AP3445/L 1MHZ, 2A STEP-DOWN DC-DC BUCK CONVERTER Description Pin Assignments The AP3445 and AP3445L is a 2A step-down DC-DC converter. At heavy load, the constant-frequency PWM control performs excellent (Top View) stability and transient response. No external compensation Pin 1 Ma rk components are required. The AP3445/L 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 1 6 FB EN adjustable from 0.6V to the input voltage. The AP3445/L 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 GND 5 PG 2 1A. Other key features include over-temperature and short circuit protection, and under-voltage lockout to prevent deep battery discharge. LX 3 4 VIN The AP3445/L delivers 2A maximum output current while consuming only 55A of no-load quiescent current. Ultra-low R integrated DS(ON) MOSFETs and 100% duty cycle operation make the AP3445/L an ideal choice for high output voltage, high current applications which SOT26 (SC74R) require a low dropout threshold. Pulse skip mode to maintain high efficiency at light-load conditions. The AP3445/L is available in SOT26 (SC74R) package. Features Applications Input Voltage: 2.7V to 5.5V Post DC-DC Voltage Regulation Output Voltage: 0.6V to V Set Top Boxes IN 0.6V Reference Voltage with 1.5% Precision Notebook Computer 55A (Typ) No Load Quiescent Current PAD Shutdown Current: <1A 100% Duty Cycle Operation 1MHz Switching Frequency No External Compensation Required Short Circuit Protection 445L: Latch Off Protection AP3445: Hiccup Mode Protection Over Voltage Protection 3445L: Latch Off Protection 445: Non Latch Off Protection Thermal Shutdown SOT26 (SC74R) Package Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. Green Device (Note 3) Notes: 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 AP3445/L Typical Applications Circuit V =2.7V to 5.5V IN VIN C IN L1 2.2mH 22 mF V =1.8V OUT LX OFF ON R1 EN C1 C OUT 22pF 200k 22mFx2 PG FB GND R2 100k Pin Descriptions Pin Number Pin Name Function Enable control input. Force this pin voltage above 1.5V enables the chip, and below 1 EN 0.4V shuts down the device. 2 GND Ground pin 3 LX The drains of the internal main and synchronous power MOSFET. 4 VIN Bias supply. Chip main power supply pin Power good indicator, open drain output. PG is pulled up to VIN when the output 5 PG voltage is within 20% of the regulation level, otherwise it is low 6 FB Feedback voltage to internal error amplifier, the threshold voltage is 0.6V. 2 of 13 AP3445/L March 2018 Diodes Incorporated www.diodes.com Document number: DS39755 Rev. 1 - 2 NEW PRODUCT AP3445/L