®
RT5785A/B
2A, 6V, 1.5MHz, 25μA IQ, ACOTTM Synchronous Step-Down
Converter
General Description
The RT5785A/B is a high-performance, Advanced Constant
On-Time (ACOTTM) monolithic synchronous step-down
DC-DC converter that can deliver up to 2A output current
from a 2.5V to 6V input supply. The proprietary ACOT
control architecture features quick transient response and
provides stable operation with small ceramic output
capacitors and without complicated external
compensation. The switching ripple voltage is easily
smoothed–out by small package filtering elements due
to a constant switching frequency of 1.5MHz and the
maximum duty cycle of 100% allows the device to operate
at low dropout use. With internal low on-resistance power
switches and extremely low quiescent current, the
RT5785A/B displays excellent efficiency and good behavior
across a range of applications.
Cycle-by-cycle current limit provides protection against
shorted outputs, input under-voltage lock-out, output
under-voltage protection, and thermal shutdown provide
safe and smooth operation in all operating conditions. The
RT5785A/B is available in the TSOT-23-8 (FC) package.
Features
Dramatically Fast Transient Response
Steady 1.5MHz ±200kHz Switching Frequency
Very Low Input Quiescent and Shutdown Currents
Advanced COT Control Loop Design
Optimized for Ceramic Output Capacitors
2.5V to 6V Input Voltage Range
Accurate Voltage Reference 0.6V ±2%
Integrated 100mΩ/60mΩ MOSFETs
Internal Start-Up into Pre-Biased Outputs
Power Good Indicator
Enable Control
Over-Current and Over-Temperature Protections
Under-Voltage Protection with Hiccup Mode
RoHS Compliant and Halogen Free
Applications
Mobile Phones and Handheld Devices
STB, Cable Modem, and xDSL Platforms
WLAN ASIC Power / Storage (SSD and HDD)
General Purpose for POL LV Buck Converter
Simplified Application Circuit
VIN
RPGOOD
PGOOD
Enable
VIN LX
CIN
RT5785A/B
PGOOD
FB
EN
PGND
VOUT
AGND
L
VOUT
R1
CFF
COUT
R2
Copyright ©2017 Richtek Technology Corporation. All rights reserved.
DS5785A/B-02 April 2017
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
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