Analog Devices Inc. LTC4070IMS8E#PBF

Overview

LTC4070IMS8E#PBF from Analog Devices is a Li-ion/polymer shunt battery charger IC designed for ultra-low-power energy harvesting and backup applications. It delivers 450nA quiescent current, ±1% float voltage accuracy (4.0V/4.1V/4.2V pin-selectable), and 50mA internal shunt current - enabling reliable charging from intermittent or micropower sources such as solar cells or thin-film batteries.

For engineers reviewing the LTC4070IMS8E#PBF datasheet, LTC4070IMS8E#PBF pinout, LTC4070IMS8E#PBF application, or LTC4070IMS8E#PBF equivalent, key selection considerations include NTC-qualified thermal float voltage adjustment, low-battery/high-battery status outputs (LBO/HBO), external PFET drive capability (DRV pin), and MSOP-8 thermal performance (θ_JA = 40°C/W).

Technical Context

The LTC4070IMS8E#PBF implements a precision shunt regulation architecture with a 3-state ADJ pin decoder to select 4.0V/4.1V/4.2V float voltages. Its pulsed NTC bias circuit samples thermistor voltage at <0.002% duty cycle, enabling ultralow power battery temperature qualification without compromising standby current.

Internal error amplifier and shunt transistor regulate VCC to the programmed float voltage; when VCC approaches VFLOAT, the device sinks increasing current via internal MOSFET or external PFET (driven by DRV pin) to clamp battery voltage. HBO and LBO outputs provide CMOS-compatible battery status signals with defined hysteresis (100mV HBO, 220–350mV LBO).

Key Specifications

Pinout & Package

The LTC4070IMS8E#PBF is housed in an 8-lead plastic MSOP package (3mm × 3mm, 0.75mm height) with exposed pad (Pin 9) requiring PCB ground connection for thermal performance (θ_JA = 40°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shunt battery charger applications.

Compared with LTC4071IMS8E#PBF, the LTC4070IMS8E#PBF trades integrated load switch functionality for 33% lower quiescent current and eliminates external FET control complexity; versus BQ29702DSER, it adds NTC qualification and 3× lower ICCQ but requires MSOP-8 footprint instead of SOT-23-6.

Availability

LTC4070IMS8E#PBF is available at Aetrix Electronics and suitable for solar-powered remote sensors, industrial memory backup systems, and automotive telematics data loggers requiring stable component supply with guaranteed long-term manufacturability.

Supply support for LTC4070IMS8E#PBF 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC4070IMS8E#PBF belongs to Analog Devices' precision battery management IC product line, engineered specifically for ultra-low-power, thermally aware Li-ion shunt charging in energy harvesting and mission-critical backup applications.

FAQ

What is the maximum shunt current capability of the LTC4070IMS8E#PBF?

The LTC4070IMS8E#PBF provides up to 50mA of internal shunt current to regulate battery voltage. When higher current is required - such as in solar chargers with high-input-power PV panels - an external P-channel MOSFET can be driven via the DRV pin to boost total shunt capability to 500mA. The internal 50mA limit ensures safe operation without external components, while the DRV interface maintains design flexibility for demanding applications.

How does the ADJ pin configure the float voltage on the LTC4070IMS8E#PBF?

The ADJ pin on the LTC4070IMS8E#PBF uses a 3-state decoder sampled every 1.5 seconds: tying ADJ to GND selects 4.0V, leaving it floating selects 4.1V, and connecting it to VCC selects 4.2V. This eliminates external resistors or DACs for float voltage programming. The sampling technique rejects board leakage currents that could corrupt the logic state, ensuring robust 1% accuracy across –40°C to 125°C.

Does the LTC4070IMS8E#PBF support battery temperature monitoring?

Yes, the LTC4070IMS8E#PBF supports NTC-based battery temperature qualification via dedicated NTCBIAS and NTC pins. Using a standard 10kΩ NTC thermistor (e.g., Vishay NTHS0402N02N1002F), it reduces the effective float voltage by 50mV/75mV/100mV per 10°C rise above 40°C - depending on ADJ pin state - to extend Li-ion battery lifetime. The pulsed 0.002% duty-cycle bias minimizes parasitic current draw.

What are the key differences between the LTC4070IMS8E#PBF and LTC4071IMS8E#PBF?

The LTC4070IMS8E#PBF focuses on minimal quiescent current (450nA) and shunt regulation, while the LTC4071IMS8E#PBF adds an integrated battery disconnect FET and reverse-current blocking. The LTC4071IMS8E#PBF consumes 600nA and requires additional control logic for load switching, making it suitable for applications needing automatic isolation - whereas the LTC4070IMS8E#PBF prioritizes simplicity and lowest possible ICCQ for energy harvesting.

Can the LTC4070IMS8E#PBF be used with stacked Li-ion cells?

Yes, the LTC4070IMS8E#PBF supports stacked-cell configurations via cascaded implementation: two devices can regulate series-connected cells by connecting the GND of the upper LTC4070IMS8E#PBF to the VCC of the lower one. Each device independently controls its respective cell's float voltage and NTC qualification. Status outputs (HBO/LBO) from the upper device are referenced to its local VCC, not system ground, requiring level-shifting for MCU interfacing.