The SiC634 is 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
5 mm x 5 mm
enables voltage regulator designs to deliver up to 50 A
continuous current per phase.
The internal power MOSFETs utilizes Vishay’s
state-of-the-art Gen IV TrenchFET® technology that delivers
industry benchmark performance to significantly reduce
switching and conduction losses.
The SiC634 incorporates 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 driver is also compatible with a wide range of PWM
controllers, supports tri-state PWM, and 5 V PWM logic.
A user selectable diode emulation mode (ZCD_EN#) is
included to improve the light load performance. The device
also supports PS4 mode to reduce power consumption
when system operates in standby state.
MLP package, SiC634
FEATURES
• Thermally enhanced PowerPAK® MLP55-31L
package
• Vishay’s Gen IV MOSFET technology and a
low-side MOSFET with integrated Schottky
diode
• Delivers in excess of 50 A continuous current, 55 A at
10 ms peak current
• High efficiency performance
• High frequency operation up to 2 MHz
• Power MOSFETs optimized for 19 V input stage
• 5 V PWM logic with tri-state and hold-off
• Supports PS4 mode light load requirement for IMVP8 with
low shutdown supply current (5 V, 3 μA)
• Under voltage lockout for V
CIN
• Material categorization: for definitions of compliance
please see www.vishay.com/doc?99912
APPLICATIONS
• Multi-phase VRDs for computing, graphics card and
memory
• Intel IMVP-8 VRPower delivery
- V
- V
• Up to 24 V rail input DC/DC VR modules
CORE
, V
GRAPHICS
, V
platforms
for Apollo Lake platforms
CCGI
SYSTEM AGENT
Skylake, Kabylake
TYPICAL APPLICATION DIAGRAM
5VV
V
DRV
V
CIN
ZCD_EN#
PWM
controller
S20-0485-Rev. C, 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
The ZCD_EN# pin enables or disables diode emulation. When ZCD_EN# is LOW, diode emulation is
2ZCD_EN#
3V
CIN
5BOOTHigh-side driver bootstrap voltage
4, 6, 30, 31N.C.
7PHASEReturn path of high-side gate driver
8 to 11, 34V
12 to 15, 28, 35P
27, 33GLLow-side MOSFET gate signal
16 to 26V
29V
S20-0485-Rev. C, 29-Jun-2020
32C
ORDERING INFORMATION
PART NUMBERPACKAGEMARKING CODEOPTION
SiC634CD-T1-GE3PowerPAK MLP55-31LSiC6345 V PWM optimized
SiC634DBReference board
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
IN
GND
SWH
DRV
GND
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
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
Pin 4 can be either left floating or connected to C
connected to GND or not internally connected depending on manufacturing
location.
Factory code “G” on line 3, pin 4 = C
Factory code “T” on line 3, pin 4 = not internally connected
GND
. Internally it is either
GND
P/N
LL
G Y W W
Power stage input voltage. Drain of high-side MOSFET
• 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)
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
(1)
(2)
(3)
Human body model, JESD22-A1142000
Charged device model, JESD22-C1011000
to P
SWH
-8 V (< 20 ns, 10 μJ), min. and 35 V (< 50 ns), max.
GND
to P
BOOT
to V
BOOT
IN
CIN
DRV
V
SWH
V
BOOT
V
BOOT-PHASE
J
A
stg
, 40 V (< 50 ns) max.
GND
, 8 V (< 50 ns) max.
PHASE
-0.3 to +28
-0.3 to +7
-0.3 to +7
-0.3 to +28
-7 to +35
-0.3 to +7
-0.3 to +8
-0.3 to V
150
-40 to +125
-65 to +150
Vishay Siliconix
33
40
+0.3
CIN
V
°CAmbient temperature T
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 ambient -10.6-
Thermal resistance from junction to case-1.6-
S20-0485-Rev. C, 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
Document Number: 76784
SiC634
UNIT
μAV
mA
V
mV
μA
V
mV
μA
ns
V
Page 5
www.vishay.com
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 an 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 SiC634 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
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 SiC634 incorporates PWM voltage
thresholds that are compatible with 5 V.
Diode Emulation Mode and PS4 Mode (ZCD_EN#)
The ZCD_EN# pin enables or disables diode emulation
mode. When ZCD_EN# is driven below V
emulation is allowed. When ZCD_EN# is driven above
V
TH_ZCD_EN#_R
Diode emulation mode allows for higher converter efficiency
under light load situations. With diode emulation active, the
SiC634 will detect the zero current crossing of the output
inductor and turn off the low-side MOSFET. This ensures
that discontinuous conduction mode (DCM) is achieved.
Diode emulation is asynchronous to the PWM signal,
therefore, the SiC634 will respond to the ZCD_EN# input
immediately after it changes state.
The ZCD_EN# pin can be floated resulting in a high
impedance state. High impedance on the input of ZCD_EN#
combined with a tri-stated PWM output will shut down the
SiC634, reducing current consumption to typically 5 μA.
This is an important feature in achieving the low standby
current requirements required in the PS4 state in ultrabooks
and notebooks.
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.
the low-side is turned on and the high-side is
TSHO
the
, both
, diode
PWM_TH_F
TH_ZCD_EN#_F
, continuous conduction mode is forced.
)
IN
SiC634
Vishay Siliconix
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.
Ground Connections (C
P
(power ground) should be externally connected
GND
to C
(control signal ground). The layout of the printed
GND
circuit board should be such that the inductance separating
and P
C
GND
GND
inductance 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 SiC634 has 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 one
turning on from tuning on until the other's gate voltage is
sufficiently low (< 1 V). Built in delays also ensure that one
power MOS 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 SiC634 also
incorporates logic to clamp the gate drive signals to zero
when the UVLO falling edge triggers the shutdown of the
device.
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
7
Document Number: 76784
Page 8
www.vishay.com
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
200 300 400 500 600 700 800 900 1000 1100
Power Loss, P
L
(W)
Switching Frequency, fS (kHz)
I
OUT
= 25 A
62
66
70
74
78
82
86
90
94
98
0510 15 2025 3035 40 4550
Efciency (%)
Output Current, I
OUT
(A)
Complete converter efciency
P
IN
= [(VINx IIN) + 5 V x (I
VDRV
+ I
VCIN
)]
P
OUT
= V
OUT
x I
OUT
, measured at output capacitor
1 MHz
750 kHz
500 kHz
15
20
25
30
35
40
45
50
55
60
0 153045607590105120135150
Output Current, I
OUT
(A)
PCB Temperature, T
PCB
(°C)
1 MHz
500 kHz
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
0510 15 2025 3035 40 4550
Power Loss, P
L
(W)
Output Current, I
OUT
(A)
750 kHz
1MHz
500 kHz
Vishay Siliconix
ELECTRICAL CHARACTERISTICS
Test condition: VIN = 13 V (unless otherwise stated), V
natural convection cooling (All power loss and normalized power loss curves show SiC634 losses only unless otherwise stated)
94
90
DRV
= V
= 5 V, ZCD_EN# = 5 V, V
CIN
OUT
= 1 V, L
= 250 nH (DCR = 0.32 m), TA = 25 °C,
OUT
SiC634
86
500 kHz
82
78
Efciency (%)
74
750 kHz
1 MHz
70
Complete converter efciency
P
66
62
= [(VINx IIN) + 5 V x (I
IN
P
= V
x I
OUT
, measured at output capacitor
OUT
OUT
0510 15 2025 30 3540 45 50
Output Current, I
VDRV
OUT
+ I
)]
VCIN
(A)
Fig. 6 - Efficiency vs. Output Current (V
= 12.6 V)
IN
Fig. 9 - Safe Operating Area (V
= 12.6 V)
IN
Fig. 7 - Power Loss vs. Switching Frequency (V
Fig. 8 - Efficiency vs. Output Current (V
S20-0485-Rev. C, 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
Test condition: VIN = 13 V (unless otherwise stated), V
natural convection cooling (All power loss and normalized power loss curves show SiC634 losses only unless otherwise stated)
DRV
= V
= 5 V, ZCD_EN# = 5 V, V
CIN
OUT
= 1 V, L
= 250 nH (DCR = 0.32 m), TA = 25 °C,
OUT
SiC634
4.2
4.0
(V)
CIN
3.8
3.6
V
UVLO_RISING
3.4
3.2
V
3.0
2.8
Control Logic Supply Voltage, V
UVLO_FALLING
2.6
-60 -40 -20020 40 6080 100 120 140
Temperature (°C)
Fig. 12 - UVLO Threshold vs. Temperature
4.8
(V)
PWM
4.2
3.6
V
TH_PWM_R
V
TRI_TH_F
3.0
2.4
1.8
V
TRI
V
TRI_TH_R
1.2
PWM Threshold Voltage, V
0.6
V
TH_PWM_F
0.0
-60 -40 -20020 40 6080 100 120 140
Temperature (°C)
Fig. 13 - PWM Threshold vs. Temperature
0.80
0.75
(V)
F
IF= 2 mA
0.70
0.65
0.60
0.55
0.50
BOOT Diode Forward Voltage, V
0.45
0.40
-60 -40 -20020 40 6080 100 120 140
Temperature (°C)
Fig. 15 - BOOT Diode Forward Voltage vs. Temperature
4.8
(V)
4.2
V
ZCD_EN#
3.6
3.0
TH_ZCD_EN#_R
V
TRI_ZCD_EN#_ F
2.4
V
TRI_ZCD_EN#_R
1.8
1.2
0.6
ZCD_EN# Threshold Voltage, V
V
TH_ZCD_EN#_F
0.0
-60 -40 -20020 40 6080 100 120 140
Temperature (°C)
Fig. 16 - ZCD_EN# Threshold vs. Temperature
1.8
1.6
PS4EXIT
1.4
1.2
1.0
0.8
0.6
0.4
Normalized PS4 Exit Latency, t
0.2
-60 -40 -20020 40 6080 100 120 140
Temperature (°C)
Fig. 14 - PS4 Exit Latency vs. Temperature
S20-0485-Rev. C, 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
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
1. The components should be placed close to IC, directly
between PHASE (pin 7) and BOOT (pin 5)
2. To reduce parasitic inductance, chip size 0402 can be
used
10
Document Number: 76784
Page 11
www.vishay.com
VIN plane
P
GND
plane
V
SWH
P
GND
V
IN
C
GND
V
SWH
P
GND
C
GND
SiC634
Vishay Siliconix
Step 5: Signal Routing
C
GND
C
GND
P
GND
1. Route the PWM / ZCD_EN# signal traces out of the top
left corner, next to DrMOS pin 1
2. PWM is an important signal, both signal and return
traces should not cross any power nodes on any layer
3. It is best to “shield” traces form power switching nodes,
e.g. V
, to improve signal integrity
SWH
4. GL (pin 27) has been connected with GL pad internally
and does not need to connect externally
Step 6: Adding Thermal Relief Vias
1. Thermal relief vias can be added on the VIN and P
pads to utilize inner layers for high-current and thermal
dissipation
2. To achieve better thermal performance, additional vias
can be added to VIN and P
3. V
pad is a noise source and not recommended to put
SWH
GND
planes
vias on this plane
4. 8 mil vias for pads and 10 mils vias for planes are the
optimal via sizes. Vias on pads may drain solder during
assembly and cause assembly issue. Please consult
with the assembly house for guideline
Step 7: Ground Connection
1. It is recommended to make a single connection between
C
GND
and P
, this connection can be done on top
GND
layer
2. It is recommended to make the entire first inner layer
(next to top layer) a ground plane and separate it into
C
GND
and P
GND
plane
3. These ground planes provide shielding between noise
sources on top layer and signal traces on bottom layer
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
Document Number: 76784
Page 12
SiC634
www.vishay.com
Multi-Phases VRPower PCB Layout
The following is an example of 6 phase layout. As can be seen, all the VRPower stages are lined in X-direction compactly with
decoupling capacitors next to them. The inductors are placed as close as possible to the SiC634 to minimize the PCB copper
loss. Vias are applied on all PADs (VIN, P
optimized. Large copper planes are used for all high current loops, such as VIN, V
duplicated in other layers to minimize the inductance and resistance. All the control signals are routed from the SiC634 to a
controller placed to the north of the power stage through inner layers to avoid the overlap of high current loops. This achieves
a compact design with the output from the inductors feeding a load located to the south of the design as shown in the figure.
V
IN
P
GND
GND
, C
) of the SiC634 to ensure that both electrical and thermal performance are
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
12
Document Number: 76784
Page 13
www.vishay.com
PRODUCT SUMMARY
Part numberSiC634
Description50 A power stage, 4.5 V
Input voltage min. (V)4.5
Input voltage max. (V)24
Continuous current rating max. (A)50
Switch frequency max. (kHz)2000
Enable (yes / no)No
Monitoring features-
ProtectionUVLO, THDN
Light load modeZCD, PS4
Pulse-width modulation (V)5
Package typePowerPAK MLP55-31L
Package size (W, L, H) (mm)5.0 x 5.0 x 0.75
Status code2
Product typeVRPower (DrMOS)
ApplicationsComputer, industrial, networking
to 24 VIN, 5 V PWM with ZCD, PS4 mode
IN
SiC634
Vishay Siliconix
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?76784
S20-0485-Rev. C, 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 17
Legal Disclaimer Notice
www.vishay.com
Vishay
Disclaimer
ALL PRODUCT, PRODUCT SPECIFICATIONS AND DATA ARE SUBJECT TO CHANGE WITHOUT NOTICE TO IMPROVE
RELIABILITY, FUNCTION OR DESIGN OR OTHERWISE.
Vishay Intertechnology, Inc., its affiliates, agents, and employees, and all persons acting on its or their behalf (collectively,
“Vishay”), disclaim any and all liability for any errors, inaccuracies or incompleteness contained in any datasheet or in any other
disclosure relating to any product.
Vishay makes no warranty, representation or guarantee regarding the suitability of the products for any particular purpose or
the continuing production of any product. To the maximum extent permitted by applicable law, Vishay disclaims (i) any and all
liability arising out of the application or use of any product, (ii) any and all liability, including without limitation special,
consequential or incidental damages, and (iii) any and all implied warranties, including warranties of fitness for particular
purpose, non-infringement and merchantability.
Statements regarding the suitability of products for certain types of applications are based on Vishay's knowledge of typical
requirements that are often placed on Vishay products in generic applications. Such statements are not binding statements
about the suitability of products for a particular application. It is the customer's responsibility to validate that a particular product
with the properties described in the product specification is suitable for use in a particular application. Parameters provided in
datasheets and / or specifications may vary in different applications and performance may vary over time. All operating
parameters, including typical parameters, must be validated for each customer application by the customer's technical experts.
Product specifications do not expand or otherwise modify Vishay's terms and conditions of purchase, including but not limited
to the warranty expressed therein.
Hyperlinks included in this datasheet may direct users to third-party websites. These links are provided as a convenience and
for informational purposes only. Inclusion of these hyperlinks does not constitute an endorsement or an approval by Vishay of
any of the products, services or opinions of the corporation, organization or individual associated with the third-party website.
Vishay disclaims any and all liability and bears no responsibility for the accuracy, legality or content of the third-party website
or for that of subsequent links.
Except as expressly indicated in writing, Vishay products are not designed for use in medical, life-saving, or life-sustaining
applications or for any other application in which the failure of the Vishay product could result in personal injury or death.
Customers using or selling Vishay products not expressly indicated for use in such applications do so at their own risk. Please
contact authorized Vishay personnel to obtain written terms and conditions regarding products designed for such applications.
No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document or by
any conduct of Vishay. Product names and markings noted herein may be trademarks of their respective owners.