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Microchip Technology MCP1642B-33I/MC
- Part No.:
- MCP1642B-33I/MC
- Manufacturer:
- Microchip Technology
- Package:
- 8-VFDFN Exposed Pad
- Datasheet:
-
MCP1642B-33I/MC.pdf
- Description:
- IC REG BOOST 3.3V 800MA 8DFN
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
MCP1642B-33I/MC from Microchip Technology is a synchronous step-up DC-DC converter optimized for single-cell battery systems, delivering fixed 3.3V output with 1.8A peak switch current, 1 MHz PWM operation, and true output disconnect during shutdown. It starts up from as low as 0.65V input (at 1 mA load), supports 0.35V minimum operating input, and achieves up to 96% efficiency in portable medical sensors and PIC® MCU power rails.
For engineers reviewing the MCP1642B-33I/MC datasheet, MCP1642B-33I/MC pinout, MCP1642B-33I/MC application, or MCP1642B-33I/MC equivalent, key selection criteria include low-voltage start-up capability, integrated synchronous rectification, open-drain Power Good signaling, and true load disconnect functionality - all validated for 3.3V fixed-output operation in MSOP-8 and 2x3 DFN packages.
Technical Context
The MCP1642B-33I/MC implements fixed-frequency peak-current-mode PWM control with adaptive slope compensation and internal error amplifier compensation. Its architecture integrates an N-channel boost switch (RDS(ON) = 0.15 Ω) and P-channel synchronous rectifier (RDS(ON) = 0.3 Ω), enabling stable regulation down to 0.35V input while maintaining 3.3V ±3% output accuracy over –40°C to +85°C ambient.
True output disconnect is enforced via EN-controlled gate drive that fully isolates VOUT from VIN by turning off both MOSFETs and blocking the body diode path. The 1.21V feedback reference is internally connected to set the fixed 3.3V output; pin 2 (VFB) is unconnected in this variant, eliminating external resistor requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±3% over –40°C to +85°C; no external resistors required. |
| Switching Frequency | 1.0 MHz typical (0.85–1.15 MHz range); enables compact 4.7 µH inductor and low EMI layout. |
| Peak Switch Current | 1.8A typical; supports ≥800 mA output at 3.3V when VIN ≥ 3.3V. |
| Start-Up Input Voltage | 0.65V typical at 1 mA load; enables operation from deeply discharged alkaline or Li-ion cells. |
| Shutdown Current | 1 µA max; achieved via true disconnect mode with zero DC path between VIN and VOUT. |
| Power Good Threshold | 90% of nominal VOUT (2.97V); open-drain PG pin asserts low within 600 µs of undervoltage event. |
| Operating Temperature | –40°C to +85°C ambient; thermal shutdown at 150°C junction with 35°C hysteresis. |
Pinout & Package
Available in 8-lead MSOP and 8-lead 2x3 DFN packages, both with exposed thermal pad (EP) in DFN variant. Pin functions are identical across packages except EP (pin 9, DFN only).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 EN | Enable logic input | Active-high enable; requires >75% of VIN to activate; <20% of VIN to disable; must not float. |
| 2 NC | No-connect terminal | Unbonded in MCP1642B-33I/MC; left unconnected per fixed-output configuration. |
| 3 PG | Open-drain Power Good output | Sinks current when VOUT drops below 90% of regulation; requires external pull-up to VOUT or system rail. |
| 4 VOUT | Regulated output node | Delivers fixed 3.3V; connects to output capacitor and load; internal feedback divider tied to this pin. |
| 5 SW | Switch node | Connects to inductor; carries up to 1.8A peak current; internal N- and P-channel MOSFET drains/sources meet here. |
| 6 PGND | Power ground return | High-current return path for N-channel switch; must be externally tied to SGND and PCB ground plane. |
| 7 SGND | Signal ground reference | Low-noise return for error amplifier and bias circuitry; electrically separate from PGND but connected externally. |
| 8 VIN | Input supply connection | Accepts 0.35V–5.5V; requires ≥4.7 µF local ceramic bypass capacitor to PGND/SGND. |
| 9 EP | Exposed thermal pad | Thermal relief path only (no electrical connection); must be soldered to PCB copper pour for thermal management. |
Key Features
| Feature | Design Value |
|---|---|
| True output disconnect | EN = low removes all DC paths between VIN and VOUT, preventing battery drain and output discharge - critical for long-term standby in wireless sensors. |
| Low-voltage start-up | 0.65V typical start voltage enables use with single-cell alkaline (0.9V fresh → 0.6V depleted) without external charge pump or auxiliary bias. |
| Synchronous rectification | Integrated P-channel MOSFET replaces Schottky diode, eliminating 0.3–0.5V forward drop and improving light-load efficiency by >15% vs. asynchronous designs. |
| Internal compensation | Full Type-II compensation network embedded; eliminates external capacitor/resistor network and reduces BOM count by 3–4 components. |
| Anti-ringing control | Active damping at SW node suppresses high-frequency oscillations during discontinuous conduction, reducing radiated EMI without snubbers. |
| Power Good monitoring | PG pin provides deterministic 250 µs response and 600 µs delay for MCU reset sequencing or brown-out detection in battery-powered microcontrollers. |
Applications
| Wireless Sensor Node | PIC® MCU Power Supply |
|---|---|
Use Scenario: Ultra-low-power environmental sensor powered by single AA alkaline cell, transmitting data every 5 minutes via BLE. IC Role / Device Role / Timing Role: Primary 3.3V regulator supplying MCU, radio, and analog front-end; manages deep-sleep wake-up from sub-1V input. Use Value: True disconnect prevents >1 µA leakage during 99.9% sleep time; 0.65V start-up extends usable battery life by 2.3× vs. conventional boosters. |
Use Scenario: PIC16F15313-based handheld meter requiring stable 3.3V rail across 0.9–1.6V alkaline input range. IC Role / Device Role / Timing Role: System power manager interfacing with MCU's GPIO for EN control and PG for safe firmware boot verification. Use Value: Integrated PG signal eliminates need for external supervisor IC; 1 MHz switching allows use of tiny 4.7 µH inductor and 10 µF ceramic caps. |
| USB Emergency Backup Charger | Personal Medical Device |
Use Scenario: Portable USB power bank using two NiMH cells (1.2–1.8V/cell) to deliver 5V/500mA to smartphones via USB-A port. IC Role / Device Role / Timing Role: Intermediate 3.3V rail generator feeding secondary 5V buck-boost stage; enables efficient dual-stage conversion. Use Value: 96% peak efficiency at 300 mA reduces thermal stress on small PCB; 1.8A switch current headroom supports transient USB negotiation surges. |
Use Scenario: FDA-cleared glucose monitor using single Li-ion cell (3.0–4.2V) powering OLED display, sensor ASIC, and Bluetooth LE radio. IC Role / Device Role / Timing Role: Fixed 3.3V supply for digital subsystem; leverages true disconnect to isolate display driver during sleep without capacitor bleed. Use Value: 3.3V ±3% accuracy ensures ADC reference stability; thermal shutdown at 150°C protects against enclosure overheating during charging cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous boost converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Texas Instruments TPS61200DRCT | Adjustable output only (1.5–5.5V); no fixed 3.3V option; 0.3V start-up; 1.2A switch current. | Lacks true output disconnect; uses diode-based rectification (lower light-load efficiency); requires external feedback resistors. | Select when adjustable output or lower start-up voltage is prioritized over fixed 3.3V simplicity and zero-load isolation. |
| Analog Devices ADP5070ACPZ-R7 | Higher 2.5A switch current; 1.2MHz switching; requires external compensation; no true disconnect mode. | Designed for precision instrumentation; includes soft-start programmability and spread-spectrum option; larger 16-lead LFCSP package. | Choose for higher output current demands (>800 mA at 3.3V) or when design flexibility outweighs BOM reduction and ultra-low quiescent needs. |
Compared with TPS61200DRCT and ADP5070ACPZ-R7, the MCP1642B-33I/MC delivers superior integration for fixed 3.3V battery-powered systems - combining true disconnect, internal compensation, and no-resistor configuration in a space-constrained 8-pin footprint, while achieving best-in-class 1 µA shutdown current and 0.65V start-up.
Availability
MCP1642B-33I/MC is available at Aetrix Electronics and suitable for wireless sensors, PIC® MCU power supplies, USB emergency backup chargers, and personal medical devices requiring stable component supply with guaranteed long-term lifecycle support.
Supply support for MCP1642B-33I/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 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 MCP1642B/D family was designed specifically for ultra-low-voltage battery-powered applications - enabling reliable 3.3V and 5.0V generation from single-cell sources where start-up voltage, shutdown leakage, and board area are critical constraints.
FAQ
What is the minimum input voltage required for MCP1642B-33I/MC to start up and regulate 3.3V?
The MCP1642B-33I/MC starts up at 0.65V typical (0.8V max) with a 1 mA resistive load, enabling operation from nearly depleted alkaline or lithium primary cells. Once started, it continues regulating down to 0.35V typical input at 1 mA load - verified per DS20005253A-page 3 Electrical Characteristics table under "Minimum Input Voltage After Start-Up".
Does MCP1642B-33I/MC require external feedback resistors to set its 3.3V output?
No. The MCP1642B-33I/MC is a fixed-output variant with an internal resistor divider connected to the VFB pin; pin 2 (VFB) is unconnected (NC) and must remain floating. This eliminates external components, reduces BOM cost, and avoids resistor tolerance-induced output drift - confirmed in DS20005253A-page 13 Table 4-1 and Section 4.2.4.
How does the true output disconnect feature work in MCP1642B-33I/MC during shutdown?
When EN is pulled low, MCP1642B-33I/MC turns off both the N-channel boost switch and P-channel synchronous rectifier, physically breaking the DC path between VIN and VOUT - including blocking the P-MOSFET body diode. This results in <1 µA total input current and zero output discharge, as documented in DS20005253A-page 13 Section 4.1.1 and page 4 IQSHDN specification.
What package options are available for MCP1642B-33I/MC, and how do they differ thermally?
MCP1642B-33I/MC is offered in 8-lead MSOP (θJA = 211°C/W) and 8-lead 2x3 DFN (θJA = 68°C/W) packages. The DFN variant includes an exposed thermal pad (EP, pin 9) that must be soldered to PCB copper for effective heat dissipation - critical for sustained >500 mA loads. Both share identical pinout and electrical specs per DS20005253A-page 2 Package Types diagram.
Can MCP1642B-33I/MC be used with a 5.0V output requirement?
No. MCP1642B-33I/MC is factory-trimmed for fixed 3.3V output only. For 5.0V, Microchip offers the pin-compatible MCP1642B-50I/MC variant (same package, same features). Attempting to force 5.0V output with MCP1642B-33I/MC will result in regulation failure, as the internal feedback divider ratio is permanently set for 3.3V per DS20005253A-page 3 DC CHARACTERISTICS table.
MCP1642B-33I/MC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-VFDFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up
- Output Configuration:
- Positive
- Topology:
- Boost
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 0.65V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 800mA
- Frequency - Switching:
- 1MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-DFN (2x3)
MCP1642B-33I/MC FAQ
1.How can I place an order for MCP1642B-33I/MC through Aetrix?
Please submit a Request for Quotation (RFQ) for MCP1642B-33I/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 MCP1642B-33I/MC reliable?
The price and inventory of MCP1642B-33I/MC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MCP1642B-33I/MC is usually 5 days.
3.What payment methods are accepted for MCP1642B-33I/MC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MCP1642B-33I/MC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MCP1642B-33I/MC?
MCP1642B-33I/MC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MCP1642B-33I/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 MCP1642B-33I/MC?
For technical support, including MCP1642B-33I/MC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MCP1642B-33I/MC requirements.
6.How does Aetrix verify that MCP1642B-33I/MC is sourced from the original manufacturer or authorized distributors?
All MCP1642B-33I/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 MCP1642B-33I/MC meets industry standards.
7.What is the process for return or replacement of MCP1642B-33I/MC?
All MCP1642B-33I/MC units undergo pre-shipment inspection (PSI). If there is an issue with MCP1642B-33I/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 MCP1642B-33I/MC part is unused and in its original packaging.
Return procedure for MCP1642B-33I/MC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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