Summary of LTC4121/LTC4121- 4.2 – 40V 400mA Synchronous Step-Down Battery Charger
The LTC4121/LTC4121-4.2 are high-efficiency (up to 95%) synchronous step-down battery chargers supporting 4.4V–40V input, programmable 50–400mA charge current, and ±1% feedback accuracy. LTC4121 offers adjustable float 3.5–18V and temperature-compensated MPPT; LTC4121-4.2 provides a fixed 4.2V float. Features include programmable 5% accurate charge current and a thermally enhanced 16-lead 3mm × 3mm QFN (0.75mm) package.
Parts used in the LTC4121/LTC4121-4.2 Project:
- LTC4121 synchronous step-down battery charger IC
- LTC4121-4.2 synchronous step-down battery charger IC (fixed 4.2V option)
LTC4121/LTC4121-4.2 – 40V 400mA Synchronous Step-Down Battery Charger
Features
- Wide Input Voltage Range: 4.4V to 40V
- Adjustable Float Voltage (3.5V to 18V): LTC4121
- Temperature Compensated Input Voltage Regulation for Maximum Power Point Tracking (MPPT)
- Fixed 4.2V Float Voltage Option: LTC4121-4.2
- High Efficiency: Up to 95%
- 50mA to 400mA Programmable Charge Current
- ±1% Feedback Voltage Accuracy
- Programmable 5% Accurate Charge Current
- Thermally Enhanced, Low Profile (0.75mm) 16-Lead (3mm × 3mm) QFN Package
For more detail: LTC4121 LTC4121
- What input voltage range do these chargers support?
They support a wide input voltage range of 4.4V to 40V. - Can the float voltage be adjusted?
The LTC4121 has an adjustable float voltage from 3.5V to 18V; the LTC4121-4.2 has a fixed 4.2V float voltage. - Do these parts provide MPPT capability?
Yes, they include temperature compensated input voltage regulation for maximum power point tracking (MPPT). - What is the programmable charge current range?
Charge current is programmable from 50mA to 400mA. - How accurate is the feedback voltage?
Feedback voltage accuracy is ±1%. - What efficiency can be expected?
They offer high efficiency up to 95%. - Is the charge current accuracy specified?
Yes, the charge current is programmable to 5% accuracy. - What package do these ICs come in?
They come in a thermally enhanced, low profile (0.75mm) 16-lead 3mm × 3mm QFN package.
