MCP1642B/D
1.8A Input Current Switch, 1 MHz Low-Voltage Start-Up
Synchronous Boost Regulator
Features
• Up to 96% Typical Efficiency
• 1.8A Typical Peak Input Current Limit:
- I
OUT
> 175 mA @ 1.2V V
IN
, 3.3V V
OUT
- I
OUT
> 600 mA @ 2.4V V
IN
, 3.3V V
OUT
- I
OUT
> 800 mA @ 3.3V V
IN
, 5.0V V
OUT
- I
OUT
> 1A @ V
IN
> 3.6V, 5.0V V
OUT
• Low Start-Up Voltage: 0.65V, typical 3.3V V
OUT
@ 1 mA
• Low Operating Input Voltage: 0.35V, typical 3.3V
V
OUT
@ 1 mA
• Output Voltage Range:
- Reference Voltage, V
FB
= 1.21V
- 1.8V to 5.5V for the adjustable device option
- 1.8V, 3.0V, 3.3V and 5.0V for fixed V
OUT
options
• Maximum Input Voltage
V
OUT
< 5.5V
• PWM Operation: 1 MHz
- Low Noise, Anti-Ringing Control
• Power Good Open-Drain Output
• Internal Synchronous Rectifier
• Internal Compensation
• Inrush Current Limiting and Internal Soft-Start
• Selectable, Logic-Controlled Shutdown States:
- True Load Disconnect Option (MCP1642B)
- Input-to-Output Bypass Option (MCP1642D)
• Shutdown Current (All States): 1 µA
• Overtemperature Protection
• Available Packages:
- 8-Lead MSOP
- 8-Lead 2x3 DFN
General Description
The
MCP1642B/D
devices
are
compact,
high-efficiency, fixed-frequency, synchronous step-up
DC-DC converters. 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, Ultimate Lithium, 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 the number of external
components. An open-drain Power Good output is
provided to indicate when the output voltage is within
10% of regulation and facilitates the interface with an
MCU. For standby applications, MCP1642B provides a
“true output disconnect” from input to output while in
shutdown (EN = GND). An additional device option
(MCP1642D) is available and connects “input to output
bypass” while in shutdown. Both options consume less
than 1 µA of input current.
For the adjustable (ADJ) device options, the output
voltage is set by a small external resistor divider. Fixed
V
OUT
device options do not require external divider
resistors. Two package options, 8-lead MSOP and 8-
lead 2x3 DFN, are available.
Package Types
MCP1642B/D-xx
MSOP
EN 1
NC 2
PG 3
V
OUT
4
8 V
IN
7 S
GND
6 P
GND
5 SW
MCP1642B/D-xx
2x3 DFN*
EN 1
NC 2
PG 3
V
OUT
4
EP
9
8 V
IN
7 S
GND
6 P
GND
5 SW
Applications
• One, Two and Three-Cell Alkaline, Lithium
Ultimate and NiMH/NiCd Portable Products
• Single-Cell Li-Ion to 5V Converters
• PIC
®
MCU Power
• USB Emergency Backup Charger from Batteries
• Personal Medical Products
• Wireless Sensors
• Hand-Held Instruments
• GPS Receivers
• +3.3V to +5.0V Distributed Power Supply
MCP1642B/D-ADJ
MSOP
EN 1
V
FB
2
PG 3
V
OUT
4
8 V
IN
7 S
GND
6 P
GND
5 SW
MCP1642B/D-ADJ
2x3 DFN*
EN 1
V
FB
2
PG 3
V
OUT
4
EP
9
8 V
IN
7 S
GND
6 P
GND
5 SW
* Includes Exposed Thermal Pad (EP); see
Table 3-1.
2014 Microchip Technology Inc.
DS20005253A-page 1
MCP1642B/D
Typical Application
L
1
4.7 µH
C
IN
4.7...10 µF
V
IN
= 0.9 to 1.6V
ALKALINE
+
V
IN
NC
SW
V
OUT
V
OUT
3.3V
MCP1642B-33
PG
EN
ON
OFF
GND
C
OUT
4.7...10 µF
-
L
4.7 µH
V
OUT
C
IN
4.7...10 µF
SW
V
IN
ALKALINE
+
V
OUT
R
TOP
976 k
R
BOT
EN
ON
ALKALINE
+
OFF
From PIC
®
MCU I/O
GND
PG
To PIC MCU I/O
309 k
R
PG
1 M
C
OUT
4.7...10 µF
5.0V
V
IN
= 1.8 to 3.2V
MCP1642D-ADJ
V
FB
-
-
100
90
80
V
IN
= 1.2V, V
OUT
= 3.3V
Efficiency (%)
70
60
50
40
30
20
10
0
1
10
V
IN
= 2.5V, V
OUT
= 5.0V
100
I
OUT
(mA)
1000
DS20005253A-page 2
2014 Microchip Technology Inc.
MCP1642B/D
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, FB, V
IN,
V
SW
, V
OUT
– GND .......................... +6.5V
EN, FB ......<maximum of V
OUT
or V
IN
> (GND – 0.3V)
Output Short-Circuit Current ...................... Continuous
Output Current Bypass Mode........................... 800 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......................................................... 300V
DC CHARACTERISTICS
Electrical Characteristics:
Unless otherwise indicated, V
IN
= 1.2V, C
OUT
= C
IN
= 10 µF, L = 4.7 µH, V
OUT
= 3.3V,
I
OUT
= 15 mA, T
A
= +25°C, MCP1642B/D-ADJ.
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
(MCP1642B/D-ADJ)
Output Voltage
(MCP1642B/D-XX)
V
IN
V
IN
V
OUT
—
—
—
—
1.8
0.65
0.9
0.35
0.5
—
0.8
1.8
—
—
5.5
V
V
V
V
V
Note 1
MCP1642B/D-50,
Note 1
Note 1, Note 5
Note 1, Note 5,
MCP1642B/D-50
V
OUT
V
IN
(MCP1642B/D-ADJ);
Note 2
V
IN
< 1.8V, MCP1642B/D-18,
Note 2
V
IN
< 3.0V, MCP1642B/D-30,
Note 2
V
IN
< 3.3V, MCP1642B/D-33,
Note 2
V
IN
< 5.0V, MCP1642B/D-50,
Note 2
1.2V V
IN
, 1.8V V
OUT
,
Note 5
1.5V V
IN
, 3.3V V
OUT
,
Note 5
3.3V V
IN
, 5.0V V
OUT
,
Note 5
Note 5
Sym.
Min.
Typ.
Max.
Units
Conditions
V
OUT
—
—
—
—
1.8
3.0
3.3
5.0
175
300
800
1.21
1.0
—
—
—
—
—
—
—
1.247
—
V
V
V
V
mA
mA
mA
V
nA
Maximum Output Current
I
OUT
—
—
—
Feedback Voltage
Feedback Input
Bias Current
Note 1:
2:
3:
V
FB
I
VFB
1.173
—
4:
5:
Resistive load, 1 mA.
For V
IN
> V
OUT
, V
OUT
will not remain in regulation.
I
QPWM
is measured from V
OUT
; V
OUT
is externally supplied with a voltage higher than the nominal 3.3V
output (device is not switching), no load. V
IN
quiescent current will vary with boost ratio. V
IN
quiescent
current can be estimated by: (I
QPWM
* (V
OUT
/V
IN
)).
220 resistive load, 3.3V V
OUT
(15 mA).
Determined by characterization, not production tested.
2014 Microchip Technology Inc.
DS20005253A-page 3
MCP1642B/D
DC CHARACTERISTICS (CONTINUED)
Electrical Characteristics:
Unless otherwise indicated, V
IN
= 1.2V, C
OUT
= C
IN
= 10 µF, L = 4.7 µH, V
OUT
= 3.3V,
I
OUT
= 15 mA, T
A
= +25°C, MCP1642B/D-ADJ.
Boldface
specifications apply over the T
A
range of -40
°
C to +85
°
C.
Parameters
Quiescent Current –
PWM Mode
Quiescent Current –
Shutdown
NMOS Switch Leakage
Sym.
I
QPWM
I
QSHDN
Min.
—
—
Typ.
400
1
Max.
500
—
Units
µA
µA
Conditions
Measured at V
OUT
, EN = V
IN
,
I
OUT
= 0 mA,
Note 3
V
OUT
= EN = GND, I
OUT
= 0 mA
includes N-Channel and
P-Channel Switch Leakage
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
= 250 mA,
Note 5
V
IN
= 3.3V, I
SW
= 250 mA,
Note 5
Note 5
MCP1642B/D-ADJ, V
IN
= 1.2V
MCP1642B/D-18, V
IN
= 1.2V
MCP1642B/D-30, V
IN
= 1.2V
MCP1642B/D-33, V
IN
= 1.2V
MCP1642B/D-50, V
IN
= 2.5V
MCP1642B/D-ADJ,
V
IN
= 1.5V to 3.0V, I
OUT
= 25 mA
MCP1642B/D-18,
V
IN
= 1.0V to 1.5V, I
OUT
= 25 mA
MCP1642B/D-30,
V
IN
= 1.5V to 2.5V, I
OUT
= 25 mA
MCP1642B/D-33,
V
IN
= 1.5V to 3.0V, I
OUT
= 25 mA
MCP1642B/D-50,
V
IN
= 2.5V to 4.2V, I
OUT
= 25 mA
I
OUT
= 25 mA to 150 mA,
V
IN
= 1.5V
MCP1642B/D-18, V
IN
= 1.5V,
I
OUT
= 25 mA to 75 mA
MCP1642B/D-30, V
IN
= 1.5V,
I
OUT
= 25 mA to 125 mA
MCP1642B/D-33, V
IN
= 1.5V,
I
OUT
= 25 mA to 150 mA
MCP1642B/D-50, V
IN
= 3.0V,
I
OUT
= 25 mA to 500 mA,
Note 5
I
NLK
—
0.5
—
µA
PMOS Switch Leakage
NMOS Switch
ON Resistance
PMOS Switch
ON Resistance
NMOS Peak
Switch Current Limit
Accuracy
I
PLK
R
DS(ON)N
R
DS(ON)P
I
N(MAX)
V
FB
%
V
OUT
%
—
—
—
—
-3
-3
-3
-3
-3
0.2
0.15
0.3
1.8
—
—
—
—
—
0.01
0.05
0.01
0.01
0.01
0.05
0.1
0.1
0.1
0.5
—
—
—
—
3
3
3
3
3
0.5
0.5
0.5
0.5
0.5
1.5
1.5
1.5
1.5
—
µA
A
%
%
%
%
%
%/V
%/V
%/V
%/V
%/V
%
%
%
%
%
Line Regulation
V
FB
/V
FB
)
/V
IN
|
V
OUT
/V
OUT
)
/V
IN
|
-0.5
-0.5
-0.5
-0.5
-0.5
Load Regulation
V
FB
/V
FB
|
V
OUT
/V
OUT
|
-1.5
-1.5
-1.5
-1.5
—
Note 1:
2:
3:
4:
5:
Resistive load, 1 mA.
For V
IN
> V
OUT
, V
OUT
will not remain in regulation.
I
QPWM
is measured from V
OUT
; V
OUT
is externally supplied with a voltage higher than the nominal 3.3V
output (device is not switching), no load. V
IN
quiescent current will vary with boost ratio. V
IN
quiescent
current can be estimated by: (I
QPWM
* (V
OUT
/V
IN
)).
220 resistive load, 3.3V V
OUT
(15 mA).
Determined by characterization, not production tested.
2014 Microchip Technology Inc.
DS20005253A-page 4
MCP1642B/D
DC CHARACTERISTICS (CONTINUED)
Electrical Characteristics:
Unless otherwise indicated, V
IN
= 1.2V, C
OUT
= C
IN
= 10 µF, L = 4.7 µH, V
OUT
= 3.3V,
I
OUT
= 15 mA, T
A
= +25°C, MCP1642B/D-ADJ.
Boldface
specifications apply over the T
A
range of -40
°
C to +85
°
C.
Parameters
Maximum Duty Cycle
Switching Frequency
EN Input Logic High
EN Input Logic Low
EN Input Leakage Current
Power Good Threshold
Power Good Hysteresis
Power Good Output Low
Power Good Output Delay
Power Good Output
Response
Power Good Input Voltage
Operating Range
Power Good
Leakage Current
Soft Start Time
Thermal Shutdown
Die Temperature
Die Temperature
Hysteresis
Note 1:
2:
3:
Sym.
DC
MAX
f
SW
V
IH
V
IL
I
ENLK
PG
THF
PG
HYS
PG
LOW
PG
DELAY
PG
RES
V
PG_VIN
PG
LEAK
t
SS
T
SD
T
SDHYS
Min.
—
0.85
75
—
—
—
—
—
—
—
0.9
—
—
—
—
Typ.
90
1.0
—
—
0.1
90
3
0.4
600
250
—
0.01
550
150
35
Max.
—
1.15
—
20
—
—
—
—
—
—
5.5
—
—
—
—
Units
%
MHz
Note 5
Note 5,
I
OUT
= 65 mA,
for MCP1642B/D-50 V
IN
= 2.5V
Conditions
% of V
IN
I
OUT
= 1 mA,
for MCP1642B/D-50 V
IN
= 2.5V
% of V
IN
I
OUT
= 1 mA,
for MCP1642B/D-50 V
IN
= 2.5V
µA
%
%
V
µs
µs
V
µA
µs
C
C
V
EN
= 1.2V
V
FB
Falling,
Note 5
Note 5
I
SINK
= 5 mA, V
FB
= 0V,
Note 5
Note 5
Note 5
I
SINK
= 5 mA, V
FB
= 0V,
Note 5
V
PG
= 5.5V,
V
OUT
in Regulation,
Note 5
EN Low to High,
90% of V
OUT
,
Note 4, Note 5
Note 5
Note 5
4:
5:
Resistive load, 1 mA.
For V
IN
> V
OUT
, V
OUT
will not remain in regulation.
I
QPWM
is measured from V
OUT
; V
OUT
is externally supplied with a voltage higher than the nominal 3.3V
output (device is not switching), no load. V
IN
quiescent current will vary with boost ratio. V
IN
quiescent
current can be estimated by: (I
QPWM
* (V
OUT
/V
IN
)).
220 resistive load, 3.3V V
OUT
(15 mA).
Determined by characterization, not production tested.
TEMPERATURE SPECIFICATIONS
Electrical Characteristics:
Unless otherwise indicated, V
IN
= 1.2V, C
OUT
= C
IN
= 10 µF, L = 4.7 µH, V
OUT
= 3.3V,
I
OUT
= 15 mA, T
A
= +25°C.
Parameters
Temperature Ranges
Operating Ambient Temperature
Range
Storage Temperature Range
Maximum Junction Temperature
Package Thermal Resistances
Thermal Resistance, 8L-MSOP
Thermal Resistance, 8L-2x3 DFN
JA
JA
—
—
211
68
—
—
°C/W
°C/W
T
A
T
A
T
J
-40
-65
—
—
—
—
+85
+150
+150
°C
°C
°C
Transient
Steady State
Sym.
Min.
Typ.
Max.
Units
Conditions
2014 Microchip Technology Inc.
DS20005253A-page 5
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