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Microchip Technology MCP1603BT-ADJI/OS
- Part No.:
- MCP1603BT-ADJI/OS
- Manufacturer:
- Microchip Technology
- Package:
- SOT-23-5 Thin, TSOT-23-5
- Datasheet:
-
MCP1603BT-ADJI/OS.pdf
- Description:
- IC REG BUCK ADJ 500MA TSOT23-5
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
MCP1603BT-ADJI/OS from Microchip Technology is a 2.0 MHz, 500 mA synchronous buck DC-DC regulator optimized for single-cell Li-Ion (2.7–5.5 V input) and USB-powered portable systems. It delivers adjustable output voltage from 0.8 V to 4.5 V with 0.8 V internal reference, 45 µA typical PFM quiescent current, and integrated overtemperature/UVLO protection. It is used in battery-powered digital cameras and headsets requiring high efficiency at light loads.
For engineers reviewing the MCP1603BT-ADJI/OS datasheet, MCP1603BT-ADJI/OS pinout, MCP1603BT-ADJI/OS application, or MCP1603BT-ADJI/OS equivalent, key selection criteria include its PWM/PFM auto-transition capability, 5-lead TSOT package footprint, 0.8 V feedback reference tolerance (±2.5%), and compatibility with low-ESR ceramic input/output capacitors (4.7 µF minimum).
Technical Context
The MCP1603BT-ADJI/OS implements current-mode control with automatic transition between 2.0 MHz fixed-frequency PWM (heavy load) and pulse-skipping PFM (light load), enabling >90% peak efficiency across 0.1–500 mA output range. Its internal 0.8 V bandgap reference feeds an error amplifier that compares divided output voltage against VFB to regulate via cycle-by-cycle peak current limiting (860 mA typical).
This variant belongs to the MCP1603/L family and supports adjustable output configuration only - no fixed-voltage options. It integrates both P-channel (500 mΩ RDS(on)) and N-channel (500 mΩ RDS(on)) MOSFETs, eliminating external switches and enabling full synchronous operation without external diode.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.7 V to 5.5 V - supports direct connection to 1-cell Li-Ion or 2–3-cell NiMH/NiCd batteries without pre-regulation. |
| Output Current | Up to 500 mA continuous - sufficient for powering core logic rails in portable microcontrollers and sensors. |
| Switching Frequency | 2.0 MHz (typical) - enables use of compact 4.7 µH inductors and 4.7 µF ceramic capacitors, minimizing board area. |
| Quiescent Current | 45 µA (PFM mode, typ.) - extends battery life in standby or low-power monitoring states. |
| Feedback Reference | 0.8 V ±2.5% (TA = +25°C to +85°C) - sets output via external resistor divider; allows precise 0.8–4.5 V adjustment with minimal component count. |
| Protection Features | UVLO (2.28 V typ., 140 mV hysteresis), thermal shutdown (150°C typ.), and cycle-by-cycle overcurrent limit (860 mA typ.) - ensures robust operation under fault conditions without external circuitry. |
| Efficiency | >90% typical at mid-load (e.g., VIN = 3.6 V, VOUT = 1.8 V, IOUT = 300 mA) - reduces thermal stress and extends runtime in space-constrained devices. |
Pinout & Package
Package: 5-Lead TSOT-23 (thin small outline transistor), lead pitch 0.95 mm, body size 2.9 mm × 1.6 mm × 1.1 mm, exposed pad not present (TSOT variant).
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | VIN | Input power supply (2.7–5.5 V); requires local 4.7 µF ceramic decoupling to GND for stable switching. |
| 2 | GND | Power and signal ground reference; must be connected to low-impedance PCB ground plane to minimize noise and thermal resistance. |
| 3 | SHDN | Active-high enable input (VIH > 45% VIN, VIL < 15% VIN); pulls to GND to disable regulator and reduce supply current to 0.1 µA. |
| 4 | VFB/VOUT | Feedback node for adjustable output - connect center of resistor divider here; internal 0.8 V reference sets regulation point. |
| 5 | LX | Switch node connecting to buck inductor; carries high di/dt current - requires short, wide trace to minimize EMI and voltage spikes. |
Key Features
| Feature | Design Value |
|---|---|
| Auto PWM-to-PFM Transition | Enables seamless efficiency optimization: 2.0 MHz PWM at >50 mA load, PFM pulse-skipping below - no external control needed. |
| Internally Compensated Control Loop | Eliminates need for external compensation network when using recommended 4.7 µH inductor and 4.7 µF output capacitor. |
| Synchronous Buck Architecture | Integrates both high-side P-MOSFET and low-side N-MOSFET - achieves >90% efficiency without external Schottky diode losses. |
| 100% Duty Cycle Operation | Allows VOUT to approach VIN closely (e.g., 4.5 V out from 4.7 V in), critical for low-dropout operation in battery discharge tails. |
| Low-Noise Fixed-Frequency PWM Mode | Delivers <15 mVpp output ripple at full load - suitable for noise-sensitive analog or RF subsystems sharing same battery rail. |
Applications
| Portable Digital Cameras | USB-Powered Headsets |
|---|---|
Use Scenario: Powering image sensor, ISP, and audio codec from single Li-Ion cell during video capture and playback. IC Role / Device Role / Timing Role: Primary 1.8 V or 2.5 V core supply regulator with fast transient response to handle burst current demands of sensor readout. Use Value: 45 µA PFM quiescent current extends standby time; 2.0 MHz switching avoids audible noise in microphone path. | Use Scenario: Regulating clean 3.3 V rail for Bluetooth radio and MEMS microphone from 5 V USB bus. IC Role / Device Role / Timing Role: Step-down converter providing low-noise, regulated power with minimal external components on compact headset PCB. Use Value: Integrated MOSFETs and internal compensation reduce BOM count to just inductor, two capacitors, and two resistors - saving >3 mm² board area. |
| Handheld Organizers / PDAs | Industrial Portable Test Equipment |
Use Scenario: Supplying 1.2 V core voltage to ARM-based application processor during active UI interaction and sleep modes. IC Role / Device Role / Timing Role: Adjustable-output buck regulator supporting dynamic voltage scaling (DVS) via firmware-controlled resistor divider. Use Value: 0.8 V reference tolerance (±2.5%) ensures stable core voltage across -40°C to +85°C ambient - critical for real-time task scheduling. | Use Scenario: Generating isolated 2.8 V analog front-end supply from 3.7 V Li-Ion battery in handheld multimeter or oscilloscope probe. IC Role / Device Role / Timing Role: High-efficiency, low-EMI power stage delivering stable rail for precision ADC and op-amp circuits. Use Value: UVLO (2.28 V) and thermal shutdown (150°C) prevent malfunction during battery deep discharge or enclosure overheating. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62231DRYR | Fixed 1.8 V output only; 3.0 MHz switching; 25 µA IQ (PFM); 350 mA max output. | Not adjustable; higher frequency enables smaller inductors but limits max current and output flexibility. | Select when fixed 1.8 V output suffices and board space is more constrained than voltage flexibility. |
| RT8059GJ6 | Adjustable 0.6–5.5 V output; 1.5 MHz switching; 30 µA IQ (PFM); 600 mA max output; different pinout (SOT-23-6). | Higher current rating and lower IQ, but lacks integrated soft-start and has different shutdown threshold behavior. | Select when >500 mA load margin or sub-30 µA quiescent current is required, and layout can accommodate SOT-23-6 footprint. |
Compared with TPS62231DRYR and RT8059GJ6, the MCP1603BT-ADJI/OS offers unique adjustability within the 0.8–4.5 V range, proven 500 mA capability with integrated thermal/UVLO protection, and TSOT-23 pin compatibility - making it optimal for legacy-replacement or multi-voltage design reuse.
Availability
MCP1603BT-ADJI/OS is available at Aetrix Electronics and suitable for portable digital cameras, USB-powered headsets, and industrial handheld test equipment requiring stable component supply across extended production lifecycles.
Supply support for MCP1603BT-ADJI/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, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The MCP1603/B/L product line was designed specifically for high-efficiency, space-constrained DC-DC conversion in battery-powered portable electronics - emphasizing low quiescent current, integrated power stages, and simplified external component requirements.
FAQ
What is the maximum output current capability of the MCP1603BT-ADJI/OS?
The MCP1603BT-ADJI/OS delivers up to 500 mA of continuous output current under typical operating conditions (VIN = 3.6 V, VOUT = 1.8 V, TA = +25°C). Peak current limit is 860 mA (cycle-by-cycle), and thermal derating applies above +85°C ambient. The device maintains regulation across this range when used with recommended 4.7 µH inductor and proper PCB thermal layout.
Does the MCP1603BT-ADJI/OS support fixed-output voltage configurations?
No - the MCP1603BT-ADJI/OS is an adjustable-output variant only, requiring an external resistor divider on the VFB/VOUT pin to set output voltage between 0.8 V and 4.5 V. Fixed-output versions (e.g., MCP1603-18I/OS for 1.8 V) are separate part numbers and not interchangeable with MCP1603BT-ADJI/OS.
What is the purpose of the SHDN pin on the MCP1603BT-ADJI/OS?
The SHDN pin is an active-high enable control: pulling it to >45% of VIN enables regulation, while pulling it to <15% of VIN disables the device and reduces input current to 0.1 µA typical. It is not a reset pin - output resumes regulation after SHDN returns high, provided VIN remains above UVLO (2.28 V typical) and no thermal fault persists.
Can the MCP1603BT-ADJI/OS operate with a 2.5 V input voltage?
Yes - the MCP1603BT-ADJI/OS operates down to 2.7 V minimum input, so 2.5 V is below specification and will trigger undervoltage lockout (UVLO). Regulation begins only when VIN rises above 2.28 V (typical UVLO threshold) and remains above 2.7 V for stable operation. For 2.5 V input, consider a lower-VIN buck regulator or boost-buck architecture.
How does the MCP1603BT-ADJI/OS manage efficiency across varying load conditions?
The MCP1603BT-ADJI/OS automatically transitions between 2.0 MHz fixed-frequency PWM mode (for loads >~50 mA) and pulse-skipping PFM mode (for lighter loads), achieving >90% peak efficiency and maintaining 80%+ efficiency even at 1 mA output. This dual-mode operation minimizes quiescent current (45 µA typ. in PFM) without requiring external mode-control signals.
MCP1603BT-ADJI/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:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.7V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 4.5V
- Current - Output:
- 500mA
- Frequency - Switching:
- 2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TSOT-23-5
MCP1603BT-ADJI/OS FAQ
1.How can I place an order for MCP1603BT-ADJI/OS through Aetrix?
Please submit a Request for Quotation (RFQ) for MCP1603BT-ADJI/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 MCP1603BT-ADJI/OS reliable?
The price and inventory of MCP1603BT-ADJI/OS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MCP1603BT-ADJI/OS is usually 5 days.
3.What payment methods are accepted for MCP1603BT-ADJI/OS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MCP1603BT-ADJI/OS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MCP1603BT-ADJI/OS?
MCP1603BT-ADJI/OS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MCP1603BT-ADJI/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 MCP1603BT-ADJI/OS?
For technical support, including MCP1603BT-ADJI/OS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MCP1603BT-ADJI/OS requirements.
6.How does Aetrix verify that MCP1603BT-ADJI/OS is sourced from the original manufacturer or authorized distributors?
All MCP1603BT-ADJI/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 MCP1603BT-ADJI/OS meets industry standards.
7.What is the process for return or replacement of MCP1603BT-ADJI/OS?
All MCP1603BT-ADJI/OS units undergo pre-shipment inspection (PSI). If there is an issue with MCP1603BT-ADJI/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 MCP1603BT-ADJI/OS part is unused and in its original packaging.
Return procedure for MCP1603BT-ADJI/OS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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