- Output voltage tracking and sequencing with pre-bias
start up
- ± 1 % output voltage accuracy at -40 °C to +125 °C
• Highly efficient
- 97 % peak efficiency
- 1 μA supply current at shutdown
- 50 μA operating current not switching
• Highly configurable
- Four programmable switching frequencies available:
300 kHz, 500 kHz, 750 kHz, and 1 MHz
- Adjustable soft start and adjustable current limit
- Three modes of operation: forced continuous
conduction, power save (SiC43xB, SiC43xD), or
ultrasonic (SiC43xA, SiC43xC)
• Robust and reliable
- Cycle-by-cycle current limit
- Output overvoltage protection
- Output undervoltage / short circuit protection with auto
retry
- Power good flag and over temperature protection
• Material categorization: for definitions of compliance
please see
www.vishay.com/doc?99912
LINKS TO ADDITIONAL RESOURCES
Simulation
Tool
Evaluation
Boards
Design Tools
DESCRIPTION
The SiC43x are synchronous buck regulators with
integrated high side and low side power MOSFETs. Its
power stage is capable of supplying 12 A (SiC437) and 8 A
(SiC438) continuous current at up to 1 MHz switching
frequency. This regulator produces an adjustable output
voltage down to 0.6 V from 3 V to 28 V input rail to
accommodate a variety of applications, including
computing, consumer electronics, telecom, and industrial.
SiC437’s and SiC438’s architecture delivers ultrafast
transient response with minimum output capacitance and
tight ripple regulation at very light load. The device is
internally compensated and is stable with any capacitor. No
external ESR network is required for loop stability purposes.
The device also incorporates a power saving scheme that
significantly increases light load efficiency.
The regulator family integrates a full protection feature set,
including output overvoltage protection (OVP), cycle by
cycle overcurrent protection (OCP) short circuit protection
(SCP) and thermal shutdown (OTP). It also has UVLO and a
user programmable soft start.
The SiC437 and SiC438 are available in lead (Pb)-free power
enhanced MLP-44L package in 4 mm x 4 mm dimension.
APPLICATIONS
•
•
•
•
5 V, 12 V, and 24 V input rail POLs
Desktop, notebooks, server, and industrial computing
Industrial and automation
consumer electronics
TYPICAL APPLICATION CIRCUIT AND PACKAGE OPTIONS
Axis Title
100
98
EN
P
GOOD
INPUT
3.0 V
DC
to 24 V
DC
V
IN
V
DD
C
IN
V
DRV
MODE1
MODE2
P
GND
A
GND
BOOT
10000
96
2nd line
eff - Efficiency (%)
C
BOOT
V
OUT
94
92
90
88
86
84
Phase
V
OUT
= 5 V, L = 1.5 µH
1000
SiC43x
SW
GL
V
OUT
V
FB
R
UP
R
DOWN
C
OUT
V
OUT
= 1.2 V, L = 0.56 µH
100
82
80
0
1
2
3
4
5
6
7
8
9 10 11 12
I
OUT
- Output Current (A)
10
Fig. 1 - Typical Application Circuit
Fig. 2 - Efficiency vs. Output Current
(V
IN
= 12 V, f
sw
= 500 kHz, Power Saving Mode)
S20-0679-Rev. D, 27-Aug-2020
Document Number: 75921
1
For technical questions, contact:
powerictechsupport@vishay.com
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
1st line
2nd line
SiC437, SiC438
www.vishay.com
PIN CONFIGURATION
21 MODE1
20 MODE2
20 MODE2
21 MODE1
24 PHASE
24 PHASE
1 V
IN
2 V
IN
3 P
GND
4 P
GND
23 BOOT
18 V
OUT
19 EN
23 BOOT
26
V
IN
SW
6
22 V
IN
18 V
OUT
19 EN
22 V
IN
27
P
GND
SW
7
Vishay Siliconix
Pin 1 indicator
17 FB
V
IN
1
V
IN
2
16 A
GND
15 V
DD
14 P
GOOD
P
GND
3
P
GND
4
13 P
GND
12 V
DRV
11
GL
SW
6
GL
10
SW
7
SW
8
SW
9
SW
5
FB 17
A
GND
16
V
DD
15
P
GOOD
14
P
GND
13
V
DRV
12
GL
11
GL
10
SW
9
SW
8
SW
5
28
GL
25
A
GND
Fig. 3 - SiC43x Pin Configuration
PIN DESCRIPTION
PIN NUMBER
1, 2, 22, 26
3, 4, 13, 27
5 to 9
10, 11, 28
12
14
15
16, 25
17
18
19
20
21
23
24
SYMBOL
V
IN
P
GND
SW
GL
V
DRV
P
GOOD
V
DD
A
GND
FB
V
OUT
EN
MODE2
MODE1
BOOT
PHASE
DESCRIPTION
Input voltage
Power signal return ground
Switching node signal; output inductor connection point
Low side power MOSFET gate signal
Supply voltage for internal gate driver. Connect a 2.2 μF decoupling capacitor to P
GND
Power good signal output; open drain
Supply voltage for internal logic. Connect a 1 μF decoupling capacitor to A
GND
Analog signal return ground
Output voltage feedback pin; connect to V
OUT
through a resistor divider network.
Output voltage sense pin
Enable pin
Soft start and current limit selection; connect a resistor to V
DD
or A
GND
per table 2
Operating mode and switching frequency selection; connect a resistor to V
DD
or A
GND
per table 1
Bootstrap pin; connect a capacitor to PHASE pin for HS power MOSFET gate voltage supply
Switching node signal for bootstrap return path
ORDERING INFORMATION
PART NUMBER
SiC437AED-T1-GE3
SiC437BED-T1-GE3
SiC437CED-T1-GE3
SiC437DED-T1-GE3
SiC438AED-T1-GE3
SiC438BED-T1-GE3
SiC438CED-T1-GE3
SiC438DED-T1-GE3
PART
MARKING
SiC437A
SiC437B
SiC437C
SiC437D
SiC438A
SiC438B
SiC438C
SiC438D
8A
External
12 A
External
Internal
MAXIMUM
CURRENT
V
DD
, V
DRV
Internal
LIGHT LOAD
MODE
Ultrasonic
Power saving
Ultrasonic
Power saving
Ultrasonic
Power saving
Ultrasonic
Power saving
-40 °C to +125 °C
PowerPAK
®
MLP44-24L
OPERATING
JUNCTION
TEMPERATURE
PACKAGE
S20-0679-Rev. D, 27-Aug-2020
Document Number: 75921
2
For technical questions, contact:
powerictechsupport@vishay.com
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
SiC437, SiC438
www.vishay.com
Vishay Siliconix
CONDITIONS
Reference to P
GND
Reference to P
GND
Reference to P
GND
Reference to P
GND
100 ns;
reference to P
GND
Reference to P
GND
LIMITS
-0.3 to +30
-0.3 to +22
-0.3 to +6
-0.3 to +30
-8 to +35
-0.3 to +6
-0.3 to +6
-0.3 to +0.3
Reference to A
GND
Reference to A
GND
T
J
T
STG
-0.3 to +30
-0.3 to +6
-40 to +150
-65 to +150
16
2
Ambient temperature = 25 °C
Human body model
Charged device model
7.75
4000
1000
V
UNIT
ABSOLUTE MAXIMUM RATINGS
(T
A
= 25 °C, unless otherwise noted)
ELECTRICAL PARAMETER
V
IN
V
OUT
V
DD
/ V
DRV
SW / PHASE
SW / PHASE (AC)
BOOT
BOOT to SW
A
GND
to P
GND
EN
All other pins
Temperature
Junction temperature
Storage temperature
Power Dissipation
Junction to ambient thermal impedance (R
JA
)
Junction to case thermal impedance (R
JC
)
Maximum power dissipation
ESD Protection
Electrostatic discharge protection
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.
°C
°C/W
W
V
RECOMMENDED OPERATING CONDITIONS
(all voltages referenced to GND = 0 V)
PARAMETER
Input voltage (V
IN
) (SiC43xA, SiC43xB)
Input voltage (V
IN
) (SiC43xC, SiC43xD)
Logic supply voltage, gate driver supply voltage (V
DD
, V
DRV
)
(SiC43xC, SiC43xD)
Enable (EN)
Input voltage (V
IN
), external supply on V
DD
/ V
DRV
Output voltage (V
OUT
)
Temperature
Recommended ambient temperature
Operating junction temperature
-40 to +105
-40 to +125
°C
MIN.
4.5
3
4.5
0
3
0.6
TYP.
-
-
-
-
-
-
MAX.
28
28
28
28
28
0.9 x V
IN
and < 20 V
V
UNIT
S20-0679-Rev. D, 27-Aug-2020
Document Number: 75921
3
For technical questions, contact:
powerictechsupport@vishay.com
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
SiC437, SiC438
www.vishay.com
Vishay Siliconix
SYMBOL
TEST CONDITIONS
V
IN
= 6 V to 28 V
(SiC43xA, SiC43xB)
MIN.
TYP.
MAX.
UNIT
ELECTRICAL SPECIFICATIONS
(V
IN
= 12 V, V
EN
= 5 V, T
J
= -40 °C to +125 °C, unless otherwise stated)
PARAMETER
Power Supplies
V
DD
supply
V
DD
UVLO threshold, rising
V
DD
UVLO hysteresis
Maximum V
DD
current
V
DRV
supply
Maximum V
DRV
current
Input current
Shutdown current
Controller and Timing
Feedback voltage
V
FB
input bias current
Minimum on-time
t
ON
accuracy
On-time range
Minimum frequency, skip mode
Minimum off-time
Power MOSFETs (SiC437)
High side on resistance
Low side on resistance
Power MOSFETs (SiC438)
High side on resistance
Low side on resistance
Fault Protections
Over current protection
(inductor valley current)
Output OVP threshold
Output UVP threshold
Over temperature protection
Power Good
Power good output threshold
Power good hysteresis
Power good on resistance
Power good delay time
EN / MODE / Ultrasonic Threshold
EN logic high level
EN logic low level
EN pull down resistance
Switching Frequency
f
sw
= 300 kHz
MODE1 (switching frequency)
R
MODE1
f
sw
= 500 kHz
f
sw
= 750 kHz
f
sw
= 1000 kHz
-
90
180
450
51
100
200
499
55
110
220
550
k
V
EN_H
V
EN_L
R
EN
1.6
-
-
-
-
5
-
0.4
-
V
M
V
FB_RISING_VTH_OV
V
FB_FALLING_VTH_UV
V
FB_HYST
R
ON_PGOOD
t
DLY_PGOOD
V
FB
rising above 0.6 V reference
V
FB
falling below 0.6 V reference
-
-
-
-
15
20
-10
40
7.5
25
-
-
-
15
35
%
mV
μs
I
OCL_P
V
OVP
V
UVP
T
OTP_RISING
T
OTP_HYST
T
J
= -10 °C to +125 °C
V
FB
with respect to 0.6 V reference
Rising temperature
Hysteresis
-20
-
-
-
-
-
20
-80
150
25
20
-
-
-
-
°C
%
R
ON_HS
R
ON_LS
V
DRV
= 5 V, T
A
= 25 °C
-
-
10.1
5.5
-
-
m
R
ON_HS
R
ON_LS
V
DRV
= 5 V, T
A
= 25 °C
-
-
10.1
3.9
-
-
m
V
FB
I
FB
t
ON_MIN.
t
ON_ACCURACY
t
ON_RANGE
f
SW_MIN.
t
OFF_MIN.
Ultrasonic version (SiC43xA, SiC43xC)
Power save version (SiC43xB, SiC43xD)
T
J
= 25 °C
T
J
= -40 °C to +125 °C
(1)
597
594
-
-
-10
65
20
0
205
600
600
2
50
-
-
-
-
250
603
606
-
65
10
2250
30
-
305
m/V
nA
ns
%
ns
kHz
ns
V
DD
V
DD_UVLO
V
DD_UVLO_HYST
I
DD
V
DRV
I
DRV
IV
IN
IV
IN_SHDN
V
IN
= 6 V to 28 V
V
IN
= 6 V to 28 V
(SiC43xA, SiC43xB)
V
IN
= 6 V to 28 V
Non-switching, V
FB
> 0.6 V
V
EN
= 0 V
4.75
3.3
-
3
4.75
50
-
-
5
3.6
300
-
5
-
50
0.5
5.25
3.9
-
-
5.25
-
120
3
mV
mA
V
mA
μA
V
S20-0679-Rev. D, 27-Aug-2020
Document Number: 75921
4
For technical questions, contact:
powerictechsupport@vishay.com
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
SiC437, SiC438
www.vishay.com
Vishay Siliconix
SYMBOL
TEST CONDITIONS
Connect R
MODE2
between
MODE2 and A
GND
Connect R
MODE2
between
MODE2 and V
DD
I
OCP
= 18 A
MIN.
TYP.
MAX.
UNIT
ELECTRICAL SPECIFICATIONS
(V
IN
= 12 V, V
EN
= 5 V, T
J
= -40 °C to +125 °C, unless otherwise stated)
PARAMETER
Soft Start
1.8
3.6
3
6
4.2
ms
8.4
Soft start time
t
ss
Over Current Protection - SiC437
450
180
90
-
450
180
90
-
499
200
100
51
499
200
100
51
550
220
110
55
550
220
110
55
k
k
I
OCP
= 14 A
I
OCP
= 9.7 A
I
OCP
= 5.4 A
Over Current Protection - SiC438
I
OCP
= 12 A
MODE 2 (over current protection)
R
MODE2
I
OCP
= 9.3 A
I
OCP
= 6.5 A
I
OCP
= 3.6 A
Note
(1)
Guaranteed by design
MODE 2 (over current protection)
R
MODE2
FUNCTIONAL BLOCK DIAGRAM
V
IN
V
OUT
V
DRV
Regulator
Sync
rectifier
V
DD
R
r
UVLO
BOOT
EN
Enable
MODE1
Over voltage
under voltage
PH
Control
logic
V
DRV
Ramp
On time
generator
SW
SW
V
OUT
FB
Reference
EA
R
c
C
c
Soft start
Over
current
Over
temperature
Zero
crossing
GL
P
GOOD
MODE2
Power good
A
GND
P
GND
Fig. 4 - SiC43x Functional Block Diagram
S20-0679-Rev. D, 27-Aug-2020
Document Number: 75921
5
For technical questions, contact:
powerictechsupport@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
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