MCP16311/2
EN
V
CC
V
IN
BOOST
SW
1
2
3
4
8
7
6
5
P
GND
V
FB
EP
9
A
GND
5
1
2
3
A
GND
SW
EN
V
IN
V
FB
MCP16311/2
MSOP
8
7
6
BOOST
4
P
GND
VCC
MCP16311/2
2x3 TDFN*
* Includes Exposed Thermal Pad (EP); see Ta b l e 3 -1 .
30V Input, 1A Output, High-Efficiency,
Integrated Synchronous Switch Step-Down Regulator
Features:
• Up to 95% Efficiency
• Input Voltage Range: 4.4V to 30V
• 1A Output Current Capability
• Output Voltage Range: 2.0V to 24V
• Integrated N-Channel Low and High-Side
Switches:
-170m, Low Side
-300m, High Side
• Stable Reference Voltage: 0.8V
• Automatic Pulse Frequency Modulation/PulseWidth Modulation (PFM/PWM) Operation
(MCP16311):
- PFM Operation Disabled (MCP16312)
- PWM Operation: 500 kHz
• Low Device Shutdown Current: 3 µA typical
• Low Device Quiescent Current:
- 44 µA (non-switching, PFM Mode)
• Internal Compensation
• Internal Soft-Start: 300 µs (EN low to high)
• Peak Current Mode Control
• Cycle-by-Cycle Peak Current Limit
• Undervoltage Lockout (UVLO):
- 4.1V typical to start
- 3.6V typical to stop
• Overtemperature Protection
• Thermal Shutdown:
- +150°C
- +25°C Hysteresis
Applications:
General Description:
The MCP16311/2 is a compact, high-efficiency, fixed
frequency, synchronous step-down DC-DC converter
in a 8-pin MSOP, or 2 x 3 TDFN package that operates
from input voltage sources up to 30V. Integrated
features include a high-side and a low-side switch,
fixed frequency Peak Current Mode Control, internal
compensation, peak-current limit and overtemperature
protection. The MCP16311/2 provides all the active
functions for local DC-DC conversion, with fast
transient response and accurate regulation.
High-converter efficiency is achieved by integrating
the current-limited, low-resistance, high-speed lowside and high-side switches, and associated drive
circuitry. The MCP16311 is capable of running in
PWM/PFM mode. It switches in PFM mode for light
load conditions and for large buck conversion ratios.
This results in a higher efficiency over all load ranges.
The MCP16312 is running in PWM mode-only, and is
recommended for noise-sensitive applications.
The MCP16311/2 can supply up to 1A of continuous
current while regulating the output voltage from 2V to
12V. An integrated, high-performance peak current
mode architecture keeps the output voltage tightly
regulated, even during input voltage steps and output
current transient conditions, that are common in power
systems.
The EN input is used to turn the device on and off.
While off, only a few micro amps of current are
consumed from the input.
Output voltage is set with an external resistor divider.
The MCP16311/2 is offered in a small MSOP-8 and
2 x 3 TDFN surface mount packages.
•PIC®/dsPIC® Microcontroller Bias Supply
• 24V Industrial Input DC-DC Conversion
• General Purpose DC-DC Conversion
• Local Point of Load Regulation
• Automotive Battery Regulation
• Set-Top Boxes
• Cable Modems
• Wall Transformer Regulation
• Laptop Computers
• Networking Systems
• AC-DC Digital Control Bias
• Distributed Power Supplies
2013 Microchip Technology Inc. DS20005255A-page 1
Package Type
MCP16311/2
0
10
20
30
40
50
60
70
80
90
100
1 10 100 1000
Efficiency (%)
PWM ONLY
PWM/PFM
V
IN
= 12V
OUT
= 5V
V
OUT
= 3.3V
V
V
IN
GND
V
FB
SW
V
IN
4.5V to 30V
V
OUT
3.3V @ 1A
C
OUT
2x10µF
C
IN
2x10µF
L
1
15 µH
BOOST
31.2 k
10 k
EN
C
BOOST
100 nF
V
CC
C
VCC
1µF
V
IN
GND
V
FB
SW
Vin
6V to 30V
V
OUT
5V, @ 1A
C
OUT
2x10µF
C
IN
2x10µF
L
1
22 µH
BOOST
52.3 k
10 k
EN
C
BOOST
100 nF
V
CC
C
VCC
1µF
Typical Applications
I
(mA)
OUT
DS20005255A-page 2 2013 Microchip Technology Inc.
MCP16311/2
1.0 ELECTRICAL
CHARACTERISTICS
† Notice: Stresses above those listed under “Maximum
Ratings” may cause permanent damage to the device.
This is a stress rating only and functional operation of
the device at those or any other conditions above those
Absolute Maximum Ratings †
V
SW ............................................................... -0.5V to 32V
IN,
BOOST – GND ................................................... -0.5V to 38V
BOOST – SW Voltage........................................-0.5V to 6.0V
Voltage ........................................................-0.5V to 6.0V
V
FB
EN Voltage ............................................. -0.5V to (V
Output Short Circuit Current .................................Continuous
Power Dissipation .......................................Internally Limited
Storage Temperature ....................................-65°C to +150°C
Ambient Temperature with Power Applied .... -40°C to +125°C
Operating Junction Temperature...................-40°C to +150°C
ESD Protection on All Pins:
HBM.....................................................................1 kV
MM ......................................................................200V
+0.3V)
IN
indicated in the operational sections of this
specification is not intended. Exposure to maximum
rating conditions for extended periods may affect
device reliability.
DC CHARACTERISTICS
Electrica l Characteristics: Unless otherwise indicated, T
V
=5.0V, I
OUT
Boldface specifications apply over the T
= 100 mA, L = 22 µH, C
OUT
OUT=CIN
range of -40°C to +125°C.
A
Parameters Sym. Min. Typ. Max. Units Conditions
V
Supply Voltage
IN
Input Voltage V
Quiescent Current I
Quiescent Current -
I
Q_PFM
IN
Q
4.4 — 30 V Note 1
—44 60 µA Non-switching,
—85 —µASwitching,
PFM Mode
Quiescent Current -
I
Q_PWM
—3.8 8 mA Switching,
PWM Mode
Quiescent Current -
I
Q_SHDN
—3 9 µA V
Shutdown
V
Undervoltage Lockout
IN
Undervoltage Lockout Start UVLO
Undervoltage Lockout Stop UVLO
Undervoltage Lockout
UVLO
STRT
STOP
HYS
—4.1 4.4 VV
3.18 3.6 — V V
0.2 0.5 1 V
Hysteresis
Output Characteristics
Feedback Voltage V
Output Voltage
V
FB
OUT
0.784 0.800 0.816 VI
2.0 — 24 V Note 2, Note 3
Adjust Range
Feedback Voltage
V
)/VIN-0.15 0.01 0.15 %/V VIN= 7V to 30V,
FB/VFB
Line Regulation
Feedback Voltage
V
/ VFB —0.25 — %I
FB
Load Regulation
Note 1: The input voltage should be greater than the output voltage plus headroom voltage; higher load currents
increase the input voltage necessary for regulation. See characterization graphs for typical input to output
operating voltage range.
2: For V
IN<VOUT
, V
will not remain in regulation; for output voltages above 12V, the maximum current
OUT
will be limited to under 1A.
3: Determined by characterization, not production tested.
4: This is ensured by design.
=+25°C, VIN=VEN=7V, V
A
BOOST-VSW
= 2 x 10 µF X7R Ceramic Capacitors.
=5.0V,
=0.9V
V
FB
=0 (MCP16311)
I
OUT
I
=0 (MCP16312)
OUT
=EN=0V
OUT
Rising
IN
Falling
IN
=5mA
OUT
=50mA
I
OUT
= 5 mA to 1A,
OUT
MCP16312
2013 Microchip Technology Inc. DS20005255A-page 3
MCP16311/2
DC CHARACTERISTICS (CONTINUED)
Electrica l Characteristics: Unless otherwise indicated, T
V
=5.0V, I
OUT
Boldface specifications apply over the T
= 100 mA, L = 22 µH, C
OUT
OUT=CIN
range of -40°C to +125°C.
A
Parameters Sym. Min. Typ. Max. Units Conditions
Feedback Input
I
FB
—10 250 nA
Bias Current
Output Current I
OUT
1— —ANotes 1 to 3, Figure 2-7
Switching Characteristics
Switching Frequency f
Maximum Duty Cycle DC
Minimum Duty Cycle DC
Buck NMOS Switch
R
DS(ONB)
SW
MAX
MIN
425 500 575 kHz
85 94 — % No te 3
—2 —%Note 4
—0.3 — V
On Resistance
Buck NMOS Switch
I
(MAX)
—1.8 — AV
Current Limit
Synchronous NMOS Switch
R
DS(ONS)
—0.17 — Note 3
On Resistance
EN Input Characteristics
EN Input Logic High V
EN Input Logic Low V
EN Input Leakage Current I
ENLK
Soft-Start Time t
IH
IL
SS
1.85 ——V
—— 0.4 V
—0.1 1 µA V
— 300 — µs EN Low to High,
Thermal Ch aracteristics
Thermal Shutdown
T
SD
—150 — °CNote 3
Die Temperature
Die Temperature Hysteresis T
SDHYS
—25 —°CNote 3
Note 1: The input voltage should be greater than the output voltage plus headroom voltage; higher load currents
increase the input voltage necessary for regulation. See characterization graphs for typical input to output
operating voltage range.
2: For V
IN<VOUT
, V
will not remain in regulation; for output voltages above 12V, the maximum current
OUT
will be limited to under 1A.
3: Determined by characterization, not production tested.
4: This is ensured by design.
=+25°C, VIN=VEN=7V, V
A
BOOST-VSW
= 2 x 10 µF X7R Ceramic Capacitors.
=5.0V,
BOOST–VSW
Note 3
BOOST–VSW
Note 3
=5V
EN
90% of V
OUT
= 5V,
= 5V,
TEMPERATURE CHARACTERISTICS
Electrical Specifications:
Parameters Sym Min Typ Max Units Conditions
Temperature Ranges
Operating Junction Temperature Range T
Storage Temperature Range T
Maximum Junction Temperature T
J
A
J
Package Thermal Resistances
Thermal Resistance, 8L-MSOP
Thermal Resistance, 8L-2x3 TDFN
DS20005255A-page 4 2013 Microchip Technology Inc.
JA
JA
-40 — +125 °C Steady State
-65 — +150 °C
— — +150 °C Transient
— 211 — °C/W EIA/JESD51-3 Standard
— 52.5 — °C/W EIA/JESD51-3 Standard
MCP16311/2
0
10
20
30
40
50
60
70
80
90
100
1 10 100 1000
Efficiency (%)
V
= 6V
VIN= 12V
V
IN
= 24V
VIN= 30V
PWM/PFM
PWM ONLY
0
10
20
30
40
50
60
70
80
90
100
1 10 100
1000
Efficiency (%)
VIN= 12V
VIN= 24V
VIN= 30V
PWM/PFM
PWM ONLY
0
10
20
30
40
50
60
70
80
90
100
1 10 100 1000
Efficiency (%)
V
= 15V
V
IN
= 24V
VIN= 30V
PWM/PFM
PWM ONLY
0
20
40
60
80
100
5 1015202530
Efficiency (%)
I
OUT
= 10 mA
I
OUT
= 200 mA
I
OUT
= 800 mA
0
20
40
60
80
100
6 101418222630
Efficiency (%)
I
OUT
= 10 mA
I
OUT
= 200 mA
I
OUT
= 800 mA
PWM/PFM option
0
20
40
60
80
100
12 14 16 18 20 22 24 26 28 30
Efficiency (%)
I
OUT
= 10 mA
I
OUT
= 200 mA
I
OUT
= 800 mA
PWM/PFM option
2.0 TYPICAL PERFORMANCE CURVES
Note: The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.
Note: Unless otherwise indicated, V
=+25°C, 8L-MSOP package.
T
A
IN
I
(mA)
OUT
FIGURE 2-1: 3.3V V
I
.
OUT
Efficiency vs.
OUT
=EN=7V, C
IN
OUT=CIN
=2x10µF, L =22µH, V
OUT
VIN(V)
FIGURE 2-4: 3.3V V
=5.0V, I
OUT
LOAD
PWM/PFM option
Efficiency vs.VIN.
=100mA,
FIGURE 2-2: 5.0V V
I
.
OUT
IN
FIGURE 2-3: 12.0V V
I
.
OUT
2013 Microchip Technology Inc. DS20005255A-page 5
I
OUT
I
OUT
(mA)
Efficiency vs.
OUT
(mA)
Efficiency vs.
OUT
VIN(V)
FIGURE 2-5: 5.0V V
VIN(V)
FIGURE 2-6: 12.0V V
V
.
IN
Efficiency vs.VIN.
OUT
Efficiency vs.
OUT
MCP16311/2
0
200
400
600
800
1000
1200
1400
1600
0 5 10 15 20 25 30
I
OUT
(mA)
V
OUT
= 3.3V
V
OUT
= 5V
V
OUT
= 12V
0.79
0.792
0.794
0.796
0.798
0.8
-40 -25 -10 5 20 35 50 65 80 95 110 125
Feedback Voltage (V)
VIN=7V
V
OUT
= 3.3V
I
OUT
= 100 mA
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
-40 -25 -10 5 20 35 50 65 80 95 110 125
Switch R
DSON
(
:
)
Low Side
High Side
VIN= 12V
V
OUT
= 5V
I
OUT
= 500 mA
3
3.4
3.8
4.2
4.6
5
-40 -25 -10 5 20 35 50 65 80 95 110
125
Input Voltage (V)
UVLO START
UVLO STOP
0.9
1
1.1
1.2
1.3
-40 -25 -10 5 20 35 50 65 80 95 110 125
HIGH
LOW
VIN= 12V
V
OUT
= 3.3V
I
OUT
= 200 mA
Note: Unless otherwise indicated, V
=+25°C, 8L-MSOP package.
T
A
VIN(V)
FIGURE 2-7: Max I
OUT
vs.V
=EN=7V, C
IN
IN.
OUT=CIN
=2x10µF, L =22µH, V
Temperature (°C)
OUT
=5.0V, I
LOAD
=100mA,
FIGURE 2-10: Undervoltage Lockout vs. Temperature.
1.4
FIGURE 2-8: VFB vs. Temperature;
V
=3.3V.
OUT
Temperature (°C)
FIGURE 2-9: Switch R
Temperature.
DS20005255A-page 6 2013 Microchip Technology Inc.
Temperature (°C)
DSON
vs.
Enable Voltage (V)
Temperature (°C)
FIGURE 2-11: Enable Threshold Voltage vs. Temperature.
5.03
VIN= 12V
= 5V
V
OUT
5.02
5.01
4.99
Output Voltage (V)
4.98
4.97
FIGURE 2-12: V
= 100 mA
I
OUT
5
-40 -25 -10 5 20 35 50 65 80 95 110 125
Temperature (°C)
vs. Temperature.
OUT
MCP16311/2
0
20
40
60
-40 -25 -10 5 20 35 50 65 80 95 110 125
Quiescent Current (μA)
Non-Swithcing
Shutdown
VIN= 12V
V
OUT
= 5V
0
10
20
30
40
50
5 1015202530
Quiescent Current (μA)
Non-Switching
Shutdown
V
OUT
= 3.3V
40
60
80
100
120
5 1015202530
No Load Input Current (μA)
V
OUT
= 3.3V
1
1.2
1.4
1.6
1.8
5 1015202530
Input Current (mA)
V
OUT
= 3.3V
Note: Unless otherwise indicated, V
=+25°C, 8L-MSOP package.
T
A
Temperature (°C)
=EN=7V, C
IN
FIGURE 2-13: Input Quiescent Current vs. Temperature.
Input Voltage (°C)
OUT=CIN
=2x10µF, L =22µH, V
OUT
VIN(V)
=5.0V, I
LOAD
=100mA,
FIGURE 2-16: PWM No Load Input Current
vs.V
, MCP16312.
IN
150
125
100
75
50
Output Current (mA)
25
0
5 1015202530
V
= 3.3V
OUT
V
= 5V
OUT
V
= 12V
OUT
VIN(V)
FIGURE 2-14: Input Quiescent Current vs. Input Voltage.
Input Voltage (V)
FIGURE 2-15: PFM No Load Input Current vs. Input Voltage, MCP16311.
2013 Microchip Technology Inc. DS20005255A-page 7
FIGURE 2-17: PF M /PW M I
vs. V
.
IN
50
40
30
20
Output Current (mA)
10
0
5 1015202530
VIN(V)
OUT
V
= 3.3V
OUT
V
= 5V
OUT
FIGURE 2-18: Skipping/PWM I
Threshold vs. Input Voltage.
Threshold
V
= 12V
OUT
OUT
MCP16311/2
3.5
4
4.5
0 200 400 600 800 1000
V
IN
(V)
To Start
To Stop
V
OUT
= 3.3V
450
475
500
525
-40 -25 -10 5 20 35 50 65 80 95 110 125
VIN= 12V
V
OUT
= 3.3V
I
OUT
= 200 mA
V
OUT
2 V/div
EN
2 V/div
80 µs/div
V
OUT
2 V/div
V
IN
5 V/div
200 µs/div
V
OUT
2 V/div
I
OUT
2A/div
10 µs/div
I
L
500 mA/div
V
OUT
100 mV/div
I
OUT
500 mA/div
200 µs/div
AC Coupled
Load Step from
100 mA to 800 mA
Note: Unless otherwise indicated, V
=+25°C, 8L-MSOP package.
T
A
Output Current (mA)
=EN=7V, C
IN
FIGURE 2-19: Typical Minimum Input Voltage vs. Output Current.
OUT=CIN
=2x10µF, L =22µH, V
OUT
=5.0V, I
LOAD
FIGURE 2-22: Startup From VIN.
=100mA,
Switching Frequency (kHz)
FIGURE 2-20: Switching Frequency vs. Temperature.
FIGURE 2-21: Startup From Enable.
DS20005255A-page 8 2013 Microchip Technology Inc.
Temperature (°C)
FIGURE 2-23: Short-Circuit Response.
FIGURE 2-24: Load Transient Response.
MCP16311/2
V
OUT
50 mV/div
V
IN
5 V/div
400 µs/div
AC Coupled
V
IN
Step from 7V to 12V
V
OUT
100 mV/div
I
L
200 mA/div
20 µs/div
VIN = 24V
SW
10 V/div
I
OUT
= 25 mA
AC Coupled
V
OUT
10 mV/div
I
L
100 mA/div
1µs/div
V
IN
= 24V
SW
10 V/div
I
OUT
= 15 mA
AC Coupled
V
OUT
50 mV/div
I
L
200 mA/div
2µs/div
V
IN
= 12V
SW
10 V/div
V
OUT
= 5V
I
OUT
= 800 mA
AC Coupled
V
OUT
100 mV/div
Load Current
50 mA/div
400 µs/div
V
IN
= 12V
SW
5 V/div
V
OUT
= 5V
AC Coupled
Note: Unless otherwise indicated, V
=+25°C, 8L-MSOP package.
T
A
=EN=7V, C
IN
FIGURE 2-25: Line Transient Response.
OUT=CIN
=2x10µF, L =22µH, V
OUT
=5.0V, I
LOAD
=100mA,
FIGURE 2-28: Heavy Load Switching Waveforms.
FIGURE 2-26: PFM Light Load Switching Waveforms.
FIGURE 2-27: PW M Lig ht Load Swi tc hin g Waveforms.
2013 Microchip Technology Inc. DS20005255A-page 9
FIGURE 2-29: PFM to PWM Transition; Load Step from 5 mA to 100 mA.
MCP16311/2
NOTES:
DS20005255A-page 10 2013 Microchip Technology Inc.
MCP16311/2
3.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Ta bl e 3 -1 .
TABLE 3-1: PIN FUNCTION TABLE
MCP16311/2
2x3 TDFN
11VFBOutput Voltage Feedback pin. Connect V
22V
3 3 EN Enable pin. Logic high enables the operation. Do not allow this pin to
44V
55P
6 6 SW Output Switch Node pin, connects to the inductor and the bootstrap
7 7 BOOST
88A
9 — EP Exposed Thermal Pad
MCP16311/2
MSOP
Symbol Description
divider to set the output voltage.
CC
IN
GND
GND
Internal Regulator Output pin. Bypass Capacitor is required on this
pin to provide high peak current for gate drive.
float.
Input Supply Voltage pin for power and internal biasing.
Power Ground pin
capacitor.
Boost Voltage pin that supplies the driver used to control the highside NMOS switch. A bootstrap capacitor is connected between the
BOOST and SW pins.
Signal Ground pin
to an external resistor
FB
3.1 Feedback Voltage Pin (VFB)
The VFB pin is used to provide output voltage regulation
by using a resistor divider. The V
0.800V typical with the output voltage in regulation.
voltage will be
FB
3.2 Internal Bias Pin (VCC)
The VCC internal bias is derived from the input voltage
. VCC is set to 5.0V typical. The VCC is used to pro-
V
IN
vide a stable low bias voltage for the upper and lower
gate drive circuits. This output should be decoupled to
with a 1 µF capacitor, X7R. This capacitor should
A
GND
be connected as close as possible to the V
A
pin.
GND
CC
and
3.3 Enable Pin (EN)
The EN pin is a logic-level input used to enable or
disable the device and lower the quiescent current
while disabled. A logic high (> 1.3V) will enable the regulator output. A logic low (< 1V) will ensure that the regulator is disabled.
3.4 Power Supply Input Voltage Pin
(V
)
IN
Connect the input voltage source to VIN. The input
source should be decoupled to GND with a
4.7 µF - 20 µF capacitor, depending on the impedance
of the source and output current. The input capacitor
provides current for the switch node and a stable voltage source for the internal device power. This capacitor
should be connected as close as possible to the V
and GND pins. For light-load applications, a 2.2 µF
X7R or X5R ceramic capacitor can be used.
3.5 Analog Ground Pin (A
This ground is used by most internal circuits, such as
the analog reference, control loop and other circuits.
3.6 Power Ground Pin (P
This is a separate ground connection used for the lowside synchronous switch.The length of the trace from
the input cap return, output cap return and GND pin
should be made as short as possible to minimize the
noise in the system. The power ground and the analog
ground should be connected in a single point.
GND
GND
)
)
3.7 Switch Node Pin (SW)
The switch node pin is connected internally to the lowside and high-side switch, and externally to the SW
node, consisting of the inductor and boost capacitor.
The SW node can rise very fast as a result of the
internal switch turning on.
3.8 Boost Pin (BOOST)
The high side of the floating supply used to turn the
integrated N-Channel high-side MOSFET on and off is
connected to the boost pin.
3.9 Exposed Thermal Pad Pin (EP)
There is an internal electrical connection between the
EP and the P
IN
GND
and A
GND
pins.
2013 Microchip Technology Inc. DS20005255A-page 11
MCP16311/2
NOTES:
DS20005255A-page 12 2013 Microchip Technology Inc.
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