Datasheet > RT6545A

RT6545A

更新时间： 2022-02-26 11:49:27

品牌	Logo	应用领域
立锜 - RICHTEK		/
页数	文件大小	规格书
21页	260K
描述
Dual-Channel Synchronous DC/DC Step-Down Controller with 5V/3.3V LDOs

阅读下载

获取价格

数据手册

如果您发现信息不准确，欢迎纠错

RT6545A 数据手册

RT6545A/B

Operation

Over-Voltage Protection (OVP) and Under-Voltage

Protection (UVP)

The RT6545A/B includes two constant on-time

synchronous step-down controllers and two linear

regulators.

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.

Buck Controller

In normal operation, the high-side N-MOSFET is turned

on when the output is lower than VREF, and is turned off

after the internal one-shot timer expires. While the high-

sideN-MOSFET is turned off, the low-sideN-MOSFET is

turned on to conduct the inductor current until next cycle

begins.

LDO5 and LDO3

Soft-Start

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.

For internal soft-start function, an internal current source

charges an internal capacitor to build the soft-start ramp

voltage. The output voltage will track the internal ramp

voltage during soft-start interval.

Switching Over

PGOOD

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.

The power good output is an open-drain architecture. When

the Channel 2 soft-start is finished, the PGOOD open-

drain output will be high impedance.

Current Limit

The current limit circuit employs a unique “valley” current

sensing algorithm. If the magnitude of the current sense

signal at PHASE is above the current limit threshold, the

PWM is not allowed to initiate a new cycle. Thus, the

current to the load exceeds the average output inductor

current, the output voltage falls and eventually crosses

the under-voltage protection threshold, inducing IC

shutdown.

is a registered trademark of Richtek Technology Corporation.

www.richtek.com

DS6545A/B-00 May 2016

1 2 345 6 7...21

下载PDF

与RT6545A相关器件

型号	品牌	描述	获取价格	数据表
RT6545AGQW	RICHTEK	Dual-Channel Synchronous DC/DC Step-Down Controller with 5V/3.3V LDOs	获取价格
RT6545BGQW	RICHTEK	Dual-Channel Synchronous DC/DC Step-Down Controller with 5V/3.3V LDOs	获取价格
RT6550A	RICHTEK	暂无描述	获取价格
RT6551A	RICHTEK	Complete DDR Memory Power Supply Controller	获取价格
RT6551B	RICHTEK	暂无描述	获取价格
RT6575A	RICHTEK	暂无描述	获取价格