MCP1253 DC/DC Converter: Specifications, Pinout and Datasheet

The MCP1253 is inductorless, positive-regulated charge pump DC/DC converter. The device generates a regulated fixed (3.3V or 5.0V) or adjustable output voltage. It is specifically designed for applications requiring low noise and high efficiency and is able to deliver up to 120 mA output current. The device allows the input voltage to be lower or higher than the output voltage, by automatically switching between buck/boost operation. 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. 

MCP1253 Pinout

Pin Function Table

Symbol

Footprint

3D-Model

• 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:

  - Industrial Temperature (I): -40°C to +85°C

  - Extended Temperature (E): -40°C to +125°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

• AEC-Q100 Qualified

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. The device features 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 the device ideal for small, batterypowered applications. A shutdown mode is also provided for further power reduction. The MCP1253 features thermal and short-circuit protection and are offered in space-saving, 8-lead, MSOP package.

Microchip Technology MCP1253-33X50I/MS technical specifications, attributes, parameters and parts with similar specifications to Microchip Technology MCP1253-33X50I/MS.

MCP1253 Functional Block Diagram

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. 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. 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.

Power Efficiency

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.

Soft-Start and Short-Circuit Protection

The MCP1252 and MCP1253 feature 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.

Thermal Shutdown

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.

• 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

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Package marking

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Download datasheets and manufacturer documentation for Microchip Technology MCP1253-33X50I/MS.