XR79115 Datasheet, PDF (1/19 Pages) Exar Corporation – 22V, 15A Synchronous Step Down COT Power Module

XR79115
22V, 15A Synchronous Step Down COT Power Module
General Description
The XR79115 is a 15A synchronous step-down Power Module for point-of
load supplies. A wide 5V to 22V input voltage range allows for single sup-
ply operation from industry standard 5V, 12V, and 19.6V rails.
With a proprietary emulated current mode Constant On-Time (COT) con-
trol scheme, the XR79115 provides extremely fast line and load transient
response using ceramic output capacitors. It requires no loop compensa-
tion hence simplifying circuit implementation and reducing overall compo-
nent count. The control loop also provides 0.35% load and 0.1% line
regulation and maintains constant operating frequency. A selectable
power saving mode allows the user to operate in discontinuous mode
(DCM) at light current loads thereby significantly increasing the converter
efficiency. With a 96% peak efficiency and 90% for loads as low as
100mA, the XR79115 is suitable for applications where low power losses
are important.
A host of protection features, including over-current, over-temperature,
short-circuit and UVLO, help achieve safe operation under abnormal
operating conditions.
The XR79115 is available in a RoHS compliant, green/halogen free
space-saving 68-pin 12x12x4mm QFN package. With integrated control-
ler, drivers, bootstrap diode and capacitor, MOSFETs, inductor, CIN and
COUT, this solution allows the smallest possible 15A POL design.
FEATURES
 Controller, drivers, bootstrap diode and capaci-
tor, MOSFETs, Inductor, CIN and COUT integrated
in one package
 15A Step Down Module
 Wide 5V to 22V Input Voltage Range
 >0.6V Adjustable Output Voltage
 Proprietary Constant On-Time Control
 No Loop Compensation Required
 Stable Ceramic Output Capacitor Operation
 Programmable 200ns to 2μs On-Time
 Constant 400kHz to 600kHz Frequency
 Selectable CCM or CCM/DCM
 CCM/DCM for high efficiency at light-load
 CCM for constant frequency at light-load
 Programmable Hiccup Current Limit with Ther-
mal Compensation
 Precision Enable and Power Good flag
 Programmable Soft-start
 68-pin 12x12x4mm QFN package
APPLICATIONS
 Networking and Communications
 Fast Transient Point-of-Loads
 Industrial and Medical Equipment
 Embedded High Power FPGA
Ordering Information – back page
Typical Application
VIN
Enable/Mode
Power Good
CIN
R3
VIN
PVIN
EN/MODE
PGOOD
VOUT
VCC XR79115 SW
RLIM
SS
ILIM
CVCC
CSS
TON
RON
AGND
FB
PGND
Line Regulation
1.220
1.215
VOUT
1.210
1.205
1.200
R1
1.195
COUT
1.190
R2
1.185
1.180
4 6 8 10 12 14 16 18 20 22
V_IN (V)
© 2014 Exar Corporation
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exar.com/XR79115
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