The
XR76201
,
XR76203
,
XR76205
and
XR76208
are synchronous
step-down regulators combining the controller, drivers, bootstrap diode
and MOSFETs in a single package for point-of-load supplies. The
XR76201, XR76203, XR76205 and XR76208 have load current ratings
of 1.5A, 3A, 5A and 8A, respectively. A wide 5V to 40V input voltage
range allows for single supply operation from industry standard 24V
±10%, 18V to 36V and rectified 18VAC and 24VAC rails.
With a proprietary emulated current mode Constant On-Time (COT)
control scheme, the XR76201, XR76203, XR76205 and XR76208
provide extremely fast line and load transient response using ceramic
output capacitors. They require no loop compensation, simplifying circuit
implementation and reducing overall component count. The control
loop also provides 0.07% load and 0.15% line regulation and maintains
constant operating frequency. A selectable power saving mode allows
the user to operate in Discontinuous Conduction Mode (DCM) at light
current loads thereby significantly increasing the converter efficiency.
A host of protection features, including over-current, over temperature,
short-circuit and UVLO, helps achieve safe operation under abnormal
operating conditions. These 40V regulators deliver power to a wide
range of industrial, networking and telecom equipment.
OVERVIEW
XR76201 40V, 1.5A
XR76203 40V, 3A
XR76205 40V, 5A
XR76208 40V, 8A
FEATURES
Controller, drivers, bootstrap diode and
MOSFETs integrated in one package
1.5A, 3A, 5A and 8A step-down regulators
5V to 40V operating range
3V to 40V PVIN with 5V bias
4.5V to 5.5V single supply operation
≥0.6V adjustable output voltage
Patented COT control
Programmable 200ns-2µs on-time
(100ns-1µs XR76201)
Constant 100kHz-800kHz switching frequency
(400kHz-800kHz XR76201)
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
thermal compensation
Precision enable and Power Good flag
Programmable soft-start
Common scalable footprint
5mm x 5mm QFN package
BENEFITS
Excellent line and load regulation compared to
standard COT
Stable with ceramic output capacitors
No compensation required
Fast transient response with ability to
work with low ESR capacitors
APPLICATIONS
Automotive infotainment
UAV or drone power systems
Industrial FPGA, DSP and SoC power
Industrial automation
XR76201/03/05/08
40V 1.5A/3A/5A/8A PowerBlox™
Synchronous Step-Down Regulators
Exar Corporation reserves the right to make changes to the products contained in this publication in order to improve design, performance
or reliability. Exar Corporation conveys no license under any patent or other right and makes no representation that the circuits are free
of patent infringement. While the information in this publication has been carefully checked, no responsibility, however, is assumed for
inaccuracies.
Reproduction, in part or whole, without the prior written consent of Exar Corporation is prohibited. Exar, XR and the XR logo are registered
trademarks of Exar Corporation. All other trademarks are the property of their respective owners.
©2016 Exar Corporation
XR7620x_FL_102016
XR76201/03/05/08
48760 Kato Road
Fremont, CA 94538
USA
Tel.: +1 (510) 668-7000
Fax: +1 (510) 668-7001
Email: powertechsupport@exar.com
www.exar.com
XR76201/03/05/08
Evaluation Board
XR76203 Efficiency
70
72
74
76
78
80
82
84
86
88
90
92
94
96
98
100
012345678
12V CCM
5.0V CCM
3.3V CCM
1.8V CCM
200kHz, 8.2
μ
H
3.3
μ
H
2.2
μ
H
1.5
μ
H
IOUT(A)
Efficiency (%)
VIN = 24V, f = 400kHz
IOUT(A)
Efficiency (%)
70
72
74
76
78
80
82
84
86
88
90
92
94
96
98
100
012345
6.8μH
4.7μH
3.3μH
2.2μH
200kHz
12V CCM
5.0V CCM
3.3V CCM
1.8V CCM
VIN = 24V, f = 400kHz
IOUT(A)
I
OUT
(A)
Efficiency (%)
70
72
74
76
78
80
82
84
86
88
90
92
94
96
98
100
0.0 1.0 2.0 3.0
3.3μH
4.7μH
6.8μH
10μH
200kHz
12V CCM
5.0V CCM
3.3V CCM
1.8V CCM
VIN = 24V, f = 400kHz
50
55
60
65
70
75
80
85
90
95
100
0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5
Efficiency (%)
12V CCM
5.0V CCM
3.3V CCM
1.8V CCM
V
IN
= 24V
L = 6.8µH
800kHz
600kHz
400kHz
700kHz
CVCC
CIN
L1
R1
R2
VOUT
COUT
PGND
FB
ILIM
SW
BST
VIN
EN/MODE
PGOOD
VCC
SS
TON
AGND
PVIN
CSS
XR7620x RLIM
CBST
RON
CFF
VIN
R
Power Good
Enable/Mode
Typical Schematic
XR76205 Efficiency XR76208 Efficiency
Part
Number
IOUT
(A)
VIN
Range
(V)
VOUT
Range
(V)
Frequency
(kHz)
Accuracy
(%)
Efficiency
(%)
Package
(mm)
Features
XR76201 1. 5
3 to 40 0.6 to 30 100 to 800 0.5
95
5 x 5
QFN
Patented COT provides fast transient
response with excellent line and load
regulation
UVLO, OTP, soft-start,adjustable
hiccup current limit and short-circuit
protection
XR76203 3 95
XR76205 5 96
XR76208 8 96
XR76201 Efficiency
