®
RT2657BQ
2.25MHz 600mA Synchronous Step-Down Converter
General Description
The RT2657BQ is a high efficiency Pulse-Width-
Modulated (PWM) step-down DC/DC converter, capable
of delivering 600mA output current over a wide input voltage
range from 2.7V to 5.5V. The RT2657BQ is ideally suited
for portable electronic devices that are powered from 1-
cell Li-ion battery or from other power sources such as
cellular phones, PDAs, hand-held devices, game console
and related accessories.
The internal synchronous rectifier with low R
DS(ON)
dramatically reduces conduction loss at PWM mode.
No external Schottky diode is required in practical
applications. The RT2657BQ enters Low Dropout Mode
when normal Pulse -Width Mode cannot provide regulated
output voltage by continuously turning on the high-side
P-MOSFET. The RT2657BQ enters shut-down mode and
consumes less than 5μA when the EN pin is pulled low.
The switching ripple is easily smoothed-out by small
package filtering elements due to a fixed operating
frequency of 2.25MHz.
The RT2657BQ is available in the small WDFN-8L 3x3
package.
Features
V
IN
Range 2.7V to 5.5V
V
OUT
Range 0.6V to 5.5V (100% Duty Ratio Operation)
V
REF
= 0.6V
I
SD
≤
5μA (V
EN
= 0V)
μ
Current Mode Control, Internal Compensation
Fixed F
SW
2.25MHz
R
DS(ON)
230mΩ HS/250mΩ LS (P-MOSFET/
Ω
Ω
N-MOSFET)
Enable (V
IH
= 1V, V
IL
= 0.4V)
Internal Soft-Start (0.3ms)
Up to 600mA Output Current
Up to 90% Efficiency
Peak I
LIMIT
(1.5A Typical / 0.8A Min); UVLO; UVP;
V
IN
and V
OUT
OVP; and OTP (150°C)
°
No Schottky Diode Required
Internal Compensation to Reduce External
Components
AEC-Q100 Grade 3 Certification
Applications
Automotive Audio, Information & Navigation
Industrial-Grade General Purpose Point-of -Load
Marking Information
5L= : Product Code
5L=YM
DNN
YMDNN : Date Code
Simplified Application Circuit
RT2657BQ
V
IN
C
IN
EN
GND
FB
R2
VIN
LX
C1
R1
L1
V
OUT
C
OUT
Copyright
©
2014 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS2657BQ-00 July 2014
www.richtek.com
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RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
