Analog Devices Inc. LTC4080EDD#TRPBF

Overview

LTC4080EDD#TRPBF from Analog Devices (formerly Linear Technology) is a monolithic Li-ion battery charger IC with integrated 300mA synchronous buck converter, designed for USB-compliant portable systems. It delivers 500mA constant-current/4.2V constant-voltage charging with thermal regulation, 4.5-hour safety timer, and C/10 charge termination detection - enabling compact, thermally robust power management in wireless headsets and Bluetooth peripherals.

For engineers reviewing the LTC4080EDD#TRPBF datasheet, LTC4080EDD#TRPBF pinout, LTC4080EDD#TRPBF application, or LTC4080EDD#TRPBF equivalent, key selection criteria include its dual-function architecture (charger + buck), BAT-powered regulator input (2.7–4.5V), MODE-selectable Burst Mode® (23µA no-load) vs PWM (2.25MHz), and DFN-10 (3mm × 3mm, 0.75mm height) package with exposed pad for thermal performance.

Technical Context

The LTC4080EDD#TRPBF integrates two independent power subsystems: a linear battery charger with three-loop control (constant-current, constant-voltage, constant-temperature at 115°C) and a BAT-input synchronous buck converter with programmable output (0.8V to V_BAT). Its PROG pin serves both charge current programming (via R_PROG) and real-time monitoring (V_PROG = 1.0V in CC mode), while CHRG provides open-drain status with C/10 detection and defective-battery pulsing (2Hz, 75% duty).

Charge initiation requires V_CC > 3.6V and V_CC – V_BAT > 82mV; shutdown occurs if either condition fails. The buck converter supports two operating modes: fixed-frequency PWM (2.25MHz) for low-noise loads or Burst Mode® (23µA I_{BAT_NL_BM}) for ultra-low-power standby, selected via the MODE pin - with EN_BUCK enabling/disabling independently of the charger.

Key Specifications

Pinout & Package

Package: 10-lead (3mm × 3mm) plastic DFN with exposed pad (Pin 11 = GND), 0.75mm profile - optimized for space-constrained portable designs and requires soldering of exposed pad for thermal and electrical integrity (θ_JA = 43°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1555 and BQ24075, the LTC4080EDD#TRPBF uniquely combines charger, synchronous buck, thermal regulation, and USB-compliant input in a 10-pin DFN - delivering superior integration, efficiency across discharge, and design simplicity for space-constrained portable electronics.

Availability

LTC4080EDD#TRPBF is available at Aetrix Electronics and suitable for wireless headsets, Bluetooth audio modules, and portable MP3 players requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LTC4080EDD#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 precision instrumentation, communications, and portable power markets.

The LTC4080EDD#TRPBF belongs to Linear's Power Management family, engineered specifically for USB-powered portable electronics where space, thermal headroom, and dual-function integration are critical constraints.

FAQ

What is the maximum charge current supported by the LTC4080EDD#TRPBF?

The LTC4080EDD#TRPBF supports a maximum programmable charge current of 500mA with ±5% accuracy, set by a precision resistor connected between the PROG pin and ground. This value is confirmed across the full –40°C to 85°C operating temperature range and remains stable under thermal regulation - allowing reliable fast-charging implementation in compact handheld devices without external current-sense components.

Does the LTC4080EDD#TRPBF require external MOSFETs for charging?

No, the LTC4080EDD#TRPBF integrates an internal P-channel power MOSFET for the linear charger and synchronous NMOS/PMOS switches for the buck converter - eliminating all external power FETs. This reduces bill-of-materials count, PCB footprint, and layout complexity while maintaining 750mΩ typical R_ON for the charger FET and 0.95Ω/0.85Ω for buck switches - verified in the Electrical Characteristics table.

How does the LTC4080EDD#TRPBF handle low-battery or defective-cell conditions?

The LTC4080EDD#TRPBF initiates trickle charge (10% of programmed current) if V_BAT < 2.9V at startup, and detects defective batteries if that condition persists for >1.125 hours - triggering 2Hz pulsing on the CHRG pin with 75% duty cycle. This behavior is fully documented in the "Trickle Charge and Defective Battery Detection" section and validated across temperature, ensuring robust field reliability without firmware intervention.

Can the buck converter operate independently of the battery charger?

Yes, the LTC4080EDD#TRPBF allows independent control: EN_CHRG disables only the charger while EN_BUCK enables/disables the buck converter separately. When V_CC is absent, the buck can still operate from BAT (2.7–4.5V) to power system rails - confirmed by the "Buck Converter" subsection in Electrical Characteristics and the block diagram showing isolated control paths.

What thermal performance can be expected from the LTC4080EDD#TRPBF in a standard PCB layout?

With the exposed pad (Pin 11) properly soldered to a 1-in² copper pour, the LTC4080EDD#TRPBF achieves θ_JA = 43°C/W - enabling continuous 500mA charging at ambient temperatures up to 65°C before thermal regulation activates. This value is specified in the Absolute Maximum Ratings table and assumes standard JEDEC 51-7 test conditions; actual performance depends on copper area and airflow.