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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Battery Chargers

Microchip Technology MCP73843T-420I/MS

Name: MCP73843T-420I/MS
Brand: Microchip Technology
SKU: MCP73843T-420I/MS
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MCP73843T-420I/MS

Manufacturer:: Microchip Technology

Category:: Battery Chargers

Package:: 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)

Datasheet:: MCP73843T-420I/MS.pdf

Description:: IC BATT CONTRL LI-ION 1CEL 8MSOP

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Product details

Overview

MCP73843T-420I/MS from Microchip Technology is a linear lithium-ion battery charge management controller in an 8-pin MSOP package, designed for single-cell Li-ion/Li-polymer packs with 4.2 V regulation, ±0.5% voltage accuracy, programmable fast-charge current via external sense resistor, and integrated safety timers. It enables compact, cost-sensitive portable chargers such as USB-powered cradle chargers and handheld medical instruments.

For engineers reviewing the MCP73843T-420I/MS datasheet, MCP73843T-420I/MS pinout, MCP73843T-420I/MS application, or MCP73843T-420I/MS equivalent, key selection criteria include its 4.2 V fixed regulation, absence of thermistor monitoring (vs. MCP73841), 8-pin MSOP footprint, -40°C to +85°C operating range, and compatibility with P-channel MOSFET gate drive for linear charging topologies.

Technical Context

The MCP73843T-420I/MS implements a three-phase linear charging algorithm: preconditioning (trickle-charge at ~10% I_REG when V_BAT < 2.85 V), constant-current fast charge (regulated by V_FCS = 110 mV across R_SENSE), and constant-voltage termination (at 4.2 V ±0.5%). It uses internal reference-based comparators for UVLO (4.45 V start), recharge threshold (V_REG − 200 mV), and charge termination (7% I_REG).

Unlike MCP73841/42, this variant omits THREF and THERM pins-eliminating continuous cell temperature monitoring-and integrates all timing functions (precondition, fast-charge, elapsed-time) via a single external capacitor on TIMER pin. Its DRV output directly sinks up to 2 mA to drive the gate of an external P-MOSFET in linear regulation mode.

Key Specifications

Parameter	Value and Actual Design Meaning
Regulation Voltage	4.2 V ±0.5% - precise termination for graphite-anode Li-ion cells; ensures full capacity without overvoltage stress.
Fast Charge Threshold	110 mV (V_FCS) - sets I_REG = 110 mV / R_SENSE; enables accurate, resistor-programmable charge current.
Precondition Threshold	2.85 V (V_PTH) - triggers safe trickle-charge for deeply depleted cells below this voltage.
Safety Timers	Configured by 0.1 µF TIMER capacitor: 60 min precondition, 1.5 hr fast-charge, 3.0 hr elapsed-time termination.
Operating Temp Range	-40°C to +85°C - fully specified for industrial and portable consumer environments.
Supply Voltage Range	4.5 V to 12 V - supports USB 5 V, wall adapters, and higher-input power sources.
Output Reverse Leakage	≤1 µA at V_BAT = 4.2 V - minimizes self-discharge when input power is removed.

Pinout & Package

Package: 8-pin MSOP (3.0 mm × 3.0 mm, 0.65 mm pitch), moisture-sensitive level 1, RoHS-compliant.

Pin/Terminal	Circuit Role	Design Meaning
1 SENSE	Current sense input	Voltage drop (V_FCS = 110 mV typ.) across external R_SENSE sets fast-charge current; precondition uses same node at reduced threshold.
2 VDD	Input supply	4.5–12 V main power input; includes UVLO (4.45 V start) and automatic power-down when removed.
3 STAT1	Status output	Open-drain, current-limited (7 mA typ.) - drives LED directly or interfaces to MCU with pull-up.
4 EN	Enable control	Logic-high enables charge; logic-low forces termination and reduces quiescent current to 0.25 µA.
5 TIMER	Timer capacitor interface	Connects to 0.1 µF capacitor to ground to set all three safety timers (precondition, fast-charge, elapsed).
6 VSS	Ground reference	0 V reference for battery negative terminal and internal circuitry; must be low-impedance connection.
7 VBAT	Battery voltage sense	Direct connection to battery positive; internal precision divider regulates to 4.2 V; bypass with ≥4.7 µF ceramic.
8 DRV	Gate drive output	Sinks up to 2 mA to control P-channel MOSFET gate; operates in linear region for CV/CC regulation.

Key Features

Feature	Design Value
High-accuracy voltage regulation	±0.5% tolerance at 4.2 V ensures compliance with Li-ion cell manufacturer specifications and extends cycle life.
Programmable charge current	Set via external R_SENSE (e.g., 220 mΩ → 500 mA); eliminates need for current-setting DAC or digital interface.
Integrated safety timers	Single capacitor configures precondition (60 min), fast-charge (1.5 hr), and elapsed-time (3.0 hr) limits - prevents thermal runaway.
Automatic end-of-charge control	Terminates when charge current drops to ≤7% I_REG or timer expires - avoids overcharging and electrolyte decomposition.
Preconditioning for deep discharge	Activates trickle-charge at 2.85 V threshold - safely recovers cells down to ~2.5 V without damaging anodes.

Applications

USB-Powered Cradle Charger	Portable Medical Monitor
Use Scenario: Desktop cradle that charges handheld diagnostic devices via micro-USB input while providing status feedback via dual-color LED. IC Role / Device Role / Timing Role: Standalone linear charger managing CC/CV profile, driving P-MOSFET, and controlling STAT1 LED blink patterns (ON during charge, OFF at completion). Use Value: Eliminates need for host MCU supervision; 4.2 V ±0.5% regulation ensures safe full-charge of single-cell Li-polymer packs used in FDA-cleared devices.	Use Scenario: Battery-backed vital signs monitor requiring reliable, low-noise charging in clinical environments with intermittent AC power. IC Role / Device Role / Timing Role: Primary charge controller interfacing with 5 V wall adapter; EN pin tied high for always-on operation; TIMER capacitor sets conservative 3-hour termination window. Use Value: Low 0.25 µA shutdown current preserves battery during AC loss; reverse leakage <1 µA prevents standby drain - critical for >72 hr runtime certification.
Handheld Barcode Scanner	Industrial Handheld Terminal
Use Scenario: Ruggedized scanner used in warehouse logistics, recharged daily via dock station with no firmware update capability. IC Role / Device Role / Timing Role: Fully autonomous charge manager handling precondition, CC ramp, CV hold, and auto-recharge (VRTH = V_REG − 200 mV) without host intervention. Use Value: 8-pin MSOP footprint saves PCB area vs. 10-pin alternatives; absence of thermistor circuit simplifies BOM and layout in non-temperature-critical applications.	Use Scenario: Field-deployed inventory terminal operating in wide ambient temperatures (−20°C to +60°C) with hot-swap battery support. IC Role / Device Role / Timing Role: Linear charge controller with UVLO (4.45 V) preventing erratic behavior during brownout; STAT1 provides visual charge state to user via front-panel LED. Use Value: −40°C to +85°C specification guarantees operation in uncontrolled environments; 206 °C/W θ_JA enables thermal design without heatsink in sealed enclosures.

USB-Powered Cradle Charger

Portable Medical Monitor

Use Scenario: Desktop cradle that charges handheld diagnostic devices via micro-USB input while providing status feedback via dual-color LED.

IC Role / Device Role / Timing Role: Standalone linear charger managing CC/CV profile, driving P-MOSFET, and controlling STAT1 LED blink patterns (ON during charge, OFF at completion).

Use Value: Eliminates need for host MCU supervision; 4.2 V ±0.5% regulation ensures safe full-charge of single-cell Li-polymer packs used in FDA-cleared devices.

Use Scenario: Battery-backed vital signs monitor requiring reliable, low-noise charging in clinical environments with intermittent AC power.

IC Role / Device Role / Timing Role: Primary charge controller interfacing with 5 V wall adapter; EN pin tied high for always-on operation; TIMER capacitor sets conservative 3-hour termination window.

Use Value: Low 0.25 µA shutdown current preserves battery during AC loss; reverse leakage <1 µA prevents standby drain - critical for >72 hr runtime certification.

Handheld Barcode Scanner

Industrial Handheld Terminal

Use Scenario: Ruggedized scanner used in warehouse logistics, recharged daily via dock station with no firmware update capability.

IC Role / Device Role / Timing Role: Fully autonomous charge manager handling precondition, CC ramp, CV hold, and auto-recharge (VRTH = V_REG − 200 mV) without host intervention.

Use Value: 8-pin MSOP footprint saves PCB area vs. 10-pin alternatives; absence of thermistor circuit simplifies BOM and layout in non-temperature-critical applications.

Use Scenario: Field-deployed inventory terminal operating in wide ambient temperatures (−20°C to +60°C) with hot-swap battery support.

IC Role / Device Role / Timing Role: Linear charge controller with UVLO (4.45 V) preventing erratic behavior during brownout; STAT1 provides visual charge state to user via front-panel LED.

Use Value: −40°C to +85°C specification guarantees operation in uncontrolled environments; 206 °C/W θ_JA enables thermal design without heatsink in sealed enclosures.

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear lithium-ion charge management applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MCP73831T-2DCI/OT	Single-cell 4.2 V charger in SOT-23-5; no TIMER pin - fixed 3 hr termination; no EN or STAT1; lower integration.	Limited to ultra-compact designs where only basic CC/CV is needed and status feedback is unnecessary.	Select when board space is extreme constraint and safety timer configurability is not required.
BQ24075RGTR	Texas Instruments part in QFN-16; includes integrated MOSFET, USB-compatible input current limit, and I²C interface.	Requires PCB redesign for larger package and digital control; adds complexity but enables dynamic current adjustment and fault reporting.	Select when system-level intelligence (e.g., host-controlled charge rate or thermal derating) is needed beyond standalone analog control.

Compared with MCP73831T-2DCI/OT, the MCP73843T-420I/MS offers configurable timers and status indication; compared with BQ24075RGTR, it delivers simpler, lower-cost, and lower-power analog-only operation without integrated FET or communication overhead.

Availability

MCP73843T-420I/MS is available at Aetrix Electronics and suitable for USB-powered cradle chargers, portable medical monitors, handheld barcode scanners, and industrial handheld terminals requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MCP73843T-420I/MS 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 battery management ICs, headquartered in Chandler, Arizona, with global manufacturing and support infrastructure.

The MCP7384X family was designed specifically for space-constrained, cost-sensitive linear charging of single- and dual-cell Li-ion/Li-polymer batteries - emphasizing accuracy, safety timer flexibility, and minimal external component count.

FAQ

What is the exact regulated output voltage of the MCP73843T-420I/MS?

The MCP73843T-420I/MS provides a fixed 4.2 V regulation voltage with a maximum tolerance of ±0.5% (4.179 V to 4.221 V) across -5°C to +55°C, as specified in the DS21823D datasheet. This value is factory-trimmed and applies under standard test conditions: V_DD = V_REG(Typ) + 1 V and I_OUT = 10 mA. The "420" in the part number explicitly denotes the 4.2 V version.

Does the MCP73843T-420I/MS support battery temperature monitoring?

No, the MCP73843T-420I/MS does not support battery temperature monitoring. Unlike the MCP73841/MCP73842 variants, it lacks THREF and THERM pins. This omission is intentional per the device family documentation: MCP73843 and MCP73844 exclude the thermistor interface to reduce cost and simplify designs where thermal qualification is not required.

How is the charge current programmed on the MCP73843T-420I/MS?

Charge current is programmed using an external sense resistor (R_SENSE) between VDD and the source of the external P-MOSFET. The MCP73843T-420I/MS regulates fast-charge current by maintaining 110 mV (typical) across R_SENSE, so I_REG = 0.11 V / R_SENSE. For example, a 220 mΩ resistor sets I_REG ≈ 500 mA. Precondition and termination currents scale proportionally to I_REG.

What safety timers are implemented in the MCP73843T-420I/MS and how are they configured?

The MCP73843T-420I/MS implements three independent safety timers: precondition (60 min), fast-charge (1.5 hr), and elapsed-time termination (3.0 hr). All are scaled by a single external capacitor (C_TIMER) connected between the TIMER pin and VSS. With C_TIMER = 0.1 µF, the timers achieve their nominal durations; values scale linearly (e.g., 0.2 µF doubles all periods).

Can the MCP73843T-420I/MS be used with a dual-cell battery pack?

No, the MCP73843T-420I/MS is designed exclusively for single-cell Li-ion/Li-polymer battery packs with 4.2 V regulation. Dual-cell applications require 8.2 V or 8.4 V variants (e.g., MCP73842 or MCP73844). Using MCP73843T-420I/MS with a dual-cell pack would result in undercharging - each cell receiving only ~2.1 V - and failure to reach full capacity or proper termination.

MCP73843T-420I/MS Specifications

Product attributes: Attribute value

Manufacturer:: Microchip Technology

Series:: -

Package/Case:: 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Active

Battery Chemistry:: Lithium Ion/Polymer

Number of Cells:: 1

Current - Charging:: -

Programmable Features:: Timer

Fault Protection:: -

Charge Current - Max:: -

Battery Pack Voltage:: 4.2V

Voltage - Supply (Max):: 12V

Interface:: -

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-MSOP

MCP73843T-420I/MS FAQ

1.How can I place an order for MCP73843T-420I/MS through Aetrix?

Please submit a Request for Quotation (RFQ) for MCP73843T-420I/MS 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 MCP73843T-420I/MS reliable?

The price and inventory of MCP73843T-420I/MS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MCP73843T-420I/MS is usually 5 days.

3.What payment methods are accepted for MCP73843T-420I/MS?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MCP73843T-420I/MS transactions.

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4.How is shipping managed for MCP73843T-420I/MS?

MCP73843T-420I/MS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MCP73843T-420I/MS 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 MCP73843T-420I/MS?

For technical support, including MCP73843T-420I/MS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MCP73843T-420I/MS requirements.

6.How does Aetrix verify that MCP73843T-420I/MS is sourced from the original manufacturer or authorized distributors?

All MCP73843T-420I/MS 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 MCP73843T-420I/MS meets industry standards.

7.What is the process for return or replacement of MCP73843T-420I/MS?

All MCP73843T-420I/MS units undergo pre-shipment inspection (PSI). If there is an issue with MCP73843T-420I/MS, 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 MCP73843T-420I/MS part is unused and in its original packaging.

Return procedure for MCP73843T-420I/MS:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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