1.5MHz PFM/PWM 700mA Synchronous Buck Regulator

1.5MHz PFM/PWM 700mA Synchronous Buck Regulator AP2406L

Overview

This chip can replace LTC3406, RT8008

AP2406L is a high-efficiency, monolithic synchronous buck regulator that provides adjustable output voltage and fixed output voltages of 1.2V and 1.8V. The internal PFM and PWM adaptive switching modes can be realized according to the load current. When the load current is large, the fixed operating frequency of PWM reaches 1.5MHz, which can achieve very low output ripple; when the load current becomes low, the circuit switches to the PFM mode, and its own consumption can be as low as 40uA, which can still guarantee more than 80% conversion efficiency; when it is turned off, the operating current drops below 1uA. The input operating voltage range is 2.5V to 6.5V, which is very suitable for electronic products powered by a single lithium-ion battery or two to four dry batteries. AP2406L adopts a 100% duty cycle to achieve a low voltage dropout mode, extending the battery life of portable devices. The 1.5MHz switching frequency allows the peripheral inductors and capacitors to be miniaturized. AP2406L has built-in power switch tubes and synchronous rectification switches, and no external Schottky diodes are required. The feedback voltage is set to 0.6 V, which can make the output voltage as low as 0.6 V. The tiny SOT23-5 package saves printed circuit board area.

Application Areas

Mobile phones and smartphones

lMicroprocessor and digital signal processor core power supply

Wireless or wired modem

Pocket PC

l Various media players

Digital still cameras and digital video cameras

l Various handheld devices with standby or sleep mode

Key Features

lHigh efficiency: up to 96%

1.5MHz constant switching frequency

1700mA output current (V _IN =3.6V)

l Built-in power switch tube and synchronous rectification switch, no external Schottky diode required

2.5V to 6.5V input voltage range

l Output voltage can be as low as 0.6V

l Allows low dropout operation: duty cycle up to 100%

l Low quiescent operating current: 40μA (V _IN＜ 4.2V＝

l Current mode for excellent line and load transient response

lShort circuit protection and over temperature protection

l Standby current is less than 1μA

l Space-saving 5-pin SOT23 package

Typical application circuit diagram

Typical efficiency curve