PAM2307AJEADJR

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PAM2307 Document number: DSxxxxx Rev. 2 - 1 1 of 14 www.diodes.com September 2012 © Diodes Incorporated PAM2307 A Product Line of Diodes Incorporated 3A LOW NOISE STEP-DOWN DC-DC CONVERTER Description The PAM2307 is a 3A step-down DC-DC converter. At heavy load, the constant-frequency PWM control performs excellent stability and transient response. No external compensation components are required. The PAM2307 supports a range of input voltages from 2.7V to 5.5V, allowing the use of a single Li+/Li-polymer cell, multiple Alkaline/ NiMH cell,and other standard power sources. The output voltage is adjustable from 0.6V to the input voltage. The PAM2307 employs internal power switch and synchronous rectifier to minimize external part count and realize high efficiency. During shutdown, the input is disconnected from the output and the shutdown current is less than 1µA. Other key features include over-temperature and short circuit protection, and under-voltage lockout to prevent deep battery discharge. The PAM2307 delivers 3A maximum output current while consuming only 42µA of no-load quiescent current. Ultra-low RDS(ON) integrated MOSFETs and 100% duty cycle operation make the PAM2307 an ideal choice for high output voltage, high current applications which require a low dropout threshold. The PAM2307 is available in QFN3x3 16-Pin and SOP-8(EP) package. Features • Output Current: Up to 3A • Output Voltage: 0.6V to VIN • Input Voltage: 2.7 to 5.5V • Efficiency up to 95% • 42µA (Typ) No Load Quiescent Current • Shutdown Current: <1µA • 100% Duty Cycle Operation • 1.5MHz Switching Frequency • Internal Soft Start • No external Compensation Required • Current Limit Protection • Thermal Shutdown • QFN3x3 16-Pin and SOP-8(EP) Package Pin Assignments Applications • 5V or 3.3V Point of Load Conversion • Telecom/Networking Equipment • Set Top Boxes • Storage Equipment • Video Cards • DDR Power Supply

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PAM2307 Document number: DSxxxxx Rev. 2 - 1 2 of 14 www.diodes.com September 2012 © Diodes Incorporated PAM2307 A Product Line of Diodes Incorporated Typical Applications Circuit V 2R 1R 16.0O ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ +×= Pin Descriptions Pin Name Package Name Function QFN3x3-16L SOP-8(EP) PGND 1, 2, 3 2 Main power ground pin. FB 4 3 Feedback voltage to internal error amplifier, the threshold voltage is 0.6V. GND 5 4 Signal ground for small signal components. NC 6, 16 — No connection. EN 7 5 Enable control input. Force this pin voltage above 1.5V, enables the chip, and below 0.3V shuts down the device. TEST 8 6 Test Mode(no connect or to Ground). VIN 9 7 Bias supply. Chip main power supply pin. PVIN 10, 11, 12 8 Input supply for power stage. Must be closely decoupled to PGND. SW 13, 14, 15 1 The drains of the internal main and synchronous power MOSFET. Functional Block Diagram

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PAM2307 Document number: DSxxxxx Rev. 2 - 1 3 of 14 www.diodes.com September 2012 © Diodes Incorporated PAM2307 A Product Line of Diodes Incorporated Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.) These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. All voltages are with respect to ground. Parameter Rating Unit Input Voltage PVIN, VIN 6 V SW Pin Voltage -0.3 to (PVIN +0.3) V FB Pin Voltage -0.3 to (VIN +0.3) V EN Pin Voltage -0.3 to +6.0 V Maximum Junction Temperature 150 °C Storage Temperature Range -65 to +150 °C Soldering Temperature 300, 5sec °C Recommended Operating Conditions (@TA = +25°C, unless otherwise specified.) Parameter Rating Unit Supply Voltage 2.5 to 5.5 V Junction Temperature Range -40 to +125 °C Ambient Temperature Range -40 to +85 Thermal Information Parameter Symbol Package Max Unit Thermal Resistance (Junction to Ambient) θJA QFN3x3-16 35 °C/W SOP-8(EP) 90 Thermal Resistance (Junction to Case) θJC QFN3x3-16 14 SOP-8(EP) 11

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PAM2307 Document number: DSxxxxx Rev. 2 - 1 4 of 14 www.diodes.com September 2012 © Diodes Incorporated PAM2307 A Product Line of Diodes Incorporated Electrical Characteristics (@TA = +25°C, VIN = 3.6V, VO = 1.8V, CIN = 22µF, CO = 22µF, L = 2.2µH, unless otherwise specified.) Parameter Symbol Test Conditions Min Typ Max Units Input Voltage Range VIN 2.5 5.5 V Output Voltage Range VO 0.6 VIN V UVLO Threshold VUVLO VIN Rising 2.4 2.5 V Hysteresis 240 mV VIN Falling 1.8 V Regulated Output Votlage Accuracy VO IO = 0 to 3A, VIN = 2.5 to 5.5V -2 +2 % Regulated Feedback Voltage VFB 0.588 0.600 0.612 V FB Leakage Current IFB VO =1V 0.2 µA Output Voltage Line Regulation LNR VIN = 2.5V to 5V 0.2 %/V Output Voltage Load Regulation LDR IO = 0A to 3A 0.5 %/A Quiescent Current IQ No Load 42 90 µA Shutdown Current ISD VEN = 0V 1 µA Current Limit ILIM 3.5 A Oscillator Frequency fOSC 1.2 1.5 1.8 MHz Drain-Source On-State Resisitance RDS(ON) High Side 0.140 Ω Low Side 0.09 Ω High Efficiency η 95 % Start-Up Time tS From enable to output regulation 3 ms EN Threshold High VEH 1.5 V EN Threshold Low VEL 0.3 V EN Leakage Current IEN VIN = VEN = 0V -1.0 +1.0 µA Over Temperature Protection OTP 150 °C OTP Hysteresis OTH 30 °C

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PAM2307 Document number: DSxxxxx Rev. 2 - 1 5 of 14 www.diodes.com September 2012 © Diodes Incorporated PAM2307 A Product Line of Diodes Incorporated Typical Performance Characteristics (@TA = +25°C, CIN = 22*2µF, CO = 22µF, unless otherwise specified.)

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PAM2307 Document number: DSxxxxx Rev. 2 - 1 6 of 14 www.diodes.com September 2012 © Diodes Incorporated PAM2307 A Product Line of Diodes Incorporated Typical Performance Characteristics (cont.) (@TA = +25°C, CIN = 22*2µF, CO = 22µF, unless otherwise specified.)

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PAM2307 Document number: DSxxxxx Rev. 2 - 1 7 of 14 www.diodes.com September 2012 © Diodes Incorporated PAM2307 A Product Line of Diodes Incorporated Typical Performance Characteristics (cont.) (@TA = +25°C, CIN = 22*2µF, CO = 22µF, unless otherwise specified.)

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PAM2307 Document number: DSxxxxx Rev. 2 - 1 8 of 14 www.diodes.com September 2012 © Diodes Incorporated PAM2307 A Product Line of Diodes Incorporated Typical Performance Characteristics (cont.) (@TA = +25°C, CIN = 22*2µF, CO = 22µF, unless otherwise specified.)

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PAM2307 Document number: DSxxxxx Rev. 2 - 1 9 of 14 www.diodes.com September 2012 © Diodes Incorporated PAM2307 A Product Line of Diodes Incorporated Application Information The basic PAM2307 application circuit is shown in Page 1. External component selection is determined by the load requirement, selecting L first and then CIN and COUT. Inductor Selection For most applications, the value of the inductor will fall in the range of 1μH to 2.7μH. Its value is chosen based on the desired ripple current and efficiency. Large value inductors lower ripple current and small value inductors result in higher ripple currents. Higher VIN or VOUT also increases the ripple current as shown in equation 3A reasonable starting point for setting ripple current is ΔIL = 1.2A (40% of 3A). ( )( ) ⎟⎟⎠ ⎞ ⎜⎜ ⎝ ⎛ −=Δ V V1V Lf 1 I IN OUT OUTL Equation (1) The DC current rating of the inductor should be at least equal to the maximum load current plus half the ripple current to prevent core saturation. Thus, a 4.2A rated inductor should be enough for most applications (3A + 1.2A). For better efficiency, choose a low DC-resistance inductor. VO 1.2V 1.5V 1.8V 2.5V 3.3V L 1.2µH 1.5µH 2.2µH 2.2µH 2.2µH CIN and COUT Selection In continuous mode, the source current of the top MOSFET is a square wave of duty cycle VOUT/VIN. To prevent large voltage transients, a low ESR input capacitor sized for the maximum RMS current must be used. The maximum RMS capacitor current is given by: ( )[ ] V VVV IIrequiredC IN 2/1 OUTINOUT OMAXRMSIN − ≅ This formula has a maximum at VIN = 2VOUT, where IRMS =IOUT /2. This simple worst-case condition is commonly used for design because even significant deviations do not offer much relief. Note that the capacitor manufacturer's ripple current ratings are often based on 2000 hours of life. This makes it advisable to further derate the capacitor, or choose a capacitor rated at a higher temperature than required. Consult the manufacturer if there is any question. The selection of COUT is driven by the required effective series resistance (ESR). Typically, once the ESR requirement for COUT has been met, the RMS current rating generally far exceeds the IRIPPLE (P-P) requirement. The output ripple ΔVOUT is determined by: ( )Cf8/1ESRIV OUTLOUT +Δ≈Δ Where f = operating frequency, COUT = output capacitance and ΔIL = ripple current in the inductor. For a fixed output voltage, the output ripple is highest at maximum input voltage since ΔIL increases with input voltage. Using Ceramic Input and Output Capacitors Higher values, lower cost ceramic capacitors are now becoming available in smaller case sizes. Their high ripple current, high voltage rating and low ESR make them ideal for switching regulator applications. Using ceramic capacitors can achieve very low output ripple and small circuit size. When choosing the input and output ceramic capacitors, choose the X5R or X7R dielectric formul ations. These dielectrics have the best temperature and voltage characteristics of all the ceramics for a given value and size. Thermal Consideration Thermal protection limits power dissipation in the PAM2307. When the junction temperature exceeds +150°C, the OTP (Over Temperature Protection) starts the thermal shutdown and turns the pass transistor off. The pass transistor resumes operation after the junction temperature drops below +120°C. For continuous operation, the junction temperature should be maintained below +125°C. The power dissipation is defined as: ( ) ( )VIIFt V RVVRV IP INQOSSW IN L)ON(DSOINH)ON(DSO2 OD ++ −+ = IQ is the step-down converter quiescent current. The term tsw is used to estimate the full load step-down converter switching losses.