SGM61220 [SGMICRO]

4.5V to 28V Input, 2A Output, Synchronous Buck Converter;
SGM61220
型号: SGM61220
厂家: Shengbang Microelectronics Co, Ltd    Shengbang Microelectronics Co, Ltd
描述:

4.5V to 28V Input, 2A Output, Synchronous Buck Converter

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中文:  中文翻译
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SGM61220  
4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
GENERAL DESCRIPTION  
FEATURES  
Wide 4.5V to 28V Input Voltage Range  
2A Continuous Output Current  
Integrated 66/36Power MOSFETs  
Low Quiescent Current: 25μA (TYP)  
Shutdown Current: 2μA (TYP)  
The SGM61220 is a synchronous Buck converter with a  
wide input voltage range of 4.5V to 28V. This device can  
deliver up to 3A to the output over a wide input voltage.  
It is an easy-to-use device with power switches and peak  
current mode control compensation all integrated in a  
small 6-pin package. A typical 5ms soft-start ramp is also  
included to minimize the inrush current.  
5ms Internal Soft-Start Time  
Fixed 410kHz Switching Frequency  
Pulse Skip Mode and PWM Mode  
Peak Current Mode Control  
This device employs cycle-by-cycle peak current limit,  
output over-voltage protection and thermal shutdown  
with auto recovery. The current limit is implemented for  
both switches and has foldback feature to prevent  
overheating (and thermal shutdown) when an output short  
is detected. Auto recovery after over-current, output short,  
overheating or over-voltage fault maintains the system  
operational with no shutdown.  
Internal Loop Compensation  
Over-Current Protection for Both MOSFETs  
Output Over-Voltage Protection  
Adjustable Input Under-Voltage Lockout  
Thermal Shutdown with Auto Recovery  
Available in a Green TSOT-23-6 Package  
This converter has a fixed 410kHz switching frequency  
that minimizes the EMI noise problems. However the  
actual frequency drops during PSM (pulse skip mode)  
to maximize efficiency at light load. It also drops in  
some fault conditions.  
APPLICATIONS  
12V Distributed Power Supply Buses  
Industrial and Consumer Applications  
White Goods  
Audio Equipment  
The SGM61220 is available in a Green TSOT-23-6  
package.  
Set Top Boxes  
Digital Television Printers  
TYPICAL APPLICATION  
BOOT  
VIN  
VIN  
CBOOT  
VOUT  
CIN  
SW  
L
SGM61220  
COUT  
RFB1  
EN  
FB  
GND  
RFB2  
Figure 1. Typical Application Circuit  
SG Micro Corp  
APRIL 2022 – REV. A. 1  
www.sg-micro.com  
 
4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
SGM61220  
PACKAGE/ORDERING INFORMATION  
SPECIFIED  
TEMPERATURE  
RANGE  
PACKAGE  
DESCRIPTION  
ORDERING  
NUMBER  
PACKAGE  
MARKING  
PACKING  
OPTION  
MODEL  
SGM61220  
TSOT-23-6  
SGM61220XTN6G/TR  
R47XX  
Tape and Reel, 3000  
-40to +125℃  
MARKING INFORMATION  
NOTE: XX = Date Code.  
YYY X X  
Date Code - Week  
Date Code - Year  
Serial Number  
Green (RoHS & HSF): SG Micro Corp defines "Green" to mean Pb-Free (RoHS compatible) and free of halogen substances. If  
you have additional comments or questions, please contact your SGMICRO representative directly.  
OVERSTRESS CAUTION  
ABSOLUTE MAXIMUM RATINGS  
Stresses beyond those listed in Absolute Maximum Ratings  
may cause permanent damage to the device. Exposure to  
absolute maximum rating conditions for extended periods  
may affect reliability. Functional operation of the device at any  
conditions beyond those indicated in the Recommended  
Operating Conditions section is not implied.  
Input Voltage Range.......................................... -0.3V to 30V  
EN and BOOT-SW Voltages................................ -0.3V to 6V  
SW Voltage........................................................ -0.3V to 30V  
SW (20ns transient) Voltage................................. -5V to 30V  
FB Voltage........................................................ -0.3V to 3.5V  
Package Thermal Resistance  
TSOT-23-6, θJA ........................................................ 123/W  
RθJC(TOP) ................................................................... 45/W  
Junction Temperature.................................................+150℃  
Storage Temperature Range.......................-65to +150℃  
Lead Temperature (Soldering, 10s)............................+260℃  
ESD Susceptibility  
ESD SENSITIVITY CAUTION  
This integrated circuit can be damaged by ESD if you don’t  
pay attention to ESD protection. SGMICRO recommends that  
all integrated circuits be handled with appropriate precautions.  
Failureto observe proper handlingand installation procedures  
can cause damage. ESD damage can range from subtle  
performance degradation tocomplete device failure. Precision  
integrated circuits may be more susceptible to damage  
because very small parametric changes could cause the  
device not to meet its published specifications.  
HBM.............................................................................2000V  
CDM ............................................................................1500V  
RECOMMENDED OPERATING CONDITIONS  
Input Voltage Range............................................4.5V to 28V  
EN and BOOT-SW Voltages............................. -0.1V to 5.5V  
SW Voltage........................................................ -0.1V to 28V  
FB Voltage........................................................... -0.1V to 3V  
Operating Junction Temperature Range......-40to +125℃  
DISCLAIMER  
SG Micro Corp reserves the right to make any change in  
circuit design, or specifications without prior notice.  
SG Micro Corp  
www.sg-micro.com  
APRIL 2022  
2
 
4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
SGM61220  
PIN CONFIGURATION  
(TOP VIEW)  
GND  
SW  
1
2
3
6
5
4
BOOT  
EN  
VIN  
FB  
TSOT-23-6  
PIN DESCRIPTION  
PIN  
NAME  
TYPE  
DESCRIPTION  
1
GND  
Device Ground Reference Pin.  
Switching Node. Connection point of the internal converter lower and upper power MOSFETs.  
Connect this pin to the output inductor and the bootstrap capacitor.  
2
3
SW  
VIN  
O
Input Supply Voltage Pin. VIN powers the internal control circuitry and the power converter.  
Decouple this pin for very high frequency and high di/dt transitions, with small and high  
frequency ceramic capacitors placed as close as possible between VIN and GND pins. Input  
under-voltage is protected by a UVLO comparator.  
Feedback (Sense) Pin for Output Voltage and Programming. It is normally regulated at  
0.603V. Tap an output feedback resistor divider to this pin.  
4
5
FB  
EN  
I
I
Device Enable Pin. Device will operate if EN voltage is high and will shut down if it is low.  
Device will be enabled if this pin is left float. EN pin can be used to increase the UVLO  
thresholds.  
Bootstrap Pin. Place a 0.1µF capacitor (CBOOT) between BOOT and SW pins close to the  
device to provide the required drive voltage for the high-side switch. Do not place any series  
6
BOOT  
O
resistor with CBOOT  
.
NOTE: O = Output, I = Input.  
SG Micro Corp  
www.sg-micro.com  
APRIL 2022  
3
4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
SGM61220  
ELECTRICAL CHARACTERISTICS  
(TJ = -40to +125, VIN = 4.5V to 28V, unless otherwise noted.)  
PARAMETER  
SYMBOL  
CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
V
Input Voltage Range  
VIN  
IQ  
4.5  
28  
Non-Switching Quiescent Current  
Shutdown Supply Current  
VEN = 5V, VFB = 1V  
EN = GND  
Rising  
25  
2
µA  
ISD  
VIH  
VIL  
IIL  
µA  
1.19  
1.10  
0.45  
1.44  
1.33  
EN Terminal Input Threshold  
EN Terminal Leakage Current  
V
Falling  
0.93  
VEN = 0.5V  
VEN = 1.5V  
μA  
IIH  
Feedback and Error Amplifier  
Feedback Voltage  
VFB  
0.585  
0.603  
0.620  
V
VIN = 12V, TJ = +25  
Power Stage  
High-side FET On-Resistance  
Low-side FET On-Resistance  
Current Limit  
RDSON_HS VBOOT - VSW = 5V  
RDSON_LS VIN = 12V  
66  
36  
116  
63  
mΩ  
mΩ  
High-side Current Limit  
Low-side Current Limit  
Input Under-Voltage Lockout  
ILIM_HS  
ILIM_LS  
3.2  
3.4  
3.8  
2.2  
4.5  
4.5  
A
A
Maximum inductor peak current, TJ = +25℃  
Maximum inductor valley current, TJ = +25℃  
Rising VIN  
Falling VIN  
4.1  
3.7  
400  
UVLO Threshold Voltage  
VUVLO  
V
UVLO Hysteresis  
VUVLO_HYS  
mV  
Over-Temperature Protection  
Thermal Shutdown  
TSHDN  
THYS  
Rising temperature  
165  
10  
Thermal Shutdown Hysteresis  
Oscillator  
Switching Frequency  
Timing Requirements  
Soft-Start Time  
fSW  
340  
410  
5
480  
kHz  
ms  
tSS  
SG Micro Corp  
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APRIL 2022  
4
4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
SGM61220  
TYPICAL PERFORMANCE CHARACTERISTICS  
TJ = +25, VIN = 4.5V to 28V, unless otherwise noted.  
Quiescent Current vs. Junction Temperature  
VIN = 12V  
Shutdown Current vs. Junction Temperature  
VIN = 12V  
60  
50  
40  
30  
20  
10  
0
6
5
4
3
2
1
0
-50 -25  
0
25  
50  
75 100 125 150  
-50 -25  
0
25  
50  
75 100 125 150  
Junction Temperature ()  
Junction Temperature ()  
RDSON_HS vs. Junction Temperature  
VIN = 12V  
RDSON_LS vs. Junction Temperature  
VIN = 12V  
140  
120  
100  
80  
140  
120  
100  
80  
60  
60  
40  
40  
20  
20  
0
0
-50 -25  
0
25  
50  
75 100 125 150  
-50 -25  
0
25  
50  
75 100 125 150  
Junction Temperature ()  
Junction Temperature ()  
Efficiency vs. Output Current  
Feedback Voltage Production Distribution  
100  
90  
80  
70  
60  
50  
40  
30  
20  
10  
0
25  
20  
15  
10  
5
12660 Samples  
1 Production Lot  
VIN = 12V  
V
IN = 24V  
VOUT = 5.0V  
0.001 0.01  
0
0.1  
1
10  
Output Current (A)  
VFB (V)  
SG Micro Corp  
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APRIL 2022  
5
4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
SGM61220  
TYPICAL PERFORMANCE CHARACTERISTICS (continued)  
TJ = +25, VIN = 4.5V to 28V, unless otherwise noted.  
Line Regulation  
Load Regulation  
0.5  
0.4  
0.5  
0.4  
0.3  
0.3  
0.2  
0.2  
0.1  
0.1  
0.0  
0.0  
-0.1  
-0.2  
-0.3  
-0.4  
-0.5  
-0.1  
-0.2  
-0.3  
-0.4  
-0.5  
VIN = 12V  
IN = 24V  
V
6
8
10 12 14 16 18 20 22 24 26 28  
0.0  
0.5  
1.0  
1.5  
2.0  
Input Voltage (V)  
Output Current (A)  
Switching Frequency vs. Ambient Temperature  
VIN = 12V  
Feedback Voltage vs. Ambient Temperature  
VIN = 12V  
440  
430  
420  
410  
400  
390  
380  
0.608  
0.606  
0.604  
0.602  
0.600  
0.598  
0.596  
-50 -25  
0
25  
50  
75 100 125 150  
-50 -25  
0
25  
50  
75 100 125 150  
Ambient Temperature ()  
Ambient Temperature ()  
UVLO Threshold Voltage vs. Junction Temperature  
EN Terminal Input Threshold vs. Junction Temperature  
VIN = 28V  
4.4  
4.3  
4.2  
4.1  
4.0  
3.9  
3.8  
3.7  
3.6  
1.6  
1.5  
1.4  
1.3  
1.2  
1.1  
1.0  
0.9  
0.8  
Rising VIN  
VIH  
VIL  
Falling VIN  
-50 -25  
0
25  
50  
75 100 125 150  
-50 -25  
0
25  
50  
75 100 125 150  
Junction Temperature ()  
Junction Temperature ()  
SG Micro Corp  
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APRIL 2022  
6
4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
SGM61220  
TYPICAL PERFORMANCE CHARACTERISTICS (continued)  
TJ = +25, VIN = 24V, VOUT = 5V, CIN = 10μF, COUT = 2 × 22μF, unless otherwise noted.  
Power On  
Power Off  
RLOAD = 500Ω  
RLOAD = 500Ω  
VIN  
VIN  
VOUT  
VOUT  
Time (5ms/div)  
Turn On  
Time (50ms/div)  
Turn Off  
RLOAD = 500Ω  
RLOAD = 500Ω  
VIN  
VIN  
EN  
EN  
VOUT  
VOUT  
Time (2ms/div)  
Time (10ms/div)  
Load Transient Response  
Load Transient Response  
IOUT = 0.1A to 1.0A, 0.25A/μs  
IOUT = 0.75A to 1.75A, 0.25A/μs  
AC Coupled  
AC Coupled  
VOUT  
VOUT  
IOUT  
IOUT  
Time (200μs/div)  
Time (200μs/div)  
SG Micro Corp  
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APRIL 2022  
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4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
SGM61220  
TYPICAL PERFORMANCE CHARACTERISTICS (continued)  
TJ = +25, VIN = 24V, VOUT = 5V, CIN = 10μF, COUT = 2 × 22μF, unless otherwise noted.  
Input Voltage Ripple  
Output Voltage Ripple  
EN = Floating, IOUT = 600mA  
EN = Floating, IOUT = 0mA  
AC Coupled  
AC Coupled  
VIN  
VOUT  
VSW  
VSW  
Time (2μs/div)  
Time (4ms/div)  
Output Voltage Ripple  
Output Voltage Ripple  
EN = Floating, IOUT = 10mA  
EN = Floating, IOUT = 100mA  
AC Coupled  
AC Coupled  
VOUT  
VOUT  
VSW  
VSW  
Time (40μs/div)  
Time (4μs/div)  
Output Voltage Ripple  
EN = Floating, IOUT = 1.5A  
AC Coupled  
VOUT  
VSW  
Time (2μs/div)  
SG Micro Corp  
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APRIL 2022  
8
4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
SGM61220  
FUNCTIONAL BLOCK DIAGRAM  
VIN  
HS Current  
Sensor  
OV  
Voltage  
UVLO  
Thermal  
Sensor  
Boot Regulator  
HS Driver  
BOOT  
Reference  
HS Current  
Comparator and  
Limit  
+
-
FB  
Slope  
Compensation  
Control Logic  
SW  
Soft-Start  
Oscillator  
LS Driver  
EN  
LS Current Limit  
SGM61220  
GND  
Figure 2. Block Diagram  
SG Micro Corp  
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APRIL 2022  
9
4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
SGM61220  
DETAILED DESCRIPTION  
maximize power and limit the maximum peak current in  
high-side and valley current in low-side, the device  
keeps in cycle-by-cycle limit to obtain the system’s  
power request. The SGM61220 does not shut down  
until the device heats and then goes to thermal  
shutdown. The load increase, the output voltage goes  
low, if the output voltage drops to 20%, the device will  
go into short protection. It reduces current limit  
threshold and the switching frequency goes down due  
to reduce power dissipation and device goes into  
thermal shutdown. When the output current is low  
enough, the device goes into PFM mode.  
Overview  
The SGM61220 is a 28V/2A synchronous Buck  
converter with over-current, short-circuit and thermal  
shutdown with auto recovery. Figure 2 shows the  
simplified block diagram of the SGM61220. The two  
integrated MOSFET switches of the power stage  
(66high-side and 36low-side) can provide up to  
2A of continuous current with high efficiency.  
The device is powered up when VIN exceeds the UVLO  
threshold (4.1V TYP). At no load and with no switching,  
the typical operating current is 25μA and when the  
device is disabled by EN pin, it is only 2µA (TYP). The  
internal loop compensation minimizes the BOM cost and  
simplifies the design. The inrush current is also limited  
by an internal 5ms soft-start ramp.  
Pulse Skip Mode (PSM) and PWM Mode  
In light load, OVP does not occur and the device can  
operate in the normal PWM mode, but to improve light  
load efficiency, the device is designed to skip some  
pulses by entering to the PSM mode. When the peak  
current is lower than 500mA typically, the device enters  
PSM. In PSM, when the output voltage is detected to  
be above the internal voltage reference level of the  
error amplifier, the high-side MOSFET is kept off for a  
few cycles (skipping clock pulses) by clamping current  
reference until the output voltages are discharged  
below the internal voltage reference level. Note that the  
integrated current comparator operates based on the  
peak inductor current and the average load current may  
vary depending on the output filters and load type.  
Operating Principle  
Peak current mode (PCM) control is used in the  
SGM61220 to regulate the output voltage. VOUT is  
sensed by the external resistor divider on the FB pin  
and compared to the internal 0.603V reference voltage  
by a trans-conductance error amplifier. The error  
amplifier (EA) output (current) is fed to the internal  
compensation components between the EA output and  
GND to generate a voltage that is used as the peak  
current reference for comparing with the sensed  
high-side switch current. The output of this comparator  
(COMP) can reset the flipflop that controls the switches.  
This flipflop receives fixed frequency clock pulses from  
the internal 410kHz oscillator. In the normal operation  
the high-side switch is turned on in the beginning of  
each switching cycle. The current in the high-side  
switch starts to rise until the peak current reference is  
reached that resets the flipflop. This will turn off the  
high-side switch and turn on the low-side switch. The  
low-side switch stays on until the end of the cycle.  
Enable Pin and UVLO Adjustment  
The EN pin can be used to turn the device on and off or  
to change the UVLO thresholds. The device is enabled  
when the EN pin voltage exceeds its high threshold. A  
low EN voltage disables the device brings it to the  
low-quiescent (IQ) state.  
The EN pin is internally pulled up by a small current  
source (IP) so the device is enabled if EN pin is floated.  
An open drain or open collector output can be used to  
control the EN pin.  
Slope Compensation  
Peak current mode-controlled devices in general are  
subject to sub-harmonic oscillation instability at higher  
duty cycles (typically > 50%). To avoid this instability a  
compensating ramp signal is used. The ramp starts  
from zero in the beginning of each cycle with a specific  
slop and is added to the sensed high-side switch  
current before it is compared to the peak current  
reference.  
VIN is monitored by the internal under-voltage lockout  
circuit and if it is below UVLO threshold, the device is  
disabled. The internal UVLO has a 400mV hysteresis. If  
higher thresholds are needed, EN pin can be used as  
shown in Figure 3.  
The EN pull-up current is used to set the hysteresis.  
The pull-up current is increased by IIH - IIL when the EN  
pin exceeds its high threshold. Use Equations 1 and 2  
to calculate the R1 and R2 values for the desired UVLO  
low (VUV_L) and high (VUV_H) thresholds.  
Anti-High-Overload Mode  
The SGM61220 supports overload mode. When the  
output current continues overload while the system  
power up or in turbo mode, the SGM61220 exports the  
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APRIL 2022  
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4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
SGM61220  
DETAILED DESCRIPTION (continued)  
VUV _H × V VUV _L × V  
voltage begins to rise from near 0V to slightly above  
0.603V with a ramp time of 5ms. The lower of VREF and  
this ramp is used as reference for the error amplifier,  
therefore during startup the ramp provides a soft-start  
for the output. The soft-start is needed to avoid high  
inrush currents caused by rapid increase of output  
voltage across output capacitors and the load. Without  
a soft-start the current limiting protections could trigger  
that interrupts the monotonic rising of the load voltage  
that may result in instability or improper system  
initialization.  
IL  
IH  
(1)  
R1 =  
I × V I × V  
IH  
IH  
IL  
IL  
R1 × V  
IL  
(2)  
R2 =  
VUV _L V + R1 ×I  
IL  
IH  
where:  
IIL = 0.45μA (TYP)  
IIH= 1.44μA (TYP)  
VIL = 1.10V (TYP)  
VIH = 1.19V (TYP)  
VIN  
Bootstrap Voltage (BOOT)  
SGM61220  
IH = IIH - IIL  
To power the upper switch gate driver, a voltage higher  
than VIN is needed. Bootstrapping technique is used to  
provide this voltage from the switching node by using a  
0.1µF bootstrap capacitor between SW and BOOT pins  
along with an internal bootstrap diode. The voltage is  
internally regulated for driving the high-side switch. An  
X5R or X7R ceramic capacitor is recommended for  
CBOOT to have stable capacitance against temperature  
and voltage variations. To improve drop out, the device  
is designed to operate at 100% duty cycle.  
R1  
IIL  
EN  
R2  
Output Short-Circuit Protection  
When the output voltage down to 20% of set value, the  
device goes into short-circuit mode, and a foldback  
mode will limit the current output. The high-side peak  
current limit to 2.4A (TYP) and the valley current limit to  
1.4A (TYP), then it avoids the device thermal shutdown  
by the power dissipation.  
Figure 3. Adjustable VIN Under-Voltage Lockout  
Output Voltage Programming  
The output voltage is set by a resistor divider between  
VOUT and GND that is tapped to the FB pin. It is  
recommended to use resistors with 1% tolerance or  
better because it directly affects the output accuracy.  
Use Equation 3 and Figure 1 to calculate the output  
voltage. To improve efficiency at light load consider  
larger resistors. Start with 100kΩ for the upper resistor  
(RFB1). Note that if RFB1||RFB2 is too high, the FB pin  
leakage current and other noises can easily affect the  
accuracy and performance of the regulator.  
A short-circuit is detected when VFB falls below 0.12V  
(TYP). In this condition the current limits of both  
switches are internally reduced to less than half of the  
normal value (foldback). This will reduce the constant  
output current during an output short and prevents  
overheating. During the soft-start period there is no  
foldback and the current limits are normal.  
Output Over-Voltage Protection (OVP)  
An over-voltage protection is included in the device to  
minimize the output voltage overshoots that may occur  
after recovery from an output fault or a large unloading  
transient. The FB pin voltage is compared with the OVP  
thresholds. If the VFB exceeds 108% of the VREF, the  
high-side switch is forced to turn off. When the VFB falls  
below 104%, the high-side switch is allowed to turn on  
again.  
RFB1  
RFB2  
(3)  
VOUT = VFB  
×
+1  
Internal Voltage Reference and Soft-Start  
The SGM61220 device has an internal 0.603V  
reference (VREF) to program the output at the desired  
level. The output voltage is determined by the  
reference voltage seen by the error amplifier. When the  
converter starts (or is enabled), an internal ramp  
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4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
SGM61220  
DETAILED DESCRIPTION (continued)  
low-side current-limit (ILIM_LS). If the inductor valley  
current exceeds the low-side current limit, the high-side  
MOSFET will not turn on in the next cycle and the  
low-side MOSFET continues to conduct (cycle skipped).  
The high-side switch turns on again when the valley  
current falls below ILIM_LS at the start of another cycle.  
Over-Current Protection (OCP)  
The device is protected from over-current conditions by  
cycle-by-cycle current limiting on both high-side and  
low-side MOSFETs.  
High-side MOSFET Over-Current Protection  
The internal peak current mode controller provides an  
inherent current limiting capability for the high-side  
switch on a cycle-by-cycle basis. When high-side  
switch current exceeds peak current limit threshold,  
high-side switch is turned off, until the next cycle.  
During an over-current fault, the above limits cause  
cycle skipping that slows down the switching frequency  
and reduces the output voltage (due to reduced duty  
cycle).  
Thermal Shutdown  
Low-side MOSFET Over-Current Protection  
The low-side MOSFET current is also monitored for  
over-current protection. Normally this MOSFET  
sources current to the load (source to drain direction)  
while the inductor current is decreasing. At the end of  
each cycle, this current is compared to the preset  
If the junction temperature exceeds +165(TYP), the  
device is forced to stop switching. It will recover  
automatically when TJ falls below the recovery threshold.  
SG Micro Corp  
www.sg-micro.com  
APRIL 2022  
12  
4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
SGM61220  
APPLICATION INFORMATION  
BOOT  
CBOOT  
0.1μF  
SGM61220  
L
V
IN = 24V  
VOUT = 5V, 2A  
VIN  
SW  
10μH  
R1  
500kΩ  
C1  
10μF  
C2  
0.1μF  
C3  
22μF  
C4  
22μF  
RFB1  
100kΩ  
EN  
FB  
R2  
RFB2  
100kΩ  
GND  
13.3kΩ  
Figure 4. A Reference Design for 5V, 2A Application  
Design Requirements  
A 10pF feedforward capacitor is optioned to improve the response.  
When the output is shorted, a large input capacitor is required to ensure that the output voltage ripple is lower than  
1V, otherwise the device may not be stable.  
To reduce the output ripple and keep the device stable, the output capacitor must be large. The recommended  
value should not be lower than 22μF + 22μF, and a 100μF output capacitor will be very helpful for reducing ripple.  
0.1% RFB1, RFB2 will be chosen to improve the output voltage precision, if it is needed.  
In order to obtain a small VOUT ripple, it is recommended that the VIN is higher than 7V when the VOUT is 5V, and the  
VIN is lower than 20V when the VOUT is 1.8V.  
Layout Guide  
Layout guide schematic for PCB Layout.  
J1  
VIN  
TP1  
VIN  
8V~28V  
3
5
4
6
2
1
VIN  
BOOT  
SW  
C4  
0.1μF  
C1  
10μF  
C2  
0.1μF  
R4  
510kΩ  
100μF/35V  
J3  
VOUT  
Optional  
TP2  
VOUT  
SGM61220  
EN  
L
10μH 5A  
J2  
GND  
C5  
22μF  
C6  
22μF  
C7  
NC  
TP3  
SW  
5V/2A  
EN  
FB  
GND  
2
1
TP4  
GND  
TP5  
GND  
R2 100kΩ  
J4  
GND  
JP1  
R1 49.9Ω  
R5  
105kΩ  
R3  
13.3kΩ  
C3  
10pF  
Figure 5. Schematic for PCB Layout  
SG Micro Corp  
www.sg-micro.com  
APRIL 2022  
13  
 
4.5V to 28V Input, 2A Output,  
Synchronous Buck Converter  
SGM61220  
APPLICATION INFORMATION (continued)  
Figure 6. PCB Top Layer  
Figure 7. PCB Bottom Layer  
REVISION HISTORY  
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.  
APRIL 2022 ‒ REV.A to REV.A.1  
Page  
Updated the Absolute Maximum Ratings and Layout Guide sections............................................................................................................. 2, 13  
Changes from Original (NOVEMBER 2020) to REV.A  
Page  
Changed from product preview to production data.............................................................................................................................................All  
SG Micro Corp  
www.sg-micro.com  
APRIL 2022  
14  
PACKAGE INFORMATION  
PACKAGE OUTLINE DIMENSIONS  
TSOT-23-6  
0.69  
0.95  
D
e
2.59  
E1  
E
0.99  
b
RECOMMENDED LAND PATTERN (Unit: mm)  
L
A
θ
0.25  
A1  
c
A2  
Dimensions  
In Millimeters  
Dimensions  
In Inches  
Symbol  
MIN  
MAX  
MIN  
MAX  
0.043  
0.004  
0.039  
0.020  
0.008  
0.116  
0.065  
0.116  
A
A1  
A2  
b
1.000  
0.100  
0.900  
0.500  
0.200  
2.950  
1.650  
2.950  
0.000  
0.700  
0.300  
0.080  
2.850  
1.550  
2.650  
0.000  
0.028  
0.012  
0.003  
0.112  
0.061  
0.104  
c
D
E
E1  
e
0.950 BSC  
0.037 BSC  
L
0.300  
0°  
0.600  
8°  
0.012  
0°  
0.024  
8°  
θ
SG Micro Corp  
www.sg-micro.com  
TX00038.001  
PACKAGE INFORMATION  
TAPE AND REEL INFORMATION  
REEL DIMENSIONS  
TAPE DIMENSIONS  
P2  
P0  
W
Q2  
Q4  
Q2  
Q4  
Q2  
Q4  
Q1  
Q3  
Q1  
Q3  
Q1  
Q3  
B0  
Reel Diameter  
P1  
A0  
K0  
Reel Width (W1)  
DIRECTION OF FEED  
NOTE: The picture is only for reference. Please make the object as the standard.  
KEY PARAMETER LIST OF TAPE AND REEL  
Reel Width  
Reel  
Diameter  
A0  
B0  
K0  
P0  
P1  
P2  
W
Pin1  
Package Type  
W1  
(mm)  
(mm) (mm) (mm) (mm) (mm) (mm) (mm) Quadrant  
TSOT-23-6  
7″  
9.5  
3.20  
3.10  
1.10  
4.0  
4.0  
2.0  
8.0  
Q3  
SG Micro Corp  
TX10000.000  
www.sg-micro.com  
PACKAGE INFORMATION  
CARTON BOX DIMENSIONS  
NOTE: The picture is only for reference. Please make the object as the standard.  
KEY PARAMETER LIST OF CARTON BOX  
Length  
(mm)  
Width  
(mm)  
Height  
(mm)  
Reel Type  
Pizza/Carton  
7″ (Option)  
7″  
368  
442  
227  
410  
224  
224  
8
18  
SG Micro Corp  
www.sg-micro.com  
TX20000.000  

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