XRP6141
35A Synchronous Step Down COT Controller
December 2013
Rev. 1.0.1
GENERAL DESCRIPTION
APPLICATIONS
The XRP6141 is a synchronous step-down
controller for point-of load supplies up to 35A.
A wide 4.5V to 22V input voltage range allows
for single supply operation from industry
standard 5V, 12V and 19.6V rails.
With a proprietary emulated current mode
Constant On-Time (COT) control scheme, the
XRP6141 provides extremely fast line and load
transient response using ceramic output
capacitors. It requires no loop compensation
hence simplifying circuit implementation and
reducing overall component count.
The
control loop also provides exceptional 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.
A host of protection features, including overcurrent, over-temperature, short-circuit and
UVLO, help achieve safe operation under
abnormal operating conditions.
The XRP6141 is available in RoHS compliant,
green/halogen free space-saving 16-pin 3x3
QFN package.
• Networking and Communications
• Fast Transient Point-of-Loads
• Industrial and Medical Equipment
• Embedded High Power FPGA
FEATURES
• 35A Capable Step Down Controller
− Wide Input Voltage Range
o
o
5V to 22V Single Supply
4.5V to 5.5V Low Vin
− Integrated high Current 2A/3A Drivers
− 0.6V to 18V Adjustable Output Voltage
• Proprietary Constant On-Time Control
− No Loop Compensation Required
− Ceramic Output Cap. Stable operation
− Programmable 200ns-2µs
− Constant 200kHz-800kHz Frequency
− Selectable CCM or CCM/DCM Operation
• Programmable hiccup current limit
with thermal compensation
• Precision Enable and Power-Good Flag
• Programmable Soft-start
• Integrated Bootstrap diode
• 16-pin QFN Package
TYPICAL APPLICATION DIAGRAM
Fig. 1: XRP6141 Application Diagram
Exar Corporation
48720 Kato Road, Fremont CA 94538, USA
www.exar.com
Tel. +1 510 668-7000 – Fax. +1 510 668-7001
XRP6141
35A Synchronous Step Down COT Controller
ABSOLUTE MAXIMUM RATINGS
OPERATING RATINGS
These are stress ratings only and functional operation of
the device at these ratings or any other above those
indicated in the operation sections of the specifications
below is not implied. Exposure to absolute maximum
rating conditions for extended periods of time may affect
reliability.
VIN ........................................................... -0.3V to 22V
VCC .......................................................... -0.3V to 5.5V
SW, ILIM ................................................... -1V to 26V1
PGOOD, VCC, TON, SS, EN, GL, FB ............ -0.3V to 5.5V
Switching Frequency ............................. 200kHz-800kHz3
Junction Temperature Range ....................-40°C to 125°C
VIN ............................................................ -0.3V to 28V
VCC .......................................................... -0.3V to 6.0V
BST ......................................................... -0.3V to 34V2
BST-SW ...................................................... -0.3V to 6V
SW, ILIM .................................................. -5V to 28V1,2
GH................................................... -0.3V to BST+0.3V
GH-SW........................................................ -0.3V to 6V
ALL other pins ................................... -0.3V to VCC+0.3V
Storage Temperature .............................. -65°C to 150°C
Junction Temperature .......................................... 150°C
Power Dissipation ................................ Internally Limited
Lead Temperature (Soldering, 10 sec) ................... 300°C
ESD Rating (HBM - Human Body Model) .................... 2kV
Note 1: SW pin’s minimum DC range is -1V, transient is
-5V for less than 50ns
Note 2: No external voltage applied
Note 3: Recommended
ELECTRICAL SPECIFICATIONS
Specifications are for Operating Junction Temperature of TJ = 25°C only; limits applying over the full Operating Junction
Temperature range are denoted by a “•”. Minimum and Maximum limits are guaranteed through test, design, or statistical
correlation. Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for reference purposes
only. Unless otherwise indicated, VIN = 12V, BST=VCC, SW=GND=PGND=0V, CGH=CGL=3.3nF.
Parameter
Min.
Typ.
Max.
Units
Conditions
Power Supply Characteristics
5
12
22
4.5
5.0
5.5
IVIN, VIN supply current
0.7
2
mA
IVCC, VCC Quiescent current
0.7
2
mA
VIN, Input Voltage Range
V
•
VCC regulating
VCC tied to VIN
• Not switching, VIN=12V, VFB=0.7V
• Not switching, VCC=VIN=5V, VFB=0.7V
IVIN, VIN supply current
11
mA
f=300kHz, RON=108.8k, VFB=0.58V
IOFF, Shutdown current
0.1
μA
Enable=0V, VIN=12V
Enable and Under-Voltage Lock-Out UVLO
VIH_EN, EN Pin Rising Threshold
1.8
VEN_HYS, EN Pin Hysteresis
VIH_EN, EN Pin Rising Threshold for
DCM/CCM operation
2.0
50
2.9
VEN_HYS, EN Pin Hysteresis
VCC UVLO start threshold, rising
edge
1.9
3.0
3.1
100
4.00
VCC UVLO Hysteresis
4.25
V
•
mV
V
•
mV
4.50
200
V
•
mV
Reference voltage
0.597
0.600 0.603
V
VIN =5V-22Và VCC regulating
0.596
0.604
V
VIN =4.5V-5.5Và tie VCC to VIN
0.594
0.600 0.606
V
DC Line regulation
±0.1
%
CCM operation, closed loop, applies to any
COUT
DC Load regulation
±0.25
%
CCM operation, closed loop, applies to any
VREF, Reference voltage
© 2013 Exar Corporation
2/14
•
VIN =5V-22Và VCC regulating,
VIN =4.5V-5.5Và tie VCC to VIN
Rev. 1.0.1
XRP6141
35A Synchronous Step Down COT Controller
Parameter
Min.
Typ.
Max.
Units
Conditions
COUT
Programmable Constant On-Time
On-Time 1
f corresponding to On-Time 1
1855
2182
2509
ns
217
250
294
kHz
Minimum Programmable
On-Time
On-Time 2
109
VIN=22V, VOUT=12V
ns
RON = 7.059kΩ, VIN=22V
• RON = 7.059kΩ, VIN=12V
170
200
230
ns
f corresponding to On-Time 2
1618
1375
1196
kHz
f corresponding to On-Time 2
490
417
362
kHz
On-Time 3
391
460
529
ns
250
350
ns
Minimum Off-Time
• RON = 141.2kΩ, VIN=22V
VOUT=3.3V
VOUT=1.0V
• RON = 16.235kΩ, VIN=12V
•
Diode Emulation Mode
Zero crossing threshold
-4
-1
-14
-10
DC value measured during test
mV
SoftStart
SS Charge current
-6
µA
SS Discharge current
mA
1
VCC Linear Regulator (VCC should be tied to VIN, for 4.5V ≤VIN≤5.5V)
VCC Output Voltage
Dropout Voltage
4.8
5.0
4.51
4.7
5.2
200
300
490
-10
-7.5
-5
%
2
4
%
V
mV
•
• Fault present
• VIN=6V to 22V, Iload=0 to 30mA
• VIN=5V, Iload=0 to 20mA
• IVCC=30mA
Power Good Output
Power Good Threshold
Power Good Hysteresis
Power Good Sink Current
mA
1
Protection: OCP, OTP, Short-circuit
Hiccup timeout
ILIM pin source current
110
45
ILIM current temperature coeff.
OCP comparator offset
50
ms
55
0.4
-8
0
µA
%/°C
+8
mV
•
Current limit blanking
100
ns
GL rising>1V
Thermal shutdown threshold1
150
°C
Rising temperature
15
°C
Thermal Hysteresis1
VSCTH Feedback pin short-circuit
threshold
50
60
70
%
1.35
2.0
Ω
•
Percent of VREF, short circuit is active
After PGOOD is up
Output Gate drivers
GH Pull-Down Resistance
GH Pull-up Resistance
IGH=200mA
1.8
2.8
Ω
IGH=200mA
1.35
1.9
Ω
IGL=200mA
GL Pull-up Resistance
1.7
2.7
Ω
IGL=200mA
GH and GL pull-down Resistance
50
---
kΩ
GH and GL rise time
35
50
ns
10% to 90%
GH and GL fall time
30
40
ns
90% to 10%
GL Pull-Down Resistance
GL to GH non-overlap time
20
30
60
ns
Measured GL falling edge =1V to
GH rising edge =1V, BST=VCC, SW=0V
GH to GL non-overlap time
15
20
40
ns
Measured GH falling edge =1V to
GL rising edge =1V
Note 1: Guaranteed by design
© 2013 Exar Corporation
3/14
Rev. 1.0.1
XRP6141
35A Synchronous Step Down COT Controller
BLOCK DIAGRAM
VCC
TON
VCC UVLO
Enable LDO
VIN
4.25 V
LDO
Switching
Enabled
+
-
VCC
VCC
OTP
TJ
150 C
+
ESR
emulation &
DC correction
-
PGOOD
On-Time
+
-
Switching
Enabled
BST
0.6 V
Feedback
comparator
TON
+
-
R
Q
S
Q
PGOOD comparator
+
0.555 V
+
-
Enable LDO
EN/Mode
1.9 V
+
R
Q
S
Q
-1 mV
Hiccup
Mode
Enable LDO
-
If four
consecutive OCP
If 8 consecutive ZCD
Then DCM
If 1 non-ZCD
Then exit DCM
+
-
Zero Cross Detect
SW
GL
Enable
Hiccup
Forced CCM or DCM/CCM
3V
SW
VCC
Switching
Enabled
Short-circuit detection
0.36 V
GH
Dead
Time
Control
Minimum
On Time
-
50uA
+
-
FB
VIN
10uA
SS
OCP
comparator
+
-
AGND
ILIM
PGND
Fig. 2: XRP6141 Block Diagram
PIN ASSIGNMENT
GL
1
NC
2
PGND
VCC
VIN
AGND
16
15
14
13
12 AGND
11 FB
EXPOSED PAD
SW
3
GH
4
10 PGOOD
9
5
6
7
8
BST
ILIM
EN
TON
SS
Fig. 3: XRP6141 Pin Assignment
© 2013 Exar Corporation
4/14
Rev. 1.0.1
XRP6141
35A Synchronous Step Down COT Controller
PIN DESCRIPTION
Name
Pin Number
Description
GL
1
Driver output for Low-side N-channel synchronous MOSFET.
NC
2
Internally not connected. Leave this pin floating.
SW
3
Lower supply rail for high-side gate driver GH. Connect this pin to the junction between
the two external N-channel MOSFETs.
GH
4
Driver output for high-side N-channel switching MOSFET.
BST
5
High-side driver supply pin. Connect a 0.1uF bootstrap capacitor between BST and SW.
ILIM
6
Over-current protection programming. Connect with a resistor to the Drain of the lowside MOSFET.
EN/MODE
7
Precision enable pin. Pulling this pin above 1.9V will turn the IC on and it will operate in
Forced CCM. If the voltage is raised above 3.0V then the IC will operate in DCM or CCM
depending on load.
TON
8
Constant on-time programming pin. Connect with a resistor to AGND.
SS
9
Soft-Start pin. Connect an external capacitor between SS and AGND to program the
soft-start rate based on the 10uA internal source current.
PGOOD
10
Power-good output. This open-drain output is pulled low when VOUT is outside the
regulation.
FB
11
Feedback input to feedback comparator. Connect with a set of resistors to VOUT and
GND in order to program VOUT.
AGND
12, 13
VIN
14
VCC
15
The output of LDO. For operation using a 5V rail, VCC should be shorted to VIN.
PGND
16
Low side driver ground
Analog ground. Control circuitry of the IC is referenced to this pin.
IC supply input. Provides power to internal LDO.
Thermal pad for heat dissipation. Connect to AGND with a short trace.
Exposed Pad
ORDERING INFORMATION
Part Number
Temperature
Range
XRP6141EL-F
-40°C≤TJ≤+125°C
XRP6141ELMTR-F
-40°C≤TJ≤+125°C
XRP6141ELTR-F
XRP6141EVB
Marking
Package
Packing
Quantity
6141
YWW
XXXX
3x3mm
QFN16
250/Tape & Reel
-40°C≤TJ≤+125°C
XRP6141 Evaluation Board
Tray
3k/Tape & Reel
Note 1
Lead Free and/or
Halogen Free
“Y” = Year – “WW” = Work Week – “X” = Lot Number; when applicable.
© 2013 Exar Corporation
5/14
Rev. 1.0.1
XRP6141
35A Synchronous Step Down COT Controller
TYPICAL PERFORMANCE CHARACTERISTICS
All data taken at VIN = 12V, VOUT=1.2V, f=300kHz, TA = 25°C, unless otherwise specified - Schematic and BOM from
Application Information section of this datasheet.
1.250
1.250
+1%
1.240
1.220
1.220
1.210
1.210
1.200
1.190
1.190
1.180
1.170
1.170
1.160
1.160
1.150
0
5
10
15
20
-1%
1.200
1.180
1.150
Typical
1.230
-1%
VOUT (V)
VOUT (V)
1.230
+1%
1.240
Typical
25
5
10
15
20
VIN (V)
IOUT (A)
Fig. 5: Line regulation, IOUT=25A
Fig. 4: Load regulation, VIN=12V
SW
SW
VOUT
VOUT
IL
IL
20ms/d
2us/d
Fig. 6: VOUT ripple is 22mV at 25A, 12VIN, 1.2VOUT
Fig. 7: VOUT ripple is 22mV at 0A, DCM, 12VIN, 1.2VOUT
VIN
VIN
VOUT
VOUT
SW
SW
IL
IL
Fig. 8: Powerup, Forced CCM, IOUT=0A
Fig. 9: Powerup, Forced CCM, IOUT=25A
© 2013 Exar Corporation
6/14
Rev. 1.0.1
XRP6141
35A Synchronous Step Down COT Controller
VIN
VIN
VOUT
VOUT
SW
SW
IL
IL
Fig. 11: Powerup, DCM/CCM, IOUT=25A
100%
100%
95%
95%
90%
90%
Efficiency
Efficiency
Fig. 10: Powerup, DCM/CCM, IOUT=0A
85%
80%
75%
Forced CCM
70%
80%
75%
Forced CCM
70%
DCM/CCM
DCM/CCM
65%
65%
60%
85%
60%
0.1
1
10
0.1
IOUT (A)
100%
100%
95%
95%
90%
90%
85%
80%
75%
Forced CCM
85%
80%
75%
Forced CCM
70%
DCM/CCM
DCM/CCM
65%
65%
60%
10
Fig. 13: Efficiency, 5VIN, 1.2VOUT, 0.47uH, 300kHz
Efficiency
Efficiency
Fig. 12: Efficiency, 5VIN, 1.8VOUT, 0.47uH, 300kHz
70%
1
IOUT (A)
60%
0.1
1
10
IOUT (A)
1
10
IOUT (A)
Fig. 14: Efficiency, 5VIN, 1.0VOUT, 0.47uH, 300kHz
© 2013 Exar Corporation
0.1
Fig. 15: Efficiency, 12VIN, 3.3VOUT, 1uH, 300kHz
7/14
Rev. 1.0.1
XRP6141
100%
100%
95%
95%
90%
90%
85%
85%
Efficiency
Efficiency
35A Synchronous Step Down COT Controller
80%
75%
Forced CCM
70%
75%
Forced CCM
70%
DCM/CCM
DCM/CCM
65%
65%
60%
80%
60%
0.1
1
10
0.1
IOUT (A)
100%
100%
95%
95%
90%
90%
85%
80%
75%
Forced CCM
85%
80%
75%
Forced CCM
70%
DCM/CCM
DCM/CCM
65%
65%
60%
10
Fig. 17: Efficiency, 12VIN, 1.8VOUT, 1uH, 300kHz
Efficiency
Efficiency
Fig. 16: Efficiency, 12VIN, 2.5VOUT, 1uH, 300kHz
70%
1
IOUT (A)
60%
0.1
1
10
0.1
1
10
IOUT (A)
IOUT (A)
Fig. 18: Efficiency, 12VIN, 1.2VOUT, 0.47uH, 300kHz
Fig. 19: Efficiency, 12VIN, 1.0VOUT, 0.47uH, 300kHz
EN
VIN
VOUT
IL
1ms/d
Fig. 20: Enable turn on/turn off, 12VIN, 1.2VOUT, 25A
© 2013 Exar Corporation
8/14
Rev. 1.0.1
XRP6141
400
610
350
605
VREF (mV)
f (kHz)
35A Synchronous Step Down COT Controller
300
250
200
600
595
590
0
5
10
15
20
25
-40
-20
0
20
IOUT (A)
40
60
80
100
120
Tj (°C)
Fig. 22: frequency versu IOUT, Forced CCM
Fig. 23: VREF versus temperature
500
70
490
480
60
460
ILIM (uA)
TON (ns)
470
450
440
430
50
40
420
410
400
-40
-20
0
20
40
60
80
30
100 120
Tj (°C)
-20
0
20
40
60
80
100 120
Tj (°C)
Fig. 24: On-Time versus temperature
Fig. 25: ILIM versus temperature
IL
IL
VOUT
SW
-40
VOUT
SW
20us/d
Fig. 26: Load step, DCM/CCM, 0A-25A-0A
© 2013 Exar Corporation
20us/d
Fig. 27: Load step, Forced CCM, 0A-25A-0A
9/14
Rev. 1.0.1
XRP6141
35A Synchronous Step Down COT Controller
IL
DETAILED OPERATION
TON
XRP6141 is a synchronous step-down proprietary
emulated current-mode Constant On-Time (COT)
controller. The on-time, which is programmed via RON,
is inversely proportional to VIN and maintains a nearly
constant frequency. The emulated current-mode control
allows the use of ceramic output capacitors.
TOFF
IOUT
IL > 1mV / Rds
Each switching cycle begins with GH signal turning the
high-side (switching) FET for a preprogrammed time. At
the end of the on-time the high-side FET is turned off and
the low-side (synchronous) FET is turned on for a preset
minimum time (250ns nominal). This parameter is
termed Minimum Off-Time. After the minimum off-time
the voltage at the feedback pin FB is compared to an
internal voltage ramp at the feedback comparator. When
VFB drops below the ramp voltage, the high-side FET is
turned on and the cycle repeats. This voltage ramp
constitutes an emulated current ramp and makes
possible the use of ceramic capacitors, in addition to
other capacitor types, for output filtering.
1mV/Rds
0A
VSW
VIN
0V
-1mV
ENABLE/MODE
EN/MODE pin accepts a tri-level signal that is used to
control turn on/off. It also selects between two modes of
operation: ‘Forced CCM’ and ‘DCM/CCM’. If EN is pulled
below 1.9V the IC shuts down. A voltage between 1.9V
and 3V selects the Forced CCM mode, which will run the
converter in continuous conduction at all times. A voltage
higher than 3V selects the DCM/CCM mode, which will
run the converter in discontinuous conduction at light
loads. DCM/CCM, which is based on diode emulation, is
described below.
IL x Rds < -1mV
Figure 28. Continuous conduction during diode emulation
IL
TON
TOFF
Diode Emulation Mode (DCM/CCM)
IOUT
Diode Emulation Mode is designed to increase the
converter efficiency at light loads. Light-load efficiency is
increased by preventing negative inductor current. This is
achieved by monitoring the inductor current valley
(bottom) via SW and turning off the synchronous FET as
inductor current IL approaches zero. IL is monitored
indirectly by monitoring VSW during the synchronous FET
conduction (i.e., VSW=IL x Rds). If VSW does not drop to 1mV the converter operates in continuous conduction as
shown in figure 28. If VSW equals -1mV then a zerocrossing is detected (figure 29). Eight consecutive zerocrossings activate the diode emulation mode. Then, on
every subsequent switching cycle, GL is turned off when
VSW reaches -1mV (figure 30). If IOUT decreases further,
discontinuous conduction ensues (figure 30). The
constant on-time delivers a fixed energy at the start of
each switching cycle. The synchronous FET is turned off
when VSW drops to -1mV. Remaining inductor energy is
discharged through the FET’s body diode. Now, because
IOUT is low, it takes longer for VOUT to drop below
regulation and trigger a new switching cycle. Hence
switching frequency f decreases. This increase the
efficiency at light loads.
© 2013 Exar Corporation
1mV/Rds
0A
IL = 1mV / Rds
VSW
VIN
0V
-1mV
IL x Rds = -1mV
àZero-Cross detected
Figure 29. Zero-Crossing detection
10/14
Rev. 1.0.1
XRP6141
35A Synchronous Step Down COT Controller
IL
Where:
TON
TOFF
RLIM is resistor value for programming IOCP
IOCP is the overcurrent value to be programmed
RDS is the MOSFET rated on resistance
8mV is the OCP comparator offset
IOUT
ILIM is the internal current that generates the necessary
OCP comparator threshold (use 45uA)
1mV/Rds
0A
VSW
Note that ILIM has a positive temperature coefficient of
0.4%/°C. This is meant to roughly match and
compensate for positive temperature coefficient of the
synchronous FET. In order for this feature to be effective
the temperature rise of the IC should approximately
match the temperature rise of the FET.
IL = 1mV / Rds
VIN
VOUT
SHORT-CIRCUIT PROTECTION (SCP)
0V
If the output voltage drops below 60% of its programmed
value, the IC will enter hiccup mode. Hiccup will persist
until short-circuit is removed. SCP circuit becomes active
after PGOOD asserts high.
-1mV
IL x Rds = -1mV
à GL is turned off
Figure 30.
emulation
Discontinuous
conduction
during
OVER-TEMPERATURE PROTECTION (OTP)
diode
OTP triggers at a nominal die temperature of 150°C. The
gate of switching FET and synchronous FET are turned
off. When die temperature cools down to 135°C, softstart
is initiated and operation resumes.
PROGRAMMING THE ON-TIME
PROGRAMMING THE OUTPUT VOLTAGE
The on-time TON is programmed via resistor RON
according to following equation:
Use an external voltage divider as shown in figure 1 to
program the output voltage VOUT.
(3.4𝐸 − 10) × 𝑅𝑂𝑁
𝑇𝑂𝑁 =
𝑉𝐼𝑁
𝑉𝑂𝑈𝑇
− 1�
𝑅1 = 𝑅2 × �
0.6
R2 recommended range is 2k Ω to 10kΩ.
The required TON for a given application is calculated
from:
𝑇𝑂𝑁 =
PROGRAMMING THE SOFTSTART
𝑉𝑂𝑈𝑇
𝑉𝐼𝑁 × 𝑓
Place a capacitor CSS between the SS and GND pins to
program the softstart. In order to program a softstart
time of TSS, calculate the required capacitance CSS from
the following equation:
Note that switching frequency f will increase somewhat,
as a function of increasing load current and increasing
losses (see figure 22).
𝐶𝑆𝑆 = 𝑇𝑆𝑆 ×
10𝑢𝐴
0.6𝑉
OVER-CURRENT PROTECTION (OCP)
FEED-FORWARD CAPACITOR CFF
If load current exceeds the programmed overcurrent
IOCP for four consecutive switching cycles, then IC enters
hiccup mode of operation. In hiccup the MOSFET gates
are turned off for 110ms (hiccup timeout). Following the
hiccup timeout a soft-start is attempted. If OCP persists,
hiccup timeout will repeat. The IC will remain in hiccup
mode until load current is reduced below the
programmed IOCP. In order to program overcurrent
protection use the following equation:
A feed-forward capacitor CFF is recommended. CFF
provides a low-impedance/high-frequency path for the
output voltage ripple to be transmitted to FB. It also
helps get an optimum load transient response. Calculate
CFF from:
𝑅𝐿𝐼𝑀 =
(𝐼𝑂𝐶𝑃 × 𝑅𝐷𝑆) + 8𝑚𝑉
𝐼𝐿𝐼𝑀
© 2013 Exar Corporation
𝐶𝐹𝐹 =
11/14
1
2 × 𝜋 × 𝑓𝑠 × 0.1 × 𝑅1
Rev. 1.0.1
XRP6141
35A Synchronous Step Down COT Controller
Applications Circuit
D1
MMSZ4699T1G
R9 2.5k,
R8 1k,
R7 6k,
R6 2k
J1
1
2
3
1
2
3
Forced CCM
DCM/CCM
EN/MODE
RLIM 1.8k,1%
11.8k
EXPAD
5
BST
ILIM
GL
13
AGND
NC
4
L1 IHLP-5050FD-01
CVCC
2
1
MB
FDMS7650DC
T8
C5
22uF
T9
T10
VIN-
Csnub
6.8nF
C5,C6,C7,C8 POSCAP
2R5TPE330M7
1.2V @ 0-25A
VOUT+
C6
C7
C8
C9
C10 C11 C12 C13 T1
330uF 330uF 330uF 330uF OPEN OPEN OPEN OPEN
T2
Rsnub
1 Ohm
VOUT-
R3
0 Ohm
CFF
0.56nF
0.1uF
4.7uF
C4
22uF
0.47uH @ 41A, 1mOhm
3
T7
CIN
C3
22uF
T6
PGND
AGND
VCC
17
U1
XRP6141
FB
SW
T5
16
12
15
11
VIN
10k
PGOOD
C2
22uF
FDMS7578
RBST
0 Ohm
GH
AGND
R4
SS
14
9
10
EN
TON
47nF
PWRGD
6
8
CSS
C1
22uF
VIN+
MT
CBST 1uF
7
RON
12V
C1,C2,C3,C4
CERAMIC 1210 X7R
VIN
R1
10k,1%
T3
R5
OPEN
R2
10k,1%
VIN
T4
VCC
Note: If jumper J1 is set to CCM position, the converter will operate in ‘Forced CCM’ at VIN=12V(+/-10%). In order to
operate in Forced CCM over a wider VIN range, remove Jumper and apply an auxilary voltage in the 1.9V-3V range to the
EN/MODE test point.
If jumper J1 is set to DCM/CCM position the converter will operate at DCM or CCM, depending on load, at VIN=12V(+/10%). In order to operate in DCM/CCM over a wider VIN range, remove Jumper and apply an auxilary voltage in the 3.1V5V range to the EN/MODE test point.
© 2013 Exar Corporation
12/14
Rev. 1.0.1
XRP6141
35A Synchronous Step Down COT Controller
PACKAGE SPECIFICATION
© 2013 Exar Corporation
16 PIN 3X3 QFN
13/14
Rev. 1.0.1
XRP6141
35A Synchronous Step Down COT Controller
REVISION HISTORY
Revision
Date
Description
1.0.0
12/16/2013
Initial release
1.0.1
12/20/2013
Specification improvement
FOR FURTHER ASSISTANCE
Email:
customersupport@exar.com
powertechsupport@exar.com
Exar Technical Documentation:
http://www.exar.com/TechDoc/default.aspx?
EXAR CORPORATION
HEADQUARTERS AND SALES OFFICES
48720 Kato Road
Fremont, CA 94538 – USA
Tel.: +1 (510) 668-7000
Fax: +1 (510) 668-7030
www.exar.com
NOTICE
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 assumes no responsibility for the use of any circuits described herein,
conveys no license under any patent or other right, and makes no representation that the circuits are free of patent
infringement. Charts and schedules contained here in are only for illustration purposes and may vary depending upon a
user’s specific application. While the information in this publication has been carefully checked; no responsibility, however,
is assumed for inaccuracies.
EXAR Corporation does not recommend the use of any of its products in life support applications where the failure
malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect
safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation receives,
writing, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized; (b) the user assumes
such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances.
or
its
in
all
Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited.
© 2013 Exar Corporation
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Rev. 1.0.1
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