Overview
The NCP1522B, specifically the NCP1522BSNT1G model from onsemi, is a monolithic integrated circuit designed as a step-down DC-DC converter. This device is optimized for portable applications powered by one cell Li-Ion or three cell Alkaline/NiCd/NiMH batteries. It offers adjustable output voltage ranging from 0.9 V to 3.3 V and can deliver up to 600 mA. The NCP1522B features synchronous rectification, which enhances efficiency and reduces the need for external components. It also includes a built-in 3 MHz oscillator, allowing for smaller inductors and capacitors, and automatic switching between PWM and PFM modes to improve system efficiency.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Input Voltage Range | 2.7 to 5.5 | V |
| Output Voltage Range | 0.9 to 3.3 | V |
| Maximum Output Current | 600 | mA |
| Oscillator Frequency | 2.4 to 3.6 | MHz |
| Efficiency | Up to 93% | % |
| Package Type | TSOP-5, UDFN6 | - |
| Thermal Shutdown Threshold | 160 | °C |
| Thermal Shutdown Hysteresis | 25 | °C |
| P-Channel On-Resistance | 400 | mΩ |
| N-Channel On-Resistance | 400 | mΩ |
| Peak Inductor Current | 1200 | mA |
Key Features
- Synchronous rectification to increase efficiency and reduce external part count.
- Automatic switching between PWM and PFM modes to improve system efficiency.
- Integrated soft-start to limit inrush current during startup.
- Cycle-by-cycle current limiting and thermal shutdown protection for enhanced reliability.
- Low dropout operation with 100% duty cycle capability.
- Undervoltage lockout and shutdown mode for power management.
- Short circuit protection to limit inductor current during short circuit conditions.
- Compact TSOP-5 and UDFN6 packages for space-saving designs.
Applications
The NCP1522B is suitable for various portable applications, including:
- Single-cell Li-Ion battery-powered devices.
- Three-cell Alkaline/NiCd/NiMH battery-powered devices.
- Handheld electronics such as smartphones, tablets, and e-readers.
- Wearable devices like smartwatches and fitness trackers.
- Other battery-powered consumer electronics requiring efficient DC-DC conversion.
Q & A
- What is the input voltage range of the NCP1522B?
The input voltage range is from 2.7 V to 5.5 V.
- What is the maximum output current of the NCP1522B?
The maximum output current is 600 mA.
- What are the available package types for the NCP1522B?
The device is available in TSOP-5 and UDFN6 packages.
- How does the NCP1522B manage efficiency under different load conditions?
The device automatically switches between PWM and PFM modes to optimize efficiency based on the load current.
- What protection features are integrated into the NCP1522B?
The device includes thermal shutdown, cycle-by-cycle current limiting, undervoltage lockout, and short circuit protection.
- How is the output voltage set for the NCP1522B?
The output voltage is set using an external resistor divider connected from VOUT to FB and then to GND.
- What is the typical efficiency of the NCP1522B?
The device can achieve up to 93% efficiency.
- What is the purpose of the soft-start feature in the NCP1522B?
The soft-start feature limits the inrush current during startup by gradually increasing the reference voltage.
- How does the NCP1522B handle thermal issues?
The device includes thermal shutdown protection that shuts down the IC if the junction temperature exceeds 160°C and restarts when the temperature drops below 135°C.
- What is the recommended inductor value for the NCP1522B?
The recommended inductor value is 2.2 μH.
