Microchip Technology MCP73834T-CNI/UN

Overview

MCP73834T-CNI/UN from Microchip Technology is a stand-alone linear Li-ion/Li-polymer battery charge management controller in MSOP-10 package, featuring 4.20 V ±0.75% constant-voltage regulation, programmable 100 mA–1 A fast-charge current via PROG resistor, thermal regulation, and integrated reverse discharge protection. It enables USB-compliant charging in space-constrained portable devices such as Bluetooth headsets and digital cameras.

For engineers reviewing the MCP73834T-CNI/UN datasheet, MCP73834T-CNI/UN pinout, MCP73834T-CNI/UN application, or MCP73834T-CNI/UN equivalent, key selection criteria include its timer-enable (TE) input for dynamic safety timer control, thermistor-based temperature monitoring with 50 µA bias current, and factory-set 4.20 V regulation optimized for standard single-cell Li-ion batteries.

Technical Context

The MCP73834T-CNI/UN implements a three-phase linear charge algorithm-preconditioning (trickle), constant-current fast charge, and constant-voltage termination-with ratiometric current thresholds (e.g., 5% I_REG termination, 10% preconditioning) and factory-configured 4.20 V regulation. Its TE pin provides active low enable/disable of the internal safety timer, distinguishing it from the MCP73833 series.

Thermal regulation dynamically reduces charge current above ~105°C using die temperature sensing, while integrated P-channel MOSFET pass transistor (R_DS(on) = 300 mΩ max) and reverse discharge protection (<2 µA leakage) eliminate external components. The device operates across –40°C to +85°C ambient and supports system test (LDO) mode when THERM > VDD–100 mV.

Key Specifications

Pinout & Package

Package: MSOP-10 (3 mm × 3 mm, 0.5 mm pitch), exposed thermal pad (EP) electrically connected to VSS and requiring PCB thermal vias for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP73833T-CNI/UN, the MCP73834T-CNI/UN trades PG output for TE control-enabling dynamic timer management during system load sharing-while maintaining identical regulation accuracy and thermal performance; versus BQ24075RGTR, it offers superior timer flexibility and lower reverse leakage but requires Microchip-specific design integration.

Availability

MCP73834T-CNI/UN is available at Aetrix Electronics and suitable for USB-powered portable audio, wearable health monitors, industrial handheld scanners, and smart home sensors requiring stable component supply and long-term production continuity.

Supply support for MCP73834T-CNI/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 is a U.S.-based semiconductor manufacturer specializing in microcontrollers, analog, and interface solutions with broad industrial and automotive qualification.

The MCP7383x family delivers highly integrated, space-efficient linear battery chargers targeting cost-sensitive, size-constrained portable electronics with stringent USB compliance and safety requirements.

FAQ

What is the factory-set regulation voltage for MCP73834T-CNI/UN?

The MCP73834T-CNI/UN is factory-configured for 4.20 V ±0.75% constant-voltage regulation, matching the nominal full-charge voltage of standard single-cell Li-ion and Li-polymer batteries. This value is fixed and cannot be adjusted externally; other variants in the MCP73833/4 family offer 4.35 V, 4.40 V, or 4.50 V options, but MCP73834T-CNI/UN specifically implements the 4.20 V variant.

How does the TE pin on MCP73834T-CNI/UN affect charge timing?

The TE (Timer Enable) pin on MCP73834T-CNI/UN is an active-low input that directly controls the internal safety timer: pulling TE low enables the timer (default 4–8 hour timeout), while holding TE high disables it entirely. This allows the MCP73834T-CNI/UN to sustain continuous charging during system load sharing-preventing false timeout faults-unlike the MCP73833 series, which lacks this feature.

Can MCP73834T-CNI/UN be used without a thermistor?

Yes, MCP73834T-CNI/UN can operate without a thermistor: connect a 10 kΩ resistor from THERM to VSS to disable temperature monitoring. In this configuration, the device retains all charge functions (CC/CV, preconditioning, termination) but omits thermal fault suspension. Full temperature protection requires a compatible NTC thermistor biased by the internal 50 µA current source.

What is the maximum charge current supported by MCP73834T-CNI/UN?

The MCP73834T-CNI/UN supports a maximum fast-charge current of 1000 mA, achieved by connecting a 1.0 kΩ resistor from PROG to VSS. At this setting, preconditioning current is 100 mA (10% of I_REG) and termination occurs at 50 mA (5% of I_REG). Current scales inversely with PROG resistance per I_REG = 1000 V / R_PROG (kΩ), with minimum R_PROG = 833 Ω for full 1.2 A limit.

Does MCP73834T-CNI/UN provide reverse battery discharge protection?

Yes, MCP73834T-CNI/UN integrates reverse discharge protection that limits current flow from battery to input when VDD is absent or below VBAT. Measured reverse leakage is ≤2 µA under all conditions-including VDD < VSTOP, VDD < VBAT, or floating PROG-ensuring minimal self-discharge during storage or standby, critical for long-life portable applications.