0.4-18V; 500mW; secondary, off-line battery changer controller. For battery changer controlled for: lilon batteries (ADP3810) NiCad, NiMH batteries (ADP3811)# ADP3810AR84 Technical Documentation
## 1. Application Scenarios
### Typical Use Cases
The ADP3810AR84 is a precision current monitor and controller IC primarily designed for battery charging applications and power management systems. Key use cases include:
Battery Charging Systems
- Li-ion/Li-polymer battery chargers : Provides accurate current monitoring and control for constant-current charging phases
- Multi-cell battery packs : Enables precise current regulation in series-connected battery configurations
- Fast-charging circuits : Supports high-current charging applications up to 4A with proper external components
Power Supply Regulation
- Switch-mode power supplies : Current feedback control for buck/boost converters
- LED driver circuits : Constant current regulation for high-power LED arrays
- Motor control systems : Current limiting and monitoring in DC motor drives
### Industry Applications
- Consumer Electronics : Smartphones, tablets, laptops, and portable devices
- Telecommunications : Base station power systems, network equipment backup power
- Industrial Automation : PLC power supplies, motor drives, control systems
- Automotive : Electric vehicle charging systems, automotive infotainment power management
- Renewable Energy : Solar charge controllers, battery management systems
### Practical Advantages and Limitations
Advantages:
- High Accuracy : ±1% typical current sense accuracy
- Wide Voltage Range : Operates from 4.5V to 28V supply voltage
- Low Quiescent Current : 450μA typical, suitable for battery-operated applications
- Integrated Protection : Over-current and thermal shutdown protection
- Flexible Configuration : Adjustable current limit and monitoring thresholds
Limitations:
- External Components Required : Needs external sense resistor and compensation network
- Limited Maximum Current : Dependent on external MOSFET selection
- Temperature Sensitivity : Performance degrades above 85°C without proper heat sinking
- PCB Layout Sensitivity : Performance heavily dependent on proper layout techniques
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Current Sense Accuracy Issues
- Pitfall : Poor sense resistor selection leading to measurement errors
- Solution : Use 1% tolerance metal film resistors with low TCR (<50ppm/°C)
- Implementation : Place sense resistor close to IC with Kelvin connections
Stability Problems
- Pitfall : Oscillations in current control loop
- Solution : Proper compensation network design using manufacturer-recommended values
- Implementation : Calculate compensation components based on load characteristics
Thermal Management
- Pitfall : Overheating during high-current operation
- Solution : Adequate PCB copper area and thermal vias
- Implementation : Minimum 2oz copper, thermal relief patterns for power components
### Compatibility Issues with Other Components
Microcontroller Interfaces
- ADC Compatibility : Output voltage range (0-2.5V) compatible with most 3.3V and 5V ADCs
- Digital Control : Requires level shifting for 1.8V logic systems
- Communication : No built-in digital interface; requires external ADC for digital systems
Power Stage Components
- MOSFET Selection : Must consider RDS(on), gate charge, and voltage rating compatibility
- Sense Resistors : Power rating and temperature coefficient matching critical
- Passive Components : Ceramic capacitors recommended for stability; avoid electrolytic in signal path
### PCB Layout Recommendations
Power Stage Layout
- Current Sense Path : Keep sense traces short and symmetrical
- Power Ground : Separate analog and power grounds, star-point connection
- Component Placement : Position sense resistor, MOSFET, and IC in close proximity
Signal Integrity
- Bypass Capacitors : Place 100nF ceramic capacitor within 5mm of VCC pin
