AP3429/A 1.0MHZ, 2A STEP-DOWN DC-DC BUCK CONVERTER Description Pin Assignments NEW PRODUCT The AP3429/A is a 2A 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 AP3429/A 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 AP3429/A 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. (Top View) EN 1 GND 2 LX 3 Output Current: Up to 2A Output Voltage: 0.6V to VIN Input Voltage: 2.7V to 5.5V MOSFETs and 100% duty cycle operation make the AP3429/A an ideal choice for high output voltage, high current applications which require a low dropout threshold. Shutdown Current: <1μA 100% Duty Cycle Operation 1MHz Switching Frequency Internal Soft Start No External Compensation Required Applications 5V or 3.3V Point of Load Conversion Telecom/Networking Equipment Set Top Boxes Storage Equipment Video Cards DDR Power Supply Notes: 4 VIN Features FB TSOT25 The AP3429/A delivers 2A maximum output current while consuming only 90μA of no-load quiescent current. Ultra-low RDS(ON) integrated The AP3429/A is available in TSOT25 package. 5 Short Circuit Protection AP3429: Latch Off Protection AP3429A: Hiccup Mode Protection Over Voltage Protection AP3429: Latch Off Protection AP3429A: No Latch Off Protection Thermal Shutdown TSOT25 package Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. “Green” Device (Note 3) 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See http://www.diodes.com/quality/lead_free.html 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. AP3429/A Document number: DS36561 Rev. 3 - 2 1 of 11 www.diodes.com August 2015 © Diodes Incorporated AP3429/A Typical Applications Circuit VIN=2.7V to 5.5V 4 VIN NEW PRODUCT 2 GND 1 ON OFF AP3429/A CIN 22mF EN LX 3 L1 2.2mH C1 22pF FB VOUT=1.8V R1 300k COUT 22mFx2 5 R2 150k Pin Descriptions Pin Number Pin Name Function 1 EN Enable control input. Force this pin voltage above 1.5V enables the chip, and below 0.4V shuts down the device. 2 GND 3 LX The drains of the internal main and synchronous power MOSFETs. 4 VIN Bias supply. Chip main power supply pin. 5 FB Feedback voltage to internal error amplifier. The threshold voltage is 0.6V. AP3429/A Document number: DS36561 Rev. 3 - 2 Ground pin. 2 of 11 www.diodes.com August 2015 © Diodes Incorporated AP3429/A Functional Block Diagram 4 SLOPE COMP 5 FB ____ OSC FREQ SHIFT S Q R _ Q _ EA VIN EN 1 PWM + COMP _ VIN IAMP _ + SWITCHING LOGIC AND BLOCKING CIRCUIT 3 ANTISHOOT THRU LX 0.6V REF SHUTDOWN _ 2 GND OVP 120% REF + Function Block Diagram of AP3429 4 1M OSC + SLOPE COMP 5 FB ____ OSC S Q R _ Q _ VIN EN 1 IAMP _ FREQ SHIFT PWM + COMP _ VIN + NEW PRODUCT + + 1M OSC EA + SWITCHING LOGIC AND BLOCKING CIRCUIT 3 ANTISHOOT THRU LX 0.6V REF 2 SHUTDOWN GND Function Block Diagram of AP3429A AP3429/A Document number: DS36561 Rev. 3 - 2 3 of 11 www.diodes.com August 2015 © Diodes Incorporated AP3429/A Absolute Maximum Ratings (Note 4) NEW PRODUCT Symbol Note 4: Parameter Rating Unit -0.3 to 6 V VIN Input Voltage VEN EN Pin Voltage -0.3 to VIN+0.3 V VLX LX Pin Voltage -0.3 to VIN+0.3 V VFB Feedback Pin Voltage -0.3 to VIN+0.3 V PD Power Dissipation (on PCB, TA = +25°C) 0.4 W θJA Thermal Resistance (Junction to Ambient) 220 °C/W θJC Thermal Resistance (Junction to Case, Simulation) 130 ºC/W TJ Operating Junction Temperature +150 °C TSTG Storage Temperature -55 to +150 °C VMM ESD (Machine Model) 200 V VHBM ESD (Human Body Model) 2000 V Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “Recommended Operating Conditions” is not implied. Exposure to “Absolute Maximum Ratings” for extended periods may affect device reliability. Recommended Operating Conditions Symbol Parameter Min Max Unit VIN Input Voltage Range 2.7 5.5 V TA Operating Ambient Temperature -40 +85 °C TJ Junction Temperature Range -40 +125 °C AP3429/A Document number: DS36561 Rev. 3 - 2 4 of 11 www.diodes.com August 2015 © Diodes Incorporated AP3429/A Electrical Characteristics (@VIN = 5V, VOUT = 1.8V, L = 2.2µH, CIN = 22µF, COUT = 22µF×2, TA = +25°C, unless otherwise specified.) NEW PRODUCT Symbol Parameters Conditions Min Typ Max Unit VIN Input Voltage Range – 2.7 – 5.5 V VFB Regulated Feedback Voltage – 0.588 0.6 0.612 V IFB FB Leakage Current VFB = 1V – – 0.2 μA IQ Quiescent Current VFB = 0.65V – 90 – μA ISD Shutdown Current VEN = 0V – 0.1 1 μA ILIM Peak Inductor Current – 3 – – A VSCP Short Circuit Protection Latch Off Threshold – – 0.3 – V fOSC Oscillator Frequency – – 1 – MHz Drain to Source On-state Resistance ILX = 100mA, high side – 110 – ILX = 100mA, low side – 80 – VENH EN High Threshold – 1.5 – – V VENL EN Low Threshold – – – 0.4 V EN Leakage Current VIN = VEN = 5V -1.0 – 1.0 μA VUVLO Input UVLO Threshold – – 2.4 2.7 V VHYS UVLO Hysteresis – – 0.2 – V Maximum Duty Cycle – 100 – – % RDSCH Output Discharge Switch On Resistance – – 50 – Ω TOTP Over Temperature Protection – – +160 – °C TOTH OTP Hysteresis – – +30 – °C VIOVP VIN Over Voltage Protection – – 6.25 – V VIHSY IOVP Hysteresis – – 0.25 – V Soft-start Time – – 1.8 – ms RDS(ON) IEN – tSS AP3429/A Document number: DS36561 Rev. 3 - 2 mΩ 5 of 11 www.diodes.com August 2015 © Diodes Incorporated AP3429/A Performance Characteristics (@TA = +25°C, VIN = 5V, VOUT = 1.8V, unless otherwise specified.) Efficiency vs. Load Current Feedback Reference Voltage vs. Temperature 0.620 100 90 Feedback Reference Voltage (V) 0.615 80 Efficiency (%) 60 50 40 30 VIN=5V, VOUT=1.0V VIN=5V, VOUT=1.8V VIN=5V, VOUT=3.3V 20 10 1 10 100 0.610 0.605 0.600 0.595 0.590 0.585 0.580 -60 0 1000 -40 -20 0 20 40 60 80 100 120 140 o Temperature ( C) IOUT (mA) PFET Drain-Source On-State Resistance vs. Temperature NFET Drain-Source On-State Resistance vs. Temperature 200 120 190 110 180 NFET RDS(ON) (m) PFET RDS(ON)(m) 170 160 150 140 130 100 90 80 70 120 60 110 100 -60 -40 -20 0 20 40 60 80 100 120 50 -60 140 -40 -20 0 40 60 80 100 120 140 o Temperture ( C) Inductor Current Limit vs. Temperature Oscillation Frequency vs. Temperature 1.20 4.4 1.15 4.2 1.10 Oscillation Frequency (MHz) 4.6 4.0 3.8 3.6 3.4 3.2 3.0 1.05 1.00 0.95 0.90 0.85 0.80 0.75 2.8 2.6 -60 20 Temperture ( C) o Inductor Current Limit (A) NEW PRODUCT 70 -40 -20 0 20 40 60 80 100 120 0.70 -60 140 AP3429/A Document number: DS36561 Rev. 3 - 2 -40 -20 0 20 40 60 80 100 120 140 o Temperature ( C) o Temperature ( C) 6 of 11 www.diodes.com August 2015 © Diodes Incorporated AP3429/A Performance Characteristics (Cont. @TA = +25°C, VIN = 5V, VOUT = 1.8V, unless otherwise specified.) Enable Turn on Characteristic (IOUT=2A) Enable Turn off Characteristic (IOUT=2A) VEN (2V/div) NEW PRODUCT VEN (2V/div) VOUT (1V/div) VOUT (1V/div) IL (2A/div) IL (2A/div) VSW (5V/div) VSW (5V/div) Time (5ms/div) Time (5ms/div) Short Current Protection (IOUT=2A) SCP Recovery (IOUT=2A) VOUT (1V/div) VOUT (1V/div) IL (2A/div) IL (2A/div) VSW (5V/div) VSW (5V/div) Time (50ms/div) Time (50ms/div) Load Transient (IOUT=0.1A to 2A) VOUT_AC (100mV/div) Load Transient (IOUT=1A to 2A) VOUT_AC (100mV/div) IOUT (1A/div) IOUT (1A/div) Time (100µs/div) AP3429/A Document number: DS36561 Rev. 3 - 2 Time (100µs/div) 7 of 11 www.diodes.com August 2015 © Diodes Incorporated AP3429/A Application Information Typical application circuit is shown in the application circuit and for the circuit parameters setting please refers to the following descriptions. NEW PRODUCT Under Voltage Lockout (UVLO) Circuit The AP3429/A provides an under voltage lockout circuit to prevent it from undefined status. When the VIN drops lower than the UVLO detector threshold, the UVLO circuit starts to operate, VREF stops, and high-side and low-side built-in switch transistors turn “OFF”. As a result, VOUT drops according to the COUT capacitance value and the load. When the VIN is rising higher than UVLO released voltage, the IC will restart the operation. Over Current Protection The AP3429/A has internal over current protection function to protect from catastrophic failures. The IC can monitor the PMOS current, if the peak current is higher than the current limit threshold, OCP function will be triggered and enter cycle by cycle current limit mode. If VFB drops under 0.3V for example, output node shorted to GND, AP3429 will enter latch off mode. IC will turn off both power switches. It will remain latch off state until the VIN or Enable recycled to release it. AP3429A will enter hiccup mode to protect itself, if short circuit is removed, and VFB rises over 0.3V, the AP3429A recovers to normal operation again. Over Voltage Protection The AP3429 has internal output OVP circuits. When VOUT is exceeds 120% of the regulation level for more than 40µs, the power switching will be turned off. IC enter latch off mode and will restart until VIN or Enable voltage recycled. Over Temperature Protection The internal thermal temperature protection circuitry of AP3429/A is provided to protect the integrated circuit in the event that the maximum junction temperature is exceeded. When the junction temperature exceeds +160°C, it shuts down the internal control circuit and switching power MOSFET. The AP3429/A will restart automatically under the control of soft start circuit when the junction temperature decreases to +130°C. Input Over Voltage Protection When input voltage of AP3429/A is near 6.25V, the IC will enter Input-Over-Voltage-Protection. It would be shut down and there will be no output voltage in this state. As the input voltage goes down below 6V, it will leave input OVP and recover the output voltage. AP3429/A Document number: DS36561 Rev. 3 - 2 8 of 11 www.diodes.com August 2015 © Diodes Incorporated AP3429/A Ordering Information AP3429X XX XX – XX NEW PRODUCT Product Name Product Version A : AP3429A Blank : AP3429 Package Temperature Range TSOT25 -40 to +85°C Package KT : TSOT25 Packing RoHS/Green TR : Tape & Reel G1 : Green Part Number Marking ID Packing AP3429AKTTR-G1 L2E 3000/Tape & Reel AP3429KTTR-G1 L2F 3000/Tape & Reel Marking Information AP3429 (Top View) First Line: Logo and Marking ID AP3429A (Top View) First Line: Logo and Marking ID AP3429/A Document number: DS36561 Rev. 3 - 2 9 of 11 www.diodes.com August 2015 © Diodes Incorporated AP3429/A Package Outline Dimensions Please see AP02002 at http://www.diodes.com/datasheets/ap02002.pdf for the latest version. (1) Package Type: TSOT25 D e1 01(4x) NEW PRODUCT E1/2 E/2 E1 c E Gauge Plane 0 L L2 01(4x) b e Seating Plane 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 θ 0° 8° 4° θ1 4° 12° All Dimensions in mm Suggested Pad Layout Please see AP02001 at http://www.diodes.com/datasheets/ap02001.pdf for the latest version. (1) Package Type: TSOT25 C Dimensions Value (in mm) C 0.950 X 0.700 Y 1.000 Y1 3.199 Y1 Y X AP3429/A Document number: DS36561 Rev. 3 - 2 10 of 11 www.diodes.com August 2015 © Diodes Incorporated AP3429/A IMPORTANT NOTICE NEW PRODUCT 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). 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LIFE SUPPORT Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein: A. Life support devices or systems are devices or systems which: 1. are intended to implant into the body, or 2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or to affect its safety or effectiveness. Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems. Copyright © 2015, Diodes Incorporated www.diodes.com AP3429/A Document number: DS36561 Rev. 3 - 2 11 of 11 www.diodes.com August 2015 © Diodes Incorporated