MPS MP2214DL 16v, 4a, 600khz synchronous step-down converter Datasheet

MP2214
16V, 4A, 600kHz Synchronous
Step-Down Converter
The Future of Analog IC Technology
DESCRIPTION
FEATURES
The MP2214 is an internally compensated
600kHz fixed frequency PWM synchronous
step-down regulator with a 3V to 6V bias supply
(VCC). MP2214 operates from a 3V to 16V input
and generates an adjustable output voltage
from 0.8V to 0.9xVIN at up to 4A load current.
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•
•
•
•
•
•
•
•
•
•
•
•
•
The MP2214 integrates an 80mΩ high-side
switch and an 80mΩ synchronous rectifier for
high efficiency without an external Schottky
diode. With peak current mode control and
internal compensation, it is stable with a output
ceramic capacitor and a small inductor. Fault
protection
includes
hiccup
short-circuit
protection, cycle-by-cycle current limiting and
thermal shutdown. Other features include
frequency synchronization and internal softstart.
4A Output Current
Input Supply Range: 3V to 16V
80mΩ Internal Power MOSFET Switches
All Ceramic Output Capacitors Design
Up to 95% Efficiency
600kHz Fixed Switching Frequency
Adjustable Output from 0.8V to 0.9xVIN
Internal Soft-Start
Power Good Pin
Frequency Synchronization Input
Thermal Shutdown
Cycle-by-Cycle Current Limiting
Hiccup Short Circuit Protection
14-Lead, 3mm x 4mm QFN and 8-lead
SOICE Packages
APPLICATIONS
The MP2214 is available in small 3mm x 4mm
14-lead QFN and 8-lead SOIC with exposed
pad packages.
•
•
•
•
µP/ASIC/DSP/FPGA Core and I/O Supplies
Printers and LCD TVs
Network and Telecom Equipment
Point of Load Regulators
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TYPICAL APPLICATION
VIN
3V to 16V
C1
33uF
VCC
3V to 6V
OFF ON
5,10
8
7
IN
VCC
C4
1uF
C3
100nF
BS
SW
4,11
MP2214
13
9
EN/SYNC
L1
3.3uH
C6
560PF
FB
POK
GND
VOUT
1.8V / 4A
14
C2
47uF
1,3,12
MP2214 Rev. 0.9
9/1/2010
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1
MP2214 – 16V, 4A, 600kHz SYNCHRONOUS STEP-DOWN CONVERTER
PACKAGE REFERENCE
TOP VIEW
PIN 1 ID
AGND
1
14
FB
N/C
2
13
EN/SYNC
PGND
3
12
PGND
SW
4
11
SW
IN
5
10
IN
N/C
6
9
POK
BS
7
8
VCC
TOP VIEW
FB
1
8
EN/SYNC
GND
2
7
SW
IN
3
6
SW
BS
4
5
VCC
EXPOSED PAD
ON BACKSIDE
CONNECT TO GND
EXPOSED PAD
ON BACKSIDE
CONNECT TO GND
Part Number*
MP2214DL
*
Package
QFN14
(3mm x 4mm)
Temperature
–40°C to +85°C
For Tape & Reel, add suffix –Z (e.g. MP2214DL–Z)
For RoHS Compliant Packaging, add suffix –LF
(e.g. MP2214DL–LF–Z)
ABSOLUTE MAXIMUM RATINGS (1)
IN to GND .................................... –0.3V to +18V
SW to GND .......................... –0.3V to VIN + 0.3V
...................................-3V to VIN + 3V for < 50ns
FB, EN/SYNC, VCC to GND.......... –0.3V to +6.5V
BS to SW .................................... –0.3V to +6.5V
Junction Temperature ...............................150°C
Lead Temperature ....................................260°C
Storage Temperature............... –65°C to +150°C
Part Number*
Package
Temperature
MP2214ADN
SOIC8E
–40°C to +85°C
** For Tape & Reel, add suffix –Z (e.g. MP2214ADN–Z)
For RoHS Compliant Packaging, add suffix –LF
(e.g. MP2214ADN–LF–Z)
Recommended Operating Conditions
(2)
Supply Voltage VIN .............................. 3V to 16V
Bias Voltage VCC ................................... 3V to 6V
Output Voltage VOUT ................. 0.8V to 0.9 x VIN
Operating Temperature ............. –40°C to +85°C
Thermal Resistance
(3)
θJA
θJC
SOIC8E .................................. 50 ...... 10... °C/W
QFN14 (3mm x 4mm) ............. 48 ...... 10... °C/W
Notes:
1) Exceeding these ratings may damage the device.
2) The device is not guaranteed to function outside of its
operating conditions.
3) Measured on approximately 1” square of 1 oz copper.
MP2214 Rev. 0.9
9/1/2010
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MP2214 – 16V, 4A, 600kHz SYNCHRONOUS STEP-DOWN CONVERTER
ELECTRICAL CHARACTERISTICS (4)
VCC = 3.6V, VIN=12V, TA = +25°C, unless otherwise noted.
Parameters
VCC Supply Current
VCC Shutdown Current
VCC Under Voltage Lockout Threshold
VCC Under Voltage Lockout Hysteresis
IN Shutdown Current
IN Under Voltage Lockout Threshold, Rising
Edge
IN Under Voltage Lockout Hysteresis
Regulated FB Voltage
FB Input Current
EN High Threshold
EN Low Threshold
Internal Soft-Start Time
High-Side Switch On-Resistance
Low-Side Switch On-Resistance
SW Leakage Current
BS Under Voltage Lockout Threshold
High-Side Switch Current Limit
Low-Side Switch Current Limit
Oscillator Frequency
Synch Frequency
Minimum On Time
Maximum Duty Cycle
Thermal Shutdown Threshold
Condition
VEN = VCC
VFB = 0.85V
VEN = 0V, VCC= 6V
Rising Edge
Min
Typ
750
1
2.8
200
4
VEN = 0V
2.85
TA = +25°C
–40°C ≤ TA ≤ +85°C
VFB = 0.85V
–40°C ≤ TA ≤ +85°C
–40°C ≤ TA ≤ +85°C
ISW = 300mA
ISW = –300mA
VEN = 0V; VIN = 12V
VSW = 0V or 12V
Sourcing
Sinking
Max
0.780
0.772
-50
1.6
300
0.800
μA
2.95
2.95
0.820
0.828
50
0.4
120
80
80
–10
5.5
450
Hysteresis = 20°C
10
1.8
7.5
3
600
2
50
90
150
Units
750
μA
V
mV
μA
V
mV
V
V
nA
V
V
µs
mΩ
mΩ
μA
V
A
A
KHz
MHz
ns
%
°C
Note:
4) Production test at +25°C. Specifications over the temperature range are guaranteed by design and characterization.
MP2214 Rev. 0.9
9/1/2010
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MP2214 – 16V, 4A, 600kHz SYNCHRONOUS STEP-DOWN CONVERTER
PIN FUNCTIONS
8-SOICE
Pin #
14-QFN
Pin #
Name
5
8
VCC
3
5, 10
IN
6,7
4, 11
SW
2
1, 3, 12
PGND,
AGND,
Exposed
Pad
4
7
BS
1
14
FB
8
13
EN/SYNC
9
2, 6
POK
N/C
MP2214 Rev. 0.9
9/1/2010
Description
Bias Supply. This supplies power to both the internal control circuit and the
gate drivers. A decoupling capacitor to ground is required close to this pin.
Input Supply. This supplies power to the high side switch. A decoupling
capacitor to ground is required close to this pin to reduce switching spikes.
Switch Node Connection to the Inductor. These pins connect to the internal
high and low-side power MOSFET switches. All SW pins must be
connected together externally.
Ground. Connect these pins with larger copper areas to the negative
terminals of the input and output capacitors. Connect exposed pad to GND
plane for proper thermal performance.
Bootstrap. A capacitor between this pin and SW provides a floating supply
for the high-side gate driver.
Feedback. This is the input to the error amplifier. An external resistive
divider connected between the output and GND is compared to the internal
0.8V reference to set the regulation voltage.
Enable and Frequency Synchronization Input Pin. Forcing this pin below
0.4V shuts down the part. Forcing this pin above 1.6V turns on the part.
Applying a 500kHz to 2MHz clock signal to this pin synchronizes the
internal oscillator frequency to the external source.
Power Good Pin.
No Connect.
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MP2214 – 16V, 4A, 600kHz SYNCHRONOUS STEP-DOWN CONVERTER
FUNCTIONAL BLOCK DIAGRAM
VCC
UVLO
UVLO
IN
EN
IN
BS
EN/SYNC
LOGIC
EN
EXCLK
LOGIC
CLK
OSC
+
--
EN/SYNC
PWM
CURRENT
COMPARATOR
SW
SLOPE
SW
0.5pF
1.2 MEG 17pF
FB
0.8V
-+
+
COMP
SLOPE
COMPENSATION
AND PEAK
CURRENT LIMIT
SOFT
-START
GND
GND
Figure 1—Functional Block Diagram
MP2214 Rev. 0.9
9/1/2010
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MP2214 – 16V, 4A, 600kHz SYNCHRONOUS STEP-DOWN CONVERTER
FUNCTIONAL DESCRIPTION
PWM Control
The MP2214 is a constant frequency peakcurrent-mode control PWM switching regulator.
Refer to the functional block diagram. The high
side N-Channel DMOS power switch turns on at
the beginning of each clock cycle. The current in
the inductor increases until the PWM current
comparator trips to turn off the high side DMOS
switch. The peak inductor current at which the
current comparator shuts off the high side power
switch is controlled by the COMP voltage at the
output of feedback error amplifier. The
transconductance from the COMP voltage to the
output current is set at 11.25A/V.
This current-mode control greatly simplifies the
feedback compensation design by approximating
the switching converter as a single-pole system.
Only Type II compensation network is needed,
which
is
integrated
into
the
MP2214.
Compensation in the MP2214 simplifies the
compensation
design,
minimizes
external
component counts.
Enable and Frequency Synchronization
(EN/SYNC PIN)
This is a dual function input pin. Forcing this pin
below 0.4V for longer than 4us shuts down the
part; forcing this pin above 1.6V for longer than
4µs turns on the part. Applying a 500KHz to 2MHz
clock signal to this pin also synchronizes the
internal oscillator frequency to the external clock.
When the external clock is used, the part turns on
after detecting the first few clocks regardless of
duty cycles. If any ON or OFF period of the clock
is longer than 4µs, the signal will be intercepted
as an enable input and disables the
synchronization.
Soft-Start and Output Pre-Bias Startup
When the soft-start period starts, an internal
current source begins charging an internal softstart capacitor. During soft-start, the voltage on
the soft-start capacitor is connected to the noninverting input of the error amplifier. The soft-start
period lasts until the voltage on the soft-start
capacitor exceeds the reference voltage of 0.8V.
At this point the reference voltage takes over at
the non-inverting error amplifier input. The softstart time is internally set at 120µs. If the output of
MP2214 Rev. 0.9
9/1/2010
the MP2214 is pre-biased to a certain voltage
during startup, the IC will disable the switching of
both high-side and low-side switches until the
voltage on the internal soft-start capacitor
exceeds the sensed output voltage at the FB pin.
Over Current Protection
The MP2214 offers cycle-to-cycle current limiting
for both high-side and low-side switches. The
high-side current limit is relatively constant
regardless of duty cycles. When the output is
shorted to ground, causing the output voltage to
drop below 70% of its nominal output, the IC is
shut down momentarily and begins discharging
the soft start capacitor. It will restart with a full
soft-start when the soft- start capacitor is fully
discharged. This hiccup process is repeated until
the fault is removed.
Bootstrap (BST PIN)
The gate driver for the high-side N-channel
DMOS power switch is supplied by a bootstrap
capacitor connected between the BS and SW pins.
When the low-side switch is on, the capacitor is
charged through an internal boost diode. When
the high-side switch is on and the low-side switch
turns off, the voltage on the bootstrap capacitor is
boosted above the input voltage and the internal
bootstrap diode prevents the capacitor from
discharging.
No external bootstrap diode is required for typical
applications. For applications with low input VCC
voltage or where output voltage is very close to
input voltage, an external Schottky diode may be
connected from the VCC to BS pins to charge the
bootstrapped capacitor more strongly for
increased gate drive voltage. When using the
external bootstrap diode, a resistor at the
regulator output or a minimal load current may be
required as the bootstrapped capacitor always
see the supply voltage even when the part is
disabled.
Input UVLO
Both VCC and IN pins have input UVLO detection.
Until both VCC and IN voltage exceed under
voltage lockout threshold, the parts remain in
shutdown condition. There are also under voltage
lockout hysesteres at both VCC and IN pins.
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MP2214 – 16V, 4A, 600kHz SYNCHRONOUS STEP-DOWN CONVERTER
VCC Power Supply
VCC is the power supply of both the internal control
circuit and the gate drivers.
Generally, the VCC power supply could be provided
directly by a proper power rail or generated from
other VCC generation circuits. For instance, Figure4
shows a typical VCC generation circuit for VOUT=5V
application.
It is noteworthy that the voltage applied on the VCC
pin should never be higher than 6V.
Selecting the Inductor
A 1µH to 4.7µH inductor with DC current rating at
least 25% higher than the maximum load current
is recommended for most applications. For best
efficiency, the inductor DC resistance shall be
<10mΩ. See Table 2 for recommended inductors
and manufacturers. For most designs, the
inductance value can be derived from the
following equation:
L=
APPLICATION INFORMATION
Setting the Output Voltage
The external resistor divider sets the output
voltage (see Figure1). For typical applications,
choose R2 to be 10kΩ, R1 is then given by:
1.2
1.5
1.8
2.5
3.3
5
8.75
12.5
21.25
31.25
10
10
10
10
10
1μH-4.7μH
1μH-4.7μH
1μH-4.7μH
1μH-4.7μH
1μH-4.7μH
ΔIL
2
Under light load conditions, larger inductance is
recommended for improved efficiency
Table 1—Resistor Selection vs. Output
Voltage Setting
L (μH)
where ∆IL is Inductor Ripple Current. Choose
inductor ripple current approximately 30% of the
maximum load current, 4A. The maximum
inductor peak current is:
IL(MAX) = ILOAD +
V
R1 = R 2( OUT − 1)
0.8V
VOUT (V) R1 (kΩ) R2 (kΩ)
VOUT x(VIN − VOUT )
VIN xΔIL xfOSC
COUT
(ceramic)
47μF
47μF
47μF
47μF
47μF
Input Capacitor Selection
The input capacitor reduces the surge current
drawn from the input and switching noise from
the device. The input capacitor impedance at the
switching frequency shall be less than input
source impedance to prevent high frequency
switching current passing to the input. Ceramic
capacitors with X5R or X7R dielectrics are highly
recommended because of their low ESR and
small temperature coefficients. For most
applications, a 47µF capacitor is sufficient.
Table 2—Suggested Surface Mount Inductors
Manufacturer
Part Number
Inductance
(μH)
Max
DCR
(mΩ)
Current
Rating
(A)
Dimensions
L x W x H (mm3)
FDA1055-3R3M
3.3
7.3
11.7
10.8x11.6x5.5
744314330
3.3
9.6
8
7x6.9x5
ULF100457-3R3N6R9
3.3
11.6
7.5
10x9.7x4.5
TOKO
Wurth Electronics
TDK
MP2214 Rev. 0.9
9/1/2010
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MP2214 – 16V, 4A, 600kHz SYNCHRONOUS STEP-DOWN CONVERTER
Output Capacitor Selection
The output capacitor keeps output voltage ripple
small and ensures regulation loop stable. The
output capacitor impedance shall be low at the
switching frequency. Ceramic capacitors with
X5R or X7R dielectrics are recommended. If
electrolytic capacitor is used, pay attention to
output ripple voltage, extra heating, and the
selection of feedback resistor R1 (refer to “Output
Voltage Setting” section) due to large ESR of
electrolytic capacitor. The output ripple ∆VOUT is
approximately:
ΔVOUT ≤
VOUT x(VIN − VOUT )
1
x(ESR +
)
VIN xfOSC xL
8xfOSC xC3
3) Two input ceramic capacitors (2 x
(10μF~22μF)) are strongly recommended to be
placed on both sides of the MP2214DL package
and keep them as close as possible to the “IN”
and “GND” pins.
4) A RC low pass filter is recommended for VCC
supply. The VCC decoupling capacitor must be
placed as close as possible to “VCC” pin and
“GND” pin.
5) The external feedback resistors shall be
placed next to the FB pin. Keep the FB trace as
short as possible.
6) Keep the switching node SW short and away
from the feedback network.
External Schottky Diode
For this part, an external schottky diode is
recommended to be placed close to "SW" and
"GND" pins, especially when the output current is
larger than 2A.
With the external schottky diode, the voltage
spike and negative kick on "SW" pin can be
minimized; moreover, the conversion efficiency
can also be improved a little.
For the external schottky diode selection, it's
noteworthy that the maximum reverse voltage
rating of the external diode should be larger than
the maximum input voltage. As for the current
rating of this diode, 0.5A rating should be
sufficient.
Top Layer
PCB Layout Guide
PCB layout is very important to achieve stable
operation. It is highly recommended to duplicate
EVB layout for optimum performance. If change
is necessary, please follow these guidelines as
follows. Here, the typical application circuit is
taken as an example to illustrate the key layout
rules should be followed.
1) For MP2214, a PCB layout with >=4 layers is
recommended.
2) The high current paths (GND, IN and SW)
should be placed very close to the device with
short, direct and wide traces.
MP2214 Rev. 0.9
9/1/2010
Inner Layer1
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MP2214 – 16V, 4A, 600kHz SYNCHRONOUS STEP-DOWN CONVERTER
Inner Layer2
Bottom Layer
Figure2―Recommended PCB Layout
MP2214 Rev. 0.9
9/1/2010
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MP2214 – 16V, 4A, 600kHz SYNCHRONOUS STEP-DOWN CONVERTER
TYPICAL APPLICATION CIRCUITS
Figure 3―Typical Application Circuit of MP2214
D2
B0530
Vin
9V to 16V
C1
22uF
R4
10k
C2
22uF
8
Z1
4.7V
Q1
MMBT3904
C4
1uF
13
R3
100k
R5
100k
C5
100nF
5,10
9
IN
BS
Vcc
SW
D1
B0530
MP2214
EN/SYNC
4,11
L1
3.3uH
FB
POK
N/C
AGND/PGND
14
2
Vout
5V/4A
R1
10k
R2
1.91k
C3
47uF
1,3,12
Figure 4―MP2214 with A VCC Generation Circuit
MP2214 Rev. 0.9
9/1/2010
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MP2214 – 16V, 4A, 600kHz 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
7
8
TOP VIEW
BOTTOM VIEW
PIN 1 ID OPTION A
0.30x45º TYP.
0.80
1.00
0.20 REF
PIN 1 ID OPTION B
R0.20 TYP.
0.00
0.05
SIDE VIEW
DETAIL A
2.90
0.70
NOTE:
1.70
1)
2)
3)
4)
5)
0.25
ALL DIMENSIONS ARE IN MILLIMETERS.
EXPOSED PADDLE SIZE DOES NOT INCLUDE MOLD FLASH.
LEAD COPLANARITY SHALL BE 0.10 MILLIMETER MAX.
DRAWING CONFORMS TO JEDEC MO-229, VARIATION VEED-5.
DRAWING IS NOT TO SCALE.
3.30
0.50
RECOMMENDED LAND PATTERN
MP2214 Rev. 0.9
9/1/2010
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MP2214 – 16V, 4A, 600kHz SYNCHRONOUS STEP-DOWN CONVERTER
SOIC8E (EXPOSED PAD)
0.189(4.80)
0.197(5.00)
0.124(3.15)
0.136(3.45)
8
5
0.150(3.80)
0.157(4.00)
PIN 1 ID
1
0.228(5.80)
0.244(6.20)
0.089(2.26)
0.101(2.56)
4
TOP VIEW
BOTTOM VIEW
SEE DETAIL "A"
0.051(1.30)
0.067(1.70)
SEATING PLANE
0.000(0.00)
0.006(0.15)
0.013(0.33)
0.020(0.51)
0.0075(0.19)
0.0098(0.25)
SIDE VIEW
0.050(1.27)
BSC
FRONT VIEW
0.010(0.25)
x 45o
0.020(0.50)
GAUGE PLANE
0.010(0.25) BSC
0.050(1.27)
0.024(0.61)
0o-8o
0.016(0.41)
0.050(1.27)
0.063(1.60)
DETAIL "A"
0.103(2.62)
0.138(3.51)
RECOMMENDED LAND PATTERN
0.213(5.40)
NOTE:
1) CONTROL DIMENSION IS IN INCHES. DIMENSION IN
BRACKET IS IN MILLIMETERS.
2) PACKAGE LENGTH DOES NOT INCLUDE MOLD FLASH,
PROTRUSIONS OR GATE BURRS.
3) PACKAGE WIDTH DOES NOT INCLUDE INTERLEAD FLASH
OR PROTRUSIONS.
4) LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING)
SHALL BE 0.004" INCHES MAX.
5) DRAWING CONFORMS TO JEDEC MS-012, VARIATION BA.
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.
MP2214 Rev. 0.9
9/1/2010
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