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Specifications
SKU: 1215969
Linear Li-Ion Battery Charger with Thermal Regulation in ThinSOT; Package: SOT; No of Pins: 5; Temperature Range: -40°C to +125°C
| Parameter | Symbol | Min | Typical | Max | Units | Notes |
|---|---|---|---|---|---|---|
| Input Voltage Range | VIN | 2.9 | - | 5.5 | V | Operating input voltage range |
| Battery Charge Current | ICHG | - | 1.5 | 1.5 | A | Maximum charge current |
| Battery Float Voltage | VFB | - | 4.2 | 4.2 | V | Battery float voltage setting (fixed) |
| Battery Precharge Voltage | VPRE | - | 3.0 | 3.0 | V | Precharge voltage threshold |
| Battery Termination Current | ITERM | - | 100 | 100 | mA | Charge termination current |
| Battery Safety Timer | TSAFE | - | 16 | 16 | Hours | Maximum charge time before termination |
| Battery Temperature Sense | TSENSE | -10 | 25 | 60 | °C | Temperature range for battery charging |
| Thermal Shutdown | TSD | - | 140 | 140 | °C | Temperature at which the device shuts down |
| Quiescent Current | IQ | - | 80 | 80 | μA | Quiescent current during charge |
| Shutdown Current | ISD | - | 0.1 | 0.1 | μA | Current consumption in shutdown mode |
Instructions for Using LTC4057ES5-4.2
Input Connection:
- Connect the input power supply to the VIN pin. Ensure the input voltage is within the specified range (2.9V to 5.5V).
Battery Connection:
- Connect the battery to the BATT pin. The battery should have a nominal voltage of 3.7V or 4.2V (fully charged).
Charge Current Setting:
- The charge current is set by an external resistor connected between the ISET pin and GND. Use the formula: [ R_ = frac ] where ( I_ ) is the desired charge current in amperes.
Precharge and Float Voltage:
- The precharge voltage is fixed at 3.0V, and the float voltage is fixed at 4.2V. These settings cannot be adjusted externally.
Charge Termination:
- The charge cycle will terminate when the battery current drops below 100mA or after 16 hours, whichever comes first.
Temperature Sensing:
- Connect a thermistor between the THERM pin and GND to monitor the battery temperature. The device will stop charging if the temperature is outside the -10°C to 60°C range.
Thermal Shutdown:
- The device will shut down if the internal temperature exceeds 140°C to prevent damage.
Quiescent and Shutdown Modes:
- The quiescent current during charging is 80μA, and the shutdown current is 0.1μA. To enter shutdown mode, pull the SHDN pin low.
Status Indicators:
- The CHRG and STAT pins provide status information. CHRG is high during charging and low when charging is complete. STAT is high when the battery is fully charged and low otherwise.
PCB Layout Considerations:
- Ensure proper thermal management by providing adequate copper area for heat dissipation. Use short and wide traces for high-current paths.
Capacitors:
- Place input and output capacitors close to the respective pins to minimize noise and improve stability. Use ceramic capacitors with low ESR.
Inductor Selection:
- Choose an inductor with a saturation current higher than the maximum charge current and a low DCR to minimize losses.
By following these instructions, you can effectively use the LTC4057ES5-4.2 for charging single-cell lithium-ion batteries.
(For reference only)Inquiry - LTC4057ES5-4.2
