The SiC531 and SiC531A are integrated power stage
solutions optimized for synchronous buck applications
to offer high current, high efficiency, and high power
density performance. Packaged in Vishay’s proprietary
4.5 mm x 3.5 mm MLP package, SiC531 and SiC531A
enable voltage regulator designs to deliver up to 30 A
continuous current per phase.
The internal power MOSFETs utilize Vishay’s
state-of-the-art Gen IV TrenchFET
industry benchmark performance to significantly reduce
switching and conduction losses.
The SiC531 and SiC531A incorporate an advanced
MOSFET gate driver IC that features high current driving
capability, adaptive dead-time control, an integrated
bootstrap Schottky diode, and zero current detection to
improve light load efficiency. The drivers are also
compatible with a wide range of PWM controllers, support
tri-state PWM, and 3.3 V (SiC531A) / 5 V (SiC531) PWM
logic.
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
emulation is allowed. When ZCD_EN# is high, continuous conduction mode is forced.
ZCD_EN# can also be put in a high impedance mode by floating the pin. If both
ZCD_EN# and PWM are floating, the device shuts down and consumes typically 3 μA
(9 μA max.) current
Supply voltage for internal logic circuitry
Signal ground
Power stage input voltage. Drain of high-side MOSFET
Power ground
Phase node of the power stage
Supply voltage for internal gate driver
PowerPAK
®
MLP4535-22L
2
SiC5315 V PWM optimized
Document Number: 65999
Page 3
SiC531, SiC531A
=pin 1 indicator
P/N =part number code
=Siliconix logo
=ESD symbol
F
Y=year code
WW
LL
F Y W W
P/N
LL
=assembly factory code
=week code
=lot code
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PART MARKING INFORMATION
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL PARAMETER CONDITIONSLIMITUNIT
Input voltageV
Control logic supply voltageV
Drive supply voltageV
Switch node (DC voltage)
Switch node (AC voltage)
BOOT voltage (DC voltage)
BOOT voltage (AC voltage)
BOOT to PHASE (DC voltage)
BOOT to PHASE (AC voltage)
All logic inputs and outputs
(PWM and ZCD_EN#)
Max. operating junction temperatureT
Storage temperatureT
Electrostatic discharge protection
Note
(1)
The specification values indicated “AC” is V
(2)
The specification value indicates “AC voltage” is V
(3)
The specification value indicates “AC voltage” is V
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation
of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect device reliability.
(1)
(2)
(3)
Human body model, JESD22-A1143000
Charged device model, JESD22-C1011000
to P
SWH
, -8 V (< 20 ns, 10 μJ), min. and 30 V (< 50 ns), max.
GND
to P
BOOT
to V
BOOT
IN
CIN
DRV
V
SWH
V
BOOT
V
BOOT- PHASE
J
A
stg
, 36 V (< 50 ns) max.
GND
, 8 V (< 20 ns) max.
PHASE
-0.3 to 28
-0.3 to 7
-0.3 to 7
-0.3 to 28
-8 to 35
33
40
-0.3 to 7
-0.3 to 8
-0.3 to V
150
-40 to 125
-65 to 150
Vishay Siliconix
+0.3
CIN
V
°CAmbient temperatureT
V
RECOMMENDED OPERATING RANGE
ELECTRICAL PARAMETER MINIMUMTYPICALMAXIMUMUNIT
Input voltage (V
Drive supply voltage (V
Control logic supply voltage (V
BOOT to PHASE (V
Thermal resistance from junction to PCB -5-
Thermal resistance from junction to case-2.5-
S20-0486-Rev. B, 29-Jun-2020
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
Vishay Siliconix
LIMITS
-225-
-325-
-225-
-275-
-20-
-150-
-20-
-10-
-20-
-10-
-575-mV
Document Number: 65999
UNIT
μA
mA
V
mV
μA
V
mV
μA
ns
V
Page 5
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DETAILED OPERATIONAL DESCRIPTION
PWM Input with Tri-state Function
The PWM input receives the PWM control signal from the VR
controller IC. The PWM input is designed to be compatible
with standard controllers using two state logic (H and L) and
advanced controllers that incorporate tri-state logic (H, L,
and tri-state) on the PWM output. For two state logic, the
PWM input operates as follows. When PWM is driven above
V
PWM_TH_R
turned on. When PWM input is driven below V
high-side is turned off and the low-side is turned on. For
tri-state logic, the PWM input operates as previously stated
for driving the MOSFETs when PWM is logic high and logic
low. However, there is a third state that is entered as the
PWM output of tri-state compatible controller enters its high
impedance state during shut-down. The high impedance
state of the controller’s PWM output allows the SiC531 and
SiC531A to pull the PWM input into the tri-state region (see
definition of PWM logic and tri-state, fig. 4). If the PWM input
stays in this region for the tri-state hold-off period, t
both high-side and low-side MOSFETs are turned off. The
function allows the VR phase to be disabled without
negative output voltage swing caused by inductor ringing
and saves a Schottky diode clamp. The PWM and tri-state
regions are separated by hysteresis to prevent false
triggering. The SiC531A incorporates PWM voltage
thresholds that are compatible with 3.3 V logic and the
SiC531 thresholds are compatible with 5 V logic.
Diode Emulation Mode (ZCD_EN#)
When ZCD_EN# pin is logic low and PWM signal switches
low, GL is forced ON (after normal BBM time). During this
time, it is under control of the ZCD (zero crossing detect)
comparator. If, after the internal blanking delay, the inductor
current becomes zero, the low-side is turned OFF. This
improves light load efficiency by avoiding discharge of
output capacitors. If PWM enters tri-state, then device will
go into normal tri-state mode after tri-state delay. The GL
output will be turned OFF regardless of Inductor current, this
is an alternative method of improving light load efficiency by
reducing switching losses.
Voltage Input (V
This is the power input to the drain of the high-side power
MOSFET. This pin is connected to the high power
intermediate BUS rail.
Switch Node (V
The switch node, V
This is the output applied to the power inductor and output
filter to deliver the output for the buck converter. The PHASE
pin is internally connected to the switch node, V
is to be used exclusively as the return pin for the BOOT
capacitor. A 20 k resistor is connected between GH and
PHASE to provide a discharge path for the HS MOSFET in
the event that V
the low-side is turned off and the high-side is
PWM_TH_F
)
IN
and PHASE)
SWH
, is the circuit power stage output.
SWH
SWH
goes to zero while VIN is still applied.
CIN
the
TSHO
. This pin
SiC531, SiC531A
Vishay Siliconix
Ground Connections (C
P
(power ground) should be externally connected to
GND
C
(signal ground). The layout of the printed circuit board
GND
should be such that the inductance separating C
is minimized. Transient differences due to inductance
P
GND
effects between these two pins should not exceed 0.5 V.
Control and Drive Supply Voltage Input (V
V
is the bias supply for the gate drive control IC. V
CIN
the bias supply for the gate drivers. It is recommended to
separate these pins through a resistor. This creates a low
pass filtering effect to avoid coupling of high frequency gate
drive noise into the IC.
Bootstrap Circuit (BOOT)
The internal bootstrap diode and an external bootstrap
capacitor form a charge pump that supplies voltage to the
BOOT pin. An integrated bootstrap diode is incorporated so
,
that only an external capacitor is necessary to complete the
bootstrap circuit. Connect a boot strap capacitor with one
leg tied to BOOT pin and the other tied to PHASE pin.
Shoot-Through Protection and Adaptive Dead Time
The SiC531 and SiC531A have an internal adaptive logic to
avoid shoot through and optimize dead time. The shoot
through protection ensures that both high-side and low-side
MOSFETs are not turned on at the same time. The adaptive
dead time control operates as follows. The high-side and
low-side gate voltages are monitored to prevent the
MOSFET turning on from tuning on until the other
MOSFET’s gate voltage is sufficiently low (< 1 V). Built in
delays also ensure that one power MOSFET is completely
off, before the other can be turned on. This feature helps to
adjust dead time as gate transitions change with respect to
output current and temperature.
Under Voltage Lockout (UVLO)
During the start up cycle, the UVLO disables the gate
drive, holding high-side and low-side MOSFET gates low,
until the supply voltage rail has reached a point at which
the logic circuitry can be safely activated. The SiC531 and
SiC531A also incorporate logic to clamp the gate drive
signals to zero when the UVLO falling edge triggers the
shutdown of the device. As an added precaution, a 20 k
resistor is connected between GH and PHASE to provide a
discharge path for the HS MOSFET.
1. Route the PWM and ZCD_EN# signal traces out of the
top left corner next to pin 1.
2. The PWM signal is an important signal, both signal and
return traces should not cross any power nodes on any
layer.
3. It is best to “shield” these traces from power switching
nodes, e.g. V
, with a GND island to improve signal
SWH
integrity.
4. GL (pin 19) has been connected with GL pad (pin 24)
internally.
Step 6: Adding Thermal Relief Vias
A
GND
P
GND
V
IN
Plane
P
GND
VINPlane
1. Thermal relief vias can be added on the V
pads to utilize inner layers for high-current and thermal
dissipation.
2. To achieve better thermal performance, additional vias
can be placed on VIN plane and P
3. V
pad is a noise source, it is not recommended to
SWH
GND
plane.
place vias on this pad.
4. 8 mil vias for pads and 10 mils vias for planes are the
optimal via sizes. Vias on pad may drain solder during
assembly and cause assembly issues. Consult with the
assembly house for guidelines.
V
SWH
and A
IN
GND
Step 7: Ground Connection
A
GND
P
GND
V
SWH
1. It is recommended to make a single connection between
A
GND
and P
which can be made on the top layer.
GND
2. It is recommended to make the entire first inner layer
(below top layer) the ground plane and separate them
into A
GND
and P
GND
planes.
3. These ground planes provide shielding between noise
sources on top layer and signal traces on bottom layer.
Vishay Siliconix maintains worldwide manufacturing capability. Products may be manufactured at one of several qualified locations. Reliability data for Silicon
Technology and Package Reliability represent a composite of all qualified locations. For related documents such as package / tape drawings, part marking, and
reliability data, see www.vishay.com/ppg?65999
S20-0486-Rev. B, 29-Jun-2020
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
Page 16
Legal Disclaimer Notice
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Vishay
Disclaimer
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with the properties described in the product specification is suitable for use in a particular application. Parameters provided in
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