MICROCHIP MCP1252

MCP1252/3
Low Noise, Positive-Regulated Charge Pump
Features
Description
• Inductorless, Buck/Boost, DC/DC Converter
• Low Power: 80 µA (Typical)
• High Output Voltage Accuracy:
- ±2.5% (VOUT Fixed)
• 120 mA Output Current
• Wide Operating Temperature Range:
- -40°C to +85°C
• Thermal Shutdown and Short-Circuit Protection
• Uses Small Ceramic Capacitors
• Switching Frequency:
- MCP1252: 650 kHz
- MCP1253: 1 MHz
• Low Power Shutdown Mode: 0.1 µA (Typical)
• Shutdown Input Compatible with 1.8V Logic
• VIN Range: 2.0V to 5.5V
• Selectable Output Voltage (3.3V or 5.0V) or
Adjustable Output Voltage
• Space-saving, 8-Lead MSOP
• Soft-Start Circuitry to Minimize In-Rush Current
The MCP1252/3 are inductorless, positive-regulated
charge pump DC/DC converters. The devices generate
a regulated fixed (3.3V or 5.0V) or adjustable output
voltage. They are specifically designed for applications
requiring low noise and high efficiency and are able to
deliver up to 120 mA output current. The devices allow
the input voltage to be lower or higher than the output
voltage, by automatically switching between buck/
boost operation.
Applications
•
•
•
•
•
•
•
White LED Backlighting
Color Display Bias
Local 3V-to-5V Conversions
Flash Memory Supply Voltage
SIM Interface Supply for GSM Phones
Smart Card Readers
PCMCIA Local 5V Supplies
The MCP1252 has a switching frequency of 650 kHz,
avoiding interference with sensitive IF bands. The
MCP1253 has a switching frequency of 1 MHz and
allows the use of smaller capacitors than the
MCP1252, thus saving board space and cost.
Both devices feature a power-good output that can be
used to detect out-of-regulation conditions. Extremely
low supply current and low external parts count (three
capacitors) make these devices ideal for small, batterypowered applications. A shutdown mode is also provided for further power reduction. The MCP1252 and
MCP1253 feature thermal and short-circuit protection
and are offered in space-saving, 8-lead, MSOP
packages.
Package Types
MSOP (FIXED)
PGOOD
1
VOUT
2
VIN
3
GND
4
8
SELECT
MCP1252
7
SHDN
MCP1253
6
C+
5
C-
MSOP (ADJUSTABLE)
1
8
FB
VOUT
2 MCP1252
7
SHDN
VIN
3 MCP1253
6
C+
4
5
C-
PGOOD
GND
 2002-2013 Microchip Technology Inc.
DS21752B-page 1
MCP1252/3
Functional Block Diagram
MCP1252-33X50
MCP1253-33X50
PGOOD
140 k
SELECT
+
-
173 k
84 mV
+
1.21V
+
100 k
+
+
VOUT
200 mV
+
SHDN
C+
C-
Switch
Control
VIN
GND
MCP1252-ADJ
MCP1253-ADJ
PGOOD
FB
+
84 mV
+
1.21V
+
+
+
VOUT
200 mV
+
Switch
Control
SHDN
C+
C-
VIN
GND
DS21752B-page 2
 2002-2013 Microchip Technology Inc.
MCP1252/3
1.0
ELECTRICAL
CHARACTERISTICS
PIN FUNCTION TABLE
Name
Function
Absolute Maximum Ratings †
PGOOD
Open-Drain Power GOOD Output
Power Supply Voltage, VIN ...............................................6.0V
VOUT
Regulated Output Voltage
Voltage on Any Pin w.r.t. GND ............... -0.3V to (VIN + 0.3V)
VIN
Power Supply Input
Output Short Circuit Duration ................................continuous
GND
Ground Terminal
Storage Temperature Range .........................-65°C to +150°C
C-
Flying Capacitor Negative Terminal
Ambient Temperature with Power Applied ....-55°C to +125°C
C+
Flying Capacitor Positive Terminal
Junction Temperature ................................................. +150°C
SHDN
Shutdown Mode, Active-Low Input
ESD Ratings:
SELECT
Output Voltage Select Pin.
(MCP1252-33X50, MCP1253-33X50)
FB
Feedback Input Pin for Adjustable Output
(MCP1252-ADJ, MCP1253-ADJ)
Human Body Model (1.5 k in Series with 100 pF 4 kV
Machine Body Model (200 pF, No Series Resistance400V
†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 listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may
affect device reliability.
ELECTRICAL CHARACTERISTICS
Electrical Specifications: Unless otherwise specified, all limits are specified for TA = -40°C to +85°C, SHDN = VIN,
CIN = COUT = 10 µF, CFLY = 1 µF, IOUT = 10 mA. Typical values are for TA = +25°C.
Parameters
Sym
Min
Typ
Max
Units
Conditions
Selectable Output - MCP1252-33X50, MCP1253-33X50: SELECT = VIN, VOUT = 3.3V
VIN
2.1
—
5.5
V
Output Voltage Accuracy
VOUT
-2.5
+/-0.5
+2.5
%
Output Current
IOUT
80
120
100
150
—
mA
mA
SELECT Logic Input Voltage High
VIH
1.4
—
—
V
Supply Voltage
2.3V  VIN < 2.5V, IOUT 80 mA
2.5V VIN 5.5V, IOUT120 mA
2.3V  VIN < 2.5V
2.5V  VIN  5.5V
MCP1252-33X50, MCP1253-33X50
Selectable Output - MCP1252-33X50, MCP1253-33X50: SELECT = GND, VOUT = 5.0V
Supply Voltage
VIN
2.7
—
5.5
V
Output Voltage Accuracy
VOUT
-2.5
+/-0.5
+2.5
%
Output Current
IOUT
40
120
80
150
—
mA
mA
VIL
—
—
0.4
V
V
SELECT Logic Input Voltage Low
2.7V VIN < 3.0V, IOUT 40 mA
3.0V VIN5.5V, IOUT120 mA
2.7V  VIN < 3.0V
3.0V  VIN  5.5V
MCP1252-33X50, MCP1253-33X50
Adjustable Output - MCP1252-ADJ, MCP1253-ADJ
VIN
2.0
—
5.5
VOUT
1.5
—
5.5
V
VOUT(MAX) < 2 x VIN
VFB
1.18
1.21
1.24
V
MCP1252-ADJ, MCP1253-ADJ
Supply Current
IDD
—
60
120
µA
No load
Output Short-Circuit Current
ISC
—
200
—
mA
VOUT = GND, foldback current
ISHDN
—
0.1
2.0
µA
SHDN = 0V

—
81
68
—
%
%
VIN = 3.0V, VOUT = 5V
VIN = 3.6V, VOUT = 5V
IOUT =120 mA
Supply Voltage
Output Voltage Adjustment Range
FB Regulation Voltage
ALL DEVICES
Shutdown Current
Power Efficiency
SHDN Logic Input Voltage Low
VIL
—
—
0.4
V
SHDN Logic Input Voltage High
VIH
1.4
—
—
V
PGOOD Threshold Voltage
VTH
—
0.93VOUT
—
V
PGOOD Hysteresis
VHYS
—
0.04VOUT
—
V
 2002-2013 Microchip Technology Inc.
DS21752B-page 3
MCP1252/3
AC CHARACTERISTICS
Electrical Specifications: Unless otherwise specified, all limits are specified for TA = -40°C to +85°C,
VIN = 2.7V to 5.5V, SELECT = GND, SHDN = VIN, CIN = COUT = 10 µF, CFLY = 1 µF, IOUT = 10 mA.
Typical values are for TA = +25°C.
Parameters
Sym
Min
Typ
Max
Units
Internal Oscillator Frequency
FOSC
520
800
650
1000
780
1200
kHz
kHz
MCP1252
MCP1253
Ripple Voltage
VRIP
—
50
45
—
mVp-p
mVp-p
MCP1252
MCP1253
—
200
300
—
µsec
µsec
SELECT = VIN
SELECT = GND
VIN = 3.6V, IOUT = 10 mA,
SHDN = VIH(MIN),
VOUT from 0 to 90% Nominal
Regulated Output Voltage
VOUT Wake-Up Time From Shutdown TWKUP
Conditions
TEMPERATURE SPECIFICATIONS
Parameters
Symbol
Min
Typ
Max
Units
Specified Temperature Range
TA
-40
—
+85
°C
Maximum Operating Junction
Temperature
TJ
—
—
+125
°C
Storage Temperature Range
TA
-65
—
+150
°C
JA
—
206
—
°C/W
Conditions
Temperature Ranges:
Thermal Package Resistances:
Thermal Resistance, 8 Pin MSOP
DS21752B-page 4
Single-Layer SEMI G42-88
Board, Natural Convection
 2002-2013 Microchip Technology Inc.
MCP1252/3
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, VIN = 3.6V, TA = 25°C, CIN = COUT = 10 µF, CFLY = 1 µF, all capacitors X7R ceramic.
5.04
10 mA
5.03
5.02
80 mA
120 mA
5.01
MCP1252-33X50
SELECT = GND
VOUT = 5.0V
5.00
Percent Efficiency (%)
Output Voltage (V)
5.05
4.99
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
100
90
80
70
60
50
40
30
20
10
0
10 mA
MCP1252-33X50
SELECT = GND
VOUT = 5.0V
2.0
6.0
80 mA
120 mA
2.5
3.0
Supply Voltage (V)
3.5
4.0
4.5
5.0
5.5
6.0
Supply Voltage (V)
FIGURE 2-1:
Output Voltage vs. Supply
Voltage (MCP1252-33X50).
FIGURE 2-4:
Percent Efficiency vs.
Supply Voltage (MCP1252-33X50).
.
Power Efficiency (%)
Output Voltage (V)
3.34
80 mA
3.33
120 mA
3.32
10 mA
MCP1252-33X50
SELECT = VIN
VOUT = 3.3V
3.31
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
100
90
80
70
60
50
40
30
20
10
0
10 mA
80 mA
120 mA
MCP1252-33X50
SELECT = VIN
VOUT = 3.3V
2.0
6.0
2.5
3.0
Supply Voltage (V)
FIGURE 2-2:
Output Voltage vs. Supply
Voltage (MCP1252-33X50).
10 mA
80 mA
MCP1252-ADJ
VOUT = 3.0V
2.99
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
Supply Voltage (V)
FIGURE 2-3:
Output Voltage vs. Supply
Voltage (MCP1252-ADJ).
 2002-2013 Microchip Technology Inc.
Power Efficiency (%)
Output Voltage (V)
3.01
120 mA
4.0
4.5
5.0
5.5
6.0
FIGURE 2-5:
Power Efficiency vs. Supply
Voltage (MCP1252-33X50).
3.02
3.00
3.5
Supply Voltage (V)
100
90
80
70
60
50
40
30
20
10
0
10 mA
80 mA
120 mA
MCP1252-ADJ
VOUT = 3.0V
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
Supply Voltage (V)
FIGURE 2-6:
Power Efficiency vs. Supply
Voltage (MCP1252-ADJ).
DS21752B-page 5
MCP1252/3
Note: Unless otherwise indicated, VIN = 3.6V, TA = 25°C, CIN = COUT = 10 mF, CFLY = 1 mF, all capacitors X7R ceramic.
80
Output Voltage (V)
MCP1253-33X50
5.02
5.01
MCP1252-33X50
5.00
SELECT = GND
VOUT = 5.0V
IOUT = 120 mA
4.99
Supply Current (uA)
5.03
VIN = 5.5V
75
70
VIN = 3.6V
65
VIN = 2.7V
60
55
VIN = 2.3V
50
45
40
4.98
-40 -25 -10 5
-40 -25 -10
20 35 50 65 80 95 110 125
5
FIGURE 2-7:
Output Voltage vs.
Temperature (MCP1252-33X50,
MCP1253-33X50).
FIGURE 2-10:
Quiescent Current vs.
Temperature (MCP1253-33X50).
3.33
3.32
3.31
MCP1252-33X50
3.30
SELECT = VIN
VOUT = 3.3V
IOUT = 120 mA
3.29
3.28
Supply Current (uA)
80
MCP1253-33X50
20 35 50 65 80 95 110 125
Temperature (°C)
Temperature (°C)
Output Voltage (V)
MCP1253-33X50
SELECT = GND
VOUT = 5.0V, IOUT = 0 mA
75
70
VIN = 5.5V
VIN = 3.6V
65
60
VIN = 2.7V
55
50
MCP1252-33X50
SELECT = GND
VOUT = 5.0V, IOUT = 0 mA
VIN = 2.3V
45
40
-40 -25 -10 5
20 35 50 65 80 95 110 125
-40 -25 -10
Temperature (°C)
5
20 35 50 65 80 95 110 125
Temperature (°C)
FIGURE 2-8:
Output Voltage vs.
Temperature (MCP1252-33X50,
MCP1253-33X50).
FIGURE 2-11:
Quiescent Current vs.
Temperature (MCP1252-33X50).
FIGURE 2-9:
FIGURE 2-12:
DS21752B-page 6
Line Transient Response.
Load Transient Response.
 2002-2013 Microchip Technology Inc.
MCP1252/3
Output Voltage Ripple (mV)
Note: Unless otherwise indicated, VIN = 3.6V, TA = 25°C, CIN = COUT = 10mF, CFLY = 1mF, all capacitors X7R ceramic.
70
60
50
40
30
80 mA
10 mA
120 mA
20
MCP1252-33X50
SELECT = GND
VOUT = 5.0V
10
0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
Supply Voltage (V)
FIGURE 2-13:
Output Voltage Ripple vs.
Supply Voltage (MCP1252-33X50).
FIGURE 2-16:
Time.
Output Voltage Ripple vs.
FIGURE 2-14:
Output Voltage Ripple vs.
Supply Voltage (MCP1252-33X50).
FIGURE 2-17:
Time.
Output Voltage Ripple vs.
FIGURE 2-15:
FIGURE 2-18:
Start-Up (MCP1253-33X50).
Output Voltage Ripple (mV)
70
60
50
40
30
120 mA
80 mA
10 mA
MCP1252-33X50
SELECT = VIN
VOUT = 3.3V
20
10
0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
Supply Voltage (V)
Start-Up (MCP1252-33X50).
 2002-2013 Microchip Technology Inc.
DS21752B-page 7
MCP1252/3
3.0
PIN FUNCTIONS
TABLE 3-1:
Pin
No.
1
3.6
PIN FUNCTION TABLE
Name
Function
PGOOD Open-Drain Power GOOD Output
2
VOUT
3
VIN
4
GND
5
C-
Flying Capacitor Negative Terminal
6
C+
Flying Capacitor Positive Terminal
7
8
3.7
Ground Terminal
A logic-low signal applied to SHDN disables the device.
A logic-high signal applied to this pin allows normal
operation.
Feedback Input Pin for Adjustable Output
(MCP1252-ADJ, MCP1253-ADJ)
Open-Drain Power Good Output
(PGOOD)
PGOOD is a high-impedance when the output voltage
is in regulation. A logic-low is asserted when the output
falls 7% (typical) below the nominal value. The PGOOD
output remains low until VOUT is within 3% (typical) of
its nominal value. On start-up, this pin indicates when
the output voltage reaches its final value. PGOOD is
high-impedance when SHDN is low.
3.2
Proper orientation is imperative when using a polarized
capacitor.
Power Supply Input
(MCP1252-33X50, MCP1253-33X50)
3.1
The charge pump capacitor (flying capacitor) is used to
transfer charge from the input supply to the regulated
output.
Regulated Output Voltage
SHDN Shutdown Mode, Active-Low Input
SELECT Output Voltage Select Pin.
FB
Flying Capacitor Positive Terminal
(C+)
3.8
Shutdown Input (SHDN)
Select (SELECT) Input or
Feedback (FB) Input
MCP1252-33X50, MCP1253-33X50:
SELECT: Select Input Pin.
Connect SELECT to VIN for 3.3V fixed output. Connect
SELECT to GND for a 5.0V fixed output.
MCP1252-ADJ, MCP1253-ADJ:
FB: Feedback Pin.
A resistor divider connected to this pin determines the
adjustable VOUT value (1.5V to 5.5V).
Regulated Output Voltage (VOUT)
Bypass to GND with a filter capacitor.
3.3
Power Supply Input (VIN)
It is recommended that VIN be tied to a ceramic bypass
capacitor.
3.4
Ground (GND)
It is recommended that the ground pin be tied to a
ground plane for best performance.
3.5
Flying Capacitor Negative
Terminal (C-)
The charge pump capacitor (flying capacitor) is used to
transfer charge from the input supply to the regulated
output.
It is recommended that a low ESR (equivalent series
resistance) capacitor be used.
DS21752B-page 8
 2002-2013 Microchip Technology Inc.
MCP1252/3
4.0
DEVICE OVERVIEW
4.1
Theory of Operation
The MCP1252 and MCP1253 family of devices employ
a switched capacitor charge pump to buck or boost an
input supply voltage (VIN) to a regulated output voltage.
Referring to the Functional Block Diagram and
Figure 4-1, the devices perform conversion and regulation in three phases. When the devices are not in shutdown mode and a steady-state condition has been
reached, the three phases are continuously cycled
through. The first phase transfers charge from the input
to the flying capacitor (CFLY) connected to pins C+ and
C-. This phase always occurs for half of the internal
oscillator period. During this phase, switches S1 and S2
are closed.
START
PHASE 1:
Charge Transfer
From VIN to CFLY
No
Yes
PHASE 2:
Idle State
Once the first phase is complete, all switches are
opened and the second phase (idle phase) is entered.
The device compares the internal or external feedback
voltage with an internal reference. If the feedback voltage is below the regulation point, the device transitions
to the third phase.
VFB > VREF
The devices automatically transition between buck or
boost operation. This provides a low-cost, compact and
simple solution for step-down/step-up DC/DC conversion. This is especially true for battery-operated applications that require a fixed output above or below the
input.
 2002-2013 Microchip Technology Inc.
Yes
No
The third phase transfers energy from the flying capacitor to the output capacitor connected to VOUT and the
load. If regulation is maintained, the device returns to
the idle phase. If the charge transfer occurs for half the
internal oscillator period, more charge is needed in the
flying capacitor and the device transitions back to the
first phase.
The regulation control is hysteretic, otherwise referred
to as a bang-bang control. The output is regulated
around a fixed reference with some hysteresis. As a
result, typically 50 mV of peak-to-peak ripple will be
observed at the output independent of load current.
The frequency of the output ripple, however, will be
influenced heavily by the load current and output
capacitance. The maximum frequency that will be
observed is equal to the internal oscillator frequency.
1
t1 = 2FOSC
PHASE 3:
Charge Transfer
From CFLY to COUT
1
t3 = 2FOSC
Yes
No
No
VFB > VREF
Yes
FIGURE 4-1:
Flow Algorithm.
DS21752B-page 9
MCP1252/3
4.2
Power Efficiency
4.6
Thermal Shutdown
The power efficiency, , is determined by the mode of
operation. In boost mode, the efficiency is approximately half of a linear regulator. In buck mode, the efficiency is approximately equal to that of a linear
regulator. The following formulas can be used to
approximate the power efficiency with any significant
amount of output current. At light loads, the quiescent
current of the device must be taken into consideration.
The MCP1252 and MCP1253 feature thermal shutdown with temperature hysteresis. When the die temperature exceeds 160°C, typically, the device shuts
down. When the die cools by 15°C, typically, the device
automatically turns back on. If high die temperature is
caused by output overload and the load is not removed,
the device will turn on and off, resulting in a pulse output.
EQUATION
5.0
 BOOST
POUT
V OUT  I OUT
VOUT
= ------------= -----------------------------------= ----------------VIN  2  IOUT
PIN
V IN  2
POUT
VOUT  I OUT
VOUT
= ------------------------------ BUCK = ------------- = ------------V IN  I OUT
P IN
V IN
APPLICATIONS
The MCP1252 and MCP1253 are inductorless, positive
regulated, charge pump DC/DC converters. A typical
circuit configuration for the fixed output version is
depicted in Figure 5-1. The adjustable version is
depicted in Figure 5-2.
SELECTABLE OUTPUT VOLTAGE
MCP1252-33X50
6
4.3
Shutdown Mode
Driving SHDN low places the MCP1252 or MCP1253 in
a low power shutdown mode. This disables the charge
pump switches, oscillator and control logic, reducing
the quiescent current to 0.1 µA (typical). The PGOOD
output is in a high-impedance state during shutdown.
4.4
PGOOD Output
The PGOOD output is an open-drain output that sinks
current when the regulator output voltage falls below
0.93VOUT (typical). The output voltage can either be
fixed when the selectable output device is chosen
(MCP1252-33X50, MCP1253-33X50) or adjustable
from an external resistive divider when the adjustable
device is chosen (MCP1252-ADJ, MCP1253-ADJ). If
the regulator output voltage falls below 0.93VOUT (typical) for less than 200 µsec and then recovers, glitchimmunity circuits prevent the PGOOD signal from transitioning low. A 10 k to 1 M pull-up resistor from
PGOOD to VOUT may be used to provide a logic output.
Connect PGOOD to GND or leave unconnected if not
used.
4.5
CFLY
Soft-Start and Short-Circuit
Protection
The MCP1252 and MCP1253 features foldback shortcircuit protection. This circuitry provides an internal
soft-start function by limiting in-rush current during
startup and also limits the output current to 200 mA
(typical) if the output is shorted to GND. The internal
soft-start circuitry requires approximately 300 µsec,
typical with a 5V output, from either initial power-up or
release from shutdown for the output voltage to be in
regulation.
DS21752B-page 10
5
2.7V to 5.5V
C+
+5.0V ±2.5%
VOUT 2
+
C-
RPU
3 V
IN
+
PGOOD
CIN
7
SELECT
SHDN
ON
1
8
GND
4
OFF
Shutdown
Control
COUT
PGOOD Flag
To PIC®
Microcontroller
CFLY = 1 µF
CIN = 10 µF
COUT = 10 µF
RPU = 100 k
FIGURE 5-1:
Typical Circuit Configuration
for Fixed Output Device.
ADJUSTABLE OUTPUT VOLTAGE
MCP1252-ADJ
6
CFLY
5
2.7V to 5.5V
+
7
ON
VOUT 2
+4.0V
RPU
C-
3 V
IN
CIN
OFF
Shutdown
Control
C+
+ COUT
R1
PGOOD 1
SHDN
GND
4
FB 8
VOUT = 1.21V (1 + R1/R2)
PGOOD Flag
To PIC®
Microcontroller
R2
CFLY = 1 µF
CIN = 10 µF
COUT = 10 µF
RPU = 100 k
R1 = 23.2 k
R2 = 10 k
FIGURE 5-2:
Typical Circuit Configuration
for Adjustable Output Device.
 2002-2013 Microchip Technology Inc.
MCP1252/3
5.1
Capacitor Selection
The style and value of capacitors used with the
MCP1252 and MCP1253 family of devices determine
several important parameters such as output voltage
ripple and charge pump strength. To minimize noise
and ripple, it is recommended that low ESR (0.1 )
capacitors be used for both CIN and COUT. These
capacitors should be either ceramic or tantalum and
should be 10 µF or higher. Aluminum capacitors are not
recommended because of their high ESR.
If the source impedance to VIN is very low, up to several
megahertz, CIN may not be required. Alternatively, a
somewhat smaller value of CIN may be substituted for
the recommended 10 µF, but will not be as effective in
preventing ripple on the VIN pin.
The value of COUT controls the amount of output voltage ripple present on VOUT. Increasing the size of
COUT will reduce output ripple at the expense of a
slower turn-on time from shutdown and a higher in-rush
current.
The flying capacitor (CFLY) controls the strength of the
charge pump. In order to achieve the maximum rated
output current (120 mA), it is necessary to have at least
1 µF of capacitance for the flying capacitor. A smaller
flying capacitor delivers less charge per clock cycle to
the output capacitor, resulting in lower output ripple.
The output ripple is reduced at the expense of maximum output current and efficiency.
5.2
Output Voltage Setting
The MCP1252-33X50 and MCP1253-33X50 feedback
controllers select between an internally-set, regulated
output voltage (3.3V or 5.0V). Connect SELECT to
GND for a regulated 5.0V output and connect SELECT
to VIN for a regulated 3.3V output.
Note that the tolerance of the external resistors will
have an effect on the accuracy of the output voltage.
For optimum results, it is recommended that the
external resistors have a tolerance no larger than 1%.
5.3
Recommended Layout
The MCP1252 and MCP1253 family of devices transfer
charge at high switching frequencies, producing fast,
high peak, transient currents. As a result, any stray
inductance in the component layout will produce
unwanted noise in the system. Proper board layout
techniques are required to ensure optimum performance. Figure 5-3 depicts the recommended board
layout. The input capacitor connected between VIN and
GND, and the output capacitor connected between
VOUT and GND, are 10 µF ceramic, X7R dielectric, in
1206 packages. The flying capacitor connected
between C+ and C- is a 1 µF ceramic, X7R dielectric in
a 0805 package. The layout is scaled 3:1.
PGOOD
VOUT
SELECT
SHDN
C+
GND
C-
VIN
FIGURE 5-3:
Recommended Printed
Circuit Board Layout.
The MCP1252-ADJ and MCP1253-ADJ utilize an
external resistor divider that allows the output voltage
to be adjusted between 1.5V and 5.5V. For an adjustable output, connect a resistor between VOUT and FB
(R1) and another resistor between FB and GND (R2). In
the following equation, choose R2 to be less than or
equal to 30 k and calculate R1 from the following
formula:
EQUATION
R 1 = R 2   V OUT  V FB  – 1 
and
EQUATION
V OUT = V FB  1 + R 1  R 2 
where:
VOUT is the desired output voltage from 1.5V to 5.5V
VFB is the internal regulation voltage, nominally 1.21V
 2002-2013 Microchip Technology Inc.
DS21752B-page 11
MCP1252/3
6.0
TYPICAL APPLICATION CIRCUITS
Single Cell Lithium-Ion Battery To 5V Converter
1 µF
5
6
C3
Single
Li-Ion
Cell
+ 10 µF
-
7
100 k
1
C+
VIN
VOUT
SHDN
SELECT
PGOOD
GND
2
8
5V
10 µF
4
MCP1252-33X50
White LED Bias
1 µF
5
6
C-
C+
UP TO 6 WHITE LEDS
3
Single
Li-Ion
Cell
+ 10 µF
-
7
100 k
1
VIN
VOUT
SHDN
SELECT
PGOOD
GND
2
8
10 µF
59  59  59  59  59  59 
4
MCP1252-ADJ
PWM Contrast
Control
Alternative White LED Bias
1 µF
5
C-
6
C+
UP TO 6 WHITE LEDS
3
Single
Li-Ion
Cell
+ 10 µF
-
7
100 k
1
VIN
SHDN
VOUT
SELECT
2
8
10 µF
24 k
10 k
PGOOD
GND
4
10  10  10  10  10  10 
MCP1252-ADJ
PWM Contrast
Control
DS21752B-page 12
 2002-2013 Microchip Technology Inc.
MCP1252/3
7.0
PACKAGING INFORMATION
7.1
Package Marking
8-Lead MSOP (Fixed)
1252SX
233025
XXXXX
YWWNNN
8-Lead MSOP (Adjustable)
Note:
*
XX...X
YY
WW
NNN
Example:
1253DJ
233025
XXXXX
YWWNNN
Legend:
Example:
Customer specific information*
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
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.
Standard OTP marking consists of Microchip part number, year code, week code, and traceability code.
 2002-2013 Microchip Technology Inc.
DS21752B-page 13
MCP1252/3
8-Lead Plastic Micro Small Outline Package (MS) (MSOP)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located
at http://www.microchip.com/packaging
E
E1
p
D
2
B
n
1

A2
A
c

A1
(F)
L

Number of Pins
Pitch
Overall Height
MILLIMETERS*
INCHES
Units
Dimension Limits
n
p
MAX
NOM
MIN
MIN
NOM
0.65
.026
.044
A
1.18
.038
0.76
.006
0.05
.193
.200
.114
.118
.114
.118
L
.016
.035
Foot Angle
F

Lead Thickness
c
.004
Lead Width
B

.010
Mold Draft Angle Top
Mold Draft Angle Bottom

Molded Package Thickness
A2
.030
Standoff
A1
.002
E
.184
Molded Package Width
E1
Overall Length
D
Foot Length
Footprint (Reference)
§
Overall Width
MAX
8
8
0.86
0.97
4.67
4.90
.5.08
.122
2.90
3.00
3.10
.122
2.90
3.00
3.10
.022
.028
0.40
0.55
0.70
.037
.039
0.90
0.95
1.00
6
0
.006
.008
0.10
0.15
0.20
.012
.016
0.25
0.30
0.40
.034
0
0.15
6
7
7
7
7
*Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not
exceed .010" (0.254mm) per side.
Drawing No. C04-111
DS21752B-page 14
 2002-2013 Microchip Technology Inc.
MCP1252/3
8.0
REVISION HISTORY
Revision B (January 2013)
Added a note to each package outline drawing.
 2002-2013 Microchip Technology Inc.
DS21752B-page 15
MCP1252/3
DS21752B-page 16
 2002-2013 Microchip Technology Inc.
MCP1252/3
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.
Device
X
/XX
Temperature
Range
Package
Examples:
a)
b)
c)
Device:
MCP1252: Low Noise, Positive-Regulated Charge Pump
MCP1252T: Low Noise, Positive-Regulated Charge Pump
(Tape and Reel)
MCP1253: Low Noise, Positive-Regulated Charge Pump
MCP1253T: Low Noise, Positive-Regulated Charge Pump
(Tape and Reel)
a)
b)
Temperature Range:
I
= -40°C to +85°C
Package:
MS = Plastic Micro Small Outline (MSOP), 8-lead
c)
MCP1252-33X50I/MS: Low Noise, PositiveRegulated Charge Pump, Fixed Output
MCP1252-ADJI/MS: Low Noise, PositiveRegulated Charge Pump, Adjustable Output
MCP1252T-33X50I/MS: Tape and Reel,
Low Noise, Positive-Regulated Charge
Pump, Fixed Output
MCP1253-33X50I/MS: Low Noise, Positive-Regulated Charge Pump, Fixed Output
MCP1253-ADJI/MS:
Low Noise, Positive-Regulated Charge Pump, Adjustable
Output
MCP1253T-ADJI/MS: Tape and Reel,
Low Noise, Positive-Regulated Charge
Pump, Adjustable Output
Sales and Support
Data Sheets
Products supported by a preliminary Data Sheet may have an errata sheet describing minor operational differences and recommended workarounds. To determine if an errata sheet exists for a particular device, please contact one of the following:
1.
2.
Your local Microchip sales office
The Microchip Worldwide Site (www.microchip.com)
Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using.
New Customer Notification System
Register on our web site (www.microchip.com/cn) to receive the most current information on our products.
 2002-2013 Microchip Technology Inc.
DS21752B-page17
MCP1252/3
NOTES:
DS21752B-page 18
 2002-2013 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, KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro,
PICSTART, PIC32 logo, rfPIC, SST, SST Logo, SuperFlash
and UNI/O are registered trademarks of Microchip Technology
Incorporated in the U.S.A. and other countries.
FilterLab, Hampshire, HI-TECH C, Linear Active Thermistor,
MTP, SEEVAL and The Embedded Control Solutions
Company are registered trademarks of Microchip Technology
Incorporated in the U.S.A.
Silicon Storage Technology is a registered trademark of
Microchip Technology Inc. in other countries.
Analog-for-the-Digital Age, Application Maestro, BodyCom,
chipKIT, chipKIT logo, CodeGuard, dsPICDEM,
dsPICDEM.net, dsPICworks, dsSPEAK, ECAN,
ECONOMONITOR, FanSense, HI-TIDE, In-Circuit Serial
Programming, ICSP, Mindi, MiWi, MPASM, MPF, MPLAB
Certified logo, MPLIB, MPLINK, mTouch, Omniscient Code
Generation, PICC, PICC-18, PICDEM, PICDEM.net, PICkit,
PICtail, REAL ICE, rfLAB, Select Mode, SQI, Serial Quad I/O,
Total Endurance, TSHARC, UniWinDriver, WiperLock, ZENA
and Z-Scale 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.
GestIC and ULPP are 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.
© 2002-2013, Microchip Technology Incorporated, Printed in
the U.S.A., All Rights Reserved.
Printed on recycled paper.
ISBN: 9781620768969
QUALITY MANAGEMENT SYSTEM
CERTIFIED BY DNV
== ISO/TS 16949 ==
 2002-2013 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.
DS21752B-page 19
Worldwide Sales and Service
AMERICAS
ASIA/PACIFIC
ASIA/PACIFIC
EUROPE
Corporate Office
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Technical Support:
http://www.microchip.com/
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Web Address:
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DS21752B-page 20
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11/29/12
 2002-2013 Microchip Technology Inc.