Analog Devices Inc. LTC4000IUFD-1#TRPBF

Overview

LTC4000IUFD-1#TRPBF from Analog Devices is a high-voltage, high-performance battery charge controller with input voltage regulation and maximum power point tracking (MPPT) for solar panel inputs. It converts externally compensated DC/DC supplies into full-featured chargers supporting 3V–60V input, ±0.25% float voltage accuracy, and programmable C/X or timer-based termination. It enables instant-on operation during charging of deeply discharged LiFePO₄ batteries.

For engineers reviewing the LTC4000IUFD-1#TRPBF datasheet, LTC4000IUFD-1#TRPBF pinout, LTC4000IUFD-1#TRPBF application, or LTC4000IUFD-1#TRPBF equivalent, key selection criteria include input voltage regulation loop (vs. current regulation in LTC4000), 28-lead 4mm × 5mm QFN package, ±1% charge current accuracy, NTC-based temperature qualification, and PowerPath™ ideal diode control for reverse-blocking and seamless system power handoff.

Technical Context

The LTC4000IUFD-1#TRPBF implements three independent regulation loops: input voltage (regulated to 1.000 V on IFB), battery float voltage (1.136 V on BFB), and output voltage (1.193 V on OFB). Its ITH pin serves as a high-impedance control node that sinks up to 1 mA to coordinate external DC/DC converter compensation.

It integrates dual ideal diode controllers: IGATE drives an external PFET for input-side reverse current protection and load sharing; BGATE controls a second PFET for battery-side PowerPath™, enabling instant-on by regulating output to 86% of float voltage when VOFB falls below 0.974 V during low-battery charging.

Key Specifications

Pinout & Package

Package: 28-lead plastic QFN (UFD), 4 mm × 5 mm, exposed pad (Pin 29) tied to GND. Thermal resistance θJA = 43°C/W, θJC = 4°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery charge controller applications.

Compared with LTC4000EUFD-1#TRPBF and LTC4000IGN-1#TRPBF, the LTC4000IUFD-1#TRPBF delivers guaranteed industrial-temperature operation and superior thermal management in a compact QFN, making it optimal for high-reliability solar-charged systems where ambient extremes and sustained high current are design constraints.

Availability

LTC4000IUFD-1#TRPBF is available at Aetrix Electronics and suitable for solar-powered remote monitoring stations, military portable radio systems, and industrial battery-equipped IoT gateways requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC4000IUFD-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, Inc. is a global semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision instrumentation, power management, and industrial systems.

The LTC4000-1 product line delivers high-voltage battery charge controllers with integrated MPPT and PowerPath™ architecture, designed specifically for solar, fuel cell, and other high-impedance energy harvesting applications demanding robustness and accuracy.

FAQ

What is the key functional difference between LTC4000IUFD-1#TRPBF and the standard LTC4000?

The LTC4000IUFD-1#TRPBF replaces the input current regulation loop of the LTC4000 with an input voltage regulation loop. This change enables stable operation with high-impedance sources like solar panels where current-mode control can cause oscillation or suboptimal MPPT tracking. The LTC4000IUFD-1#TRPBF regulates the IFB pin to 1.000 V, allowing precise input voltage setpoints independent of source current capability.

How does the instant-on feature work in LTC4000IUFD-1#TRPBF?

The LTC4000IUFD-1#TRPBF activates instant-on when the OFB pin voltage falls below 0.974 V (86% of the 1.136 V BFB reference). In this state, the BGATE driver regulates the external battery PFET to maintain the OFB voltage at 0.974 V, delivering immediate downstream system power-even from a heavily discharged battery-as soon as input is applied. This avoids boot delays in mission-critical applications.

Can LTC4000IUFD-1#TRPBF support Li-ion batteries with NTC thermistor qualification?

Yes, the LTC4000IUFD-1#TRPBF supports NTC-based temperature qualification for Li-ion batteries only. The NTC pin accepts a voltage divider between BIAS (2.9 V) and GND; charging is suspended if the NTC voltage falls outside the cold (75% VBIAS) or hot (35% VBIAS) thresholds, with 5% hysteresis. This function is explicitly disabled for LiFePO₄ and other chemistries per the datasheet.

What are the absolute maximum ratings for the IN and BAT pins of LTC4000IUFD-1#TRPBF?

The IN and BAT pins of the LTC4000IUFD-1#TRPBF have identical absolute maximum ratings: –0.3 V to +62 V relative to GND. Exceeding +62 V may cause permanent damage. These ratings apply regardless of whether the device is powered or unpowered, and they define the safe operating envelope for interfacing with solar arrays, fuel cells, or battery packs in harsh transient environments.

Does LTC4000IUFD-1#TRPBF require external compensation components for stability?

Yes, the LTC4000IUFD-1#TRPBF requires external compensation via the CC pin, which connects an R-C network to the ITH pin. This network tailors loop response for the specific external DC/DC converter used. The datasheet provides design procedures and example values; omitting or misconfiguring this network risks instability, poor transient response, or failure to regulate any of the four control loops (input, battery, output, or current).