Analog Devices Inc. LTC4007EUFD-1#TRPBF

Overview

LTC4007EUFD-1#TRPBF from Analog Devices (formerly Linear Technology) is a synchronous constant-current/constant-voltage battery charger controller for 3- or 4-cell Li-ion packs. It delivers up to 4A charging current with ±4% accuracy, ±0.8% float voltage accuracy, and operates from 6V–28V input. Its quasi-constant-frequency, constant-off-time PWM architecture eliminates audible noise with ceramic capacitors and supports thermistor-based temperature qualification.

For engineers reviewing the LTC4007EUFD-1#TRPBF datasheet, LTC4007EUFD-1#TRPBF pinout, LTC4007EUFD-1#TRPBF application, or LTC4007EUFD-1#TRPBF equivalent, key selection criteria include programmable 3/4-cell float voltage (12.6V/16.8V), integrated input current limiting, low-battery trickle charge enablement below 3.25V/cell, and 24-pin 4mm × 5mm QFN package with exposed thermal pad.

Technical Context

The LTC4007EUFD-1#TRPBF implements a current-mode synchronous buck topology with constant off-time control, delivering stable switching frequencies from 20kHz (dropout) to 345kHz (normal operation). Its dual-loop regulation uses ITH as the inner current loop control node and an internal 1.19V reference with precision resistor divider at BAT for outer voltage loop control.

Thermistor monitoring occurs via periodic sample-and-hold on NTC with programmable timing (R_RT), while safety logic suspends charging if temperature thresholds are violated or if low-battery condition persists beyond 25% of total charge time. Input FET control (INFET) enforces reverse-current protection and AC adapter presence detection (ACP).

Key Specifications

Pinout & Package

Package: 24-lead plastic QFN (4mm × 5mm), exposed thermal pad connected to GND and PGND for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Li-ion battery charger controller applications.

Compared with BQ24725ARHBT and MP2617GR-Z, the LTC4007EUFD-1#TRPBF offers superior analog configurability (pin-selectable 3/4-cell and 4.1/4.2V/cell), autonomous thermistor management, and higher input voltage tolerance (28V), making it ideal for industrial and high-reliability portable platforms requiring design-in flexibility and robust safety.

Availability

LTC4007EUFD-1#TRPBF is available at Aetrix Electronics and suitable for notebook computers, portable instruments, and battery-backup systems requiring stable component supply, long-lifecycle support, and guaranteed traceable sourcing.

Supply support for LTC4007EUFD-1#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 and maintains its high-performance analog IC portfolio with rigorous automotive and industrial qualification standards.

The LTC4007EUFD-1#TRPBF belongs to Linear's precision battery management controller family, engineered for high-efficiency, low-noise, and thermally robust Li-ion charging in space-constrained portable and industrial systems.

FAQ

What is the maximum supported battery configuration for the LTC4007EUFD-1#TRPBF?

The LTC4007EUFD-1#TRPBF supports both 3-cell and 4-cell Li-ion battery stacks. Configuration is selected via the 3C4C pin: grounding selects 12.6V float (3 × 4.2V), while leaving it open selects 16.8V float (4 × 4.2V). The CHEM pin further allows selection between 4.1V/cell (grounded) and 4.2V/cell (open), enabling compatibility with multiple Li-ion chemistries. This dual-pin configuration ensures precise voltage matching without external resistors or firmware.

How does the LTC4007EUFD-1#TRPBF handle low-battery preconditioning?

The LTC4007EUFD-1#TRPBF monitors cell voltage via the BAT pin and asserts LOBAT when voltage drops below 3.25V/cell (or 3.173V/cell for 4.1V chemistry). In this state, the controller enables low-current conditioning-typically ~10% of programmed full-scale current-to safely recover deeply discharged cells. If the low-voltage condition persists beyond 25% of the total charge time set by R_RT, the LTC4007EUFD-1#TRPBF terminates charging and pulls FAULT low, preventing unsafe operation.

Can the LTC4007EUFD-1#TRPBF operate without an external thermistor?

Yes-the LTC4007EUFD-1#TRPBF can operate without a thermistor. The NTC pin may be disabled by connecting a 300kΩ–500kΩ resistor from DCIN to NTC, which forces the thermistor circuit into a valid range and bypasses temperature qualification. However, disabling NTC removes critical thermal safety protection; Analog Devices strongly recommends retaining the thermistor network for all production designs involving user-accessible batteries or elevated ambient temperatures.

What is the role of the ITH pin in the LTC4007EUFD-1#TRPBF control architecture?

The ITH pin serves as the inner current loop control node in the LTC4007EUFD-1#TRPBF's current-mode PWM architecture. It integrates outputs from the voltage error amplifier (EA), current sense amplifier (CA2), and input current limit amplifier (CL1) to determine peak inductor current. A typical compensation network-a 6kΩ resistor in series with ≥0.1µF to GND-stabilizes the loop. ITH voltage directly scales charging current: higher ITH increases peak current, while EA reduces ITH as battery voltage approaches float level to achieve constant-voltage regulation.

Does the LTC4007EUFD-1#TRPBF support input current limiting from an AC adapter?

Yes-the LTC4007EUFD-1#TRPBF includes dedicated input current limiting via the CLP and CLN pins. By placing a sense resistor between CLP and CLN, the internal CL1 amplifier compares the resulting voltage drop against a 100mV threshold. When exceeded, CL1 reduces the ITH voltage to throttle charging current and asserts the ICL pin low. This feature maximizes charge rate without overloading the AC adapter, and is fully independent of battery voltage or state-of-charge-enabling robust operation across varying input sources.