Overview
The NCP1421DMR2G is a monolithic micropower high-frequency step-up switching converter IC designed by onsemi. This IC is specifically tailored for battery-operated handheld electronic products, capable of handling loads up to 600 mA. It features a high switching frequency of up to 1.2 MHz, allowing for the use of small-sized inductors and output capacitors, which is ideal for low-profile designs. The NCP1421 integrates Sync-Rect technology to improve efficiency and eliminate the need for an external Schottky diode. Additionally, it includes a True-Cutoff function that significantly reduces shutdown current to typically only 50 nA, and a Ring-Killer to eliminate high-frequency ringing in discontinuous conduction mode.
Key Specifications
| Characteristic | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Operating Voltage (VIN) | 1.0 | 5.0 | V | |
| Output Voltage Range (VOUT) | 1.5 | 5.0 | V | |
| Reference Voltage (VREF_NL) at 25°C | 1.183 | 1.200 | 1.217 | V |
| Reference Voltage Temperature Coefficient (TCVREF) | -0.03 | mV/°C | ||
| EN Pin Shutdown Threshold (VSHDN) at 25°C | 0.35 | 0.5 | 0.67 | V |
| Thermal Shutdown Temperature (TSHDN) | 145 | °C | ||
| Thermal Shutdown Hysteresis (TSDHYS) | 30 | °C | ||
| Switching Frequency | Up to 1.2 MHz | |||
| Cycle-by-Cycle Current Limit | 1.5 A | |||
| Shutdown Current | Typically 50 nA |
Key Features
- High switching frequency up to 1.2 MHz for low-profile designs.
- Sync-Rect technology to improve efficiency and eliminate the external Schottky diode.
- True-Cutoff function to reduce shutdown current to typically only 50 nA.
- Ring-Killer to eliminate high-frequency ringing in discontinuous conduction mode.
- Low-Battery Detector with adjustable threshold.
- Logic-Controlled Shutdown Pin for multi-function control.
- On-chip thermal shutdown with hysteresis.
- Pb-Free package available.
- High accuracy reference voltage with ±2% load regulation.
Applications
- Personal Digital Assistants (PDA).
- Handheld Digital Audio Products.
- Camcorders and Digital Still Cameras.
- Hand-held Instruments.
- Conversion from one to two Alkaline, NiMH, NiCd battery cells to 3.0-5.0 V or one Lithium-ion cell to 5.0 V.
- White LED Flash for Digital Cameras.
Q & A
- What is the maximum output current of the NCP1421?
The NCP1421 can handle loads up to 600 mA.
- What is the typical shutdown current of the NCP1421?
The typical shutdown current is 50 nA.
- What is the operating voltage range of the NCP1421?
The operating voltage range is from 1.0 V to 5.0 V.
- What is the output voltage range of the NCP1421?
The output voltage range is from 1.5 V to 5.0 V.
- What is the switching frequency of the NCP1421?
The switching frequency can be up to 1.2 MHz.
- Does the NCP1421 have thermal shutdown protection?
Yes, it includes on-chip thermal shutdown with hysteresis.
- How is the low battery detection threshold set in the NCP1421?
The low battery detection threshold is set using an external divider network comprised of resistors R3 and R4.
- What type of package is available for the NCP1421?
The NCP1421 is available in a Pb-Free Micro8 package.
- What are some typical applications of the NCP1421?
Typical applications include personal digital assistants, handheld digital audio products, camcorders, digital still cameras, and handheld instruments.
- How does the True-Cutoff function work in the NCP1421?
The True-Cutoff function isolates the current through the body diode of switch M2 to the load, eliminating leakage current from the battery to the load in shutdown mode.
