Key Specs
| Spec | Value | Condition | Source |
|---|---|---|---|
| Battery Chemistry | Lithium Ion/Polymer | Digi-Key | |
| Number Of Cells | 1 | Digi-Key | |
| Current Charging | Constant - Programmable | Digi-Key | |
| Programmable Features | Current, Timer | Digi-Key | |
| Fault Protection | Over Temperature | Digi-Key | |
| Charge Current (Max) | 1A | Digi-Key | |
| Battery Pack Voltage | 4.2V | Digi-Key | |
| Voltage Supply (Max) | 12V | Digi-Key | |
| Interface | - | Digi-Key | |
| Operating Temperature Range | -40°C ~ 125°C (TJ) | Digi-Key | |
| Mounting Type | Surface Mount | Digi-Key | |
| Package Case | 16-VFQFN Exposed Pad | Digi-Key | |
| Supplier Device Package | 16-VFQFPN (3x3) | Digi-Key |
When To Use
Use the L6924D013TR in single-cell Lithium Ion or Lithium Polymer battery charging applications where:
- A regulated battery pack voltage of approximately 4.2 V is required (output voltage typ 4.2 V)
- Programmable constant current charging up to 3 A max is needed, with precise current and timer control
- Operating input voltage ranges from 4.5 V to 6.5 V typically, with a maximum of 7 V
- Surface mount assembly with a compact 16-VFQFN package is preferred
- Operating temperature range from -40°C to +125°C junction temperature is required
- Fault protection including over temperature monitoring is critical
Do not use this device when:
- Multi-cell battery packs are involved, as it supports only a single cell configuration
- Charge current requirements exceed 3 A max; consider higher current chargers instead
- Input voltage exceeds 7 V maximum rating; use a device rated for higher input voltages
- Applications requiring integrated fast charge current programming with values outside the 450 mA to 2 A typical range
- When a larger output current capability than 30 mA status sink current is needed
In these cases, select a charger IC designed for multi-cell packs, higher current, or wider input voltage ranges.
When Not To Use
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Charging >3 A current from a 12 V supply: The max charge current spec is 3 A, which disqualifies this part from high-current applications. Use a high-current synchronous buck with external FETs to handle higher currents efficiently and avoid MOSFET overstress.
-
Applications requiring switching frequencies above 500 kHz for miniaturization: The switching frequency max is 3 MHz, but the typical recommended range tops at 2 MHz, and stable operation is guaranteed from 100 kHz to 2 MHz. For designs requiring precise control beyond 2 MHz or optimized high-frequency performance, a high-frequency buck controller is a better fit.
-
Low quiescent current battery-powered sensor node with μA sleep currents: The shutdown mode current maxes out at 500 nA, but typical is around 60 µA, which is too high for ultra-low power applications. Use a low-IQ PFM buck to achieve the required minimal quiescent current and extend battery life.
Application Notes
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The switching node (SW) pin must be routed with minimal parasitic inductance and placed close to the power MOSFET and input/output capacitors to reduce voltage overshoot and EMI. Use a solid ground plane underneath.
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the NTC pin and the SHUTDOWN pin are noise-sensitive and should be routed away from the switching node and high-current traces to prevent false triggering of thermal fault or shutdown modes.
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The exposed pad on the 16-VFQFN package must be soldered directly to a large copper thermal pad connected to multiple vias to the PCB inner planes for effective heat dissipation, maintaining junction temperature below 125°C.
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The programming resistor for fast charge current (typ 48.6 kΩ) and timer capacitor (typ 10 nF) should be placed close to the IC pins to minimize noise pickup and ensure accurate current and timing regulation.
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Input and output capacitors (1 µF ceramic typ) must be low-ESR types and placed close to the IC pins to maintain stability and reduce switching noise coupling into the battery and supply lines.
Pin numbers are package-specific. Verify against the datasheet pinout diagram before routing.
Gotchas
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Incorrect Programming Resistor Values
- Mistake: Engineer uses incorrect resistor values for fast charge or pre-charge current programming
- Failure Mode: Charge current exceeds battery specifications, risking battery overheating or damage
- Fix: Use the specified 48.6 kΩ resistor for fast charge current and 68 kΩ for pre-charge current to ensure correct current limits
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Omission of Input and Output Capacitors
- Mistake: Engineer omits or uses undervalued input/output capacitors
- Failure Mode: Excessive voltage ripple and switching noise cause unstable regulation and possible device malfunction
- Fix: Include 1 µF ceramic input capacitor and at least 1 µF output capacitor (4.7 µF recommended) rated for operating voltages
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Neglecting NTC Temperature Sensing Components
- Mistake: Engineer does not implement or improperly selects NTC thermistor and associated resistors
- Failure Mode: