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Microchip Technology MCP1603LT-120I/OS
- Part No.:
- MCP1603LT-120I/OS
- Manufacturer:
- Microchip Technology
- Package:
- SOT-23-5 Thin, TSOT-23-5
- Datasheet:
-
MCP1603LT-120I/OS.pdf
- Description:
- IC REG BUCK 1.2V 500MA TSOT23-5
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
MCP1603LT-120I/OS 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 automatic PWM-to-PFM mode transition, and integrates both high-side and low-side MOSFETs in a space-saving 5-lead TSOT package. It is used in USB-powered devices and digital cameras requiring stable, low-noise 1.2 V rail generation.
For engineers reviewing the MCP1603LT-120I/OS datasheet, MCP1603LT-120I/OS pinout, MCP1603LT-120I/OS application, or MCP1603LT-120I/OS equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative options with functional distinctions, and supply-ready availability details - all grounded in Microchip's DS22042B specification.
Technical Context
The MCP1603LT-120I/OS is a member of the MCP1603/L family with fixed 1.2 V output and PFM/PWM auto-transition capability. It uses current-mode control with internal 0.8 V reference, 2.0 MHz (typ) fixed-frequency PWM under heavy load, and pulse-skipping PFM at light loads to achieve 45 µA typical quiescent current.
It integrates undervoltage lockout (UVLO = 2.28 V typ, 140 mV hysteresis), overtemperature shutdown (150 °C trip), cycle-by-cycle overcurrent protection (860 mA peak limit), and soft-start. The device requires no external compensation when used in fixed-output configuration and supports 100% duty cycle operation for low-dropout scenarios.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.2 V ±2.5% over –40°C to +85°C; enables direct replacement of LDOs in 1.2 V logic rails without feedback divider. |
| Max Output Current | 500 mA continuous; sufficient to power core logic in portable microcontrollers and sensor subsystems. |
| Input Voltage Range | 2.7 V to 5.5 V; compatible with 1-cell Li-Ion (2.7–4.2 V), 2- or 3-cell NiMH/NiCd (2.4–4.5 V), and USB 5 V sources. |
| Quiescent Current | 45 µA typical in PFM mode; extends battery runtime in standby or low-power sensing states. |
| Switching Frequency | 2.0 MHz typical in PWM mode; allows use of small 4.7 µH inductors and 4.7 µF ceramic capacitors for compact PCB layout. |
| Efficiency | >90% typical at 500 mA (VIN = 3.6 V, VOUT = 1.2 V); reduces thermal load in sealed enclosures and improves energy utilization. |
| Protection Features | UVLO (2.28 V), overtemperature shutdown (150 °C), and cycle-by-cycle current limiting (860 mA); eliminates need for external fault management circuitry. |
Pinout & Package
Package: 5-Lead TSOT-23 (MCP1603/MCP1603B variant), lead-free, RoHS-compliant, moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Power supply input | Accepts 2.7–5.5 V input; must be decoupled with ≥4.7 µF low-ESR ceramic capacitor close to pin. |
| GND | Ground reference | Primary return path for power and control circuits; connect directly to PCB ground plane with minimal loop area. |
| SHDN | Enable/disable control | Logic-high (>45% VIN) enables regulation; logic-low (<15% VIN) disables output and reduces current draw to 0.1 µA typical. |
| VFB/VOUT | Feedback / output sense | Internally connected to 1.2 V output; no external resistor divider required - simplifies BOM and layout. |
| LX | Switch node | Connects directly to buck inductor; carries high di/dt current - routing must be short, wide, and adjacent to GND plane. |
Key Features
| Feature | Design Value |
|---|---|
| Automatic PWM-to-PFM mode transition | Enables high efficiency across full load range (0.1–500 mA) without external control or firmware intervention. |
| Internally compensated fixed-output architecture | Eliminates need for external compensation network - reduces component count and design validation effort. |
| 100% duty cycle capability | Supports dropout operation down to VIN ≈ VOUT, critical for battery end-of-discharge scenarios. |
| Integrated overtemperature and overcurrent protection | Provides self-recovering fault handling - avoids latch-up or catastrophic failure during transient overload or thermal stress. |
| Low-profile TSOT-23 package | 0.9 mm height, 2.9 mm × 1.6 mm footprint - fits tight spaces in handheld and wearable form factors. |
Applications
| Portable Medical Sensors | Digital Camera Core Logic |
|---|---|
Use Scenario: Powering ultra-low-power MCU and analog front-end in battery-operated glucose monitors or pulse oximeters. IC Role / Device Role / Timing Role: Primary 1.2 V supply for ARM Cortex-M0+ core and ADC reference. Use Value: 45 µA PFM quiescent current extends single-cell Li-Ion battery life beyond 7 days in sleep mode. |
Use Scenario: Supplying image signal processor (ISP) and memory interface in compact digital cameras. IC Role / Device Role / Timing Role: Regulated 1.2 V rail for high-speed digital logic with low noise and fast transient response. Use Value: 2.0 MHz switching frequency minimizes output ripple (<15 mV) and enables use of tiny 4.7 µH inductors. |
| USB-Powered Audio Accessories | Industrial Handheld Terminals |
Use Scenario: Converting 5 V USB power to clean 1.2 V for DSP and codec in Bluetooth headsets. IC Role / Device Role / Timing Role: Efficient DC-DC conversion stage with integrated MOSFETs and UVLO for plug-and-play operation. Use Value: >90% efficiency at 300 mA reduces heat buildup in thermally constrained plastic enclosures. |
Use Scenario: Providing main logic voltage in ruggedized barcode scanners powered by 3-cell NiMH packs. IC Role / Device Role / Timing Role: Robust 1.2 V regulator tolerant of battery voltage sag (down to 2.7 V) and temperature extremes (–40°C to +85°C). Use Value: Built-in 150 °C thermal shutdown and 860 mA current limit ensure reliable operation in unventilated industrial environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MCP1603T-120I/OS | Same electrical specs and pinout; differs only in tape-and-reel packaging (3,000 pcs/reel vs. 1,000 pcs/reel for LT version). | No functional difference; selected when high-volume automated assembly is required. | Choose MCP1603T-120I/OS for SMT production runs; MCP1603LT-120I/OS suits prototyping and low-volume builds. |
| TPS62231DRYR | Fixed 1.2 V, 500 mA, 3 MHz switching, 17 µA IQ (PFM), but uses 6-pin WSON package and requires external soft-start capacitor. | Better light-load IQ and higher frequency, but adds BOM complexity and lacks 100% duty cycle support. | Select TPS62231DRYR only if 3 MHz operation and sub-20 µA quiescent current are mandatory; otherwise MCP1603LT-120I/OS offers simpler integration. |
Compared with MCP1603T-120I/OS, the LT variant offers identical performance in smaller reel packaging for flexibility; versus TPS62231DRYR, MCP1603LT-120I/OS trades slightly higher light-load IQ for zero-compensation design, 100% duty cycle, and proven field reliability in portable battery systems.
Availability
MCP1603LT-120I/OS is available at Aetrix Electronics and suitable for portable medical sensors, digital camera core logic, USB-powered audio accessories, and industrial handheld terminals requiring stable component supply, long-lifecycle support, and RoHS-compliant sourcing.
Supply support for MCP1603LT-120I/OS 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 software platforms.
The MCP1603/B/L family was designed specifically for high-efficiency, low-quiescent-current DC-DC conversion in space-constrained, battery-powered portable electronics - emphasizing simplicity, reliability, and minimal external component count.
FAQ
What is the input voltage range supported by the MCP1603LT-120I/OS?
The MCP1603LT-120I/OS supports an input voltage range of 2.7 V to 5.5 V. This makes it compatible with single-cell Li-Ion batteries (2.7–4.2 V), two- or three-cell NiMH/NiCd packs (2.4–4.5 V), and standard 5 V USB sources. Operation below 2.7 V is prevented by undervoltage lockout (UVLO), which activates at 2.28 V typical with 140 mV hysteresis.
Does the MCP1603LT-120I/OS require external compensation components?
No, the MCP1603LT-120I/OS does not require external compensation components when used in its fixed 1.2 V output configuration. The device is internally compensated, eliminating the need for external RC networks. This simplifies design, reduces BOM cost, and improves layout robustness - a key advantage over adjustable regulators like the MCP1603-ADJ variants.
What protection features are integrated into the MCP1603LT-120I/OS?
The MCP1603LT-120I/OS integrates undervoltage lockout (UVLO), overtemperature shutdown (150 °C trip), and cycle-by-cycle overcurrent protection (860 mA peak limit). These features operate autonomously without external circuitry. Thermal shutdown includes 10 °C hysteresis, enabling self-recovery after cooling, and UVLO prevents startup until input voltage exceeds 2.28 V, ensuring stable regulation.
Can the MCP1603LT-120I/OS operate with 100% duty cycle?
Yes, the MCP1603LT-120I/OS supports 100% duty cycle operation, allowing it to maintain regulation even when input voltage drops close to the 1.2 V output level. This is essential for extending runtime in battery-powered systems nearing end-of-discharge, where VIN may fall to ~1.3–1.4 V while still sustaining regulated output - a feature not available in many competing buck regulators.
What is the typical quiescent current of the MCP1603LT-120I/OS in light-load conditions?
The MCP1603LT-120I/OS draws 45 µA typical quiescent current in PFM mode at light loads (e.g., <10 mA), significantly lower than its 2.7 mA typical PWM-mode IQ. This low IQ directly extends battery life in standby or intermittent-sensing applications such as portable medical monitors and IoT edge nodes, where average current draw is dominated by idle periods.
MCP1603LT-120I/OS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- SOT-23-5 Thin, TSOT-23-5
- Packaging:
- Tape & Reel (TR)
- 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:
- TSOT-23-5
MCP1603LT-120I/OS FAQ
1.How can I place an order for MCP1603LT-120I/OS through Aetrix?
Please submit a Request for Quotation (RFQ) for MCP1603LT-120I/OS 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 MCP1603LT-120I/OS reliable?
The price and inventory of MCP1603LT-120I/OS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MCP1603LT-120I/OS is usually 5 days.
3.What payment methods are accepted for MCP1603LT-120I/OS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MCP1603LT-120I/OS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MCP1603LT-120I/OS?
MCP1603LT-120I/OS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MCP1603LT-120I/OS 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 MCP1603LT-120I/OS?
For technical support, including MCP1603LT-120I/OS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MCP1603LT-120I/OS requirements.
6.How does Aetrix verify that MCP1603LT-120I/OS is sourced from the original manufacturer or authorized distributors?
All MCP1603LT-120I/OS 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 MCP1603LT-120I/OS meets industry standards.
7.What is the process for return or replacement of MCP1603LT-120I/OS?
All MCP1603LT-120I/OS units undergo pre-shipment inspection (PSI). If there is an issue with MCP1603LT-120I/OS, 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 MCP1603LT-120I/OS part is unused and in its original packaging.
Return procedure for MCP1603LT-120I/OS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MCP1603LT-120I/OS Tags
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