Features

 3A Converter With Built-in 85mΩ/40mΩ Low RDS(ON)

Power FETs

 Input Supply Voltage Range : 4.5V to 24V

 Output Voltage Range : 0.791V to 6V

 Advanced Constant On-Time (ACOTTM) Control

 Ultrafast Transient Response

 No Needs For External Compensations

 Optimized for Low-ESR Ceramic Output Capacitors

 0.791V ±1.5 High-Accuracy Feedback Reference

Voltage

 Low Quiescent Current (150μA typ.)

 Both HS/LS FETs Protection for Robust Over-Current

Protection

 Optional for Operation Modes :

 Power Saving Mode (PSM) at Light Load (RT6217A)

 Forced PWM Mode (RT6217B)

 Light-load VOUT Ripple Reduction Technology in

PSM

 Fixed Switching Frequency : 500kHz

 Externally Adjustable Soft-Start

 Monotonic Start-up for Pre-biased Output

 Input Under-Voltage Lockout (UVLO)

 Output Under-Voltage Protection (UVP) with Hiccup

Mode

 Power Good Indication

 Enable Control

 Available In TSOT-23-8 (FC) Package

General Description

The RT6217A/B is a simple, easy-to-use, 3A synchronous

step-down DC-DC converter with an input supply voltage

range of 4.5V to 24V. The device build-in an accurate

0.791V reference voltage and integrates low RDS(ON) power

MOSFETs to achieve high efficiency in a TSOT-23-8 (FC)

package.

The RT6217A/B adopts Advanced Constant On-Time

ACOTTM) control architecture to provide an ultrafast

transient response with few external components and to

operate in nearly constant switching frequency over the

line, load, and output voltage range. The RT6217A operates

in automatic PSM that maintains high efficiency during

light load operation. The RT6217B operates in Forced

PWM that helps meet tight voltage regulation accuracy

requirements.

The RT6217A/B senses both FETs current for a robust

over-current protection. It features cycle-by-cycle current

limit protection and prevent the device from the catastrophic

damage in output short circuit, over current or inductor

saturation. An externally adjustable soft-start function

prevents inrush current during start-up. The device also

includes input under-voltage lockout, output under-voltage

protection, and over-temperature protection (thermal

shutdown) to provide safe and smooth operation in all

operating conditions. The RT6217A/B is offered in a TSOT-

23-8(FC) package.