Microchip Technology MCP73834T-CNI/MF

Overview

MCP73834T-CNI/MF from Microchip Technology is a stand-alone linear Li-ion/Li-polymer battery charge management controller in a 10-lead DFN-10 (3 mm × 3 mm) package. It delivers constant-current/constant-voltage charging with thermal regulation, 4.20 V ±0.75% voltage regulation, up to 1 A programmable charge current via external resistor, and integrated reverse discharge protection - designed for USB-powered portable devices requiring compact, reliable single-cell charging.

For engineers reviewing the MCP73834T-CNI/MF datasheet, MCP73834T-CNI/MF pinout, MCP73834T-CNI/MF application, or MCP73834T-CNI/MF equivalent, key selection criteria include its timer-enable (TE) input for system-controlled safety timing, thermistor-based temperature qualification, low-dropout LDO mode for battery-less system test, and DFN-10 thermal performance (θJA = 41°C/W).

Technical Context

The MCP73834T-CNI/MF implements a fully autonomous linear charging algorithm with preconditioning, fast-charge, constant-voltage, and automatic recharge phases. Its internal P-channel MOSFET pass transistor (RDSON = 300 mΩ) enables direct battery connection at VBAT, while the TE pin provides active control over the internal safety timer - distinguishing it from the MCP73833 variant which uses PG instead.

Thermal regulation dynamically scales charge current above 105°C junction temperature, and dual thermistor comparators (VT1 = 1.23 V, VT2 = 0.25 V) monitor NTC/PTC sensors with 50 µA bias current. 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: DFN-10 (3 mm × 3 mm), exposed thermal pad (EP) electrically connected to VSS - requires soldering EP to ground plane for optimal thermal performance and reliability.

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/MF, the MCP73834T-CNI/MF adds host-controllable timer suspension via TE - critical for load-sharing architectures; versus BQ24075RGTR, it offers tighter voltage tolerance (±0.75% vs ±1.0%), integrated LDO test mode, and simpler thermistor biasing, at the cost of lower max current.

Availability

MCP73834T-CNI/MF is available at Aetrix Electronics and suitable for USB-powered portable devices, wearable health monitors, industrial handheld scanners, and smart home sensors requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MCP73834T-CNI/MF 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 microcontrollers, analog, and Flash-IP solutions, serving automotive, industrial, consumer, and communications markets with high-reliability silicon and development tools.

The MCP73833/4 product line delivers highly integrated, space-efficient linear battery chargers optimized for cost-sensitive, size-constrained portable electronics - emphasizing autonomous operation, thermal safety, and USB compliance.

FAQ

What distinguishes MCP73834T-CNI/MF from MCP73833T-CNI/MF?

The MCP73834T-CNI/MF substitutes the PG (power-good) output of the MCP73833T-CNI/MF with a TE (timer enable) input, allowing external control of the internal safety timer. This enables host MCU-driven suspension of the timer during system load sharing - a critical feature for applications where the battery powers both the charger and host simultaneously. All other electrical specifications, including 4.20 V ±0.75% regulation and 1 A max charge current, remain identical between the two variants.

How is charge current programmed on MCP73834T-CNI/MF?

Charge current on the MCP73834T-CNI/MF is set using a single external resistor (RPROG) connected between the PROG pin and VSS. The relationship follows IREG = 1000 V / RPROG (with RPROG in kΩ and IREG in mA). For example, a 1.0 kΩ resistor yields 1000 mA, while a 10 kΩ resistor yields 100 mA. The PROG pin must not float - doing so disables the charger and limits reverse discharge to <2 µA.

Does MCP73834T-CNI/MF support battery temperature monitoring?

Yes, the MCP73834T-CNI/MF supports battery temperature monitoring via the THERM pin, which sources a precise 50 µA current into an external NTC or PTC thermistor. Internal comparators detect voltages exceeding 1.23 V (upper threshold) or falling below 0.25 V (lower threshold), suspending charge immediately upon fault detection. If temperature monitoring is not required, a 10 kΩ resistor from THERM to VSS satisfies bias requirements.

Can MCP73834T-CNI/MF operate without a battery connected?

Yes, the MCP73834T-CNI/MF supports system test (LDO) mode: when the THERM pin voltage exceeds VDD–100 mV and no battery is present, the device regulates VBAT to its factory-set voltage (4.20 V) and supplies up to the programmed charge current. This enables functional validation of downstream circuitry - such as PMICs or RF modules - without requiring a battery, simplifying production testing and debug.

What thermal performance can be expected from MCP73834T-CNI/MF in DFN-10 package?

The MCP73834T-CNI/MF in DFN-10 package achieves θJA = 41°C/W on a 4-layer JC51-7 standard board with natural convection - significantly better than the MSOP-10 variant (θJA = 113°C/W). This enables sustained 1 A charging at ambient temperatures up to +60°C without thermal shutdown, provided the exposed thermal pad (EP) is soldered to a solid ground plane per Microchip's layout guidelines.