PAM2301 800mA STEP-DOWN DC-DC CONVERTER Description Pin Assignments NEW PRODUCT The PAM2301 is a step-down current-mode, DC-DC converter. At heavy load, the constant frequency PWM control performs excellent stability and transient response. To ensure the longest battery life in portable applications, the PAM2301 provides a power-saving PulseSkipping Modulation (PSM) mode to reduce quiescent current under light load operation to save power. The PAM2301 supports a range of input voltages from 2.5V to 5.5V, allowing the use of a single Li+/Li-polymer cell, multiple Alkaline/NiMH cell, USB and other standard power sources. The output voltage is adjustable from 0.6V to the input voltage, while the part number suffix PAM2301-XX indicates pre-set output voltage of 3.3V, 1.2V or adjustable. All versions employ 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 0.1mA. Other key features include under-voltage lockout to prevent deep battery discharge. Applications The PAM2301 is available in TSOT25 package. Features Efficiency up to 96% Only 40A (typ) Quiescent Current Output Current: Up to 800mA Internal Synchronous Rectifier 1.5MHz Switching Frequency Soft Start Under-Voltage Lockout Short Circuit Protection Thermal Shutdown TSOT25 Package Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. "Green" Device (Note 3) Notes: TSOT25 Cellular Phone Portable Electronics Wireless Devices Cordless Phone Computer Peripherals Battery-Powered Widgets Electronic Scales Digital Frame 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant. 2. See https://www.diodes.com/quality/lead-free/ for more information about Diodes Incorporated's definitions of Halogen- and Antimony-free, "Green" and Lead-free. 3. Halogen- and Antimony-free "Green" products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and <1000ppm antimony compounds. PAM2301 Document number: DS36384 Rev. 3 - 2 1 of 13 www.diodes.com February 2018 (c) Diodes Incorporated PAM2301 Typical Applications Circuit Adjustable Output Voltage NEW PRODUCT Fixed Output Voltage R1 VO 0.6 1 R 2 Pin Descriptions Pin Number Pin Name Function 1 2 3 4 EN GND SW VIN 5 VOUT/FB Enable Control Input. Force this pin voltage above 1.5V, enables the chip, and below 0.3V shuts down the device. Ground The drains of the internal main and synchronous power MOSFET. Power Supply VOUT: Output voltage feedback pin, an internal resistive divider divides the output voltage down for comparison to the internal reference voltage. FB: Feedback voltage to internal error amplifier, the threshold voltage is 0.6V. Functional Block Diagram PAM2301 Document number: DS36384 Rev. 3 - 2 2 of 13 www.diodes.com February 2018 (c) Diodes Incorporated PAM2301 Absolute Maximum Ratings (@TA = +25C, 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 Input Voltage EN, FB Pin Voltage NEW PRODUCT SW Pin Voltage Rating -0.3 to +6.0 Unit V -0.3 to VIN V -0.3 to (VIN + 0.3) V +150 -65 to +150 +300, 5s C C C Junction Temperature Storage Temperature Range Soldering Temperature Recommended Operating Conditions (@TA = +25C, unless otherwise specified.) Parameter Rating Unit Supply Voltage 2.5 to 5.5 V Operation Temperature Range -40 to +85 Juntion Temperature Range -40 to +125 C Thermal Information Parameter Symbol Max Thermal Resistance (Junction to Case) JC 130 Thermal Resistance (Junction to Ambient) JC 250 Internal Power Dissipation PD 400 Unit C/W mW Electrical Characteristics (@TA = +25C, VIN = 3.6V, VO = 1.8V, CIN = 10F, L = 4.7H unless otherwise specified.) Parameter Min Typ Max Units VIN - 2.5 - 5.5 V VFB - 0.588 0.600 0.612 V Reference Voltage Line Regulation VFB - - 0.3 - %/V Regulated Output Voltage Accuracy VO IO = 100mA -3 - +3 % Peak Inductor Current IPK VIN = 3V,VFB = 0.5V or VO = 90% - 1.2 - A %/V Input Voltage Range Regulated Feedback Voltage Symbol Test Conditions Output Voltage Line Regulation LNR VIN = 2.5V to 5V, IO = 10mA - 0.2 0.5 Output Voltage Load Regulation LDR IO = 1mA to 800mA - 0.5 1.5 % Quiescent Current IQ No Load - 40 70 A Shutdown Current ISD VEN = 0V - 0.1 1.0 A Oscillator Frequency fOSC 1.2 1.5 1.8 MHz - 500 - kHz - 0.30 0.35 0.45 0.50 Drain-Source On-State Resistance SW Leakage Current High Efficiency RDS(ON) VO = 100% VFB = 0V or VO = 0V IDS = 100mA P MOSFET N MOSFET ILSW - - 0.01 1 A - 96 - % V EN Threshold High VEH - 1.5 - - EN Threshold Low VEL - - - 0.3 V EN Leakage Current IEN - - 0.01 - A OTP OTH - - +150 +30 - C C Over Temperature Protection OTP Hysteresis PAM2301 Document number: DS36384 Rev. 3 - 2 3 of 13 www.diodes.com February 2018 (c) Diodes Incorporated PAM2301 NEW PRODUCT Typical Performance Characteristics (@TA = +25C, CIN = 10F, CO = 10F, L = 4.7H, unless otherwise specified.) PAM2301 Document number: DS36384 Rev. 3 - 2 4 of 13 www.diodes.com February 2018 (c) Diodes Incorporated PAM2301 (Cont.) (@TA = +25C, CIN = 10F, CO = 10F, L = 4.7H, unless otherwise specified.) NEW PRODUCT Typical Performance Characteristics PAM2301 Document number: DS36384 Rev. 3 - 2 5 of 13 www.diodes.com February 2018 (c) Diodes Incorporated PAM2301 Typical Performance Characteristics (Cont.) (@TA = +25C, CIN = 10F, CO = 10F, L = 4.7H, unless otherwise NEW PRODUCT specified.) PAM2301 Document number: DS36384 Rev. 3 - 2 6 of 13 www.diodes.com February 2018 (c) Diodes Incorporated PAM2301 Typical Performance Characteristics (Cont.) (@TA = +25C, CIN = 10F, CO = 10F, L = 4.7H, unless otherwise NEW PRODUCT specified.) PAM2301 Document number: DS36384 Rev. 3 - 2 7 of 13 www.diodes.com February 2018 (c) Diodes Incorporated PAM2301 Typical Performance Characteristics (Cont.) (@TA = +25C, CIN = 10F, CO = 10F, L = 4.7H, unless otherwise NEW PRODUCT specified.) PAM2301 Document number: DS36384 Rev. 3 - 2 8 of 13 www.diodes.com February 2018 (c) Diodes Incorporated PAM2301 Application Information The basic PAM2301 application circuit is shown on Page 1. External component selection is determined by the load requirement, selecting L first and then CIN and COUT. Inductor Selection NEW PRODUCT For most applications, the value of the inductor will fall in the range of 1H to 4.7H. Its value is chosen based on the desired ripple current. 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 1. A reasonable starting point for setting ripple current is I L = 320mA (40% of 800mA). IL 1 1 V OUT VIN f L V OUT 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 1120mA rated inductor should be enough for most applications (800mA + 320mA). For better efficiency, choose a low DC-resistance inductor. CIN and COUT Selection In continuous mode, the source current of the top MOSFET is a square wave of duty cycle V OUT/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 OUT VIN V OUT CIN required IRMS IOMAX VIN 1/ 2 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 I RIPPLE (P-P) requirement. The output ripple VOUT is determined by: 1 V OUT IL ESR 8f COUT Where f = operating frequency, COUT = output capacitance and IL = ripple current in the inductor. For a fixed output voltage, the output ripple is highest at maximum input voltage since IL 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 formulations. These dielectrics have the best temperature and voltage characteristics of all the ceramics for a given value and size. Setting the Output Voltage The internal reference is 0.6V (Typical). The output voltage is calculated as below: R1 V O 0.6 1 R 2 The output voltage is given by Table 1. Table 1: Resistor selection for output voltage setting. R1 R2 VO 1.2V 100k 100k 1.5V 150k 100k 1.8V 200k 100k 2.5V 380k 120k 3.3V 540k 120k PAM2301 Document number: DS36384 Rev. 3 - 2 9 of 13 www.diodes.com February 2018 (c) Diodes Incorporated PAM2301 Application Information (Cont.) 100% Duty Cycle Operation As the input voltage approaches the output voltage, the converter turns the P-Channel transistor continuously on. In this mode the output voltage is equal to the input voltage minus the voltage drop across the P-Channel transistor: V OUT VIN ILOAD RDS(ON) RL where RDS(ON) = P-Channel Switch ON Resistance, I = Output Current, R = Inductor DC Resistance. NEW PRODUCT UVLO AND Soft-Start The reference and the circuit remain reset until the VIN crosses its UVLO threshold. The PAM2301 has an internal soft-start circuit that limits the in-rush current during start-up. This prevents possible voltage drops of the input voltage and eliminates the output voltage overshoot. The soft-start acts as a digital circuit to increase the switch current in several steps to the P-Channel current limit (1500mA). Short Circuit Protection The switch peak current is limited cycle-by-cycle to a typical value of 1500mA. In the event of an output voltage short circuit, the device operates with a frequency of 400kHz and minimum duty cycle, therefore the average input current is typically 200mA. Thermal Shutdown When the die temperature exceeds +150C, a reset occurs and the reset remains until the temperature decrease to 120C, at which time the circuit can be restarted. PCB Layout Check List When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the PAM2301. These items are also illustrated graphically in Figure 1. Check the following in your layout: 1. The power traces, consisting of the GND trace, the SW trace and the VIN trace should be kept short, direct and wide. 2. Does the VFB pin connect directly to the feedback resistors? The resistive divider R1/R2 must be connected between the (+) plate of C and ground. 3. Does the (+) plate of CIN connect to VIN as closely as possible? This capacitor provides the AC current to the internal power MOSFETs. 4. Keep the switching node, SW, away from the sensitive VFB node. 5. Keep the (-) plates of CIN and COUT as close as possible. Figure 1. PAM2301 Suggested Layout PAM2301 Document number: DS36384 Rev. 3 - 2 10 of 13 www.diodes.com February 2018 (c) Diodes Incorporated PAM2301 Ordering Information PAM2301 X X X X XXX Output Current NEW PRODUCT C: 800mA Pin Configuration A: Type 1. EN 2. GND 3. SW 4. VIN 5. VOUT/FB Package Type Number of Pins A: TSOT25 B: 5 Output Voltage 330: 3.3V 280: 2.8V 250: 2.5V 180: 1.8V 150: 1.5V 120: 1.2V ADJ: Adj Part Number Output Voltage (V) Part Mark Package (Note 5) 7'' Tape & Reel Quantity Status (Note 4) PAM2301CAAB330 PAM2301CAAB120 PAM2301CAABADJ 3.3 1.2 ADJ BAKYW BABYW BAAYW TSOT25 TSOT25 TSOT25 3000 3000 3000 In production In production In production Notes: 4. Variants with output voltage of 1.5V, 1.8V, 2.5V and 2.8V are End of Life with no replacement. 5. For packaging details, go to our website at https://www.diodes.com/design/support/packaging/diodes-packaging/. Marking Information TSOT25 PAM2301 Document number: DS36384 Rev. 3 - 2 11 of 13 www.diodes.com February 2018 (c) Diodes Incorporated PAM2301 Package Outline Dimensions (All dimensions in mm.) Please see http://www.diodes.com/package-outlines.html for the latest version. TSOT25 NEW PRODUCT D e1 01(4x) E1/2 E/2 E1 c E Gauge Plane 0 L e Seating Plane L2 01(4x) b A2 A1 A Seating Plane TSOT25 Dim Min Max Typ A - 1.00 A1 0.01 0.10 A2 0.84 0.90 b 0.30 0.45 c 0.12 0.20 D 2.90 E 2.80 E1 1.60 e 0.95 BSC e1 1.90 BSC L 0.30 0.50 L2 0.25 BSC 0 8 4 1 4 12 All Dimensions in mm Suggested Pad Layout Please see http://www.diodes.com/package-outlines.html for the latest version. TSOT25 C Dimensions Value (in mm) C 0.950 X 0.700 Y 1.000 Y1 3.199 Y1 Y X PAM2301 Document number: DS36384 Rev. 3 - 2 12 of 13 www.diodes.com February 2018 (c) Diodes Incorporated PAM2301 IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). NEW PRODUCT Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or trademark rights, nor the rights of others. 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Copyright (c) 2018, Diodes Incorporated www.diodes.com PAM2301 Document number: DS36384 Rev. 3 - 2 13 of 13 www.diodes.com February 2018 (c) Diodes Incorporated Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Diodes Incorporated: PAM2301CAABADJ PAM2301CAAB250 PAM2301CAAB280 PAM2301CAAB120 PAM2301CAAB180 PAM2301CAAB330