Datasheet

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 2002-2013 Microchip Technology Inc. DS21752B-page 1

MCP1252/3

Features

• Inductorless, Buck/Boost, DC/DC Converter

• Low Power: 80 µA (Typical)

• High Output Voltage Accuracy:

- ±2.5% (V

OUT

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

•V

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

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

Description

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.

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, battery-

powered applications. A shutdown mode is also pro-

vided 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)

MSOP (ADJUSTABLE)

PGOOD

OUT

GND

SELECT

SHDN

C+

C-

PGOOD

OUT

GND

SHDN

C+

C-

MCP1252

MCP1253

MCP1252

MCP1253

Low Noise, Positive-Regulated Charge Pump

Summary of content (20 pages)

PAGE 1
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.
PAGE 2
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.
PAGE 3
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 .........................
PAGE 4
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.
PAGE 5
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.
PAGE 6
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).
PAGE 7
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).
PAGE 8
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.
PAGE 9
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.
PAGE 10
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.
PAGE 11
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.
PAGE 12
MCP1252/3 6.
PAGE 13
MCP1252/3 7.0 PACKAGING INFORMATION 7.1 Package Marking 8-Lead MSOP (Fixed) 1252SX 233025 XXXXX YWWNNN 8-Lead MSOP (Adjustable) Note: * XX...
PAGE 14
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 .
PAGE 15
MCP1252/3 8.0 REVISION HISTORY Revision B (January 2013) Added a note to each package outline drawing.  2002-2013 Microchip Technology Inc.
PAGE 16
MCP1252/3 DS21752B-page 16  2002-2013 Microchip Technology Inc.
PAGE 17
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.
PAGE 18
MCP1252/3 NOTES: DS21752B-page 18  2002-2013 Microchip Technology Inc.
PAGE 19
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.
PAGE 20
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