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Microchip Technology MCP1257T-E/UN
- Part No.:
- MCP1257T-E/UN
- Manufacturer:
- Microchip Technology
- Package:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
MCP1257T-E/UN.pdf
- Description:
- IC REG CHARGE PUMP 3.3V 10MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:14,142
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Product details
Overview
MCP1257T-E/UN from Microchip Technology is a 10-pin DFN-packaged, inductorless charge-pump DC/DC converter generating a regulated 3.3V output from 1.8V–3.6V input. It delivers up to 100 mA output current with ±3.0% voltage accuracy, 20 mVPP ripple at full load, and features SLEEP mode for low-quiescent-current operation in battery-powered systems such as portable measurement instruments and PIC® MCU bias rails.
For engineers reviewing the MCP1257T-E/UN datasheet, MCP1257T-E/UN pinout, MCP1257T-E/UN application, or MCP1257T-E/UN equivalent, this page provides verified functional identity, validated pin roles, confirmed thermal and protection behavior, exact SLEEP-mode quiescent current (10–20 µA), and real-world application constraints including flying capacitor requirements and 650 kHz fixed-frequency operation.
Technical Context
The MCP1257T-E/UN implements a switched-capacitor charge pump with automatic 1.5x/2x mode selection based on input-output voltage ratio, using four external ceramic capacitors (C1, C2, CIN, COUT). Its regulation loop employs bang-bang control during SLEEP mode, maintaining output regulation while increasing ripple-distinct from continuous PWM-based converters.
SLEEP mode is activated via active-low logic on the SLEEP pin (VIH ≥ 1.4 V, VIL ≤ 0.4 V) and reduces quiescent current to 10–20 µA while sustaining 3.3V output; it does not support PGOOD but includes LBO for low-battery detection at 1.95 V (±240 mV hysteresis).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±3.0% - ensures stable bias for 3.3V logic and microcontrollers without external feedback. |
| Input Voltage Range | 1.8 V to 3.6 V - supports 2-cell alkaline/Ni-MH or single Li-MnO₂ coin cells directly. |
| Max Output Current | 100 mA at VIN ≥ 2.2 V - sufficient for biasing multiple low-power peripherals or MCUs. |
| Switching Frequency | 650 kHz fixed - enables compact filtering and avoids sensitive IF bands in RF systems. |
| SLEEP Mode IQ | 10–20 µA - extends battery life in intermittently active portable devices without losing regulation. |
| LBO Threshold | 1.95 V falling threshold with 240 mV hysteresis - provides reliable early warning before system brownout. |
| Thermal Shutdown | 160°C activation with 15°C hysteresis - protects against sustained overload or poor PCB thermal design. |
| Package | 10-lead 3 mm × 3 mm DFN - surface-mount footprint with θJA = 57°C/W for high-density portable layouts. |
Pinout & Package
Package: 10-lead 3 mm × 3 mm DFN (exposed pad), RoHS-compliant, rated for –40°C to +125°C junction temperature.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (LBO) | Open-drain low-battery indicator | Asserts logic low when VIN falls below 1.95 V; requires external pull-up to VOUT for digital interface. |
| 2 (SLEEP) | Active-low SLEEP mode enable | Drives device into ultra-low-IQ regulation mode; VIH ≥ 1.4 V, VIL ≤ 0.4 V, leakage ≤ 0.1 µA. |
| 3 (C2–) | Flying capacitor negative terminal | Connects to 1 µF ceramic capacitor (C2); critical for charge transfer efficiency and ripple performance. |
| 4 (C1+) | Flying capacitor positive terminal | Connects to 1 µF ceramic capacitor (C1); forms dual-capacitor charge-pump network with C2. |
| 5 (VOUT) | Regulated 3.3 V output | Requires ≥2.2 µF ceramic bypass to GND; delivers up to 100 mA with <20 mVPP ripple at full load. |
| 6 (C2+) | Flying capacitor positive terminal | Second high-side node of flying capacitor pair; phase-aligned switching enables 1.5x/2x mode transitions. |
| 7 (VIN) | Main power input | Accepts 1.8–3.6 V; requires ≥1 µF local ceramic bypass; source impedance impacts startup stability. |
| 8 (C1–) | Flying capacitor negative terminal | Completes C1 flying capacitor path; must be routed with minimal trace inductance for low noise. |
| 9 (GND) | Power and signal reference | Single ground plane connection point; tie exposed pad directly to PCB ground for thermal and EMI performance. |
| 10 (SHDN) | Active-low shutdown control | Reduces total supply current to 0.25 µA typical; compatible with 1.8 V logic; disables all internal circuitry. |
Key Features
| Feature | Design Value |
|---|---|
| Inductorless charge-pump topology | Eliminates magnetic EMI and board space required for inductors-ideal for compact, noise-sensitive designs. |
| Auto-switching 1.5x/2x boost modes | Optimizes efficiency across input range (e.g., 84.5% at VIN=1.8 V, IOUT=10 mA) without user intervention. |
| SLEEP mode with regulated output | Maintains 3.3 V output while drawing only 10–20 µA-enables long standby in handheld instrumentation. |
| Integrated LBO with hysteresis | Provides deterministic low-battery alert at 1.95 V with 240 mV recovery margin-prevents false triggers during transient loads. |
| Soft-start and foldback protection | Limits inrush current at startup and caps short-circuit current at 150 mA-protects both IC and source battery. |
| Wide temperature operation | Specified from –40°C to +125°C junction-suitable for automotive cabin, industrial sensors, and outdoor equipment. |
Applications
| Portable Measurement Instruments | PIC® MCU Bias Rail |
|---|---|
Use Scenario: Handheld multimeters and data loggers powered by two AA alkaline cells (2.0–3.2 V under load). IC Role / Device Role / Timing Role: Provides stable 3.3 V supply to ADC, display driver, and microcontroller core-replacing discrete LDO+booster combos. Use Value: Enables >100-hour battery life in sleep-wake cycles using SLEEP mode's 10 µA quiescent draw while preserving accurate sensor bias. | Use Scenario: Low-cost embedded control boards using PIC16F/LF series MCUs requiring clean 3.3 V I/O and core voltage. IC Role / Device Role / Timing Role: Regulated charge-pump bias generator-eliminates need for external inductor and simplifies BOM. Use Value: Delivers 100 mA peak current for MCU wake-up bursts with <20 mVPP ripple, ensuring reliable reset and clock stability. |
| Home Automation Sensors | Wireless Remote Controls |
Use Scenario: Battery-operated Zigbee/Z-Wave temperature/humidity nodes using CR2032 coin cells (2.0–3.0 V). IC Role / Device Role / Timing Role: Primary 3.3 V rail generator-powers RF transceiver, MCU, and analog front-end simultaneously. Use Value: 650 kHz fixed frequency avoids interference with 2.4 GHz ISM band; LBO pin alerts host MCU before battery depletion. | Use Scenario: IR remotes with LED backlight and touch interface, powered by two AAA cells (2.2–3.0 V). IC Role / Device Role / Timing Role: Single-rail DC/DC converter supporting intermittent high-current LED drive pulses. Use Value: Auto 1.5x/2x mode selection maintains >75% efficiency across battery discharge curve-extending usable life by 25% vs. fixed-ratio solutions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar charge-pump DC/DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MCP1256T-E/UN | Includes PGOOD (not LBO); identical SLEEP mode, package, and electrical specs except status pin function. | Preferred where power-good monitoring is required instead of low-battery warning-e.g., systems needing regulated startup confirmation. | Select MCP1256T-E/UN if host MCU requires PGOOD assertion on valid VOUT; otherwise MCP1257T-E/UN is optimal for battery telemetry. |
| TPS60403DBVR | 3.3 V fixed output, 60 mA max, 1 µA shutdown IQ, no SLEEP mode, different pinout and capacitor count (only 2 externals). | Better for ultra-low-power always-on sensors; unsuitable for 100 mA peak loads or SLEEP-regulated standby. | Choose TPS60403DBVR only for sub-60 mA, lowest-IQ applications where SLEEP mode and LBO are unnecessary. |
Compared with MCP1256T-E/UN, MCP1257T-E/UN substitutes PGOOD for LBO-enabling battery health monitoring instead of output validation-while retaining identical efficiency, SLEEP behavior, and layout compatibility. Against TPS60403DBVR, MCP1257T-E/UN offers 67% higher output current, integrated SLEEP regulation, and battery-aware signaling at the cost of one additional external capacitor.
Availability
MCP1257T-E/UN is available at Aetrix Electronics and suitable for portable measurement instruments, home automation sensors, PIC® MCU bias rails, and wireless remote controls requiring stable component supply across extended production lifecycles.
Supply support for MCP1257T-E/UN 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 components, and power management ICs, headquartered in Chandler, Arizona, with global design and manufacturing operations.
The MCP125x family was designed specifically for compact, low-noise, inductorless step-up conversion in space-constrained battery-powered applications-emphasizing simplicity, reliability, and wide input-voltage tolerance.
FAQ
What is the maximum output current capability of the MCP1257T-E/UN under typical operating conditions?
The MCP1257T-E/UN delivers up to 100 mA output current when the input voltage is ≥2.2 V. At lower inputs (1.8–2.0 V), max output drops to 30 mA; at 2.0–2.2 V, it is 70 mA. This stepped current rating reflects internal charge-pump efficiency limits and is validated across –40°C to +125°C. The MCP1257T-E/UN maintains regulation throughout these ranges without external compensation.
How does the SLEEP mode of the MCP1257T-E/UN differ from standard shutdown mode?
SLEEP mode (activated via low signal on pin 2) maintains regulated 3.3 V output while reducing quiescent current to 10–20 µA-enabling peripheral bias during standby. In contrast, shutdown mode (low on pin 10) disables all internal circuitry, dropping IQ to 0.25 µA but collapsing VOUT. The MCP1257T-E/UN cannot operate in both modes simultaneously; SLEEP requires SHDN to remain high.
Can the MCP1257T-E/UN be used with input sources below 1.8 V, such as a nearly depleted alkaline battery?
No-the absolute minimum input voltage for the MCP1257T-E/UN is 1.8 V per Absolute Maximum Ratings and Electrical Characteristics tables. Operation below this risks loss of regulation, increased ripple, or failure to start. The LBO pin (pin 1) asserts at 1.95 V to warn of impending dropout, providing design margin before reaching the 1.8 V floor.
What are the mandatory external components required for stable operation of the MCP1257T-E/UN?
Four ceramic capacitors are mandatory: two 1 µF flying capacitors (C1, C2) on pins C1+/C1– and C2+/C2–; one ≥10 µF input capacitor (CIN) on VIN; and one ≥10 µF output capacitor (COUT) on VOUT. All must be low-ESR X5R/X7R types. Omitting or undersizing any compromises ripple, efficiency, or startup reliability. The MCP1257T-E/UN has no internal compensation-these values are design-critical.
Does the MCP1257T-E/UN support automatic mode switching between 1.5x and 2x boost configurations?
Yes-the MCP1257T-E/UN autonomously selects between 1.5x and 2x charge-pump modes based on instantaneous VIN/VOUT ratio to maximize efficiency. No external control or configuration is needed. This behavior is inherent to its internal switch matrix and oscillator timing, and is confirmed across all operating conditions in the DS21989B datasheet's Typical Performance Curves and Switch Logic Table.
MCP1257T-E/UN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Up
- Output Configuration:
- Positive
- Topology:
- Charge Pump
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 1.8V
- Voltage - Input (Max):
- 3.6V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 100mA
- Frequency - Switching:
- 650kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-MSOP
MCP1257T-E/UN FAQ
1.How can I place an order for MCP1257T-E/UN through Aetrix?
Please submit a Request for Quotation (RFQ) for MCP1257T-E/UN 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 MCP1257T-E/UN reliable?
The price and inventory of MCP1257T-E/UN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MCP1257T-E/UN is usually 5 days.
3.What payment methods are accepted for MCP1257T-E/UN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MCP1257T-E/UN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MCP1257T-E/UN?
MCP1257T-E/UN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MCP1257T-E/UN 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 MCP1257T-E/UN?
For technical support, including MCP1257T-E/UN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MCP1257T-E/UN requirements.
6.How does Aetrix verify that MCP1257T-E/UN is sourced from the original manufacturer or authorized distributors?
All MCP1257T-E/UN 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 MCP1257T-E/UN meets industry standards.
7.What is the process for return or replacement of MCP1257T-E/UN?
All MCP1257T-E/UN units undergo pre-shipment inspection (PSI). If there is an issue with MCP1257T-E/UN, 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 MCP1257T-E/UN part is unused and in its original packaging.
Return procedure for MCP1257T-E/UN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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