Microchip MCP16331T-E/CH High-voltage input integrated switch step-down regulator Datasheet

MCP16331
High-Voltage Input Integrated Switch Step-Down Regulator
Features:
General Description:
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The MCP16331 is a highly integrated, high-efficiency,
fixed frequency, step-down DC-DC converter in a
popular 6-pin SOT-23 or 8-pin TDFN 2x3 package that
operates from input voltage sources up to 50V.
Integrated features include a high side switch, fixed
frequency Peak Current Mode Control, internal
compensation, peak current limit and overtemperature
protection. Minimal external components are
necessary to develop a complete step-down DC-DC
converter power supply.
High converter efficiency is achieved by integrating the
current-limited, low-resistance, high-speed N-Channel
MOSFET and associated drive circuitry. High switching
frequency minimizes the size of external filtering
components resulting in a small solution size.
The MCP16331 can supply 500 mA of continuous
current while regulating the output voltage from 2.0V to
24V. 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 µA of current are consumed from
the input for power shedding and load distribution
applications. This pin is internally pulled up, so the
device will start even if the EN pin is left floating.
Output voltage is set with an external resistor divider.
The MCP16331 is offered in a space saving 6-Lead
SOT-23 and 8-Lead 2x3 TDFN surface mount package.
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Up to 96% Efficiency
Input Voltage Range: 4.4V to 50V
Output Voltage Range: 2.0V to 24V
2% Output Voltage Accuracy
Qualification: AEC-Q100 Rev. G, Grade 1(-40oC
to 125oC)
Integrated N-Channel Buck Switch: 600 m
Minimum 500 mA Output Current Over All Input
Voltage Range (See Figure 2-9 for Maximum
Output Current vs. VIN)
- Up to 1.2A Output Current at 3.3V and 5V
VOUT, VIN>12V, SOT-23 package at 25oC
ambient temperature
- Up to 0.8A Output Current at 12V VOUT,
VIN>18V, SOT-23 package at 25oC ambient
temperature
500 kHz Fixed Frequency
Adjustable Output Voltage
Low Device Shutdown Current
Peak Current Mode Control
Internal Compensation
Stable with Ceramic Capacitors
Internal Soft-Start
Internal Pull-Up on EN
Cycle-by-Cycle Peak Current Limit
Undervoltage Lockout (UVLO): 4.1V to Start; 
3.6V to Stop
Overtemperature Protection
Available Package: 6-Lead SOT-23, 8-Lead 2x3
TDFN
Applications:
• PIC® MCU/dsPIC® DSC Microcontroller Bias
Supply
• 48V, 24V and 12V Industrial Input DC-DC
Conversion
• Set-Top Boxes
• DSL Cable Modems
• Automotive
• AC/DC Adapters
• SLA Battery Powered Devices
• AC-DC Digital Control Power Source
• Power Meters
• Consumer
• Medical and Health Care
• Distributed Power Supplies
 2014 Microchip Technology Inc.
Package Type
MCP16331
6-Lead SOT-23
BOOST 1
6 SW
GND 2
5 VIN
VFB 3
4 EN
MCP16331
8-Lead 2x3 TDFN*
SW 1
EN 2
NC 3
NC 4
8 VIN
EP
9
7 BOOST
6 VFB
5 GND
* Includes Exposed Thermal Pad (EP); see Table 3-1
DS20005308B-page 1
MCP16331
Typical Applications
1N4148
VIN
4.5V to 50V
CBOOST L
1
100 nF 15 µH
BOOST
SW
VIN
CIN
2x10 µF
EN
VOUT
3.3V at 500 mA
100V
Schottky
Diode
31.6 k
COUT
2 X10 µF
20 pF
optional
VFB
GND
10 k
1N4148
VIN
6.0V to 50V
BOOST
VIN
CIN
2x10 µF
CBOOST L1
100 nF 22 µH
SW
100V
Schottky
Diode
52.3 k
EN
VFB
GND
Note:
VOUT
5.0V at 500 mA
COUT
2 X10 µF
20 pF
optional
10 k
EN has an internal pull up, so the device will start even if the EN pin is left floating
100
VOUT=5V
90
Efficiency (%)
80
VOUT=3.3V
70
60
50
40
30
20
10
VIN=12V
0
10
DS20005308B-page 2
100
Output Current (mA)
1000
 2014 Microchip Technology Inc.
MCP16331
1.0
† 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
indicated in the operational sections of this
specification is not intended. Exposure to maximum
rating conditions for extended periods may affect
device reliability.
ELECTRICAL
CHARACTERISTICS
Absolute Maximum Ratings †
VIN, SW ............................................................... -0.5V to 54V
BOOST – GND ................................................... -0.5V to 60V
BOOST – SW Voltage........................................ -0.5V to 6.0V
VFB Voltage ........................................................ -0.5V to 6.0V
EN Voltage ............................................. -0.5V to (VIN + 0.3V)
Output Short Circuit Current ................................. Continuous
Power Dissipation ....................................... Internally Limited
Storage Temperature ................................... -65oC to +150oC
Ambient Temperature with Power Applied ... -40oC to +125oC
Operating Junction Temperature.................. -40oC to +160oC
ESD Protection on All Pins:
HBM..................................................................... 4 kV
MM ......................................................................300V
DC CHARACTERISTICS
Electrical Characteristics: Unless otherwise indicated, TA = +25°C, VIN = VEN = 12V, VBOOST - VSW = 3.3V, 
VOUT = 3.3V, IOUT = 100 mA, L = 15 µH, COUT = CIN = 2 X 10 µF X7R Ceramic Capacitors
Boldface specifications apply over the TA range of -40°C to +125°C.
Parameters
Sym.
Min.
Typ.
Max.
Units
Conditions
Input Voltage
VIN
4.4
—
50
V
Feedback Voltage
VFB
0.784
0.800
0.816
V
VOUT
2.0
—
24
V
Note 1, Note 3
Feedback Voltage 
Line Regulation
VFB/VFB)/VIN|
—
0.002
0.1
%/V
VIN = 5V to 50V
Feedback Voltage 
Load Regulation
VFB/VFB|
—
0.13
0.35
%
IOUT= 50 mA to
500 mA
Output Voltage Adjust Range
Feedback Input Bias Current
Note 1
IFB
—
+/- 3
—
nA
Undervoltage Lockout Start
UVLOSTRT
—
4.1
4.4
V
VIN Rising
Undervoltage Lockout Stop
UVLOSTOP
3
3.6
—
V
VIN Falling
Undervoltage Lockout 
Hysteresis
UVLOHYS
—
0.5
—
V
Switching Frequency
fSW
425
500
550
kHz
Maximum Duty Cycle
DCMAX
90
93
—
%
VIN = 5V; VFB = 0.7V;
IOUT = 100 mA
Minimum Duty Cycle
DCMIN
—
1
—
%
Note 4
NMOS Switch On Resistance
RDS(ON)
—
0.6
—

VBOOST - VSW = 5V,
Note 3
NMOS Switch Current Limit
IN(MAX)
—
1.3
—
A
VBOOST - VSW = 5V,
Note 3
Quiescent Current
IQ
—
1
1.7
mA
VIN = 12V; Note 2
Quiescent Current - Shutdown
IQ
—
6
10
A
VOUT = EN = 0V
Output Current
IOUT
500
—
—
mA
Note 1; see Figure 2-9
EN Input Logic High
VIH
1.9
—
—
V
Note 1:
2:
3:
4:
The input voltage should be > output voltage + headroom voltage; higher load currents increase the input voltage
necessary for regulation. See characterization graphs for typical input to output operating voltage range.
VBOOST supply is derived from VOUT.
Determined by characterization, not production tested.
This is ensured by design.
 2014 Microchip Technology Inc.
DS20005308B-page 3
MCP16331
DC CHARACTERISTICS (CONTINUED)
Electrical Characteristics: Unless otherwise indicated, TA = +25°C, VIN = VEN = 12V, VBOOST - VSW = 3.3V, 
VOUT = 3.3V, IOUT = 100 mA, L = 15 µH, COUT = CIN = 2 X 10 µF X7R Ceramic Capacitors
Boldface specifications apply over the TA range of -40°C to +125°C.
Parameters
Sym.
Min.
EN Input Logic Low
Typ.
Max.
Units
Conditions
VIL
—
—
0.4
V
IENLK
—
0.007
0.5
µA
VIN = EN = 5V
Soft-Start Time
tSS
—
600
—
µs
EN Low-to-High, 
90% of VOUT
Thermal Shutdown Die
Temperature
TSD
—
160
—
C
Note 3
TSDHYS
—
30
—
C
Note 3
EN Input Leakage Current
Die Temperature Hysteresis
Note 1:
2:
3:
4:
The input voltage should be > output voltage + headroom voltage; higher load currents increase the input voltage
necessary for regulation. See characterization graphs for typical input to output operating voltage range.
VBOOST supply is derived from VOUT.
Determined by characterization, not production tested.
This is ensured by design.
TEMPERATURE SPECIFICATIONS
Electrical Specifications:
Parameters
Sym.
Min.
Typ.
Max.
Units
Conditions
Operating Junction Temperature Range
TJ
-40
—
+125
°C
Storage Temperature Range
TA
-65
—
+150
°C
Maximum Junction Temperature
TJ
—
—
+160
°C
Thermal Resistance, 6L-SOT-23
JA
—
190.5
—
°C/W
EIA/JESD51-3 Standard
Thermal Resistance, 8L-2x3 TDFN
JA
—
52.5
—
°C/W
EIA/JESD51-3 Standard
Temperature Ranges
Steady State
Transient
Package Thermal Resistances
DS20005308B-page 4
 2014 Microchip Technology Inc.
MCP16331
2.0
TYPICAL PERFORMANCE CURVES
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:
Note: Unless otherwise indicated, VIN = EN = 12V, COUT = CIN = 2 X10 µF, L = 15 µH, VOUT = 3.3V, ILOAD = 100 mA,
TA = +25°C, 6-Lead SOT-23 package.
100
100
VIN = 6V
90
90
80
70
60
VIN = 12V
VIN = 24V
50
40
30
20
10
0
VIN = 48V
70
Efficiency (%)
Efficiency (%)
80
VIN = 48V
60
50
40
30
20
10
1
10
100
0
1000
1
IOUT (mA)
FIGURE 2-1:
IOUT.
1000
3.3V VOUT Efficiency vs.
FIGURE 2-4:
IOUT.
24V VOUT Efficiency vs.
100
90
90
VIN = 12V
80
70
VIN = 24V
60
50
VIN = 48V
40
Efficiency (%)
80
Efficiency (%)
100
IOUT (mA)
100
IOUT= 500 mA
70
60
IOUT= 100 mA
50
40
30
30
20
20
10
IOUT= 10 mA
10
0
1
10
100
0
1000
6
IOUT (mA)
FIGURE 2-2:
5V VOUT Efficiency vs. IOUT.
100
100
90
90
80
80
VIN = 48V
70
VIN = 24V
60
50
40
10
10
100
1000
FIGURE 2-3:
12V VOUT Efficiency vs. IOUT.
 2014 Microchip Technology Inc.
26 30
VIN (V)
34
38
42
46
50
3.3V VOUT Efficiency vs.
IOUT = 500 mA
IOUT = 100 mA
40
20
IOUT (mA)
22
50
30
10
18
60
20
1
14
70
30
0
10
FIGURE 2-5:
VIN.
Efficiency (%)
Efficiency (%)
10
IOUT = 10 mA
0
6
10
FIGURE 2-6:
14
18
22
26 30
VIN (V)
34
38
42
46
50
5V VOUT Efficiency vs. VIN.
DS20005308B-page 5
MCP16331
Note: Unless otherwise indicated, VIN = EN = 12V, COUT = CIN = 2 X10 µF, L = 15 µH, VOUT = 3.3V, ILOAD = 100 mA,
TA = +25°C, 6-Lead SOT-23 package.
100
0.83
IOUT = 500 mA
90
IOUT = 100 mA
Feedback Voltage (V)
Efficiency (%)
80
70
60
50
IOUT = 10 mA
40
30
20
0.82
0.81
0.8
VIN =12V
VOUT = 3.3V
IOUT = 100 mA
0.79
10
0.78
0
14
18
22
26
FIGURE 2-7:
30
34
VIN (V)
38
42
46
-40 -25 -10 5
50
12V VOUT Efficiency vs. VIN.
FIGURE 2-10:
100
Peak Current Limit (A)
IOUT = 100 mA
80
Efficiency (%)
VFB vs. Temperature.
1.8
90
IOUT = 500 mA
70
60
IOUT = 10 mA
50
40
30
20
1.6
VOUT = 5V
1.4
1.2
VOUT = 3.3V
1
VOUT = 12V
0.8
0.6
0.4
0.2
10
0
0
26
30
34
FIGURE 2-8:
38
VIN (V)
42
46
-40 -25 -10
50
24V VOUT Efficiency vs. VIN.
1400
5
FIGURE 2-11:
Temperature.
20 35 50 65 80
Temperature (°C)
95 110 125
Peak Current Limit vs.
1.2
VOUT = 5V
1200
Switch RDSON (Ω)
1
VOUT = 3.3V
1000
IOUT (mA)
20 35 50 65 80 95 110 125
Temperature (°C)
800
VOUT = 12V
VOUT = 24V
600
400
0.8
0.6
0.4
VIN = 6V
VOUT=VBOOST= 3.3V
IOUT = 200 mA
0.2
200
0
0
6
10
14
18
FIGURE 2-9:
DS20005308B-page 6
22
26 30
VIN (V)
34
38
42
Max IOUT vs. VIN.
46
50
-40 -25 -10
FIGURE 2-12:
Temperature.
5
20 35 50 65 80 95 110 125
Temperature (°C)
Switch RDSON vs.
 2014 Microchip Technology Inc.
MCP16331
Note: Unless otherwise indicated, VIN = EN = 12V, COUT = CIN = 2 X10 µF, L = 15 µH, VOUT = 3.3V, ILOAD = 100 mA,
TA = +25°C, 6-Lead SOT-23 package.
0.8
3.295
Switch RDSON (Ω)
0.75
0.7
VIN = 6V
VOUT= 3.3V
VOUT(V)
0.65
VOUT = 3.3V
IOUT=100 mA
3.29
0.6
3.285
3.28
0.55
0.5
3.275
0.45
3.27
0.4
2.5
3
3.5
4
VBOOST (V)
FIGURE 2-13:
4.5
5
5
5.5
Switch RDSON vs. VBOOST.
20 25
VIN(V)
30
35
40
45
50
VOUT vs VIN.
1.2
4.6
No Load Input Current (mA)
Input Voltage (V)
15
FIGURE 2-16:
5
VIN = 12V
VOUT = 3.3V
1.1
UVLO START
4.2
3.8
UVLO STOP
3.4
1
0.9
0.8
3
-40 -25 -10
5
FIGURE 2-14:
Temperature.
-40 -25 -10
20 35 50 65 80 95 110 125
Temperature (°C)
Undervoltage Lockout vs.
7
1.3
1.2
UP
1.1
DOWN
1
6.5
Shutdown Current (µA)
VIN = 12V
VOUT = 3.3V
IOUT = 100 mA
5
FIGURE 2-17:
Temperature.
1.4
Enable Voltage (V)
10
20 35 50 65 80
Temperature (°C)
95 110 125
Input Quiescent Current vs.
VIN = 12V
VOUT = 3.3V
6
5.5
5
4.5
4
0.9
-40 -25 -10
FIGURE 2-15:
Temperature.
5
20 35 50 65 80 95 110 125
Temperature (°C)
EN Threshold Voltage vs.
 2014 Microchip Technology Inc.
-40 -25 -10
FIGURE 2-18:
Temperature.
5
20 35 50 65 80
Temperature (°C)
95 110 125
Shutdown Current vs.
DS20005308B-page 7
MCP16331
Note: Unless otherwise indicated, VIN = EN = 12V, COUT = CIN = 2 X10 µF, L = 15 µH, VOUT = 3.3V, ILOAD = 100 mA,
TA = +25°C, 6-Lead SOT-23 package.
Switching Frequency (kHz)
525
1.9
VOUT = 3.3V
No Load Input Current (mA)
1.7
1.5
1.3
1.1
0.9
0.7
0.5
5
10
15
FIGURE 2-19:
VIN.
20
25
30
VIN (V)
35
40
45
475
VIN = 12V
VOUT = 3.3V
IOUT = 200 mA
450
50
Input Quiescent Current vs.
500
-40 -25 -10
FIGURE 2-22:
Temperature.
5
20 35 50 65 80 95 110 125
Temperature (°C)
Switching Frequency vs.
4.3
18
VOUT=3.3V
15
To Start
4.1
VIN (V)
Shutdown Current (µA)
VOUT = 3.3V
12
3.9
9
To Stop
3.7
6
3
3.5
5
10
15
FIGURE 2-20:
20
25
30
VIN (V)
35
40
45
50
Shutdown Current vs. VIN.
0
0.1
FIGURE 2-23:
Output Current.
0.2
0.3
Output Current (A)
0.4
0.5
Minimum Input Voltage vs
Output Current (mA)
20
15
VOUT = 3.3V
10
VOUT = 5V
5
0
5
10
15
FIGURE 2-21:
Threshold vs VIN.
DS20005308B-page 8
20
25
30
VIN (V)
35
40
45
50
PWM/Skipping IOUT
 2014 Microchip Technology Inc.
MCP16331
Note: Unless otherwise indicated, VIN = EN = 12V, COUT = CIN = 2 X10 µF, L = 15 µH, VOUT = 3.3V, ILOAD = 100 mA,
TA = +25°C, 6-Lead SOT-23 package.
VIN = 12V
VOUT = 3.3V
IOUT = 300 mA
VOUT
20 mV/div
AC coupled
VIN = 12V
VOUT = 3.3V
IOUT = 200 mA
VOUT
1V/div
IL
200 mA/div
EN
2V/div
SW
10V/div
2 µs/div
FIGURE 2-24:
Waveforms.
80 µs/div
Heavy Load Switching
VIN = 48V
VOUT = 3.3V
IOUT = 5 mA
VOUT
20 mV/div
AC coupled
FIGURE 2-27:
Startup from EN.
VIN = 12V
VOUT = 3.3V
IOUT
200 mA/div
Load Step from
100 mA to 500 mA
IL
50 mA/div
SW
20V/div
VOUT
50 mV/div
AC coupled
10 µs/div
FIGURE 2-25:
Waveforms.
200 µs/div
Light Load Switching
FIGURE 2-28:
VOUT = 3.3V
IOUT = 200 mA
VIN = 36V
VOUT = 3.3V
IOUT = 200 mA
VOUT
100 mV/div
AC coupled
VOUT
1V/div
VIN
10V/div
VIN
20V/div
Line Step from
5V to 24V
200 µs/div
80 µs/div
FIGURE 2-26:
Load Transient Response.
Startup from VIN.
 2014 Microchip Technology Inc.
FIGURE 2-29:
Line Transient Response.
DS20005308B-page 9
MCP16331
3.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1:
PIN FUNCTION TABLE
MCP16331
Symbol
Description
6
SW
Output switch node, connects to the inductor, freewheeling diode and the
bootstrap capacitor.
2
4
EN
Enable pin. There is an internal pull up on the VIN. To turn the device off,
connect EN to GND.
3
—
NC
Not connected
4
—
NC
Not connected
5
2
GND
Ground pin
6
3
VFB
Output voltage feedback pin. Connect VFB to an external resistor divider to set
the output voltage.
7
1
BOOST
8
5
VIN
Boost voltage that drives the internal NMOS control switch. A bootstrap
capacitor is connected between the BOOST and SW pins.
Input supply voltage pin for power and internal biasing.
9
—
EP
Exposed Thermal Pad
TDFN
SOT-23
1
3.1
Switch Node (SW)
The switch node pin is connected internally to the
NMOS switch, and externally to the SW node
consisting of the inductor and Schottky diode. The
external Schottky diode should be connected close to
the SW node and GND.
3.2
Enable Pin (EN)
The EN pin is a logic-level input used to enable or
disable the device switching, and lower the quiescent
current while disabled. By default the MCP16331 is
enabled through an internal pull-up. To turn off the
device, the EN pin must be pulled low.
3.3
3.6
Power Supply Input Voltage Pin
(VIN)
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 VIN and GND pins.
3.7
Exposed Thermal Pad Pin (EP)
There is an internal electrical connection between the
EP and GND pin for the TDFN package.
Ground Pin (GND)
The ground or return pin is used for circuit ground
connection. 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 on the GND
pin.
3.4
Feedback Voltage Pin (VFB)
The VFB pin is used to provide output voltage regulation
by using a resistor divider. The VFB voltage will be 0.8V
typical with the output voltage in regulation.
3.5
Boost Pin (BOOST)
The supply for the floating high side driver used to turn
the integrated N-Channel MOSFET on and off is
connected to the boost pin.
DS20005308B-page 10
 2014 Microchip Technology Inc.
MCP16331
NOTES:
 2014 Microchip Technology Inc.
DS20005308B-page 11
MCP16331
4.0
DETAILED DESCRIPTION
4.1.4
4.1
Device Overview
Enable input is used to disable the device, while
connected to GND. If disabled, the MCP16331 device
consumes a minimal current from the input.
The MCP16331 is a high input voltage step-down
regulator, capable of supplying 500 mA to a regulated
output voltage from 2.0V to 24V. Internally, the trimmed
500 kHz oscillator provides a fixed frequency, while the
Peak Current Mode Control architecture varies the duty
cycle for output voltage regulation. An internal floating
driver is used to turn the high-side integrated
N-Channel MOSFET on and off. The power for this
driver is derived from an external boost capacitor
(CBOOST) whose energy is supplied from a fixed
voltage ranging between 3.0V and 5.5V, typically the
input or output voltage of the converter. For
applications with an output voltage outside of this
range, 12V for example, the boost capacitor bias can
be derived from the output using a simple Zener diode
regulator.
4.1.1
INTERNAL REFERENCE VOLTAGE
VREF
An integrated precise 0.8V reference combined with an
external resistor divider sets the desired converter output voltage. The resistor divider range can vary without
affecting the control system gain. High-value resistors
consume less current, but are more susceptible to
noise.
4.1.2
4.1.5
ENABLE INPUT
SOFT START
The internal reference voltage rate of rise is controlled
during startup, minimizing the output voltage overshoot
and the inrush current.
4.1.6
UNDERVOLTAGE LOCKOUT
An integrated Undervoltage Lockout (UVLO) prevents
the converter from starting until the input voltage is high
enough for normal operation. The converter will typically
start at 4.1V and operate down to 3.6V. Hysteresis is
added to prevent starting and stopping during start-up
as a result of loading the input voltage source.
4.1.7
OVERTEMPERATURE
PROTECTION
Overtemperature protection limits the silicon die
temperature to +160°C by turning the converter off. The
normal switching resumes at +130°C.
INTERNAL COMPENSATION
All control system components necessary for stable
operation over the entire device operating range are
integrated, including the error amplifier and inductor
current slope compensation. To add the proper amount
of slope compensation, the inductor value changes
along with the output voltage (see Table 5-1).
4.1.3
EXTERNAL COMPONENTS
External components consist of:
•
•
•
•
•
•
input capacitor
output filter (inductor and capacitor)
freewheeling diode
boost capacitor
boost blocking diode
resistor divider
The selection of the external inductor, output capacitor,
input capacitor and freewheeling diode is dependent
upon the output voltage, input voltage and the
maximum output current.
DS20005308B-page 12
 2014 Microchip Technology Inc.
MCP16331
VIN
BG
REF
CIN
VOUT
VREG
Boost
Pre
Charge
SS OVERTEMP
VREF
RTOP
+
Amp
-
FB
S
-
PWM
Latch
Comp
RCOMP
VREF
EN
HS
Drive
SW
+
+
SHDN all blocks
GND
L
Schottky
Diode
R
Precharge
Overtemp
CCOMP
+
-
Boost Diode
CBOOST
500 kHz OSC
+
RBOT
BOOST
VOUT
COUT
CS
RSENSE
Slope
Comp
GND
Note: EN has an internal pull up, so the device will start even if the EN pin is left floating.
FIGURE 4-1:
4.2
4.2.1
MCP16331 Block Diagram.
Functional Description
STEP-DOWN OR BUCK
CONVERTER
The MCP16331 is a non-synchronous, step-down or
buck converter capable of stepping input voltages
ranging from 4.4V to 50V down to 2.0V to 24V for
VIN > VOUT.
The integrated high side switch is used to chop or
modulate the input voltage using a controlled duty cycle
for output voltage regulation. High efficiency is
achieved by using a low-resistance switch, low forward
drop diode, low equivalent series resistance, inductor
and capacitor. When the switch is turned on, a DC
voltage is applied across the inductor (VIN - VOUT),
resulting in a positive linear ramp of inductor current.
When the switch turns off, the applied inductor voltage
is equal to -VOUT, resulting in a negative linear ramp of
inductor current (ignoring the forward drop of the
Schottky diode).
 2014 Microchip Technology Inc.
For steady-state, continuous inductor current
operation, the positive inductor current ramp must
equal the negative current ramp in magnitude. While
operating in steady state, the switch duty cycle must be
equal to the relationship of VOUT/VIN for constant
output voltage regulation, under the condition that the
inductor current is continuous, or never reaches zero.
For discontinuous inductor current operation, the
steady-state duty cycle will be less than VOUT/VIN to
maintain voltage regulation. The average of the
chopped input voltage or SW node voltage is equal to
the output voltage, while the average of the inductor
current is equal to the output current.
DS20005308B-page 13
MCP16331
4.2.3
IL
SW
VIN
+
-
Schottky
Diode
VOUT
L
COUT
IL
IOUT
0
VIN
SW
VOUT
on
on
on
off
off
Continuous Inductor Current Mode
IL
0
IOUT
VIN
SW
on
on
off
off
on
Discontinuous Inductor Current Mode
FIGURE 4-2:
4.2.2
Step-Down Converter.
PEAK CURRENT MODE CONTROL
The MCP16331 integrates a Peak Current Mode
Control architecture, resulting in superior AC regulation
while minimizing the number of voltage loop
compensation components and their size for
integration. Peak Current Mode Control takes a small
portion of the inductor current, replicates it and
compares this replicated current sense signal with the
output of the integrated error voltage. In practice, the
inductor current and the internal switch current are
equal during the switch-on time. By adding this peak
current sense to the system control, the step-down
power train system is reduced from a 2nd order to a 1st
order. This reduces the system complexity and
increases its dynamic performance.
PULSE-WIDTH MODULATION
(PWM)
The internal oscillator periodically starts the switching
period, which in MCP16331’s case occurs every 2 µs
or 500 kHz. With the integrated switch turned on, the
inductor current ramps up until the sum of the current
sense and slope compensation ramp exceeds the
integrated error amplifier output. The error amplifier
output slews up or down to increase or decrease the
inductor peak current feeding into the output LC filter. If
the regulated output voltage is lower than its target, the
error amplifier output rises. This results in an increase
in the inductor current to correct for error in the output
voltage. The fixed frequency duty cycle is terminated
when the sensed inductor peak current summed with
the internal slope compensation exceeds the output
voltage of the error amplifier. The PWM latch is set by
turning off the internal switch and preventing it from
turning on until the beginning of the next cycle. An
overtemperature signal or boost cap undervoltage can
also reset the PWM latch to terminate the cycle.
When working close to the boundary conduction
threshold, a jitter on the SW node may occur, reflecting
in the output voltage. Although the low-frequency output component is very small, it may be desirable to
completely eliminate this component. To achieve this,
different methods can be applied to reduce or completely eliminate this component. In addition to a very
good layout, a capacitor in parallel with the top feedback resistor or an RC snubber between the SW node
and GND can be added.
Typical values for the snubber are 680 pF and 430,
while the capacitor in parallel with the top feedback
resistor can use values from 10 pF to 47 pF. Using
such a snubber eliminates the ringing on the SW node,
but decreases the overall efficiency of the converter.
For Pulse-Width Modulation (PWM) duty cycles that
exceed 50%, the control system can become bimodal
where a wide pulse followed by a short pulse repeats
instead of the desired fixed-pulse width. To prevent this
mode of operation, an internal compensating ramp is
summed into the current shown in Figure 4-2.
DS20005308B-page 14
 2014 Microchip Technology Inc.
MCP16331
4.2.4
HIGH SIDE DRIVE
The MCP16331 features an integrated high-side
N-Channel MOSFET for high-efficiency step-down
power conversion. An N-Channel MOSFET is used for
its low resistance and size (instead of a P-Channel
MOSFET). A gate drive voltage above the input is
necessary to turn on the high side N-Channel. The high
side drive voltage should be between 3.0V and 5.5V.
The N-Channel source is connected to the inductor and
Schottky diode, or switch node. When the switch is off,
the boost cap voltage is replenished, typically from the
output voltage for 3V to 5V output applications. A
boost-blocking diode is used to prevent current flow
from the boost cap back into the output during the
internal switch-on time.
Prior to startup, the boost cap has no stored charge to
drive the switch. An internal regulator is used to
“precharge” the boost cap. Once precharged, the
switch is turned on and the inductor current flows.
When the switch turns off, the inductor current freewheels through the Schottky diode, providing a path to
recharge the boost cap. Worst-case conditions for
recharge occur when the switch turns on for a very
short duty cycle at light load, limiting the inductor
current ramp. In this case, there is a small amount of
time for the boost capacitor to recharge. For high input
voltages there is enough precharge current to replace
the boost cap charge. For input voltages above 5.5V
typical, the MCP16331 device will regulate the output
voltage with no load. After starting, the MCP16331 will
regulate the output voltage until the input voltage
decreases below 4V. See Figure 2-23 for device range
of operation over input voltage, output voltage and
load.
4.2.5
ALTERNATIVE BOOST BIAS
For 3.0V to 5.0V output voltage applications, the boost
supply is typically the output voltage. For applications
with VOUT < 3.0V or VOUT > 5.0V, an alternative boost
supply can be used.
Alternative boost supplies can be from the input, input
derived, output derived or an auxiliary system voltage.
For low-voltage output applications with unregulated
input voltage, a shunt regulator derived from the input
can be used to derive the boost supply. For
applications with high-output voltage or regulated highinput voltage, a series regulator can be used to derive
the boost supply. In case the boost is biased from an
external source while in shutdown, the device will draw
slightly higher current.
 2014 Microchip Technology Inc.
DS20005308B-page 15
MCP16331
Boost Diode
C1
VZ = 5.1V
BOOST
RSH
CB
EN
VIN
L
2V
VIN
12V
VOUT
MCP16331 SW
COUT
FW Diode
CIN
RTOP
FB
GND
RBOT
3.0V to 5.5V External Supply
Boost Diode
BOOST
CB
EN
VIN
L
2V
VIN
12V
VOUT
MCP16331 SW
COUT
FW Diode
CIN
GND
RTOP
FB
RBOT
FIGURE 4-3:
Shunt and External Boost Supply.
Shunt Boost Supply Regulation is used for low-output
voltage converters operating from a wide ranging input
source. A regulated 3.0V to 5.5V supply is needed to
provide high-side drive bias. The shunt uses a Zener
diode to clamp the voltage within the 3.0V to 5.5V
range using the resistance shown in Figure 4-3.
To calculate the shunt resistance, the boost drive
current can be estimated using Equation 4-1.
DS20005308B-page 16
IBOOST_TYP for 3.3V Boost Supply = 0.6 mA
IBOOST_TYP for 5.0V Boost Supply = 0.8 mA.
EQUATION 4-1:
BOOST CURRENT
I BOOST = I BOOST_TYP  1.5 mA
 2014 Microchip Technology Inc.
MCP16331
To calculate the shunt resistance, the maximum IBOOST
and IZ current are used at the minimum input voltage
(Equation 4-2).
EQUATION 4-2:
VZ and IZ can be found on the Zener diode
manufacturer’s data sheet. Typically, IZ = 1 mA.
SHUNT RESISTANCE
V INMIN – V Z
R SH = -----------------------------I Boost + I Z
Boost Diode VZ = 7.5V
BOOST
CB
EN
VIN
L
MCP16331
12V
VIN
15V to 50V
VOUT
SW
COUT
FW Diode
CIN
RTOP
FB
GND
RBOT
Boost Diode
BOOST
VZ = 7.5V
CB
EN
VIN
SW
2V
VIN
12V
VOUT
L
MCP16331
COUT
FW Diode
CIN
GND
RTOP
FB
RBOT
FIGURE 4-4:
Series Regulator Boost Supply.
Series regulator applications use a Zener diode to drop
the excess voltage. The series regulator bias source
can be input or output voltage derived, as shown in
Figure 4-4. The boost supply must remain between
3.0V and 5.5V at all times for proper circuit operation.
 2014 Microchip Technology Inc.
DS20005308B-page 17
MCP16331
5.0
APPLICATION INFORMATION
5.1
Typical Applications
The MCP16331 step-down converter operates over a
wide input voltage range, up to 50V maximum. Typical
applications include generating a bias or VDD voltage
for the PIC® microcontroller product line, digital control
system bias supply for AC-DC converters, 24V
industrial input and similar applications.
5.2
Adjustable Output Voltage
Calculations
To calculate the resistor divider values for the
MCP16331, Equation 5-1 can be used. RTOP is
connected to VOUT, RBOT is connected to GND and
both are connected to the VFB input pin.
EQUATION 5-1:
R TOP
V OUT
= R BOT   ------------- – 1
 V FB

EXAMPLE 5-1:
VOUT
=
3.3V
VFB
=
0.8V
RBOT
=
10 k
RTOP
=
31.25 k (standard value = 31.6 k)
VOUT
=
3.328V (using standard value)
EXAMPLE 5-2:
VOUT
=
5.0V
VFB
=
0.8V
RBOT
=
10 k
RTOP
=
52.5 k (standard value = 52.3 k)
VOUT
=
4.98V (using standard value)
The transconductance error amplifier gain is controlled
by its internal impedance. The external divider resistors
have no effect on system gain so a wide range of
values can be used. A 10 k resistor is recommended
as a good trade-off for quiescent current and noise
immunity.
DS20005308B-page 18
5.3
General Design Equations
The step-down converter duty cycle can be estimated
using Equation 5-2, while operating in Continuous
Inductor Current Mode. This equation also counts the
forward drop of the freewheeling diode and internal
N-Channel MOSFET switch voltage drop. As the load
current increases, the switch voltage drop and diode
voltage drop increase, requiring a larger PWM duty
cycle to maintain the output voltage regulation. Switch
voltage drop is estimated by multiplying the switch
current times the switch resistance or RDSON.
EQUATION 5-2:
CONTINUOUS INDUCTOR
CURRENT DUTY CYCLE
 V OUT + V Diode 
D = ------------------------------------------------------ V IN –  I SW  R DSON  
The MCP16331 device features an integrated slope
compensation to prevent the bimodal operation of the
PWM duty cycle. Internally, half of the inductor current
down slope is summed with the internal current sense
signal. For the proper amount of slope compensation,
it is recommended to keep the inductor down-slope
current constant by varying the inductance with VOUT,
where K = 0.22V/µH.
EQUATION 5-3:
K = V OUT  L
TABLE 5-1:
RECOMMENDED INDUCTOR
VALUES
VOUT
K
LSTANDARD
2.0V
0.20
10 µH
3.3V
0.22
15 µH
5.0V
0.23
22 µH
12V
0.21
56 µH
15V
0.22
68 µH
24V
0.24
100 µH
 2014 Microchip Technology Inc.
MCP16331
5.4
Input Capacitor Selection
5.6
Inductor Selection
The step-down converter input capacitor must filter the
high-input ripple current, as a result of pulsing or
chopping the input voltage. The MCP16331 input
voltage pin is used to supply voltage for the power train
and as a source for internal bias. A low Equivalent
Series Resistance (ESR), preferably a ceramic
capacitor,
is
recommended.
The
necessary
capacitance is dependent upon the maximum load
current and source impedance. Three capacitor
parameters to keep in mind are the voltage rating,
equivalent series resistance and the temperature
rating. For wide temperature-range applications, a
multi-layer X7R dielectric is mandatory, while for
applications with limited temperature range, a multilayer X5R dielectric is acceptable. Typically, input
capacitance between 4.7 µF and 20 µF is sufficient for
most applications.
The MCP16331 is designed to be used with small
surface mount inductors. Several specifications should
be considered prior to selecting an inductor. To
optimize system performance, the inductance value is
determined by the output voltage (Table 5-1) so the
inductor ripple current is somewhat constant over the
output voltage range.
The input capacitor voltage rating should be a minimum
of VIN plus margin. Table 5-2 contains the
recommended range for the input capacitor value.
VOUT = 3.3V
5.5
Output Capacitor Selection
The output capacitor helps in providing a stable output
voltage during sudden load transients, and reduces the
output voltage ripple. As with the input capacitor, X5R
and X7R ceramic capacitors are well suited for this
application.
The amount and type of output capacitance and equivalent series resistance will have a significant effect on
the output ripple voltage and system stability. The
range of the output capacitance is limited due to the
integrated compensation of the MCP16331.
The output voltage capacitor voltage rating should be a
minimum of VOUT, plus margin.
Table 5-2 contains the recommended range for the
input and output capacitor value:
TABLE 5-2:
EQUATION 5-4:
INDUCTOR RIPPLE
CURRENT
V
–V
L
IN
OUT
 IL = ---------------------------  t ON
EXAMPLE 5-3:
VIN = 12V
IOUT = 500 mA
EQUATION 5-5:
INDUCTOR PEAK
CURRENT
 IL
I LPK = -------- + I OUT
2
Inductor ripple current = 319 mA
Inductor peak current = 660 mA
For the example above, an inductor saturation rating of
minimum 660 mA is recommended. Low DCR
inductors result in higher system efficiency. A trade-off
between size, cost and efficiency is made to achieve
the desired results.
CAPACITOR VALUE RANGE
Parameter
Min.
Max.
CIN
4.7 µF
none
COUT
20 µF
—
 2014 Microchip Technology Inc.
DS20005308B-page 19
MCP16331
ME3220-153
15
0.52
0.90
3.2x2.5x2.0
ME3220-223
22
0.787
0.71
3.2x2.5x2.0
LPS4414-153
15
0.440
0.92
4.4x4.4x1.4
LPS4414-223
22
0.59
0.74
4.4x4.4x1.4
LPS6235-153
15
0.125
2.00
6.2x6.2x3.5
LPS6235-223
22
0.145
1.7
6.2x6.2x3.5
MSS6132-153
15
0.106
1.56
6.1x6.1x3.2
MSS6132-223
22
0.158
1.22
6.1x6.1x3.2
MSS7341-153
15
0.055
1.78
6.6x6.6x4.1
MSS7341-223
22
0.082
1.42
6.6x6.6x4.1
15
0.700
0.62
3.0x3.0x1.5
LPS3015-223
22
0.825
0.5
3.0x3.0x1.5
0.575
0.75
2.8x2.8x2.8
ISAT (A)
Size
WxLxH
(mm)
Part Number
Value
(µH)
ISAT (A)
MCP16331 RECOMMENDED
5V INDUCTORS
DCR ()
TABLE 5-4:
Value
(µH)
MCP16331 RECOMMENDED
3.3V INDUCTORS
DCR ()
TABLE 5-3:
Size
WxLxH
(mm)
Coilcraft®
Coilcraft®
LPS3015-153
Wurth Elektronik
Part Number
®
Wurth Elektronik
744025150
15
744042150
7447779115
®
0.400 0.900 2.8x2.8x2.8
744025220
22
15
0.22
0.75
4.8x4.8x1.8
744042220
22
0.3
0.6
4.8x4.8x1.8
15
0.081
2.2
7.3x7.3x4.5
7447779122
22
0.11
1.7
7.3x7.3x4.5
Coiltronics®
Cooper Bussman®
SD12-150R
15
0.408 0.692 5.2x5.2x1.2
SD12-220-R
22
0.633 0.574 5.2x5.2x1.2
SD3118-150-R
SD52-150-R
15
0.44
0.75
3.2x3.2x1.8
SD3118-220-R
22
0.676
0.61
3.2x3.2x1.8
15
0.161
0.88
5.2x5.5.2.0
SD52-220-R
22
0.204
0.73
5.2x5.2x2
Sumida®
Sumida®
CDPH4D19FNP
-150MC
15
0.075
0.66
5.2x5.2x2.0
CDPH4D19FNP
-220MC
22
0.135
0.54
5.2x5.2x2
CDRH3D16/
HPNP-150MC
15
0.410 0.65
4.0x4.0x1.8
CDRH3D16/
HPNP-220MC
22
0.61
0.55
4.0x4.0x1.8
22
0.15
0.85
6.3x6.3x3
TDK - EPCOS®
B82462G4153M
TDK - EPCOS®
15
0.097
1.05
6.3x6.3x3
82462G4223M
5.7
Freewheeling Diode
The freewheeling diode creates a path for inductor current flow after the internal switch is turned off. The average diode current is dependent upon output load
current at duty cycle (D). The efficiency of the converter
is a function of the forward drop and speed of the freewheeling diode. A low forward drop Schottky diode is
recommended. The current rating and voltage rating of
the diode is application dependent. The diode voltage
rating should be a minimum of VIN, plus margin. The
average diode current can be calculated using
Equation 5-6.
EQUATION 5-6:
DIODE AVERAGE
CURRENT
I DAVG =  1 – D   I OUT
DS20005308B-page 20
 2014 Microchip Technology Inc.
MCP16331
the measured efficiency, the internal power dissipation
is estimated by Equation 5-7. This power dissipation
includes all internal and external component losses.
For a quick internal estimate, subtract the estimated
Schottky diode loss and inductor DCR loss from the
PDIS calculation in Equation 5-7.
EXAMPLE 5-4:
IOUT
= 0.5A
VIN
= 15V
VOUT
= 5V
D
= 5/15
IDAVG
= 333 mA
EQUATION 5-7:
A 0.5A to 1A Diode is recommended.
TABLE 5-5:
App
FREEWHEELING DIODES
Manufacturer
Part
Number
Rating
12 VIN
500 mA
Diodes 
Inc.
DFLS120L-7
20V, 1A
24 VIN
100 mA
Diodes 
Inc.
B0540Ws-7
40V, 0.5A
18 VIN
500 mA
Diodes 
Inc.
B130L-13-F
30V, 1A
48 VIN
500 mA
Diodes 
Inc.
B1100
5.8
The difference between the first term, input power, and
the second term, power delivered, is the total system
power dissipation. The freewheeling Schottky diode
losses are determined by calculating the average diode
current and multiplying by the diode forward drop. The
inductor losses are estimated by PL = IOUT2 x LDCR.
100V, 1A
DIODE POWER
DISSIPATION ESTIMATE
PDiode = VF    1 – D   I OUT 
Boost Diode
A standard 1N4148 ultra-fast diode is recommended
for its recovery speed, high voltage blocking capability,
availability and cost. The voltage rating required for the
boost diode is VIN.
For low-boost voltage applications, a small Schottky
diode with the appropriately rated voltage can be used
to lower the forward drop increasing the boost supply
for gate drive.
Boost Capacitor
The boost capacitor is used to supply current for the
internal high side drive circuitry that is above the input
voltage. The boost capacitor must store enough energy
to completely drive the high-side switch on and off. A
0.1 µF X5R or X7R capacitor is recommended for all
applications. The boost capacitor maximum voltage is
5.5V, so a 6.3V or 10V rated capacitor is recommended.
5.10
OUT  I OUT
V
- –  V OUT  I OUT  = PDis
 -----------------------------Efficiency 
EQUATION 5-8:
The boost diode is used to provide a charging path from
the low-voltage gate drive source while the switch node
is low. The boost diode blocks the high voltage of the
switch node from feeding back into the output voltage
when the switch is turned on, forcing the switch node
high.
5.9
TOTAL POWER
DISSIPATION ESTIMATE
EXAMPLE 5-5:
VIN
= 10V
VOUT
= 5.0V
IOUT
= 0.4A
Efficiency
= 90%
Total System Dissipation
= 222 mW
LDCR
= 0.15
PL
= 24 mW
Diode VF
= 0.50
D
= 50%
PDiode
= 125 mW
MCP16331 internal power dissipation estimate:
PDIS - PL - PDIODE = 73 mW
JA
= 198°C/W
Estimated Junction 
Temperature Rise
= +14.5°C
Thermal Calculations
The MCP16331 is available in 6-lead SOT-23 and 8lead TDFN packages. By calculating the power
dissipation and applying the package thermal
resistance (JA), the junction temperature is estimated.
To quickly estimate the internal power dissipation for
the switching step-down regulator, an empirical calculation using measured efficiency can be used. Given
 2014 Microchip Technology Inc.
DS20005308B-page 21
MCP16331
5.11
PCB Layout Information
Good printed circuit board layout techniques are
important to any switching circuitry, and switching
power supplies are no different. When wiring the
switching high-current paths, short and wide traces
should be used. Therefore, it is important that the input
and output capacitors be placed as close as possible to
the MCP16331 to minimize the loop area.
The feedback resistors and feedback signal should be
routed away from the switching node and the switching
current loop. When possible, ground planes and traces
should be used to help shield the feedback signal and
minimize noise and magnetic interference.
DS20005308B-page 22
A good MCP16331 layout starts with CIN placement.
CIN supplies current to the input of the circuit when the
switch is turned on. In addition to supplying highfrequency switch current, CIN also provides a stable
voltage source for the internal MCP16331 circuitry.
Unstable PWM operation can result if there are
excessive transients or ringing on the VIN pin of the
MCP16331 device. In Figure 5-1, CIN is placed close to
pin 5. A ground plane on the bottom of the board
provides a low resistive and inductive path for the
return current. The next priority in placement is the
freewheeling current loop formed by D1, COUT and L,
while strategically placing COUT return close to CIN
return. Next, the boost capacitor should be placed
between the boost pin and the switch node pin SW.
This leaves space close to the MCP16331 VFB pin to
place RTOP and RBOT. RTOP and RBOT are routed away
from the Switch node so noise is not coupled into the
high-impedance VFB input.
 2014 Microchip Technology Inc.
MCP16331
Bottom Plane is GND
Bottom Trace
RBOT RTOP 10 Ohm
MCP16331
C
1 B DB
VIN
VOUT
D1
L
2 x CIN
GND
COUT
COUT
4
BOOST
EN
GND
DB
1
CB
VIN
5
4V to 50V
CIN
MCP16331
SW
L
6
VIN
COUT
FB
3
2
Value
CIN
2 x 10 µF
COUT
2 x 10 µF
L
15 µH
RTOP
31.2 k
RBOT
10 k
D1
B1100
DB
1N4148
CB
100 nF
FIGURE 5-1:
10
D1
GND
Component
VOUT
3.3V
RTOP
RBOT
*Note: A 10 resistor is used with network analyzer, to measure
system gain and phase.
MCP16331 SOT-23-6 Recommended Layout, 500 mA Design.
 2014 Microchip Technology Inc.
DS20005308B-page 23
MCP16331
Bottom Plane is GND
MCP16331
RBOT
RTOP
DB
VIN
VOUT
CB
CIN
GND
GND
COUT
D1
4
GND
BOOST
EN
DB
1
CB
VIN
4V to 50V
CIN
Component
Value
CIN
1 µF
COUT
10 µF
L
15 µH
RTOP
31.2 k
RBOT
10 k
D1
STPS0560Z
DB
1N4148
CB
100 nF
FIGURE 5-2:
DS20005308B-page 24
5
VIN
MCP16331
SW
VOUT
L
6
3.3V
COUT
D1
GND
2
FB
3
RTOP
RBOT
Compact MCP16331 SOT-23-6 D2 Recommended Layout, Low Current Design.
 2014 Microchip Technology Inc.
MCP16331
MCP16331
CSNUB
RSNUB
RTOP
RBOT
L
CIN
COUT
D1
CB
DB
VIN
VOUT
GND
2
BOOST
EN
DB
7
CB
VIN
4V to 50V
CIN
8
VIN
MCP16331
Value
CIN
2x10 µF
COUT
2x10 µF
L
22 µH
RTOP
31.2 k
RBOT
10 k
D1
MBRS1100
DB
1N4148WS
CB
100 nF
CTOP
20 pF
CSNUB
430 pF
RSNUB
680
FIGURE 5-3:
1
CSNUB
D1
GND
5
Component
SW
Note:
FB
6
VOUT
3.3V
L
RSNUB
COUT
RTOP
CTOP
Optional
RBOT
Red represents top layer pads and traces and blue
represents bottom layer pads and traces. On the
bottom layer, a GND plane should be placed, which
is not represented in the example above for visibility
reasons.
MCP16331 TDFN-8 Recommended Layout Design.
 2014 Microchip Technology Inc.
DS20005308B-page 25
MCP16331
6.0
TYPICAL APPLICATION CIRCUITS
Boost Diode
BOOST
CB
EN
VIN
L
MCP16331
3.3V
VIN
4.5V to 50V
VOUT
SW
COUT
FW Diode
CIN
GND
RTOP
FB
RBOT
Component
Value
Manufacturer
CIN
2 x 10 µF
TDK
COUT
2 x 10 µF
Taiyo Yuden
15 µH
Coilcraft®
MSS6132-153ML
MSS6132 15 µH shielded power inductor
31.6 k
Panasonic®-ECG
ERJ-3EKF3162V
Res. 31.6 KΩ 1/10W 1% 0603 SMD
RBOT
10 k
Panasonic-ECG
ERJ-3EKF1002V
Res. 10.0 KΩ 1/10W 1% 0603 SMD
FW Diode
B1100
Diodes® Inc.
B1100-13-F
L
RTOP
Part Number
C5750X7S2A106M2 Capacitor, 10µF, 100V, X7S, 2220
30KB
JMK212B7106KG-T Cap. 10 µF 6.3V ceramic X7R 0805 10%
Boost Diode
1N4148
Diodes Inc.
1N4448WS-7-F
CB
100 nF
AVX® Corporation
0603YC104KAT2A
FIGURE 6-1:
DS20005308B-page 26
Comment
Schottky, 100V, 1A, SMA
Diode switch 75V 200 mW SOD-323
Cap. 0.1 µF 16V ceramic X7R 0603 10%
Typical Application 50V VIN to 3.3V VOUT.
 2014 Microchip Technology Inc.
MCP16331
Boost Diode
BOOST
CB
EN
VIN
MCP16331
15V to 50V
DZ
L
VOUT
SW
12V
VIN
COUT
FW Diode
CIN
GND
RTOP
FB
RBOT
Component
Value
Manufacturer
Part Number
Comment
CIN
2 x 10 µF
TDK
COUT
2 x 10 µF
Taiyo Yuden
JMK212B7106KG-T
Cap. ceramic 10 µF 25V X7R 10% 1206
C5750X7S2A106M230KB Capacitor, 10µF, 100V, X7S, 2220
L
56 µH
Coilcraft
MSS7341-563ML
MSS7341 56 µH shielded power inductor
RTOP
140 k
Panasonic-ECG
ERJ-3EKF3162V
Res. 140 KΩ 1/10W 1% 0603 SMD
RBOT
10 k
Panasonic-ECG
ERJ-3EKF1002V
FW Diode
B1100
Diodes Inc.
B1100-13-F
Boost Diode
1N4148
Diodes Inc.
1N4448WS-7-F
CB
100 nF
AVX Corp.
0603YC104KAT2A
Cap. 0.1 µF 16V ceramic X7R 0603 10%
DZ
7.5V Zener
Diodes Inc.
MMSZ5236BS-7-F
Diode Zener 7.5V 200 mW SOD-323
FIGURE 6-2:
Res. 10.0 KΩ 1/10W 1% 0603 SMD
Diode Schottky 100V 1A SMB
Diode switch 75V 200 mW SOD-323
Typical Application 15V-50V Input; 12V Output.
 2014 Microchip Technology Inc.
DS20005308B-page 27
MCP16331
DZ
Boost Diode
BOOST
CB
EN
VIN
12V
L
MCP16331
VOUT
SW
2V
VIN
COUT
FW Diode
CIN
GND
RTOP
FB
RBOT
Component
CIN
Value
Manufacturer
Part Number
Comment
2 x 10 µF
Taiyo Yuden
JMK212B7106KG-T
Cap. ceramic 10 µF 25V X7R 10% 1206
COUT
22 µF
Taiyo Yuden
JMK316B7226ML-T
Cap. ceramic 22 µF 6.3V X7R 1206
L
10 µH
Coilcraft
MSS4020-103ML
10 µH shielded power inductor
RTOP
15 k
Panasonic-ECG
ERJ-3EKF1502V
Res.15.0 KΩ 1/10W 1% 0603 SMD
RBOT
10 k
Panasonic-ECG
ERJ-3EKF1002V
FW Diode
PD3S
Diodes Inc.
PD3S120L-7
Boost Diode
1N4148
Diodes Inc.
1N4448WS-7-F
CB
100 nF
AVX Corp.
0603YC104KAT2A
Cap. 0.1 µF 16V ceramic X7R 0603 10%
DZ
7.5V Zener
Diodes Inc.
MMSZ5236BS-7-F
Diode Zener 7.5V 200 mW SOD-323
FIGURE 6-3:
DS20005308B-page 28
Res. 10.0 KΩ 1/10W 1% 0603 SMD
Diode Schottky 1A 20V POWERDI323
Diode switch 75V 200 mW SOD-323
Typical Application 12V Input; 2V Output at 500 mA.
 2014 Microchip Technology Inc.
MCP16331
Boost Diode
DZ
CZ
BOOST
RZ
CB
EN
VIN
L
MCP16331
SW
2.5V
VIN
10V to 16V
VOUT
COUT
FW Diode
CIN
GND
RTOP
FB
RBOT
Component
CIN
COUT
L
RTOP
RBOT
Value
Manufacturer
Part Number
Comment
2 x 10 µF
Taiyo Yuden
JMK212B7106KG-T
Cap. ceramic 10 µF 25V X7R 10% 1206
22 µF
Taiyo Yuden
JMK316B7226ML-T
Cap. ceramic 22 µF 6.3V X7R 1206
12 µH
Coilcraft
LPS4414-123MLB
LPS4414 12 µH shielded power inductor
21.5 k
Panasonic-ECG
ERJ-3EKF2152V
Res. 21.5 KΩ 1/10W 1% 0603 SMD
10 k
Panasonic-ECG
ERJ-3EKF1002V
DFLS120
Diodes Inc.
DFLS120L-7
Boost Diode
1N4148
Diodes Inc.
1N4448WS-7-F
CB
100 nF
AVX Corp.
0603YC104KAT2A
Cap. 0.1 µF 16V ceramic X7R 0603 10%
DZ
7.5V Zener
Diodes Inc.
MMSZ5236BS-7-F
Diode Zener 7.5V 200 mW SOD-323
CZ
1 µF
Taiyo Yuden
LMK107B7105KA-T
Cap. ceramic 1.0UF 10V X7R 0603
RZ
1 k
Panasonic-ECG
ERJ-8ENF1001V
FW Diode
FIGURE 6-4:
Res. 10.0 KΩ 1/10W 1% 0603 SMD
Diode Schottky 20V 1A POWERDI123
Diode switch 75V 200 mW SOD-323
Res. 1.00K Ohm 1/4W 1% 1206 SMD
Typical Application 10V to 16V VIN to 2.5V VOUT.
 2014 Microchip Technology Inc.
DS20005308B-page 29
MCP16331
Boost Diode
EN
BOOST
CB
L
VIN
4V to 50V
MCP16331
VOUT
SW
3.3V
VIN
COUT
FW Diode
CIN
GND
RTOP
FB
RBOT
Component
CIN
COUT
L
RTOP
RBOT
Value
Manufacturer
Part Number
2 x 10 µF
TDK
10 µF
Taiyo Yuden
JMK107BJ106MA-T
Comment
C5750X7S2A106M230KB Capacitor, 10 µF, 100V, X7S, 2220
Cap. ceramic 10 µF 6.3V X5R 0603
15 µH
Coilcraft
LPS3015-153MLB
Inductor power 15 µH 0.61A SMD
31.6 k
Panasonic-ECG
ERJ-2RKF3162X
Res. 31.6 KΩ 1/10W 1% 0402 SMD
10 k
Panasonic-ECG
ERJ-3EKF1002V
BAT46WH
NXP
BAT46WH
Boost Diode
1N4148
Diodes Inc.
1N4448WS-7-F
Diode switch 75V 200 mW SOD-323
CB
100 nF
TDK Corp.
C1005X5R0J104M
Cap. ceramic 0.10 µF 6.3V X5R 0402
FW Diode
FIGURE 6-5:
DS20005308B-page 30
Res. 10.0 KΩ 1/10W 1% 0603 SMD
BAT46WH - DIODE, SCHOTTKY,
100V, 0.25A, SOD123F
Typical Application 4V to 50V VIN to 3.3V VOUT at 150 mA.
 2014 Microchip Technology Inc.
MCP16331
7.0
PACKAGING INFORMATION
7.1
Package Marking Information
6-Lead SOT-23
Example
XXNN
MF25
8-Lead TDFN (2x3x0.75 mm)
Example
ACD
415
25
Legend: XX...X
Y
YY
WW
NNN
e3
*
Note:
Customer-specific information
Year code (last digit of calendar year)
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
Pb-free JEDEC® designator for Matte Tin (Sn)
This package is Pb-free. The Pb-free JEDEC designator ( e3)
can be found on the outer packaging for this package.
In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line, thus limiting the number of available
characters for customer-specific information.
 2014 Microchip Technology Inc.
DS20005308B-page 31
MCP16331
/$ !$% $ 0
$$ ,33... 3
" . !1 0 ! !
$ 2 0
& $ $ " $
b
4
N
E
E1
PIN 1 ID BY
LASER MARK
1
2
3
e
e1
D
A
A2
c
φ
L
A1
L1
4$!
6% 9 &2!
!5 $!
55##
6
*+
2$
7%$!" 5
8
)*+
"2$
7- : $
" "2 0
0 !!
$ "&&
7- ="$
" "2 0
7- 5 $
67
6
="$
;
<
;
)
;
)
#
;
#
;
<
;
/$5 $
5
;
/$ $
5
)
;
<
/$ >
;
>
5
"0 !!
<
;
5
"="$
9
;
)
!! "#"$%" "& ! $%!!"& ! $%!!! $ '
! "$ #()
*+, * ! ! $ ' $- % !..$%$$ !
"
!" . + <*
DS20005308B-page 32
 2014 Microchip Technology Inc.
MCP16331
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
 2014 Microchip Technology Inc.
DS20005308B-page 33
MCP16331
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
DS20005308B-page 34
 2014 Microchip Technology Inc.
MCP16331
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
 2014 Microchip Technology Inc.
DS20005308B-page 35
MCP16331
! " # $ %&'())*+,-./"#
/$ !$% $ 0
$$ ,33... 3
DS20005308B-page 36
" . !1 0 ! !
$ 2 0
& $ $ " $
 2014 Microchip Technology Inc.
MCP16331
APPENDIX A:
REVISION HISTORY
Revision B (October 2014)
The following is a list of modifications:
1.
Added edits to incorporate the AEC-Q100
qualification.
Revision A (June 2014)
• Original Release of this Document.
 2014 Microchip Technology Inc.
DS20005308B-page 37
MCP16331
PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO.
[X](1)
X
/XX
Device
Tape and Reel
Option
Temperature
Range
Package
Device:
MCP16331: High-Voltage Input Integrated Switch StepDown Regulator
MCP16331T: High-Voltage Input Integrated Switch StepDown Regulator (Tape and Reel)
Tape and Reel
Option:
T
Temperature Range:
E
Package:
CH = Plastic SOT-23, 6-lead
MNY*= Plastic Dual Flat TDFN, 8-lead
Examples:
a)
b)
MCP16331T-E/CH:
Tape and Reel,
Extended Temperature,
6LD SOT-23 package
MCP16331T-E/MNY: Tape and Reel,
Extended Temperature,
8LD TDFN package
= Tape and Reel(1)
= -40°C to +125°C
Note 1:
* Y = Nickel palladium gold manufacturing designator. Only
available on the TDFN package.
DS20005308B-page 38
Tape and Reel identifier only appears in the
catalog part number description. This identifier is used for ordering purposes and is not
printed on the device package. Check with
your Microchip Sales Office for package
availability with the Tape and Reel option.
 2014 Microchip Technology Inc.
Note the following details of the code protection feature on Microchip devices:
•
Microchip products meet the specification contained in their particular Microchip Data Sheet.
•
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
•
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
•
Microchip is willing to work with the customer who is concerned about the integrity of their code.
•
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Information contained in this publication regarding device
applications and the like is provided only for your convenience
and may be superseded by updates. It is your responsibility to
ensure that your application meets with your specifications.
MICROCHIP MAKES NO REPRESENTATIONS OR
WARRANTIES OF ANY KIND WHETHER EXPRESS OR
IMPLIED, WRITTEN OR ORAL, STATUTORY OR
OTHERWISE, RELATED TO THE INFORMATION,
INCLUDING BUT NOT LIMITED TO ITS CONDITION,
QUALITY, PERFORMANCE, MERCHANTABILITY OR
FITNESS FOR PURPOSE. Microchip disclaims all liability
arising from this information and its use. Use of Microchip
devices in life support and/or safety applications is entirely at
the buyer’s risk, and the buyer agrees to defend, indemnify and
hold harmless Microchip from any and all damages, claims,
suits, or expenses resulting from such use. No licenses are
conveyed, implicitly or otherwise, under any Microchip
intellectual property rights.
Trademarks
The Microchip name and logo, the Microchip logo, dsPIC,
FlashFlex, flexPWR, JukeBlox, KEELOQ, KEELOQ logo, Kleer,
LANCheck, MediaLB, MOST, MOST logo, MPLAB,
OptoLyzer, PIC, PICSTART, PIC32 logo, RightTouch, SpyNIC,
SST, SST Logo, SuperFlash and UNI/O are registered
trademarks of Microchip Technology Incorporated in the
U.S.A. and other countries.
The Embedded Control Solutions Company and mTouch are
registered trademarks of Microchip Technology Incorporated
in the U.S.A.
Analog-for-the-Digital Age, BodyCom, chipKIT, chipKIT logo,
CodeGuard, dsPICDEM, dsPICDEM.net, ECAN, In-Circuit
Serial Programming, ICSP, Inter-Chip Connectivity, KleerNet,
KleerNet logo, MiWi, MPASM, MPF, MPLAB Certified logo,
MPLIB, MPLINK, MultiTRAK, NetDetach, Omniscient Code
Generation, PICDEM, PICDEM.net, PICkit, PICtail,
RightTouch logo, REAL ICE, SQI, Serial Quad I/O, Total
Endurance, TSHARC, USBCheck, VariSense, ViewSpan,
WiperLock, Wireless DNA, and ZENA are trademarks of
Microchip Technology Incorporated in the U.S.A. and other
countries.
SQTP is a service mark of Microchip Technology Incorporated
in the U.S.A.
Silicon Storage Technology is a registered trademark of
Microchip Technology Inc. in other countries.
GestIC is a registered trademarks of Microchip Technology
Germany II GmbH & Co. KG, a subsidiary of Microchip
Technology Inc., in other countries.
All other trademarks mentioned herein are property of their
respective companies.
© 2014, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
ISBN: 978-1-63276-694-6
QUALITY MANAGEMENT SYSTEM
CERTIFIED BY DNV
== ISO/TS 16949 ==
 2014 Microchip Technology Inc.
Microchip received ISO/TS-16949:2009 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in California
and India. The Company’s quality system processes and procedures
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, microperipherals, nonvolatile memory and
analog products. In addition, Microchip’s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.
DS20005308B-page 39
Worldwide Sales and Service
AMERICAS
ASIA/PACIFIC
ASIA/PACIFIC
EUROPE
Corporate Office
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7200
Fax: 480-792-7277
Technical Support:
http://www.microchip.com/
support
Web Address:
www.microchip.com
Asia Pacific Office
Suites 3707-14, 37th Floor
Tower 6, The Gateway
Harbour City, Kowloon
Hong Kong
Tel: 852-2943-5100
Fax: 852-2401-3431
India - Bangalore
Tel: 91-80-3090-4444
Fax: 91-80-3090-4123
Austria - Wels
Tel: 43-7242-2244-39
Fax: 43-7242-2244-393
Denmark - Copenhagen
Tel: 45-4450-2828
Fax: 45-4485-2829
Australia - Sydney
Tel: 61-2-9868-6733
Fax: 61-2-9868-6755
Atlanta
Duluth, GA
Tel: 678-957-9614
Fax: 678-957-1455
China - Beijing
Tel: 86-10-8569-7000
Fax: 86-10-8528-2104
Austin, TX
Tel: 512-257-3370
China - Chengdu
Tel: 86-28-8665-5511
Fax: 86-28-8665-7889
Boston
Westborough, MA
Tel: 774-760-0087
Fax: 774-760-0088
Chicago
Itasca, IL
Tel: 630-285-0071
Fax: 630-285-0075
Cleveland
Independence, OH
Tel: 216-447-0464
Fax: 216-447-0643
Dallas
Addison, TX
Tel: 972-818-7423
Fax: 972-818-2924
Detroit
Novi, MI
Tel: 248-848-4000
Houston, TX
Tel: 281-894-5983
Indianapolis
Noblesville, IN
Tel: 317-773-8323
Fax: 317-773-5453
Los Angeles
Mission Viejo, CA
Tel: 949-462-9523
Fax: 949-462-9608
New York, NY
Tel: 631-435-6000
San Jose, CA
Tel: 408-735-9110
Canada - Toronto
Tel: 905-673-0699
Fax: 905-673-6509
DS20005308B-page 40
China - Chongqing
Tel: 86-23-8980-9588
Fax: 86-23-8980-9500
China - Hangzhou
Tel: 86-571-8792-8115
Fax: 86-571-8792-8116
China - Hong Kong SAR
Tel: 852-2943-5100
Fax: 852-2401-3431
China - Nanjing
Tel: 86-25-8473-2460
Fax: 86-25-8473-2470
China - Qingdao
Tel: 86-532-8502-7355
Fax: 86-532-8502-7205
China - Shanghai
Tel: 86-21-5407-5533
Fax: 86-21-5407-5066
China - Shenyang
Tel: 86-24-2334-2829
Fax: 86-24-2334-2393
China - Shenzhen
Tel: 86-755-8864-2200
Fax: 86-755-8203-1760
China - Wuhan
Tel: 86-27-5980-5300
Fax: 86-27-5980-5118
China - Xian
Tel: 86-29-8833-7252
Fax: 86-29-8833-7256
India - New Delhi
Tel: 91-11-4160-8631
Fax: 91-11-4160-8632
India - Pune
Tel: 91-20-3019-1500
Japan - Osaka
Tel: 81-6-6152-7160
Fax: 81-6-6152-9310
France - Paris
Tel: 33-1-69-53-63-20
Fax: 33-1-69-30-90-79
Germany - Dusseldorf
Tel: 49-2129-3766400
Japan - Tokyo
Tel: 81-3-6880- 3770
Fax: 81-3-6880-3771
Germany - Munich
Tel: 49-89-627-144-0
Fax: 49-89-627-144-44
Korea - Daegu
Tel: 82-53-744-4301
Fax: 82-53-744-4302
Germany - Pforzheim
Tel: 49-7231-424750
Korea - Seoul
Tel: 82-2-554-7200
Fax: 82-2-558-5932 or
82-2-558-5934
Italy - Milan
Tel: 39-0331-742611
Fax: 39-0331-466781
Italy - Venice
Tel: 39-049-7625286
Malaysia - Kuala Lumpur
Tel: 60-3-6201-9857
Fax: 60-3-6201-9859
Netherlands - Drunen
Tel: 31-416-690399
Fax: 31-416-690340
Malaysia - Penang
Tel: 60-4-227-8870
Fax: 60-4-227-4068
Poland - Warsaw
Tel: 48-22-3325737
Philippines - Manila
Tel: 63-2-634-9065
Fax: 63-2-634-9069
Singapore
Tel: 65-6334-8870
Fax: 65-6334-8850
Taiwan - Hsin Chu
Tel: 886-3-5778-366
Fax: 886-3-5770-955
Spain - Madrid
Tel: 34-91-708-08-90
Fax: 34-91-708-08-91
Sweden - Stockholm
Tel: 46-8-5090-4654
UK - Wokingham
Tel: 44-118-921-5800
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03/25/14
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