RT8249 datasheet(5/23 Pages) RICHTEK

Part #	RT8249

Description	Dual-Channel Synchronous DC/DC Step-Down Controller with 5V/3.3V LDOs

PDF	23 Pages

Scroll/Zoom	100%

Manufacturer	RICHTEK [Richtek Technology Corporation]

Direct Link	http://www.richtek.com

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5 / 23 page

RT8249A/B/C

DS8249A/B/C-02

June 2014

www.richtek.com

is a registered trademark of Richtek Technology Corporation.

Over-Voltage Protection (OVP) & Under-Voltage

Protection (UVP)

The two channel output voltages are continuously

monitored for over-voltage and under-voltage conditions.

When the output voltage exceeds over-voltage threshold

(113% of VOUT), UGATE goes low and LGATE is forced

high. When it is less than 52% of reference voltage, under-

voltage protection is triggered and then both UGATE and

LGATE gate drivers are forced low. The controller is latched

until ENx is reset or LDO5 is re-supplied.

LDO5 and LDO3

When the VIN voltage exceeds the POR rising threshold,

LDO3 will default turn-on. The LDO5 can be power on by

ENx. The linear regulator LDO5 and LDO3 provide 5V and

3.3V regulated output.

Switching Over

The BYP1 is connected to the Channel 1 output. After the

Channel 1 output voltage exceeds the set threshold

(4.66V), the output will be bypassed to the LDO5 output

to maximize the efficiency.

RT8249 Datasheet(PDF) 5 Page - Richtek Technology Corporation