NB634
High Efficiency 5A, 24V, 500kHz
Synchronous Step-down Converter
The Future of Analog IC Technology
DESCRIPTION
FEATURES
The NB634 is a high efficiency synchronous
rectified step-down switch mode converter with
built-in internal power MOSFETs. It offers a
very compact solution to achieve 5A continuous
output current over a wide input supply range
with excellent load and line regulation. The
NB634 operates at high efficiency over a wide
output current load range.
Current mode operation provides fast transient
response and eases loop stabilization.
Full protection features include latch-off OCP and
thermal shut down.
Wide 4.5V to 24V Operating Input Range
5A Output Current
Low RDS(ON) Internal Power MOSFETs
Proprietary Switching Loss Reduction
Technique
Fixed 500kHz Switching Frequency
Sync from 300kHz to 2MHz External Clock
Internal Compensation
Latch-off OCP Protection and Thermal
Shutdown
Output Adjustable from 0.8V
Available in a QFN14 (3mmx4mm) Package
APPLICATIONS
The NB634 requires a minimum number of
readily available standard external components
and is available in a space saving QFN14 (3mm x
4mm) package.
Notebook Systems and I/O Power
Networking Systems
Digital Set Top Boxes
Personal Video Recorders
Flat Panel Television and Monitors
Distributed Power Systems
All MPS parts are lead-free and adhere to the RoHS directive. For MPS green
status, please visit MPS website under Products, Quality Assurance page.
“MPS” and “The Future of Analog IC Technology” are registered trademarks of
Monolithic Power Systems, Inc.
TYPICAL APPLICATION （FOR NOTEBOOK）
Efficiency
VOUT=1.8V, L=1.0uH
4.5V-24V
VIN
VCC
C1
22uF
3.3V
9
IN
R4
11
C3
0.1uF
NB634
AAM
FB
ON/OFF
7
VOUT 1.8V
VCC
8
Rt
24.9k
R1
10k
C2
47uF
R2
8.06k
EN/SY NC
GND
12,13,14
VIN=12V
90
L1
2.3uH
2,3,4,5
SW
VIN=7V
95
C4
0.1uF
PG
R3
10
BST
100
6
EFFICIENCY(%)
1
85
80
VIN=24V
75
70
65
60
55
50
0
1
2
3
4
5
6
OUTPUT CURRENT (A)
NB634 Rev. 0.94
12/25/2013
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© 2013 MPS. All Rights Reserved.
1
NB634 –HIGH EFFICIENCY, 5A, 24V, 500kHz SYNCHRONOUS STEP-DOWN CONVERTER
ORDERING INFORMATION
Part Number*
Package
Top Marking
Free Air Temperature (TA)
NB634EL
QFN14 (3mmx4mm)
634E
-20C to +85C
* For Tape & Reel, add suffix –Z (eg. NB634EL–Z);
For RoHS compliant packaging, add suffix –LF (eg. NB634EL–LF–Z)
PACKAGE REFERENCE
TOP VIEW
IN
1
14
AGND
SW
2
13
GND
SW
3
12
GND
SW
4
11
VCC
SW
5
10
AAM
BST
6
9
PG
EN/SYNC
7
8
FB
EXPOSED PAD
ON BACKSIDE
ABSOLUTE MAXIMUM RATINGS (1)
Supply Voltage VIN ....................................... 28V
VSW ...........................-0.3V (-5V for 10ns) to 28V
VBS ....................................................... VSW + 6V
All Other Pins ..................................-0.3V to +6V
Continuous Power Dissipation
(TA = +25°C) (2)
…………………………………………………2.6W
Junction Temperature ...............................150C
Lead Temperature ....................................260C
Storage Temperature............... -65C to +150C
Recommended Operating Conditions
(3)
Supply Voltage VIN ...........................4.5V to 24V
Maximum Junction Temp. (TJ) ................+125C
NB634 Rev. 0.94
12/25/2013
Thermal Resistance
(4)
θJA
θJC
QFN14(3mmx4mm) ................48 ...... 11 ... C/W
Notes:
1) Exceeding these ratings may damage the device.
2) The maximum allowable power dissipation is a function of the
maximum junction temperature TJ (MAX), the junction-toambient thermal resistance θJA, and the ambient temperature
TA. The maximum allowable continuous power dissipation at
any ambient temperature is calculated by PD (MAX) = (TJ (MAX)TA) /θJA. Exceeding the maximum allowable power dissipation
will cause excessive die temperature, and the regulator will
go into thermal shutdown. Internal thermal shutdown circuitry
protects the device from permanent damage.
3) The device is not guaranteed to function outside of its
operating conditions.
4) Measured on JESD51-7, 4-layer PCB.
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2
NB634 –HIGH EFFICIENCY, 5A, 24V, 500kHz SYNCHRONOUS STEP-DOWN CONVERTER
ELECTRICAL CHARACTERISTICS
VIN = 12V, TA = +25C, unless otherwise noted.
Parameters
Supply Current (Shutdown)
Supply Current (Quiescent)
HS Switch On Resistance (5)
LS Switch On Resistance (5)
Symbol
IIN
IIN
HSRDS-ON
LSRDS-ON
Switch Leakage
SWLKG
Current Limit
Oscillator Frequency
Fold-back Frequency
Maximum Duty Cycle
Sync Frequency Range
Feedback Voltage
Feedback Current
EN/SYNC Input Low Voltage
EN/SYNC Input High Voltage
EN Input Current
EN Turn Off Delay
Power Good Rising Threshold
Power Good Falling Threshold
Power Good Delay
Power Good Sink Current
Capability
Power Good Leakage Current
VIN Under Voltage Lockout
Threshold Rising
VIN Under Voltage Lockout
Threshold Hysteresis
VCC Regulator
VCC Load Regulation
Thermal Shutdown
ILIMIT
FSW
FFB
DMAX
FSYNC
VFB
IFB
VILEN
VIHEN
IEN
ENTd-Off
PGVth-Hi
PGVth-Lo
PGTd
Condition
VEN = 0V
VEN = 2V, VFB = 1V
Min
VEN = 0V,
VSW = 0V or 12V
VFB = 0.75V
VFB = 100mV
VFB = 700mV
350
85
0.3
785
VFB = 805mV
Typ
2
1
120
20
Max
Units
μA
mA
mΩ
mΩ
0
10
μA
7
500
0.25
90
805
10
650
2
825
50
0.4
2
VEN = 2V
2
5
0.9
0.7
250
A
kHz
fSW
%
MHz
mV
nA
V
V
μA
μs
VFB
VFB
μs
VPG
Sink 4mA
0.4
V
IPG_LEAK
VPG = 3.3V
10
nA
4.2
V
INUVVth
3.8
4.0
INUVHYS
880
mV
VCC
5
5
150
V
%
°C
Icc=5mA
TSD
Note:
5) Guaranteed by design.
NB634 Rev. 0.94
12/25/2013
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3
NB634 –HIGH EFFICIENCY, 5A, 24V, 500kHz SYNCHRONOUS STEP-DOWN CONVERTER
PIN FUNCTIONS
Pin #
1
2,3,4,5
6
7
8
9
10
11
14
12, 13
NB634 Rev. 0.94
12/25/2013
Name
Description
Supply Voltage. The NB634 operates from a +4.5V to +24V input rail. C1 is
IN
needed to decouple the input rail. Use wide PCB traces and multiple vias to make
the connection.
SW
Switch Output. Use wide PCB traces and multiple vias to make the connection.
Bootstrap. A capacitor connected between SW and BST pins is required to form a
BST
floating supply across the high-side switch driver.
EN=1 to enable the NB634. External clock can be applied to EN pin for changing
EN/SYNC
switching frequency. For automatic start-up, connect EN pin to VIN with 100kΩ
resistor. It includes an internal 1MΩ pull-down resistor.
Feedback. An external resistor divider from the output to GND, tapped to the FB
pin, sets the output voltage. To prevent current limit run away during a short circuit
FB
fault condition, the frequency fold-back comparator lowers the oscillator frequency
when the FB voltage is below 100mV.
Power Good Output. The output of this pin is an open drain. When the FB voltage
rises to 90% of the REF voltage, Power Good (PG) output goes high after a 250μs
PG
delay. When the FB voltage drops to 70% of the REF voltage, PG goes low
immediately.
Connects to a voltage set by a resistor divider between VCC and GND to force the
AAM
NB634 into non-synchronous mode at light load.
VCC
Bias Supply. Decouple with 0.1µF capacitor.
Analog Ground. This pin is the reference ground of the regulated output voltage.
AGND
For this reason care must be taken in PCB layout.
System Ground. Connect these pins with larger copper areas to the negative
GND,
terminals of the input and output capacitors. Connect exposed pad to GND plane
Exposed PAD
for proper thermal performance.
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4
NB634 –HIGH EFFICIENCY, 5A, 24V, 500kHz SYNCHRONOUS STEP-DOWN CONVERTER
TYPICAL PERFORMANCE CHARACTERISTICS
VIN=12V, VOUT =1.8V, L=1.0µH, TA=+25°C, unless otherwise noted.
Quiescent Current vs.
Input Voltage
590
Shutdown Current vs.
Input Voltage
0.1
VCC Regulator Line Regulation
5.5
585
580
0.05
5.0
Vcc(V)
575
0
570
565
560
4.5
-0.05
4.0
-0.1
3.5
555
IOUT=0A
V FB=1V
0
5
10
15
20
INPUT VOLTAGE (V)
25
0
Peak Current vs.
Duty Cycle
5
10
15
20
INPUT VOLTAGE (V)
0
25
10
100
OUTPUT VOLTAGE (V)
PEAK CURRENT(A)
8
7
6
5
4
3
2
1
Dmax Limit
10
Minimun on time Limit
1
0.1
0
20
40
60
80
100
0
5
DUTY CYCLE(%)
15
20
0.2
VIN=7V
0.1
0
-0.2
VIN=12V
-0.3
-0.4
0
25
EFFICIENCY(%)
30
-0.1
20
10
-0.3
5
6
VIN=7V
VIN=12V
90
IO=2.5A
IO=5A
4
VOUT=1.8V, L=1.0uH
95
-0.2
3
100
40
0
2
Efficiency
50
0.1
1
OUTPUT CURRENT (A)
Case Temperature Rise
vs. Output Current
0.2
VIN=24V
-0.1
INPUT VOLTAGE (V)
Line Regulation
NORMALIZED OUTPUT VOLTAGE (%)
10
25
Load Regulation
9
0
5
10
15
20
INPUT VOLTAGE (V)
Operating Range
NORMALIZED OUTPUT VOLTAGE (%)
550
85
80
VIN=24V
75
70
65
60
55
-0.4
0
5
10
15
20
INPUT VOLTAGE (V)
NB634 Rev. 0.94
12/25/2013
25
50
0
0
1
2
3
4
5
OUTPUT CURRENT (A)
6
0
1
2
3
4
5
6
OUTPUT CURRENT (A)
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5
NB634 –HIGH EFFICIENCY, 5A, 24V, 500kHz SYNCHRONOUS STEP-DOWN CONVERTER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN=12V, VOUT =1.8V, L=1.0µH, TA=+25°C, unless otherwise noted.
Enable Startup
Enable Startup
Enable Shut Down
IOUT=0A
IOUT=5A
IOUT=0A
VOUT
1V/div
VOUT
1V/div
VOUT
1V/div
VEN
10V/div
VEN
10V/div
VEN
10V/div
VSW
10V/div
VSW
10V/div
VSW
10V/div
IINDUCTOR
1A/div
IINDUCTOR
500mA/div
IINDUCTOR
5A/div
2ms/div
2ms/div
400ms/div
Short Circuit Protection
Enable Shut Down
Output Ripple Voltage
IOUT=5A
IOUT=5A
VOUT/AC
10mV/div
VOUT
1V/div
VEN
10V/div
VOUT
1V/div
VSW
10V/div
IINDUCTOR
5A/div
VSW
10V/div
VSW
10V/div
IINDUCTOR
5A/div
IINDUCTOR
5A/div
20us/div
1ms/div
PG Delay @ Start up
Load Transient Response
250us delay
IOUT=0.5A-4.5A@ 2.5A/us
1us/div
90% VOUT
250us
VOUT
1V/div
VIN
10V/div
PG
2V/div
VSW
10V/div
IOUT
2A/div
IINDUCTOR
5A/div
1ms/div
NB634 Rev. 0.94
12/25/2013
VOUT /AC
50mV/div
100us/div
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6
NB634 –HIGH EFFICIENCY, 5A, 24V, 500kHz SYNCHRONOUS STEP-DOWN CONVERTER
BLOCK DIAGRAM
IN
+
-
VCC
Regulator
VCC
RSEN
Currrent Sense
Amplifer
Boost
Regulator
PG
250us
Delay
+
-
Oscillator
1pF
Reference
EN/SYNC
HS
Driver
+
-
PG Comparator
50pF
400k
Current Limit
Comparator
Comparator
On Time Control
Logic Control
1MEG
FB
BST
+
+
-
SW
VCC
LS
Driver
Error Amplifier
GND
AAM
Figure 1—Functional Block Diagram
NB634 Rev. 0.94
12/25/2013
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7
NB634 –HIGH EFFICIENCY, 5A, 24V, 500kHz SYNCHRONOUS STEP-DOWN CONVERTER
OPERATION
The NB634 is a high efficiency synchronous
rectified step-down switch mode converter with
built-in internal power MOSFETs. It offers a very
compact solution to achieve more than 5A
continuous output current over a wide input
supply range with excellent load and line
regulation.
The NB634 operates in a fixed frequency, peak
current control mode to regulate the output
voltage. A PWM cycle is initiated by the internal
clock. The integrated high-side power MOSFET
is turned on and remains on until its current
reaches the value set by the COMP voltage.
When the power switch is off, it remains off until
the next clock cycle starts. If, in 90% of one PWM
period, the current in the power MOSFET does
not reach the COMP set current value, the power
MOSFET will be forced to turn off.
Error Amplifier
The error amplifier compares the FB pin voltage
with the internal 0.8V reference (REF) and
outputs a current proportional to the difference
between the two. This output current is then used
to charge or discharge the internal compensation
network to form the COMP voltage, which is used
to control the power MOSFET current. The
optimized
internal
compensation
network
minimizes the external component counts and
simplifies the control loop design.
Enable/Sync Control
The NB634 has a dedicated Enable/Sync control
pin (EN/SYNC). By pulling it high or low, the IC
can be enabled and disabled. Tie EN to VIN
through a resistor for automatic start up. To
disable the part, EN must be pulled low for at
least 5µs.
The NB634 can be synchronized to an external
clock ranging from 300 kHz to 2MHz through the
EN/SYNC pin. The internal clock rising edge is
synchronized to the external clock rising edge.
NB634 Rev. 0.94
12/25/2013
Under-Voltage Lockout (UVLO)
Under-voltage lockout (UVLO) is implemented to
protect the chip from operating at insufficient
supply voltage. The NB634 UVLO comparator
monitors the output voltage of the internal
regulator, VCC. The UVLO rising threshold is
about 4.0V while its falling threshold is a
consistent 3.2V.
Internal Soft-Start
The soft-start is implemented to prevent the
converter output voltage from overshooting
during startup. When the chip starts, the internal
circuitry generates a soft-start voltage (SS)
ramping up from 0V to 1.2V. When it is lower
than the internal reference (REF), SS overrides
REF so the error amplifier uses SS as the
reference. When SS is higher than REF, REF
regains control.
Over-Current Protection and Latch-off
The NB634 has cycle-by-cycle overcurrent limit
when the inductor current peak value exceeds
the set current limit threshold.
When output voltage drops below 70% of the
reference, and inductor current exceeds the
current limit. The NB634 will be latched off. This
is especially useful to ensure system safety
under fault condition. The NB634 clears the latch
once the EN or input power is recycled.
The latch-off function is disabled during soft-start
duration.
Thermal Shutdown
Thermal shutdown is implemented to prevent the
chip from operating at exceedingly high
temperatures. When the silicon die temperature
is higher than 150C, it shuts down the whole
chip. When the temperature is lower than its
lower threshold, typically 140C, the chip is
enabled again.
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8
NB634 –HIGH EFFICIENCY, 5A, 24V, 500kHz SYNCHRONOUS STEP-DOWN CONVERTER
Floating Driver and Bootstrap Charging
The floating power MOSFET driver is powered by
an external bootstrap capacitor. This floating
driver has its own UVLO protection. This UVLO’s
rising threshold is 2.2V with a hysteresis of
150mV. The bootstrap capacitor voltage is
regulated internally by VIN through D1, M1, C4,
L1 and C2 (Figure 2). If (VIN-VSW) is more than
5V, U1 will regulate M1 to maintain a 5V BST
voltage across C4.
D1
VIN
M1
Startup and Shutdown
If both VIN and EN are higher than their
respective thresholds, the chip starts. The
reference block starts first, generating stable
reference voltage and currents, and then the
internal regulator is enabled. The regulator
provides stable supply for the remaining circuitry.
Three events can shut down the chip: EN low,
VIN low and thermal shutdown. In the shutdown
procedure, the signal path is first blocked to
avoid any fault triggering. The COMP voltage and
the internal supply rail are then pulled down. The
floating driver is not subjected to this shutdown
command.
BST
5V
U1
C4
VOUT
SW
L1
C2
Figure 2—Internal Bootstrap Charging Circuit
NB634 Rev. 0.94
12/25/2013
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9
NB634 –HIGH EFFICIENCY, 5A, 24V, 500kHz SYNCHRONOUS STEP-DOWN CONVERTER
APPLICATION INFORMATION
Setting the Output Voltage
The external resistor divider is used to set the
output voltage (see Typical Application on page
1). The feedback resistor R1 also sets the
feedback loop bandwidth with the internal
compensation capacitor (see Typical Application
on page 1). Choose R1 to be around 10kΩ. R2 is
then given by:
R1
R2
VOUT
0.805V
(1)
1
The T-type network is highly recommended when
Vo is low, as Figure 3 shows.
FB
8
R1
RT
VOUT
R2
Figure 3— T-type Network
Table 1 lists the recommended T-type resistors
value for common output voltages.
Table 1—Resistor Selection for Common
Output Voltages
VOUT (V)
1.05
1.2
1.8
2.5
3.3
5
R1 (kΩ)
3.09(1%)
4.99(1%)
10(1%)
10(1%)
10(1%)
10(1%)
R2 (kΩ)
10(1%)
10(1%)
8.06(1%)
4.75(1%)
3.16(1%)
1.91(1%)
I L
2
(3)
Under light load conditions below 100mA, larger
inductance is recommended for improved
efficiency.
Setting the AAM Voltage
The AAM voltage is used for setting the transition
point from AAM to CCM. It should be chosen to
provide the best combination of efficiency,
stability, ripple, and transient.
If the AAM voltage is set lower, then stability and
ripple improve, but efficiency during AAM mode
and transient degrade. Likewise, if the AAM
voltage is set higher, then the efficiency during
AAM and transient improve, but stability and
ripple degrade. Therefore, an optimal AAM
voltage that provides good efficiency, stability,
ripple, and transient needs to be determined.
As figure 4 shows, AAM voltage can be set by
using a resistor divider.
R6
AAM
R5
Figure 4— AAM Network
A 1µH to 10µH inductor with a DC current rating
of at least 25% percent higher than the maximum
load current is recommended for most
applications. For highest efficiency, the inductor
DC resistance should be less than 15mΩ. For
most designs, the inductance value can be
derived from the following equation.
VOUT (VIN VOUT )
VIN IL fsw
IL(MAX ) ILOAD
VCC(5V)
Rt (kΩ)
24.9(1%)
24.9(1%)
24.9(1%)
24.9(1%)
24.9(1%)
24.9(1%)
Selecting the Inductor
L1
Choose inductor current to be approximately
30% of the maximum load current. The maximum
inductor peak current is:
Refer to Figure 5 to select an optimal voltage and
then use the equation below to determine the
value of R6. Assume R5 to be around 10kΩ.
Generally, choose R5 to be around 10 kΩ, R6 is
then determined by the following equation:
VCC
R6 R5
1
AAM
(4)
(2)
Where ΔIL is the inductor ripple current.
NB634 Rev. 0.94
12/25/2013
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10
NB634 –HIGH EFFICIENCY, 5A, 24V, 500kHz SYNCHRONOUS STEP-DOWN CONVERTER
1.0
0.9
VIN
VO=3.3V
VO=5V
0.8
AAM (V)
0.7
0.6
0.5
0.4
0.3
VO=1.05V
0.1
0.0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
VOUT
Figure 5— AAM Selection for Common
Output Voltages (VIN=7V-24V)
Selecting the Input Capacitor
The input current to the step-down converter is
discontinuous, therefore a capacitor is required to
supply the AC current to the step-down converter
while maintaining the DC input voltage. Use low ESR
capacitors for the best performance. Ceramic
capacitors with X5R or X7R dielectrics are highly
recommended because of their low ESR and
small temperature coefficients. For most
applications, a 22µF capacitor is sufficient.
Since the input capacitor (C1) absorbs the input
switching current, it requires an adequate ripple
current rating. The RMS current in the input capacitor
can be estimated by:
I C1 ILOAD
VOUT VOUT
1
VIN
VIN
(5)
The worst case condition occurs at VIN = 2VOUT,
where:
IC1
ILOAD
2
(7)
Selecting the Output Capacitor
The output capacitor (C2) is required to maintain
the DC output voltage. Ceramic, tantalum, or low
ESR electrolytic capacitors are recommended.
Low ESR capacitors are preferred to keep the
output voltage ripple low. The output voltage
ripple can be estimated by:
VO=1.8V
0.2
ILOAD
V
V
OUT 1 OUT
fSW C1 VIN
VIN
(6)
(8)
V
VOUT
1
1 OUT RESR
fSW L1
VIN
8 fSW C2
Where L1 is the inductor value and RESR is the
equivalent series resistance (ESR) value of the
output capacitor.
In the case of ceramic capacitors, the impedance
at the switching frequency is dominated by the
capacitance. The output voltage ripple is mainly
caused by the capacitance. For simplification, the
output voltage ripple can be estimated by:
ΔVOUT
V
VOUT
1 OUT
2
8 fSW L1 C2
VIN
(9)
In the case of tantalum or electrolytic capacitors,
the ESR dominates the impedance at the
switching frequency. For simplification, the output
ripple can be approximated to:
ΔVOUT
VOUT
V
1 OUT
fSW L1
VIN
RESR
(10)
The characteristics of the output capacitor also
affect the stability of the regulation system. The
NB634 can be optimized for a wide range of
capacitance and ESR values.
For simplification, choose the input capacitor
whose RMS current rating is greater than half of
the maximum load current.
The input capacitor can be electrolytic, tantalum
or ceramic. When using electrolytic or tantalum
capacitors, a small, high quality ceramic
capacitor, i.e. 0.1μF, should be placed as close
to the IC as possible. When using ceramic
capacitors, make sure that they have enough
capacitance to provide sufficient charge to
prevent excessive voltage ripple at input. The
input voltage ripple caused by capacitance can
be estimated by:
NB634 Rev. 0.94
12/25/2013
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© 2013 MPS. All Rights Reserved.
11
NB634 –HIGH EFFICIENCY, 5A, 24V, 500kHz SYNCHRONOUS STEP-DOWN CONVERTER
External Bootstrap Diode
An external bootstrap diode may enhance the
efficiency of the regulator, the applicable
conditions of external BST diode are:
VOUT is 5V or 3.3V; and
Duty cycle is high: D=
VOUT
>65%
VIN
In these cases, an external BST diode is
recommended from the VCC pin to BST pin, as
shown in Figure 6.
BST
NB634
SW
External BST Diode
IN4148
VCC
CBST
L
COUT
GND
C1
IN 1
SW 2
14 AGND
SW 3
SW 5
12 GND
C3
11 VCC
R3
10 AAM
BST 6
9 PG R5
SW 4
C4
L1
EN
7
13 GND
8 FB
Rt
R4
R2
R1
C2
Top Layer
Figure 6—Add Optional External Bootstrap
Diode to Enhance Efficiency
The recommended external BST diode is IN4148,
and the BST cap is 0.1~1μF.
PC Board Layout
The high current paths (GND, IN and SW) should
be placed very close to the device with short,
direct and wide traces. The input capacitor needs
to be as close as possible to the IN and GND
pins. The external feedback resistors should be
placed next to the FB pin. Keep the switching
node SW short and away from the feedback
network.
Bottom Layer
Figure 7—PCB Layout
NB634 Rev. 0.94
12/25/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
12
NB634 –HIGH EFFICIENCY, 5A, 24V, 500kHz SYNCHRONOUS STEP-DOWN CONVERTER
PACKAGE INFORMATION
QFN14 (3mm x 4mm)
2.90
3.10
1.60
1.80
0.30
0.50
PIN 1 ID
MARKING
PIN 1 ID
SEE DETAIL A
1
14
0.18
0.30
3.20
3.40
3.90
4.10
PIN 1 ID
INDEX AREA
0.50
BSC
8
TOP VIEW
7
BOTTOM VIEW
0.80
1.00
0.20 REF
PIN 1 ID OPTION A
0.30x45º TYP.
PIN 1 ID OPTION B
R0.20 TYP.
0.00
0.05
SIDE VIEW
DETAIL A
2.90
0.70
NOTE:
1.70
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) EXPOSED PADDLE SIZE DOES NOT INCLUDE MOLD FLASH.
3) LEAD COPLANARITY SHALL BE0.10 MILLIMETER MAX.
4) JEDEC REFERENCE IS MO-229, VARIATION VGED-3.
5) DRAWING IS NOT TO SCALE.
0.25
3.30
0.50
RECOMMENDED LAND PATTERN
NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third
party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not
assume any legal responsibility for any said applications.
NB637 Rev. 0.94
12/25/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
13
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