1 VOUT1 VIN1 150K 100K 10μF 2.2μHVIN2 10μF VIN LX2 FB2 EN2 OFF ON 1.2V/1.5A VOUT2 100k 100K 10μF 2.2μH 10μF 22μF 22μF  FUNCTION DESCRIPTIONS Operation MA6001 is a dual channel, monolithic switching mode Step-Down DC-DC converter. It utilizes internal MOSFETs to achieve high efficiency and can generate very low output voltage by using internal reference at 0.6V. It operates at a fixed switching frequency, and uses the slope compensated current mode architecture. This Step-Down DC-DC Converter supplies 1.5A output current by ea ch channel with input voltage range from 2.5V to 5.5V.

Slope compensated current mode PWM control provides stable switching and cycle-by-cycle current limit for excellent load and line responses and protection of the internal main switch (P-CH MOSFET) and syn chronous rectifier (N-CH MOSFET). During normal operation, the internal P-CH MOSFET is turned on for a certain time to ramp the inductor current at each rising edge of the in ternal oscillator, and switched off when the peak inductor current is above the erro r voltage. The current comparator, I COMP, limits the peak inductor current. When the main switch is off, the synchronous rectifier will be turned on immediately and stay on until either the induc tor current starts to reverse, beginning of the next clock cycle.  APPLICATION INFORMATION Setting the Output Voltage output version. The external resistor sets the output voltage according to the following equation: 31 (6 . 0),2 11 (6 . 0 21 R RVVR RVV OUTOUT +×=+×= Table 1 Resistor select for output voltage setting VOUT R2/R4 R1/R3 1.0V 150K 100K 1.2V 100K 100K 1.5V 100K 150K 1.8V 100K 200K 2.5V 150K 470K 3.3V 100K 450K Inductor Selection For most designs, the MA6001 operates with inductors of 2.2µH to 3.3µH. Low inductance values are physically smaller but require faster switching, which results in some efficiency loss. The inductor value can be derived from the following equation: ( ) fIV VVVL OSCLIN OUTINOUT −×= Δ Where is inductor Ripple Current. Large va lue inductors lower ripple current and small value inductors result in high ripple currents. Choose inductor ripple current approximately 20% of the maximum load current 1500mA, ΔIL=400mA. For optimum voltage-positioning load transie nts, choose an inductor with DC series resistance in the 50m Ω to 150m Ω range. For higher efficiency at heavy loads (above

200mA), or minimal load regulation (but some transient overshoot), the resistance should be kept below 100m Ω. The DC current rating of the indu ctor should be at least equal to the maximum load current plus half the ripple current to prevent core saturation (1500mA+200mA). Compensation Capacitor Selection The compensation capacitors for increasing phase margin provide additional stability. It is required 22pF, Please refer to Demo Board Schematic to design. Input Capacitor Selection The input capacitor reduces the surge current drawn from the input and switching noise from the device. The input capacitor im pedance at the switching frequency shall be less than input source impedance to prevent high frequency switching current passing to the input. A low ESR input capacitor sized for maximum RMS current must be used. Ceramic capacitors with X5R or X7R dielec trics are highly recommended because of their low ESR and small temperature coefficients. A 4.7µF ceramic capacitor for most applications is sufficient. Output Capacitor Selection The output capacitor is required to be 10~47uF to keep the output voltage ripple small and to ensure regulation loop stability. The output capacitor must have low impedance at the switching frequency. Ceramic capacitors with X5R or X7R dielectrics are recommended due to their low ESR and high ripple current. Thermal Considerations The maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate of surroundings airflow and temperature difference between junctions to ambient. The maximum power dissipation can be calculated by following formula: PD(MAX) = ( TJ(MAX) - TA ) /θJA Where TJ(MAX) is the maximum junction temperature, T A is the ambient temperature and the θJA is the junction to ambient thermal resistance. For recommended operating conditions specification of MA 6001 DC/DC converter, where T J(MAX) is the maximum junction temperature of the die and TA is the ambient temperature. The junction to ambient thermal resistance θJA is layout dependent. For TDFN-12L (3x3) packages, the thermal resistance θJA is 60°C/W on the 1 in 2 Multi-layer PCB copper area (The IC exposed pad must be connected to the PCB Copper area) two-layers thermal test board. The maximum power dissipation at TA = 25°C can be calculated by following formula: PD(MAX) = (125°C - 25°C) / (60°C/W) = 1.667W for TDFN-12L (3x3) package

The maximum power dissipation depends on operating ambient temperature for fixed TJ(MAX) and thermal resistance θJA. Layout Guide 1. Input Capacitors (C5, C1) are necessarily closed to IC. 2. Feedback low-side resistor’s (R2, R4) ground trace close to input capacitor’s ground trace. 3. All power trace is wide and short. 4. Feedback trace must keep inductor’s trace away EN1 FB2 9FB1 VIN2 GND2 VIN1 GND1 LX15 EN2 LX2 NC1 NC2 OUT2 OUT1 REN1 REN2 VIN1 VIN2 GND Exposed Pad

 TYPICAL CHARACTERISTICS VIN = 5V, VOUT = 1.8V, ILOAD = No Load VIN = 5V, VOUT = 1.8V, ILOAD = 1.5A Ch1=SW , Ch2=VOUT ,Ch3=VIN , Ch4=IOUT Ch1=SW , Ch2=VOUT ,Ch3=VIN , Ch4=IOUT

 PACKAGE OUTLINES SEATING PLANE Symbol Dimensions in Millimeters Dimensions in Inches A3 0.20 REF 0.008 REF D 3.00 BSC 0.118 BSC E 3.00 BSC 0.118 BSC e 0.45 BSC 0.018 BSC