Analog Devices Inc. LTC4075EDD#TRPBF

Overview

LTC4075EDD#TRPBF from Analog Devices (formerly Linear Technology) is a dual-input standalone linear Li-Ion battery charger IC that autonomously selects between wall adapter (DCIN) and USB (USBIN) power sources. It delivers up to 800 mA from DCIN and 500 mA from USBIN, regulates float voltage at 4.2 V ±0.6%, and uses internal MOSFETs with thermal feedback to maintain die temperature ≤105°C - ideal for compact portable electronics with space-constrained PCB layouts.

For engineers reviewing the LTC4075EDD#TRPBF datasheet, LTC4075EDD#TRPBF pinout, LTC4075EDD#TRPBF application, or LTC4075EDD#TRPBF equivalent, key selection criteria include independent charge current programming via IDC/IUSB pins, programmable termination threshold (ITERM), automatic recharge at 4.1 V, and dual open-drain status outputs (CHRG, PWR) for system-level power management.

Technical Context

The LTC4075EDD#TRPBF implements a constant-current/constant-voltage (CC/CV) charging algorithm with two independent internal P-channel MOSFETs - one for DCIN-to-BAT (RON-DC = 400 mΩ), another for USBIN-to-BAT (RON-USB = 550 mΩ). Input source selection is fully autonomous, based on UVLO thresholds (VUVDC = 4.15 V, VUVUSB = 3.95 V) and voltage margin detection (≥180 mV above BAT).

Thermal regulation operates via die-temperature sensing, reducing charge current when junction temperature approaches 105°C. Charge termination is triggered when battery current falls below a resistor-programmable threshold (e.g., 100 mA with RITERM = 1 kΩ), filtered by a 1.5 ms comparator delay to reject transients.

Key Specifications

Pinout & Package

The LTC4075EDD#TRPBF is housed in a thermally enhanced 10-lead (3 mm × 3 mm) DFN package with exposed pad (Pin 11) soldered to PCB ground for electrical connection and optimal heat dissipation (θJA = 40°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-input Li-Ion charging applications.

Compared with MCP73831T-2DCI/OT and BQ24075RGTR, the LTC4075EDD#TRPBF uniquely combines autonomous dual-input arbitration, resistor-programmable charge currents per source, die-temperature-based thermal regulation, and ±0.6% float accuracy - making it optimal for thermally demanding, multi-source portable systems.

Availability

LTC4075EDD#TRPBF is available at Aetrix Electronics and suitable for portable medical sensors, wireless headsets, handheld barcode scanners, and industrial IoT edge sensors requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for LTC4075EDD#TRPBF 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

Analog Devices (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC4075EDD#TRPBF belongs to Linear's precision battery management IC family, designed specifically for space-constrained, thermally sensitive portable devices needing robust dual-input Li-Ion charging without microcontroller dependency.

FAQ

What is the maximum charge current the LTC4075EDD#TRPBF can deliver from a wall adapter input?

The LTC4075EDD#TRPBF delivers up to 800 mA from the DCIN input when programmed with RIDC = 1.25 kΩ. This value is confirmed in the Electrical Characteristics table (IBAT = 760–840 mA, typical 800 mA) and reflects operation under TA = 25°C with thermal regulation inactive. At elevated temperatures or higher input-to-battery voltage differentials, current reduces automatically to maintain TJ ≤ 105°C.

Does the LTC4075EDD#TRPBF support trickle charging for deeply discharged batteries?

No - the LTC4075EDD#TRPBF does not implement trickle charge. That feature is exclusive to the base LTC4075 (not the X variant). The LTC4075EDD#TRPBF begins full-current charging immediately when BAT voltage rises above 2.9 V. This behavior is explicitly documented in Note 6 of the datasheet and distinguishes it from the non-X version.

How does the LTC4075EDD#TRPBF determine which power source to use when both DCIN and USBIN are present?

The LTC4075EDD#TRPBF prioritizes DCIN when both inputs are valid: VDCIN must exceed 4.15 V (UVLO) and be ≥180 mV above BAT voltage. If those conditions hold, DCIN powers the charger and USBIN current drops to <25 µA. This behavior is defined in Table 1 ("Power Source Selection") and verified in the Block Diagram (Figure 4075 BD) showing DC_ENABLE logic dominance.

Can the LTC4075EDD#TRPBF terminate charging based on battery voltage alone?

No - the LTC4075EDD#TRPBF terminates charging solely based on current decay in constant-voltage mode, not voltage thresholds. Termination occurs when IBAT falls below the resistor-programmed ITERMINATE threshold (e.g., 100 mA with RITERM = 1 kΩ), detected by a filtered comparator with 1.5 ms delay. Float voltage remains fixed at 4.2 V; no voltage-based cutoff is implemented.

What is the purpose of the exposed pad on the LTC4075EDD#TRPBF DFN package?

Pin 11 (exposed pad) is electrically GND and must be soldered to the PCB ground plane. It serves dual functions: (1) providing low-impedance electrical return for internal circuits, and (2) enabling efficient heat transfer from the die to the board - critical for achieving the specified θJA = 40°C/W thermal resistance. Failure to solder this pad degrades thermal performance significantly, as noted in datasheet Note 3.