Analog Devices Inc. LTC4065AEDC#TRPBF

Overview

LTC4065AEDC#TRPBF from Analog Devices (formerly Linear Technology) is a standalone linear lithium-ion battery charger IC designed for single-cell 4.2V Li-Ion batteries in portable electronics. It delivers up to 750mA programmable charge current with ±5% accuracy, features C/10 termination detection, thermal regulation at 115°C, and integrated power MOSFET - requiring no external sense resistor, blocking diode, or external FET. It is optimized for USB-powered applications including wireless PDAs and cellular phones.

For engineers reviewing the LTC4065AEDC#TRPBF datasheet, LTC4065AEDC#TRPBF pinout, LTC4065AEDC#TRPBF application, or LTC4065AEDC#TRPBF equivalent, key selection criteria include its 2mm × 2mm DFN-6 package, ACPR input-status indicator (LTC4065A-specific), PROG-pin-based current programming, thermal feedback loop, and compatibility with USB 5V supply constraints.

Technical Context

The LTC4065AEDC#TRPBF implements a three-loop control architecture: constant-current (CA), constant-voltage (VA), and constant-temperature (TA), each governed by dedicated amplifiers and priority diodes. The TA loop activates when junction temperature approaches 115°C, dynamically reducing charge current to maintain thermal safety without external components.

It integrates an internal P-channel power MOSFET (RON = 450 mΩ @ 200mA) and uses the PROG pin as both programming interface (1V servo reference) and real-time current monitor (IBAT = VPROG × 1000 / RPROG). The ACPR pin provides open-drain indication of valid input supply (VCC > 3.6V and VCC > VBAT + 80mV), distinguishing it from the EN pin on the base LTC4065.

Key Specifications

Pinout & Package

Package: 6-lead, 2mm × 2mm × 0.75mm plastic DFN with exposed pad (Pin 7 = GND). Exposed pad must be soldered to PCB ground for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar standalone Li-Ion linear charger applications.

Compared with MAX1555 and BQ24075, the LTC4065AEDC#TRPBF uniquely combines programmable current, on-chip thermal regulation, and ACPR-based input arbitration - enabling higher reliability in thermally constrained, multi-source portable systems without sacrificing design flexibility.

Availability

LTC4065AEDC#TRPBF is available at Aetrix Electronics and suitable for wireless PDAs, USB-powered cellular handsets, and portable medical monitors requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for LTC4065AEDC#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 LTC4065AEDC#TRPBF belongs to Linear's precision battery management product line, engineered specifically for space-constrained, USB-compliant portable electronics needing autonomous, thermally robust Li-Ion charging without external power components.

FAQ

What is the function of the ACPR pin on the LTC4065AEDC#TRPBF?

The ACPR pin on the LTC4065AEDC#TRPBF is an open-drain output that pulls low only when VCC exceeds 3.6V and maintains at least 80mV above the BAT voltage - indicating a valid, adequately regulated input supply. This differs from the EN pin on the LTC4065 and enables host systems to reliably detect power source presence without polling or additional circuitry. The LTC4065AEDC#TRPBF uses this signal for intelligent input arbitration in dual-source chargers.

How is charge current programmed on the LTC4065AEDC#TRPBF?

Charge current on the LTC4065AEDC#TRPBF is set by connecting a precision resistor (RPROG) from the PROG pin to GND. The IC regulates the PROG pin voltage to 1.0V, so IBAT = 1000 × (1.0V / RPROG). For example, RPROG = 2kΩ yields 500mA (±5%). The same PROG pin voltage can be monitored to derive real-time charge current - a key enabler for fuel gauging. The LTC4065AEDC#TRPBF supports up to 750mA with appropriate RPROG selection.

Does the LTC4065AEDC#TRPBF include thermal protection?

Yes, the LTC4065AEDC#TRPBF incorporates autonomous thermal regulation via an internal TA amplifier that activates when junction temperature approaches 115°C. It dynamically reduces charge current to hold die temperature at or below this threshold - eliminating risk of thermal runaway without external sensors or feedback loops. This feature is integral to the LTC4065AEDC#TRPBF's constant-current/constant-voltage/constant-temperature architecture and operates transparently alongside voltage and current control loops.

What happens when the battery voltage is below 2.9V at startup?

When the LTC4065AEDC#TRPBF detects VBAT < 2.9V at startup, it enters trickle charge mode - delivering 10% of the programmed full-scale current to safely raise the cell voltage to a level suitable for fast charging. If the low-voltage condition persists for one quarter of the full charge time (e.g., 1.125 hours for a 4.5-hour timer), the LTC4065AEDC#TRPBF declares the battery defective and pulses the CHRG pin at 2Hz (75% duty cycle) to signal replacement required.

Can the LTC4065AEDC#TRPBF be used with a wall adapter input?

Yes, the LTC4065AEDC#TRPBF supports wall adapter inputs up to 5.5V and is commonly used in dual-input (USB + wall adapter) systems. Its undervoltage charge limiting (∆VUVCL1 ≈ 220mV) prevents instability with high-impedance supplies, and the ACPR pin enables host firmware to detect adapter presence and reconfigure charge current (e.g., switching from 500mA USB to 750mA adapter mode). The LTC4065AEDC#TRPBF's internal 450mΩ P-FET handles typical adapter power dissipation efficiently.