MPM3606 [MPS]
21V Input, 0.6A Module Synchronous Step-Down Converter with Integrated Inductor;
| 型号： | MPM3606 |
| 厂家： | 
MONOLITHIC POWER SYSTEMS |
| 描述： | 21V Input, 0.6A Module Synchronous Step-Down Converter with Integrated Inductor |
| 文件： | 总18页 (文件大小：764K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MPM3606
21V Input, 0.6A Module
Synchronous Step-Down Converter
with Integrated Inductor
The Future of Analog IC Technology
DESCRIPTION
FEATURES
The MPM3606 is a synchronous rectified, step-
down converter module with built-in power
MOSFETs, inductor and two capacitors. It
offers a very compact solution with only 5
4.5V-to-21V Operating Input Range
0.6A Continuous Load Current
200μA Low Quiescent Current
100mΩ/50mΩ Low RDS(ON) Internal Power
MOSFETs
external components to achieve
a
0.6A
continuous output current with excellent load
and line regulation over a wide input supply
range. The MPM3606 operates at 2MHz
switching frequency, which provides fast load
transient response. External AAM pin provides
selectable power save mode or forced PWM
mode.
Integrated Inductor
Integrated VCC and Bootstrap Capacitors
External AAM pin for Power-Save Mode
Programming
OCP Protection with Hiccup
Thermal Shutdown
Output Adjustable from 0.8V
Available in QFN-20 (3mmx5mmx1.6mm)
Package
Full protection features include over-current
protection and thermal shut down.
Total Solution Size 6.7mm x 6.3mm
MPM3606 eliminates design and manufacturing
risks while dramatically improving time to
market.
APPLICATIONS
Industrial Controls
The MPM3606 is available in a space-saving
QFN-20 (3mmx5mmx1.6mm) package.
Medical and Imaging Equipment
Telecom and Networking Applications
LDO Replacement
Space and Resource-limited Applications
All MPS parts are lead-free and adhere to the RoHS directive. For MPS green
status, please visit MPS website under Quality Assurance. “MPS” and “The
Future of Analog IC Technology” are Registered Trademarks of Monolithic
Power Systems, Inc.
TYPICAL APPLICATION
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
1
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
ORDERING INFORMATION
Part Number*
Package
Top Marking
MP3606
M
MPM3606GQV
QFN-20 (3mmx5mmx1.6mm)
* For Tape & Reel, add suffix –Z (e.g. MPM3606GQV–Z)
PACKAGE REFERENCE
ABSOLUTE MAXIMUM RATINGS (1)
VIN ..................................................-0.3V to 28V
Thermal Resistance (6)
QFN-20 (3mmx5mmx1.6mm) ...46.... 10... °C/W
θJA θJC
V
SW......................................................................
-0.3V (-5V for <10ns) to 28V (30V for <10ns)
Notes:
1) Exceeding these ratings may damage the device.
2) About the details of EN pin’s ABS MAX rating, please refer to
page 11, Enable control section.
VBST ........................................................VSW+6V
All Other Pins................................-0.3V to 6V (2)
3) The maximum allowable power dissipation is a function of the
maximum junction temperature TJ (MAX), the junction-to-
ambient 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)
Continuous Power Dissipation (TA = +25°C)
............................................................. 2.7W
Junction Temperature...............................150°C
Lead Temperature ....................................260°C
Storage Temperature................. -65°C to 150°C
Recommended Operating Conditions (4)
Supply Voltage VIN ...........................4.5V to 21V
Output Voltage VOUT.....................0.8V to 5.5V(5)
Operating Junction Temp. (TJ). -40°C to +125°C
4) The device is not guaranteed to function outside of its
operating conditions.
5) For output voltage setting above 5.5V, please refer to the
application information on page 13.
6) Measured on JESD51-7, 4-layer PCB.
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
2
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
ELECTRICAL CHARACTERISTICS
VIN=12V, TJ=-40°C to +125°C(7), typical value is tested at TJ=+25°C, unless otherwise noted.
Parameter
Symbol Condition
Min
Typ
Max
Units
Supply Current (Shutdown)
IIN
VEN = 0V,TJ=25°C
1
μA
VFB = 1V, VAAM=0.5V
VFB = 1V, VAAM=5V
0.2
0.7
100
50
Supply Current (Quiescent)
Iq
mA
HS Switch-On Resistance
LS Switch-On Resistance
Inductor DC Resistance
Switch Leakage
HSRDS-ON VBST-SW=5V
LSRDS-ON VCC =5V
LDCR
mΩ
mΩ
mΩ
μA
A
60
SWLKG VEN = 0V, VSW =12V
1
Current Limit (8)
ILIMIT
Under 40% Duty Cycle
VFB=0.75V, TJ=+25°C
1.8
2.4
2000
2000
0.3
1700
2400
2500
kHz
kHz
fSW
%
Oscillator Frequency
fSW
VFB=0.75V,TJ=-40°C to +125°C 1500
VFB<400mV
Fold-Back Frequency
Maximum Duty Cycle
Minimum On Time(8)
fFB
DMAX
VFB=700mV
80
85
τON_MIN
35
ns
TJ=+25°C
786
782
798
798
10
810
814
50
mV
mV
nA
μA
μA
Feedback Voltage
VFB
TJ=-40°C to +125°C
VFB=820mV
Feedback Current
IFB
TJ=+25°C
5.6
4.3
6.2
6.8
7.9
AAM Source Current
IAAM
TJ=-40°C to +125°C
6.2
EN Rising Threshold
EN Falling Threshold
EN Input Current
VEN_RISING
VEN_FALLING
IEN
1.15
1.05
1.4
1.25
2
1.65
1.45
V
V
VEN=2V
μA
VIN Under-Voltage Lockout
Threshold—Rising
INUVVth
3.65
3.9
4.15
V
VIN Under-Voltage Lockout
Threshold—Hysteresis
INUVHYS
VCC
650
mV
VCC Regulator
4.9
1.5
1.5
V
%
VCC Load Regulation
Soft-Start Time
ICC=5mA
tSS
VOUT from 10% to 90%
ms
Thermal Shutdown (8)
150
20
°C
°C
Thermal Hysteresis (8)
Notes:
7) Not tested in production; guaranteed by over-temperature correlation.
8) Guaranteed by design.
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
3
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
TYPICAL PERFORMANCE CHARACTERISTICS
Performance waveforms are captured from the evaluation board discussed in the Design
Example section.VIN = 12V, VOUT = 3.3V, TA = 25°C, unless otherwise noted.
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
4
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED)
Performance waveforms are captured from the evaluation board discussed in the Design
Example section.VIN = 12V, VOUT = 3.3V, TA = 25°C, unless otherwise noted.
Load Regulation
VOUT =1.2V
Efficiency vs. Load Current
VOUT =1V
Load Regulation
VOUT =1V
0.5
0.4
0.3
0.2
0.1
0
100
90
80
70
60
50
40
30
20
10
0
0.5
0.4
0.3
0.2
0.1
0
V
=5V
IN
V
V
=12V
=5V
V
=12V
IN
IN
V =12V
IN
V =5V
IN
IN
-0.1
-0.2
-0.3
-0.4
-0.5
-0.1
-0.2
-0.3
-0.4
-0.5
0
0.2
0.4
0.6
0.01
0.1
1
0
0.2
0.4
0.6
LOAD CURRENT (A)
LOAD CURRENT (A)
LOAD CURRENT (A)
Current Limit vs.
Duty Cycle
Case Temperature Rise vs.
Output Current
VOUT =5V
Line Regulation
VIN=5V-21V, VOUT =3.3V
30
25
20
15
10
5
3.2
3
0.3
0.2
0.1
0
2.8
2.6
2.4
2.2
2
V
=19V
IN
V
=12V
I
= 0.1A
= 0.3A
IN
OUT
I
I
= 0.6A
OUT
OUT
-0.1
-0.2
-0.3
1.8
1.6
1.4
V
=8V
IN
0
0
20
40
60
80
100
0
0.2
0.4
0.6
0.8
0
5
10
15
20
25
LOAD CURRENT (A)
INPUT VOLTAGE (V)
Case Temperature Rise vs.
Output Current
VOUT =1.2V
Bode Plot
IOUT =0.6A
Maximum VIN vs. VOUT
22
20
18
16
14
12
10
60
40
20
0
180
12
10
8
V
=12V
IN
120
60
0
6
V
=5V
IN
-20
-40
-60
-60
-120
-180
4
2
0
1,000
10,000
100,000 1,000,000
0.8 1.3 1.8 2.3 2.8 3.3 3.8 4.3 4.8 5.3
0
0.2
0.4
0.6
0.8
FREQUENCY(Hz)
VOUT(V)
LOAD CURRENT (A)
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
5
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED)
Performance waveforms are captured from the evaluation board discussed in the Design
Example section.VIN = 12V, VOUT = 3.3V, TA = 25°C, unless otherwise noted.
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
6
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED)
Performance waveforms are captured from the evaluation board discussed in the Design
Example section.VIN = 12V, VOUT = 3.3V, TA = 25°C, unless otherwise noted.
Input/Output Ripple
Input/Output Ripple
VIN Startup
I
= 0A
I
= 0.6A
I
= 0A
OUT
OUT
OUT
V
V
OUT
OUT
AC Coupled
10mV/div.
AC Coupled
10mV/div.
V
OUT
2V/div.
V
V
IN
IN
AC Coupled
50mV/div.
AC Coupled
50mV/div.
V
IN
10V/div.
V
V
V
SW
SW
SW
10V/div.
10V/div.
10V/div.
VIN Startup
VIN Shutdown
VIN Shutdown
I
= 0.6A
I
= 0A
I
= 0.6A
OUT
OUT
OUT
V
V
V
OUT
OUT
OUT
2V/div.
2V/div.
2V/div.
V
V
V
IN
IN
IN
10V/div.
10V/div.
10V/div.
V
V
SW
SW
10V/div.
10V/div.
V
SW
I
I
OUT
10V/div.
OUT
1A/div.
1A/div.
EN Startup
EN Startup
EN Shutdown
I
= 0A
I
= 0.6A
I
= 0A
OUT
OUT
OUT
V
V
OUT
OUT
V
OUT
2V/div.
2V/div.
2V/div.
V
EN
V
EN
V
EN
5V/div.
5V/div.
5V/div.
V
SW
10V/div.
V
SW
V
SW
I
10V/div.
OUT
10V/div.
1A/div.
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
7
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED)
Performance waveforms are captured from the evaluation board discussed in the Design
Example section.VIN = 12V, VOUT = 3.3V, TA = 25°C, unless otherwise noted.
EN Shutdown
Transient Response
Short Circuit Entry
I
= 0.6A
I
= 0A to 0.6A
OUT
OUT
V
OUT
V
V
OUT
OUT
2V/div.
2V/div.
AC Coupled
50mV/div.
V
EN
5V/div.
V
SW
10V/div.
V
SW
10V/div.
I
OUT
I
500mA/div.
OUT
I
OUT
1A/div.
5A/div.
Short Circuit Steady State
Short Circuit Recovery
V
OUT
2V/div.
V
OUT
2V/div.
V
SW
10V/div.
V
SW
10V/div.
I
I
OUT
OUT
2A/div.
5A/div.
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
8
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
PIN FUNCTIONS
Package
Pin #
Name
Description
Feedback. Connect to the tap of an external resistor divider from the output to AGND to
set the output voltage. The frequency fold-back comparator lowers the oscillator
frequency when the FB voltage is below 400mV to prevent current limit runaway during
a short circuit fault. Place the resistor divider as close to the FB pin as possible. Avoid
placing vias on the FB traces.
1
FB
Internal 5V LDO output. Internal circuit integrates LDO output capacitor, so there is no
need to add external capacitor.
2
3
VCC
Analog Ground. Reference ground of logic circuit. AGND is internally connected to
PGND. No need add external connections to PGND.
AGND
Switch Output. Large copper plane is recommended on pin 4, 5 and 6 for better heat
sink.
4, 5, 6
7, 8, 9
SW
OUT
NC
Power Output. Connect load to this pin. Output capacitor is needed.
DO NOT CONNECT. Pin must be left floating.
10, 15, 19,
20
Bootstrap. Bootstrap capacitor is integrated internally. External connection is not
needed.
11
BST
Power Ground. Reference ground of the power device. PCB layout requires extra care.
For best results, connect to PGND with copper and vias.
12, 13, 14
PGND
Supply Voltage. The IN pin supplies power for internal MOSFET and regulator. The
MPM3606 operates from a +4.5V to +21V input rail. Requires a low-ESR, and low-
inductance capacitor to decouple the input rail. Place the input capacitor very close to
this pin and connect it with wide PCB traces and multiple vias.
16
17
18
IN
EN
EN=high to enable the module. Float EN pin or connect it to ground will disable the
converter.
Advanced Asynchronous Modulation. AAM pin sources a 6.2μA current from internal
5V supply. Float AAM pin or drive AAM pin high (>2.5V) to force the MPM3606 to
always operate in CCM. Connect a resistor to ground to program AAM voltage in the
range of 0 to1V if non-synchronous mode is required under light load.
AAM
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
9
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
FUNCTIONAL BLOCK DIAGRAM
Figure 1: Functional Block Diagram
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
10
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
pulses for PFM (Pulse Frequency Modulation)
mode and achieves the light load power save.
OPERATION
The
MPM3606
is
a
high-frequency,
synchronous, rectified, step-down, switch-mode
converter with built-in power MOSFETs,
integrated inductor and two capacitors. It offers
a very compact solution that achieves a 0.6A
continuous output current with excellent load
and line regulation over 4.5V to 21V input
supply range.
Figure 2: Simplified AAM Control Logic
The MPM3606 operates in a fixed-frequency,
peak-current–control mode to regulate the
output voltage. An internal clock initiates a
PWM cycle. The integrated high-side power
MOSFET turns on and remains on until the
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,
within 80% of one PWM period, the current in
the power MOSFET does not reach the value
set by the COMP value, the power MOSFET is
forced off.
Error Amplifier
The error amplifier compares the FB pin voltage
to the internal 0.8V reference (VREF) and
outputs a current proportional to the difference
between the two. This output current then
charges
or
discharges
the
internal
compensation network to form the COMP
voltage, which controls the power MOSFET
current. The optimized internal compensation
network minimizes the external component
counts and simplifies the control loop design.
Internal Regulator
Under-Voltage Lockout (UVLO)
Under-voltage lockout (UVLO) protects the chip
from operating at insufficient supply voltage.
The MPM3606 UVLO comparator monitors the
output voltage of the internal regulator, VCC.
The UVLO rising threshold is about 3.9V while
its falling threshold is 3.25V.
A 5V internal regulator powers most of the
internal circuitries. This regulator takes VIN and
operates in the full VIN range. When VIN
exceeds 5.0V, the output of the regulator is in
full regulation. When VIN is less than 5.0V, the
output decreases, and the part integrates
internal decoupling capacitor. No need add
external VCC output capacitor.
Enable Control
EN is a digital control pin that turns the
regulator on and off. Drive EN high to turn on
the regulator; drive it low to turn it off. An
internal 1Mꢀ resistor from EN to GND allows
EN to be floated to shut down the chip.
AAM Operation
The
MPM3606
has
AAM
(Advanced
Asynchronous Modulation) power-save mode
for light load. Connect a resistor from AAM pin
to GND to set AAM voltage. Under the heavy
The EN pin is clamped internally using a 6.5V
series-Zener-diode as shown in Figure 3.
Connecting the EN input pin through a pullup
resistor to the voltage on the VIN pin limits the
EN input current to less than 100µA.
load condition, the VCOMP is higher than VAAM
.
When the clock goes high, the high-side power
MOSFET turns on and remains on until VILsense
reaches the value set by the COMP voltage.
The internal clock resets every time when VCOMP
For example, with 12V connected to Vin,
RPULLUP ≥ (12V – 6.5V) ÷ 100µA = 55kꢀ.
is higher than VAAM
.
Under the light load condition, the value of
VCOMP is low. When VCOMP is less than VAAM and
VFB is less than VREF, VCOMP ramps up until it
exceeds VAAM. During this time, the internal
clock is blocked, thus the MPM3606 skips some
Connecting the EN pin is directly to a voltage
source without any pull-up resistor requires
limiting the amplitude of the voltage source to
≤6V to prevent damage to the Zener diode.
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
11
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
Floating Driver and Bootstrap Charging
An internal bootstrap capacitor powers the
floating power MOSFET driver. 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 4). If (VIN-VSW)
exceeds 5V, U1 will regulate M1 to maintain a
5V BST voltage across C4.
Figure 3: 6.5V Zener Diode Connection
Internal Soft-Start
The soft-start prevents the converter output
voltage from overshooting during startup. When
the chip starts, the internal circuitry generates a
soft-start voltage (SS) that ramps up from 0V to
5V. When SS is lower than REF, the error
amplifier uses SS as the reference. When SS is
higher than REF, the error amplifier uses REF
as the reference. The SS time is internally set
to 1.5ms.
Over-Current-Protection and Hiccup
The MPM3606 has a cycle-by-cycle over-
current limit when the inductor current peak
value exceeds the set current limit threshold.
Meanwhile, the output voltage drops until VFB is
below the Under-Voltage (UV) threshold—
typically 50% below the reference. Once UV is
triggered, the MPM3606 enters hiccup mode to
periodically restart the part. This protection
mode is especially useful when the output is
dead-shorted to ground, and greatly reduces
the average short circuit current to alleviate
thermal issues and protect the regulator. The
MPM3606 exits the hiccup mode once the over-
current condition is removed.
Figure 4: Internal Bootstrap Charging Circuit
Startup and Shutdown
If both VIN and EN exceed their 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 a stable supply
for the remaining circuitries.
Three events can shut down the chip: VIN low,
EN low and thermal shutdown. During the
shutdown procedure, the signaling 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
subject to this shutdown command.
Thermal Shutdown
Thermal shutdown prevents the chip from
operating at exceedingly high temperatures.
When the silicon die reaches temperatures that
exceed 150°C, it shuts down the whole chip.
When the temperature drops below its lower
threshold, typically 130°C, the chip is enabled
again.
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
12
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
Selecting the Input Capacitor
APPLICATION INFORMATION
Setting the Output Voltage
The external resistor divider sets the output
voltage (see Typical Application on page 1).
The feedback resistor R1 also sets the
feedback loop bandwidth with the internal
The input current to the step-down converter is
discontinuous, therefore requires a capacitor is
to supply the AC current to the step-down
converter while maintaining the DC input
voltage. Use low ESR capacitors for the best
performance. Use ceramic capacitors with X5R
or X7R dielectrics for best results because of
their low ESR and small temperature
coefficients. For most applications, use a 10µF
capacitor.
compensation
capacitor
(see
Typical
Application on page 1). Choose R1 refer to
Table 1, R2 is then given by:
R1
R2
Since C1 absorbs the input switching current, it
requires an adequate ripple current rating. The
RMS current in the input capacitor can be
estimated by:
V
OUT
1
0.798V
VOUT
VIN
VOUT
VIN
IC1 ILOAD
1
The worst case condition occurs at VIN = 2VOUT
where:
,
Figure 5: Feedback Network
Table 1 lists the recommended resistors value
for common output voltages.
ILOAD
IC1
2
Table 1: Resistor Selection for Common Output
Voltages
For simplification, choose an input capacitor
with an RMS current rating greater than half of
the maximum load current.
VOUT (V) R1 (kΩ)
R2 (kΩ)
RAAM(kΩ)(9)
1.0
1.2
1.5
1.8
2.5
3.3
221
191
158
102
75
887
383
180
82
9.09
11.3
13
The input capacitor can be electrolytic, tantalum
or ceramic. When using electrolytic or tantalum
capacitors, add a small, high quality ceramic
capacitor (e.g. 0.1μF) 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 as:
18.2
25.5
33
34.8
24
75
5
100
19.1
45.3
Notes:
9) The recommended RAAM value is based on 12V input voltage,
please refer to Figure 7 for full input and output voltage
range’s RAAM value.
ILOAD
VOUT
VOUT
V
1
IN
fS C1
V
IN
V
IN
Normally output voltage is recommended to be
set from 0.8V to 5.5V. Actually it can be set
larger than 5.5V. Output voltage ripple will be
larger in this case. Additional output capacitor
may be needed to reduce the output voltage
ripple.
Setting the AAM Voltage
The AAM voltage is used to set 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 improves, but efficiency during AAM
mode and transient degrades. Likewise, if the
AAM voltage is set higher, then the efficiency
during AAM and transient improves, but stability
When output voltage is high, the chip’s heat
dissipation become more important, please
refer to PC Board layout guidelines on page 14-
15 to achieve better thermal effect.
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
13
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
and ripple degrades. So the optimal balance
For ceramic capacitors, the capacitance
dominates the impedance at the switching
frequency, and the capacitance causes the
majority of the output voltage ripple. For
simplification, the output voltage ripple can be
estimated as:
point of AAM voltage for good efficiency,
stability, ripple and transient should be found
out.
Adjust the AAM threshold by connecting a
resistor from AAM pin to ground. Take Figure 6
as reference. An internal 6.2µA current source
charges the external resistor.
VOUT
8 fS2 L1 C2
VOUT
ΔVOUT
1
V
IN
For tantalum or electrolytic capacitors, the ESR
dominates the impedance at the switching
frequency. For simplification, the output ripple
can be approximated as:
VOUT
VOUT
ΔVOUT
1
RESR
fS L1
V
IN
Figure 6: AAM Network
Generally, R4 is then given by:
VAAM=R4 x 6.2µA
The characteristics of the output capacitor also
affect the stability of the regulation system. The
MPM3606 can be optimized for a wide range of
capacitance and ESR values.
PC Board Layout (10)
Please consult the Figure 7 below when setting
the AAM resistor.
PCB layout is very important to achieve stable
operation especially for input capacitor
placement. For best results, follow these
guidelines:
1. Use large ground plane directly connect to
PGND pin. Add vias near the PGND pin if
bottom layer is ground plane.
2. The high current paths at GND, IN. Place
the ceramic input capacitor close to IN and
PGND pins. Keep the connection of input
capacitor and IN pin as short and wide as
possible.
Figure 7: AAM Resistor Selection
Selecting the Output Capacitor
3. The external feedback resistors should be
placed next to the FB pin.
The output capacitor (C2) maintains the DC
output voltage. Use ceramic, tantalum, or low-
ESR electrolytic capacitors. For best results,
use low ESR capacitors to keep the output
voltage ripple low. The output voltage ripple can
be estimated as:
4. Keep the feedback network away from the
switching node.
Notes:
10) The recommended layout is based on the Figure 8 Typical
Application circuit on page 16.
VOUT
VOUT
1
VOUT
1
R
ESR
fS L1
V
8 fS C2
IN
Where L1 is the inductor value and RESR is the
equivalent series resistance (ESR) value of the
output capacitor.
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
14
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
Design Example
VIN
GND
VOUT
Below is a design example following the
application guidelines for the specifications:
Table 2: Design Example
VIN
VOUT
IOUT
12V
3.3V
0.6A
C1
The detailed application schematic is shown in
Figure 8 through 13. The typical performance
and circuit waveforms have been shown in the
Typical Performance Characteristics section.
For more device applications, please refer to
the related Evaluation Board Datasheets.
PGND
F
VC
BS
N
AND
SW
OUT
6.3mm
Top Layer
Bottom Layer
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
15
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
TYPICAL APPLICATION CIRCUITS
Figure 8: VOUT=5V, IOUT=0.6A
Figure 9: VOUT=3.3V, IOUT=0.6A
Figure 10: VOUT=2.5V, IOUT=0.6A
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
16
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
Figure 11: VOUT=1.8V, IOUT=0.6A
Figure 12: VOUT=1.2V, IOUT=0.6A
Figure 13: VOUT=1V, IOUT=0.6A
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
17
MPM3606 – SYNCHRONOUS STEP-DOWN MODULE WITH INTEGRATED INDUCTOR
PACKAGE INFORMATION
QFN-20 (3mmx5mmx1.6mm)
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) SHADED AREA IS THE KEEP-OUT ZONE. ANY
PCB METAL TRACE AND VIA ARE NOT ALLOWED
TO CONNECT TO THIS AREA ELECTRICALLY OR
MECHANICALLY.
3) EXPOSED PADDLE SIZE DOES NOT INCLUDE
MOLD FLASH.
4) LEAD COPLANARITY SHALL BE 0.10
MILLIMETERS MAX.
5) JEDEC REFERENCE IS MO-220.
6) DRAWING IS NOT TO SCALE.
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.
MPM3606 Rev. 1.0
8/11/2014
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2014 MPS. All Rights Reserved.
18
相关型号：
©2020 ICPDF网 联系我们和版权申明