MCP16251/2
Low Quiescent Current, PFM/PWM Synchronous Boost Regulator
with True Output Disconnect or Input/Output Bypass Option
Features
• Up to 96% Typical Efficiency
• 650 mA Typical Peak Input Current Limit:
- I
OUT
> 100 mA @ 3.3V V
OUT
, 1.2V V
IN
- I
OUT
> 250 mA @ 3.3V V
OUT
, 2.4V V
IN
- I
OUT
> 225 mA @ 5.0V V
OUT
, 3.3V V
IN
• Low Device Quiescent Current:
- Output Quiescent Current: < 4 µA typical,
device is not switching (V
OUT
> V
IN
,
excluding feedback divider current)
- Input Sleep Current: 1 µA
- No Load Input Current: 14 µA typical
• Shutdown Current: 0.6 µA typical
• Low Start-Up Voltage: 0.82V, 1 mA load
• Low Operating Input Voltage: down to 0.35V
• Adjustable Output Voltage Range: 1.8V to 5.5V
• Maximum Input Voltage
V
OUT
< 5.5V
• Automatic PFM/PWM Operation:
- PWM Operation: 500 kHz
- PFM Output Ripple: 150 mV typical
• Feedback Voltage: 1.23V
• Internal Synchronous Rectifier
• Internal Compensation
• Inrush Current Limiting and Internal Soft Start
(1.5 ms typical)
• Selectable, Logic Controlled, Shutdown States:
- True Load Disconnect Option (MCP16251)
- Input-to-Output Bypass Option (MCP16252)
• Anti-Ringing Control
• Overtemperature Protection
• Available Packages:
- SOT-23, 6-Lead
- TDFN, 2 x 3 x 0.8 mm, 8-Lead
Applications
• One, Two and Three-Cell Alkaline and NiMH/NiCd
Portable Products
• Solar Cell Applications
• Personal Care and Medical Products
• Bias for Status LEDs
• Smartphones, MP3 Players, Digital Cameras
• Remote Controllers, Portable Instruments
• Wireless Sensors
• Bluetooth Headsets
• +3.3V to +5.0V Distributed Power Supply
General Description
The MCP16251/2 is a compact, high-efficiency, fixed
frequency, synchronous step-up DC-DC converter.
This family of devices provides an easy-to-use power
supply solution for applications powered by either
one-cell, two-cell or three-cell alkaline, NiCd, NiMH,
one-cell Li-Ion or Li-Polymer batteries.
Low-voltage technology allows the regulator to start-up
without high inrush current or output voltage overshoot
from a low-voltage input. High efficiency is
accomplished by integrating the low-resistance
N-Channel boost switch and synchronous P-Channel
switch. All compensation and protection circuitry are
integrated to minimize external components.
MCP16251/2 operates and consumes less than 14 µA
from battery after start-up, while operating at no load
(V
OUT
= 3.3V, V
IN
= 1.5V). The devices provide a true
disconnect from input to output (MCP16251) or an
input-to-output bypass (MCP16252), while in shutdown
(EN = GND). Both shutdown options consume less
than 0.6 µA from battery.
Output voltage is set by a small external resistor
divider. Two package options, SOT-23, 6-lead and
TDFN, 2 x 3 x 0.8 mm, 8-lead are available.
Package Types
MCP16251/2
6-Lead SOT-23
SW 1
GND 2
EN 3
6 V
IN
MCP16251/2
2x3x0.8 TDFN*
V
FB
1
EP
9
8 V
IN
7 V
OUTS
6 V
OUTP
5 SW
5 V
OUT
S
GND
2
P
GND
3
4 V
FB
EN 4
* Includes Exposed Thermal Pad (EP); see
Table 3-1.
2013 - 2016 Microchip Technology Inc.
DS20005173B-page 1
MCP16251/2
Typical Application
L
4.7 µH
V
OUT
V
IN
0.9V to 1.7V
V
IN
+
Alkaline
SW
3.3V / 75 mA
V
OUT
R
TOP
1.69 M
V
FB
R
BOT
1 M
C
OUT
10 µF
C
IN
4.7 µF
EN
-
GND
L
4.7 µH
V
OUT
5.0V / 200 mA
R
TOP
3.09 M
R
BOT
1 M
P
GND
S
GND
V
IN
3.0V to 4.2V
+
Li-Ion
SW V
OUTS
V
IN
V
OUTP
V
FB
C
IN
4.7 µF
EN
C
OUT
10 µF
-
100
95
90
Efficiency (%)
85
80
75
70
65
60
55
50
0.1
1
10
I
OUT
(mA)
100
V
OUT
= 3.3V
V
IN
= 1.5V
V
IN
= 2.4V
V
IN
= 3.0V
1000
DS20005173B-page 2
2013 - 2016 Microchip Technology Inc.
MCP16251/2
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
indicated in the operational sections of this
specification is not intended. Exposure to maximum
rating conditions for extended periods may affect
device reliability.
Absolute Maximum Ratings †
EN, V
FB
, V
IN,
V
SW
, V
OUT
- GND ......................... +6.5V
EN, V
FB
.........< maximum V
OUT
or V
IN
> (GND - 0.3V)
Output Short-Circuit Current ...................... Continuous
Output Current Bypass Mode........................... 400 mA
Power Dissipation ............................ Internally Limited
Storage Temperature ......................... -65°C to +150°C
Ambient Temp. with Power Applied...... -40°C to +85°C
Operating Junction Temperature........ -40°C to +125°C
ESD Protection On All Pins:
HBM ............................................................... 4 kV
MM ................................................................ 400V
DC CHARACTERISTICS
Electrical Characteristics:
Unless otherwise indicated, V
IN
= 1.5V, C
OUT
= C
IN
= 10 µF, L = 4.7 µH, V
OUT
= 3.3V,
I
OUT
= 0 mA, T
A
= +25°C.
Boldface
specifications apply over the T
A
range of -40°C to +85°C.
Parameters
Input Characteristics
Minimum Start-Up Voltage
Minimum Input Voltage
After Start-Up
Output Voltage Adjust
Range
Maximum Output Current
Feedback Voltage
Feedback Input
Bias Current
V
IN
V
IN
V
OUT
—
—
1.8
0.82
0.35
—
150
I
OUT
V
FB
I
VFB
100
1.1931
—
125
225
1.23
10
—
—
5.5
—
—
—
1.2669
—
V
nA
I
OUT
= 0 mA, device is not
switching, EN = V
IN
= 4.0V,
V
OUT
= 5.0V, does not
include feedback divider
current
(Note
3)
I
OUT
= 0 mA, EN = V
IN
(Note
3),
(Note
5)
I
OUT
= 0 mA,
device is switching
V
OUT
= EN = GND;
includes N-Channel and
P-Channel Switch Leakage
mA
V
V
V
Note 1
Note 1
V
OUT
V
IN
Note 2
1.2V V
IN
, 2.0V V
OUT
1.5V V
IN
, 3.3V V
OUT
3.3V V
IN
, 5.0V V
OUT
Sym.
Min.
Typ.
Max.
Units
Conditions
V
OUT
Quiescent Current
I
QOUT
—
4.0
8
µA
V
IN
Sleep Current
No Load Input Current
Quiescent Current –
Shutdown
Note 1:
2:
3:
4:
5:
I
QIN
I
IN0
I
QSHDN
—
—
—
1.0
14
0.6
2.3
25
—
µA
µA
µA
3.3 k resistive load, 3.3V
OUT
(1 mA).
For V
IN
> V
OUT
, V
OUT
will not remain in regulation.
I
QOUT
is measured at V
OUT,
V
OUT
is supplied externally for V
OUT
> V
IN
(device is not switching), I
QIN
is
measured at V
IN
pin during Sleep period, no load.
220 resistive load, 3.3V
OUT
(15 mA).
Determined by characterization, not production tested.
2013 - 2016 Microchip Technology Inc.
DS20005173B-page 3
MCP16251/2
DC CHARACTERISTICS (CONTINUED)
Electrical Characteristics:
Unless otherwise indicated, V
IN
= 1.5V, C
OUT
= C
IN
= 10 µF, L = 4.7 µH, V
OUT
= 3.3V,
I
OUT
= 0 mA, T
A
= +25°C.
Boldface
specifications apply over the T
A
range of -40°C to +85°C.
Parameters
NMOS Switch Leakage
PMOS Switch Leakage
NMOS Switch
ON Resistance
PMOS Switch
ON Resistance
NMOS Peak
Switch Current Limit
V
OUT
Accuracy
Line Regulation
Load Regulation
Maximum Duty Cycle
Switching Frequency
EN Input Logic High
EN Input Logic Low
EN Input Leakage Current
Soft Start Time
Thermal Shutdown
Die Temperature
Die Temperature
Hysteresis
Note 1:
2:
3:
4:
5:
Sym.
I
NLK
I
PLK
R
DS(ON)N
R
DS(ON)P
I
N(MAX)
V
OUT
%
(V
OUT
/V
OUT
)
/V
IN
V
OUT
/V
OUT
DC
MAX
f
SW
V
IH
V
IL
I
ENLK
t
SS
T
SD
T
SDHYS
Min.
—
—
—
—
—
-3
-0.4
-1.5
87
425
70
—
—
—
Typ.
0.15
0.15
0.45
0.9
650
—
0.3
0.1
89
500
—
—
5.0
—
Max.
—
—
—
—
—
+3
0.4
1.5
91
575
—
20
—
1.5
Units
µA
µA
mA
%
%/V
%
%
kHz
% of V
IN
I
OUT
= 1 mA
% of V
IN
I
OUT
= 1 mA
nA
ms
C
C
V
EN
= 5V
EN Low to High
90% of V
OUT
(Note
4),
(Note
5)
I
OUT
= 20 mA
V
IN
> 1.4V
Conditions
V
IN
= V
SW
= 5V
V
OUT
= 5.5V
V
EN
= V
FB
= GND
V
IN
= V
SW
= GND
V
OUT
= 5.5V
V
IN
= 3.3V
I
SW
= 100 mA
V
IN
= 3.3V
I
SW
= 100 mA
Note 5
Includes Line and Load
Regulation; V
IN
= 1.5V
V
IN
= 1.5V to 2.8V
I
OUT
= 50 mA
I
OUT
= 25 mA to 100 mA
V
IN
= 1.5V
Note 5
—
—
160
20
—
—
3.3 k resistive load, 3.3V
OUT
(1 mA).
For V
IN
> V
OUT
, V
OUT
will not remain in regulation.
I
QOUT
is measured at V
OUT,
V
OUT
is supplied externally for V
OUT
> V
IN
(device is not switching), I
QIN
is
measured at V
IN
pin during Sleep period, no load.
220 resistive load, 3.3V
OUT
(15 mA).
Determined by characterization, not production tested.
TEMPERATURE SPECIFICATIONS
Electrical Characteristics:
Unless otherwise indicated, V
IN
= 1.5V, C
OUT
= C
IN
= 10 µF, L = 4.7 µH, V
OUT
= 3.3V, I
OUT
= 0 mA.
Parameters
Temperature Ranges
Operating Temperature Range
Storage Temperature Range
Maximum Junction Temperature
Package Thermal Resistances
Thermal Resistance, SOT-23, 6-LD
Thermal Resistance, TDFN, 2x3x0.8m, 8-LD
JA
JA
—
—
190.5
52.5
—
—
°C/W EIA/JESD51-3 Standard
°C/W
T
J
T
A
T
J
-40
-65
—
—
—
—
+85
+150
+150
°C
°C
°C
Transient
Steady State
Sym.
Min.
Typ.
Max.
Units
Conditions
DS20005173B-page 4
2013 - 2016 Microchip Technology Inc.
MCP16251/2
2.0
Note:
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:
Unless otherwise indicated, V
IN
= EN = 1.5V, C
OUT
= C
IN
= 10 µF, L = 4.7 µH, V
OUT
= 3.3V, I
LOAD
= 0 mA,
T
A
= +25°C, SOT-23 package.
10
Quies
scent Current (uA)
8
6
4
2
0
-40
-25
-10
5
20
35
50
Ambient Temperature (°C)
65
80
V
OUT
= 3.3V
R
TOP
= 1.69 M
R
BOT
= 1.0 M
100
95
90
Efficiency (%)
85
80
75
70
65
60
55
50
1
10
I
OUT
(mA)
100
1000
V
IN
= 0.9V
V
IN
= 1.5V
V
IN
= 1.2V
V
OUT
= 2.0V
FIGURE 2-1:
Temperature.
30
No Load Input Current (µA)
25
20
15
10
5
0
V
OUT
= 3.3V
R
TOP
= 1.69 M
R
BOT
= 1.0 M
V
OUT
I
Q
vs. Ambient
FIGURE 2-4:
I
OUT
.
100
95
90
Efficiency (%)
85
80
75
70
65
60
55
V
OUT
= 3.3V
2.0V V
OUT
Efficiency vs.
V
IN
= 1.2V
V
IN
= 1.5V
V
IN
= 3.0V
V
IN
= 2.5V
V
IN
= 1.2V
V
IN
= 0.9V
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80
Ambient Temperature (°C)
1
10
I
OUT
(mA)
100
1000
FIGURE 2-2:
Temperature.
35
No Load Input Current (µA)
30
25
20
15
No Load Input Current vs.
FIGURE 2-5:
I
OUT
.
100
95
Efficiency (%)
90
85
80
75
70
65
V
OUT
= 5.0V
3.3V V
OUT
Efficiency vs.
R
BOT
= 1.0 M
V
IN
= 3.6V
V
IN
= 2.5V
V
OUT
= 5.0V
10
5
0
1
1.5
2
2.5
3
3.5
Input Voltage (V)
4
4.5
V
OUT
= 2.0V
V
OUT
= 3.3V
V
IN
= 1.2V
V
IN
= 1.8V
60
1
10
I
OUT
(mA)
100
1000
FIGURE 2-3:
No Load Input Current vs.
V
IN
, after Start-Up.
FIGURE 2-6:
I
OUT
.
5.0V V
OUT
Efficiency vs.
2013 - 2016 Microchip Technology Inc.
DS20005173B-page 5