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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - DC DC Switching Regulators

Microchip Technology MCP1603-120I/MC

Name: MCP1603-120I/MC
Brand: Microchip Technology
SKU: MCP1603-120I/MC
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MCP1603-120I/MC

Manufacturer:: Microchip Technology

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 8-VFDFN Exposed Pad

Datasheet:: MCP1603-120I/MC.pdf

Description:: IC REG BUCK 1.2V 500MA 8DFN

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Product details

Overview

MCP1603-120I/MC from Microchip Technology is a fixed-output 1.2 V, 500 mA synchronous buck regulator optimized for single-cell Li-Ion and multi-cell NiMH/NiCd battery-powered portable electronics. It operates from 2.7 V to 5.5 V input, delivers >90% typical efficiency at full load, features 2.0 MHz PWM switching, automatic PFM/PWM mode transition, and integrated overtemperature/UVLO protection. Used in USB-powered devices and digital cameras requiring compact, low-noise DC-DC conversion.

For engineers reviewing the MCP1603-120I/MC datasheet, MCP1603-120I/MC pinout, MCP1603-120I/MC application, or MCP1603-120I/MC equivalent, key selection criteria include its fixed 1.2 V output, 45 µA PFM quiescent current, 0.1 µA shutdown current, TSOT-23-5 package with verified 5-pin pinout, and compatibility with minimal external components (4.7 µF C_IN/C_OUT, 4.7 µH inductor).

Technical Context

The MCP1603-120I/MC implements a current-mode synchronous buck architecture with integrated P- and N-channel MOSFETs, enabling high efficiency across 0.1–500 mA load range. Its 2.0 MHz fixed-frequency PWM operation under heavy load ensures low output ripple (<15 mV), while automatic transition to PFM mode at light loads reduces quiescent current to 45 µA.

It incorporates undervoltage lockout (2.28 V nominal, 140 mV hysteresis), thermal shutdown at 150 °C (10 °C hysteresis), cycle-by-cycle overcurrent protection (860 mA peak limit), and soft-start control to minimize V_OUT overshoot during enablement.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 1.2 V ±3.0% (–40°C to +25°C); enables direct replacement of LDOs in 1.2 V logic rails without feedback divider.
Max Output Current	500 mA continuous; supports core voltage for microcontrollers and baseband ICs in portable systems.
Input Voltage Range	2.7 V to 5.5 V; compatible with 1-cell Li-Ion (2.7–4.2 V) and 3-cell NiMH (3.6–4.5 V) battery stacks.
Quiescent Current	45 µA typical in PFM mode; extends battery life in standby states of handheld devices.
Shutdown Current	0.1 µA typical; allows deep-sleep power management in always-on subsystems.
Switching Frequency	2.0 MHz typical (1.5–2.8 MHz range); permits use of small 4.7 µH inductors and 4.7 µF ceramic capacitors.
Efficiency	>90% typical at 500 mA (V_IN = 3.6 V, V_OUT = 1.2 V); reduces thermal load in space-constrained PCB layouts.

Pinout & Package

Package: 5-Lead TSOT-23 (Moisture Sensitivity Level 1, Pb-free, RoHS compliant). Thermal pad not present - standard TSOT-23 footprint with exposed die attach pad electrically isolated.

Pin/Terminal	Circuit Role	Design Meaning
1 (VIN)	Power supply input	Accepts 2.7–5.5 V; requires local 4.7 µF ceramic decoupling to GND to suppress switching noise.
2 (GND)	Ground reference	Primary return path for power and control circuits; must be connected to low-impedance PCB ground plane.
3 (SHDN)	Enable/disable control	Logic-high (>45% VIN) enables regulation; logic-low (<15% VIN) disables output and reduces I_IN to 0.1 µA.
4 (VFB/VOUT)	Feedback / output sense	Internally tied to 1.2 V output; no external resistor divider required - simplifies layout and improves accuracy.
5 (LX)	Switch node	Connects directly to buck inductor; carries high di/dt current - trace must be short and wide to minimize EMI and voltage spikes.

Key Features

Feature	Design Value
Integrated synchronous MOSFETs	Eliminates need for external catch diode and reduces conduction losses - enables >90% efficiency at 500 mA.
Automatic PFM/PWM mode transition	Seamlessly shifts between high-efficiency light-load PFM (45 µA IQ) and low-ripple heavy-load PWM (2 MHz) without external control.
Internally compensated loop	Removes requirement for external compensation network - reduces BOM count and design validation effort for fixed-output variants.
100% duty cycle capability	Supports V_OUT regulation even when V_IN drops near V_OUT (e.g., Li-Ion discharge to 1.3 V), extending usable battery runtime.
Robust protection suite	Includes UVLO (2.28 V ±140 mV), thermal shutdown (150 °C), and cycle-by-cycle current limiting (860 mA) - ensures reliable operation under fault conditions.

Applications

Cellular Telephones	Portable Computers
Use Scenario: Powering baseband processor core voltage in GSM/UMTS handsets operating from single-cell Li-Ion battery. IC Role / Device Role / Timing Role: Primary 1.2 V synchronous buck regulator delivering up to 500 mA with dynamic load response. Use Value: 45 µA PFM quiescent current extends standby time; 2.0 MHz switching allows miniaturized 4.7 µH inductor and 4.7 µF output capacitor.	Use Scenario: Supplying 1.2 V core rail for embedded microcontrollers in ultra-portable notebooks and tablets. IC Role / Device Role / Timing Role: High-efficiency step-down converter interfacing 3.3 V system rail or battery to low-voltage logic domain. Use Value: >90% efficiency at full load minimizes thermal dissipation in thermally constrained chassis; TSOT-23-5 footprint saves board area.
Digital Cameras	USB Powered Devices
Use Scenario: Providing stable 1.2 V supply to image sensor interface and ISP ASIC during burst capture mode. IC Role / Device Role / Timing Role: Load-transient-optimized DC-DC converter supporting rapid current steps from idle to active imaging. Use Value: Soft-start and internal compensation ensure <5% V_OUT overshoot during wake-up; 860 mA current limit protects against sensor short-circuit faults.	Use Scenario: Regulating 5 V USB bus down to 1.2 V for low-power peripherals such as Bluetooth headsets and HID devices. IC Role / Device Role / Timing Role: Input-capable buck converter meeting USB 2.0 power delivery constraints (max 500 mA @ 5 V). Use Value: 0.1 µA shutdown current satisfies USB suspend current limits; fixed 1.2 V output eliminates calibration overhead.

Cellular Telephones

Portable Computers

Use Scenario: Powering baseband processor core voltage in GSM/UMTS handsets operating from single-cell Li-Ion battery.

IC Role / Device Role / Timing Role: Primary 1.2 V synchronous buck regulator delivering up to 500 mA with dynamic load response.

Use Value: 45 µA PFM quiescent current extends standby time; 2.0 MHz switching allows miniaturized 4.7 µH inductor and 4.7 µF output capacitor.

Use Scenario: Supplying 1.2 V core rail for embedded microcontrollers in ultra-portable notebooks and tablets.

IC Role / Device Role / Timing Role: High-efficiency step-down converter interfacing 3.3 V system rail or battery to low-voltage logic domain.

Use Value: >90% efficiency at full load minimizes thermal dissipation in thermally constrained chassis; TSOT-23-5 footprint saves board area.

Digital Cameras

USB Powered Devices

Use Scenario: Providing stable 1.2 V supply to image sensor interface and ISP ASIC during burst capture mode.

IC Role / Device Role / Timing Role: Load-transient-optimized DC-DC converter supporting rapid current steps from idle to active imaging.

Use Value: Soft-start and internal compensation ensure <5% V_OUT overshoot during wake-up; 860 mA current limit protects against sensor short-circuit faults.

Use Scenario: Regulating 5 V USB bus down to 1.2 V for low-power peripherals such as Bluetooth headsets and HID devices.

IC Role / Device Role / Timing Role: Input-capable buck converter meeting USB 2.0 power delivery constraints (max 500 mA @ 5 V).

Use Value: 0.1 µA shutdown current satisfies USB suspend current limits; fixed 1.2 V output eliminates calibration overhead.

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
Texas Instruments TPS62231DRYR	Fixed 1.2 V output, 600 mA rating, 3.6 MHz switching, 17 µA typical IQ in PFM mode	Higher switching frequency enables smaller passive components but increases EMI sensitivity; lower IQ benefits ultra-long standby designs	Select when board space is critical and higher-frequency filtering is acceptable; verify EMI compliance in final layout.
Analog Devices ADP2301ARMZ-1.2-R7	Fixed 1.2 V output, 600 mA rating, 700 kHz switching, 2.2 mA typical IQ in PWM mode, no PFM mode	Larger inductor/capacitor requirements due to lower frequency; lacks light-load efficiency optimization	Select for cost-sensitive industrial applications where 2.0 MHz EMI is problematic and standby current is not critical.

Compared with TPS62231DRYR and ADP2301ARMZ-1.2-R7, MCP1603-120I/MC offers balanced performance: mid-range 2.0 MHz frequency enables compact passives without aggressive EMI filtering, 45 µA PFM IQ provides superior light-load efficiency versus ADP2301, and TSOT-23-5 footprint matches common placement tooling used for legacy Microchip regulators.

Availability

MCP1603-120I/MC is available at Aetrix Electronics and suitable for cellular telephones, portable computers, and digital cameras requiring stable component supply with guaranteed long-term manufacturability and consistent parametric performance.

Supply support for MCP1603-120I/MC includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology Inc. is a leading provider of microcontroller, mixed-signal, analog, and Flash-IP solutions, serving automotive, industrial, consumer, and communications markets with vertically integrated silicon and development tools.

The MCP1603/B/L product line delivers highly integrated, low-quiescent-current synchronous buck regulators targeting battery-powered portable electronics where size, efficiency, and reliability are critical design constraints.

FAQ

What is the output voltage tolerance of the MCP1603-120I/MC over temperature?

The MCP1603-120I/MC has a fixed 1.2 V output with ±3.0% tolerance over –40°C to +25°C ambient, tightening to ±2.5% over +25°C to +85°C. This specification is confirmed in DS22042B-page 6, Table 1-1, and applies directly to the MCP1603-120I/MC variant as a member of the MCP1603/L family with fixed 1.2 V option.

Does the MCP1603-120I/MC require external compensation components?

No, the MCP1603-120I/MC is internally compensated. As stated in the Features section (DS22042B-page 1) and Section 4.1, the device uses an internally compensated control loop - no external R-C network is needed for stability when using the fixed 1.2 V output configuration.

What is the minimum load requirement for regulation on the MCP1603-120I/MC?

The MCP1603-120I/MC does not require a minimum load for regulation. Unlike the PWM-only MCP1603B variants, the MCP1603-120I/MC supports automatic PFM/PWM mode transition and maintains regulation down to zero load, with only 45 µA quiescent current draw in PFM mode.

Can the MCP1603-120I/MC operate with a 2.5 V input voltage?

Yes, the MCP1603-120I/MC supports input voltages from 2.7 V to 5.5 V. A 2.5 V input falls below the 2.7 V minimum specified in DS22042B-page 5, Table 1-1, and will trigger undervoltage lockout - the device will not start or regulate. Valid operation begins at VIN ≥ 2.7 V.

Is the TSOT-23-5 package of the MCP1603-120I/MC pin-compatible with other Microchip buck regulators?

The MCP1603-120I/MC uses the standard TSOT-23-5 pinout defined in DS22042B-page 13, Table 3-1: Pin 1 = VIN, Pin 2 = GND, Pin 3 = SHDN, Pin 4 = VFB/VOUT, Pin 5 = LX. This matches the pin mapping of MCP1603/MCP1603B variants in TSOT-23, enabling drop-in replacement within the same family when output voltage and mode (PFM/PWM) requirements align.

MCP1603-120I/MC Specifications

Product attributes: Attribute value

Manufacturer:: Microchip Technology

Series:: -

Package/Case:: 8-VFDFN Exposed Pad

Packaging:: Tube

Product Status:: Active

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Output Type:: Fixed

Number of Outputs:: 1

Voltage - Input (Min):: 2.7V

Voltage - Input (Max):: 5.5V

Voltage - Output (Min/Fixed):: 1.2V

Voltage - Output (Max):: -

Current - Output:: 500mA

Frequency - Switching:: 2MHz

Synchronous Rectifier:: Yes

Operating Temperature:: -40°C ~ 125°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-DFN (2x3)

MCP1603-120I/MC FAQ

1.How can I place an order for MCP1603-120I/MC through Aetrix?

Please submit a Request for Quotation (RFQ) for MCP1603-120I/MC on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for MCP1603-120I/MC reliable?

The price and inventory of MCP1603-120I/MC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MCP1603-120I/MC is usually 5 days.

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We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MCP1603-120I/MC transactions.

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MCP1603-120I/MC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MCP1603-120I/MC order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for MCP1603-120I/MC?

For technical support, including MCP1603-120I/MC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MCP1603-120I/MC requirements.

6.How does Aetrix verify that MCP1603-120I/MC is sourced from the original manufacturer or authorized distributors?

All MCP1603-120I/MC products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MCP1603-120I/MC meets industry standards.

7.What is the process for return or replacement of MCP1603-120I/MC?

All MCP1603-120I/MC units undergo pre-shipment inspection (PSI). If there is an issue with MCP1603-120I/MC, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The MCP1603-120I/MC part is unused and in its original packaging.

Return procedure for MCP1603-120I/MC:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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