BQ24780SRUYR: A Comprehensive Analysis of Battery Charging Controllers

The Texas Instruments BQ24780SRUYR is a high-efficiency, synchronous battery charge controller designed for 1- to 4-cell battery packs. It supports various chemistries, including Li-Ion, Li-Polymer, LiFePO₄, NiCd, and NiMH.

BQ24780SRUYR Overview

The bq24780S is a 1-4 cell battery charge controller with power selection for space-constrained, multi-chemistryportable applications such as notebook and detachable ultrabook. It supports wide input range of input sourcesfrom 4.5 V to 24 V, and 1-4 cell battery for a versatile solution.

The bq24780S supports automatic system power source selection with separate drivers for n-channel MOSFETSon the adapter side and battery side.

The bq24780S features Dynamic Power Management (DPM) to limit the input power and avoid AC adapter overloading. During battery charging, as the system power increases, the charging current will reduce to maintaintotal input current below adapter rating. If system power demand is temporarily exceeds adapter rating, thebq24780S supports hybrid power boost mode (previously called "turbo boost mode") to allow battery dischargeenergy to supplement system power. For details of hybrid power boost mode, refer to Device Functional Modessection.

The bq24780S closely monitors system power (PMON), input current (IADP) and battery discharge current(IDCHG) with highly accurate current sense amplifiers. If current is too high, adapter or battery is removed, aPROCHOT signal is asserted to CPU so that the CPU optimizes its performance to the power available to thesystem.

The SMBus controls input current, charge current and charge voltage registers with high resolution, highaccuracy regulation limits. It also sets the PROCHOT timing and threshold profile to meet system requirements.

BQ24780SRUYR Features

l Industrial Innovative Charge Controller With Hybrid Power Boost Mode

-Adapter and Battery Provides Power to System Together for Intel CPU Turbo Mode

-Ultra-Fast Transient Response of 150 μs to Enter Boost Mode

-Hybrid Power Boost Mode from 4.5- to 24-V System

-Charge 1- to 4-Cell Battery Pack from 4.5-to 24-V Adapter

l High Accuracy Power and Current Monitoring for CPU Throttling

-Comprehensive PROCHOT Profile

-± 2% Current Monitor Accuracy

-± 5% System Power Monitor Accuracy (PMON)

l Automatic NMOS Power Source Selection from Adapter or Battery

-ACFET Fast Turn on in 100 μs

l Programmable Input Current, Charge Voltage, Charge and Discharge Current Limit

-±0.4% Charge Voltage (16-mV step)

-±2% Input Current (128-mA/step)

-±2% Charge Current (64-mA/step)

-±2% Discharge Current (512-mA/step)

l High Integration

-Battery LEARN Function

-Battery Present Monitor

-Boost Mode Indicator

-Loop Compensation

-BTST Diode

l Enhanced Safety Features for Overvoltage Protection, Overcurrent Protection, Battery.

Inductor, and MOSFET Short-Circuit Protection

l Switching Frequency: 600 kHz, 800 kHz, and1 MHz

l Realtime System Control on ILIM Pin to Limit Charge and Discharge Current

l 0.65 mA Adapter Standby Quiescent Current for Energy Star

Pin Configuration

Absolute Maximum Ratings

Applications

1. Notebook / Ultrabook

Application Requirements:

High-performance power delivery and smart battery management

Fast charging and extended battery life

Balanced efficiency and thermal performance

Seamless switching between adapter and battery power

BQ24780SRUYR Advantages:

Hybrid Power Boost Mode: Allows simultaneous power delivery from both adapter and battery, avoiding system crashes under high load.

SMBus Programmability: Enables precise control of charge voltage and current for smart charging strategies.

Current Monitoring (IADP, IDCHG): Supports dynamic power management and thermal control.

2. Detachable & Tablet PC

Application Requirements:

High energy efficiency and low standby power

Compact PCB layout

Compatibility with various charging methods (e.g., USB-C)

BQ24780SRUYR Advantages:

Compact 4mm × 4mm WQFN Package: Ideal for space-constrained thin-and-light designs.

Input Current Limiting: Protects USB-C and small adapters from overload.

Supports Multiple Battery Configurations (1–4 cells): Flexible for various capacity designs.

3. Handheld Terminals

Application Requirements:

All-day battery operation

Fast charging and long standby

Robust performance in harsh environments

BQ24780SRUYR Advantages:

Wide Operating Temperature Range (-40°C to +85°C): Suitable for industrial or outdoor use.

Battery Discharge Monitoring: Helps estimate remaining runtime and optimize power strategy.

Comprehensive Protection Features: Prevents overcharge, short-circuit, and other faults.

4. Industrial and Medical Equipment

Application Requirements:

Stable long-term power management

Accurate battery status monitoring

High reliability and safety compliance

BQ24780SRUYR Advantages:

SMBus Communication: Enables interaction with system MCU for precise control and status feedback.

Comprehensive Protection Suite: Meets strict industrial and medical safety standards.

Flexible Charge Parameter Configuration: Tailors to specific device requirements.

5. General Portable Equipment

Application Requirements:

Efficient battery charging

Flexible power source switching

Compatibility with various external power inputs

BQ24780SRUYR Advantages:

Three Switching Frequencies (600kHz / 800kHz / 1MHz): Balances conversion efficiency and EMI.

External Power MOSFET Driving Capability: Supports flexible power path and battery management design.

Automatic Power Source Detection and Switching (ACFET / RBFET / BATFET Control): Enables seamless transitions across working states.

Conclusion

BQ24780SRUYR is a feature-rich, highly configurable smart battery charger controller suitable for a wide range of portable devices, including notebooks, ultrabooks, tablets, handheld terminals, industrial and medical equipment, and more. It is especially ideal for applications that demand high charging efficiency, intelligent power management, and long-term reliability.