My Inquiry
My Account
Microchip Technology MCP1642B-ADJI/MC
- Part No.:
- MCP1642B-ADJI/MC
- Manufacturer:
- Microchip Technology
- Package:
- 8-VFDFN Exposed Pad
- Datasheet:
-
MCP1642B-ADJI/MC.pdf
- Description:
- IC REG BOOST ADJ 800MA 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:761
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MCP1642B-ADJI/MC from Microchip Technology is a synchronous step-up DC-DC converter with true output disconnect shutdown, 1.21V feedback reference, 1 MHz fixed-frequency PWM operation, and 0.65V typical start-up voltage for 3.3V output - designed for single-cell Li-Ion, alkaline, or NiMH battery-powered portable medical sensors and PIC® MCU power rails.
For engineers reviewing the MCP1642B-ADJI/MC datasheet, MCP1642B-ADJI/MC pinout, MCP1642B-ADJI/MC application, or MCP1642B-ADJI/MC equivalent, key selection criteria include low-voltage start-up capability, adjustable 1.8–5.5V output via external resistor divider, integrated synchronous rectification, and thermal shutdown at 150°C with 35°C hysteresis.
Technical Context
The MCP1642B-ADJI/MC implements peak-current-mode control with adaptive slope compensation, enabling stable operation across wide input (0.35–5.5V) and output (1.8–5.5V) ranges. Its dual-MOSFET architecture integrates a 0.15Ω N-channel boost switch and 0.3Ω P-channel synchronous rectifier, eliminating external diode losses.
Startup uses open-loop charge-pump-assisted pre-charge of VOUT to VIN level before transitioning to closed-loop PWM regulation. The EN pin enables logic-controlled shutdown with <1 µA quiescent current, and the PG open-drain output asserts low when VOUT falls below 90% of regulation with 3% hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Start-Up Voltage | 0.65V typical (3.3V VOUT, 1 mA load): enables operation from deeply discharged single-cell batteries. |
| Switching Frequency | 1.0 MHz ±15%: enables use of small 4.7 µH inductors and low-ESR ceramic capacitors. |
| Feedback Reference | 1.21V ±3%: sets output voltage via external resistor divider; supports 1.8–5.5V adjustable range. |
| Peak Switch Current | 1.8A typical: determines maximum deliverable output current (e.g., >800 mA @ 3.3V VIN → 5.0V VOUT). |
| Quiescent Current | 400–500 µA in PWM mode; 1 µA in shutdown: preserves battery life in intermittent-use sensor nodes. |
| Thermal Protection | 150°C trip with 35°C hysteresis: prevents damage during sustained high-load or poor PCB thermal design. |
| Power Good Threshold | 90% of VOUT with 3% hysteresis: provides reliable MCU reset or sequencing signal without external monitoring. |
Pinout & Package
Package: 8-lead MSOP (3.0 mm × 4.9 mm, 0.65 mm pitch), RoHS-compliant, with exposed thermal pad (EP) not electrically connected - requires external PCB connection to SGND/PGND plane for thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - EN | Enable control input | Logic-high (>75% VIN) enables regulation; logic-low (<20% VIN) forces true output disconnect shutdown. |
| 2 - NC | No-connect terminal | Unbonded pad; must remain floating - no routing or solder mask opening required. |
| 3 - PG | Open-drain Power Good | Sinks current when VOUT drops below 90% of target; requires external pull-up to VOUT or system rail. |
| 4 - VOUT | Regulated output node | Connects to output capacitor and external feedback divider; carries full load current. |
| 5 - SW | Switch node | High dv/dt node connecting inductor to internal N- and P-channel MOSFETs; peak current up to 1.8A. |
| 6 - PGND | Power ground return | Low-impedance return path for boost switch current; must be tied to SGND externally on PCB. |
| 7 - SGND | Signal ground reference | Reference for error amplifier and VFB comparator; connects to PGND at single point near IC. |
| 8 - VIN | Input supply | Accepts 0.35–5.5V; requires ≥4.7 µF local ceramic bypass capacitor to PGND/SGND. |
Key Features
| Feature | Design Value |
|---|---|
| True Output Disconnect | MCP1642B variant isolates VOUT from VIN in shutdown - eliminates battery drain through load or output capacitance. |
| Low-Noise Anti-Ringing Control | Integrated damping circuit suppresses high-frequency oscillations at SW node - reduces EMI in sensitive RF or analog circuits. |
| Internal Compensation | Full Type-II compensation network embedded - eliminates external capacitor/resistor requirements and simplifies layout. |
| Inrush Limiting & Soft-Start | 550 µs soft-start time and controlled pre-charge limit output overshoot and input current surge during enable. |
| 1.21V Precision Feedback | ±3% VFB accuracy over -40°C to +85°C ensures stable output regulation without trimming or calibration. |
Applications
| Wireless Sensor Node | PIC® MCU Power Supply |
|---|---|
Use Scenario: Battery-powered temperature/humidity sensor transmitting data via BLE every 30 seconds. IC Role / Device Role / Timing Role: Step-up regulator converting 1.2–1.8V alkaline cell output to stable 3.3V for MCU and radio. Use Value: 0.65V start-up enables operation down to 1.0V cell voltage; 1 µA shutdown current extends shelf life beyond 5 years. |
Use Scenario: Low-power PIC16F15323-based handheld meter requiring clean 3.3V rail from single AA cell. IC Role / Device Role / Timing Role: Primary power source with PG signal used to wake MCU from sleep upon valid VOUT. Use Value: Internal soft-start prevents brown-out during MCU boot; PG delay (600 µs) ensures stable VOUT before firmware execution. |
| USB Emergency Charger | Personal Medical Device |
Use Scenario: Portable USB-A backup charger using two NiMH cells (2.4V nominal) to deliver 5.0V/500 mA to smartphones. IC Role / Device Role / Timing Role: Synchronous boost converter with adjustable output set to 5.0V via resistor divider. Use Value: 96% peak efficiency at 3.3V→5.0V minimizes heat buildup in compact enclosure; 1.8A peak switch supports transient loads. |
Use Scenario: FDA-class II glucose monitor powered by single lithium coin cell (3.0V), requiring regulated 3.3V for ADC and display. IC Role / Device Role / Timing Role: Isolated power source with true disconnect preventing battery leakage during device off-state. Use Value: Overtemperature protection (150°C) ensures safety during accidental pocket storage; 0.35V operating minimum sustains function until cell depletion. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous boost regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Texas Instruments TPS610992RTER | Fixed 3.3V output only; 0.7V start-up; 1.2 MHz switching; no true disconnect - output remains connected in shutdown. | Better for ultra-low-VIN apps (<0.7V), but lacks adjustable output and output isolation; requires external PG monitoring. | Select when lowest possible start-up voltage is critical and fixed 3.3V suffices; avoid if true disconnect or adjustable VOUT needed. |
| Analog Devices ADP5070ACPZ-R7 | Higher 2.5 MHz switching; dual-output (boost + inverting); 1.6A switch; requires external compensation; no PG pin. | Supports dual-rail systems (e.g., ±3.3V), but larger solution size and higher BOM count; no integrated power-good signaling. | Choose for multi-rail designs needing inversion; reject for space-constrained single-output battery apps where PG and simplicity matter. |
Compared with TPS610992RTER and ADP5070ACPZ-R7, the MCP1642B-ADJI/MC uniquely combines adjustable output, true output disconnect, integrated PG, and sub-1V start-up in an 8-pin MSOP - making it optimal for compact, battery-sensitive, single-rail portable devices requiring guaranteed isolation and MCU coordination.
Availability
MCP1642B-ADJI/MC is available at Aetrix Electronics and suitable for wireless sensor nodes, PIC® MCU power supplies, USB emergency chargers, and personal medical devices requiring stable component supply with long-term lifecycle support.
Supply support for MCP1642B-ADJI/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 microcontrollers, analog, interface, mixed-signal, and Flash-IP solutions, serving automotive, industrial, consumer, and communications markets with vertically integrated silicon and software tools.
The MCP1642B/D family was engineered specifically for ultra-low-input-voltage, high-efficiency boost conversion in space-constrained battery-powered systems - emphasizing true output disconnect, minimal external components, and robust thermal protection.
FAQ
What is the minimum input voltage required for MCP1642B-ADJI/MC to start regulating 3.3V output?
The MCP1642B-ADJI/MC has a typical start-up voltage of 0.65V for a 3.3V output under 1 mA resistive load. It can begin charging the output capacitor from this level, then transition into closed-loop PWM regulation once VOUT reaches ~90% of target. This enables operation from nearly depleted single-cell alkaline or NiMH batteries.
Does MCP1642B-ADJI/MC support adjustable output voltage, and how is it configured?
Yes, MCP1642B-ADJI/MC is the adjustable version of the family. Output voltage is set using an external resistor divider between VOUT and GND, with the midpoint connected to VFB. With VFB = 1.21V, the output range is 1.8V to 5.5V. High-value resistors (e.g., 976 kΩ top / 309 kΩ bottom for 3.3V) minimize quiescent current impact on light-load efficiency.
How does the true output disconnect feature of MCP1642B-ADJI/MC operate during shutdown?
When EN is pulled low, MCP1642B-ADJI/MC turns off both its internal N-channel boost switch and P-channel synchronous rectifier, breaking the DC path between VIN and VOUT. This isolates the output capacitor and load from the battery, drawing <1 µA total input current and preventing battery discharge - unlike bypass-mode regulators that maintain VIN-to-VOUT conduction.
What is the purpose and behavior of the PG (Power Good) pin on MCP1642B-ADJI/MC?
The PG pin on MCP1642B-ADJI/MC is an open-drain output that pulls low when VOUT falls below 90% of its regulated value, with 3% hysteresis. It asserts after a 600 µs delay following VOUT reaching regulation and responds to faults within 250 µs. Used with an external pull-up, it provides a reliable MCU-ready signal for power sequencing or fault detection.
Can MCP1642B-ADJI/MC operate with input voltages higher than the desired output voltage?
No - MCP1642B-ADJI/MC is a boost-only converter. When VIN exceeds VOUT, regulation is lost because the internal P-channel rectifier cannot block reverse current, and the control loop ceases switching. The datasheet explicitly states "for VIN > VOUT, VOUT will not remain in regulation." It must be used only in step-up configurations where VIN < VOUT.
MCP1642B-ADJI/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:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 0.65V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 1.8V
- Voltage - Output (Max):
- 5.5V
- 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-ADJI/MC FAQ
1.How can I place an order for MCP1642B-ADJI/MC through Aetrix?
Please submit a Request for Quotation (RFQ) for MCP1642B-ADJI/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-ADJI/MC reliable?
The price and inventory of MCP1642B-ADJI/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-ADJI/MC is usually 5 days.
3.What payment methods are accepted for MCP1642B-ADJI/MC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MCP1642B-ADJI/MC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MCP1642B-ADJI/MC?
MCP1642B-ADJI/MC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MCP1642B-ADJI/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-ADJI/MC?
For technical support, including MCP1642B-ADJI/MC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MCP1642B-ADJI/MC requirements.
6.How does Aetrix verify that MCP1642B-ADJI/MC is sourced from the original manufacturer or authorized distributors?
All MCP1642B-ADJI/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-ADJI/MC meets industry standards.
7.What is the process for return or replacement of MCP1642B-ADJI/MC?
All MCP1642B-ADJI/MC units undergo pre-shipment inspection (PSI). If there is an issue with MCP1642B-ADJI/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-ADJI/MC part is unused and in its original packaging.
Return procedure for MCP1642B-ADJI/MC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MCP1642B-ADJI/MC Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
