K7803-1000R3
High-efficiency non-isolated switching regulator, 3.3V 1A output, pin-compatible with 7803 linear regulator.
Product Overview
Description
The K7803-1000R3 is a high-efficiency non-isolated switching regulator providing 3.3V output at 1A (3.3W). It features wide input voltage range (4.75V to 36V), high efficiency up to 93%, and compact SIP package. This converter is designed as a high-efficiency replacement for 78xx linear regulators, offering much better efficiency and lower heat generation.
Product Series
K78 Series
Primary Application
Microcontroller power supply
Key Features
- High efficiency up to 93%
- Wide input voltage 4.75V to 36V
- Pin-compatible with 78xx linear regulators
- No heat sink required in most applications
- Short circuit protection
- Over-temperature protection
- Compact SIP3 package
- Low quiescent current
Specifications
| Input Voltage | 4.75-36VDC |
|---|---|
| Output Power | 3.3W |
| Output Voltage | 3.3VDC fixed |
| Output Current | 1A |
| Efficiency | Up to 93% |
| Operating Temperature | -40°C to +85°C |
| Package | SIP3 |
| Dimensions | 11.5 x 10.0 x 17.5mm |
| Switching Frequency | 500kHz |
| Load Regulation | ±1% |
| Line Regulation | ±0.5% |
| Quiescent Current | 0.5mA typical |
Applications
Microcontroller power supply
Power conversion and supply
Sensor power supply
Power conversion and supply
Battery-powered devices
Battery and charging management
Industrial control systems
Industrial automation and control
Communication equipment
Communication and interface
Linear regulator replacement
Power conversion and supply
FAE Expert Insights
"Based on extensive field experience, this product delivers excellent performance across various operating conditions. The design incorporates proven architecture with robust protection features. Customers consistently report high satisfaction with reliability and ease of integration."
— Field Application Engineer, BeiLuo
Frequently Asked Questions
Can K7803-1000R3 replace a 3.3V linear regulator directly?
Yes, K7803 uses same pinout as 78xx series (Input, GND, Output). The SIP3 package is smaller than SOT-223 but taller. No heat sink is typically needed due to high efficiency. Add optional 10µF capacitors on input and output for best performance. The wide input voltage range makes it superior to standard linear regulators.
Excellent drop-in replacement for 3.3V linear regulators with much better efficiency. PCB footprint modification may be required.
What is the efficiency advantage over linear regulators?
Linear regulator efficiency is approximately (Vout/Vin) × 100%. For 3.3V output from 5V input, efficiency is only 66%. K7803 provides 93% efficiency regardless of input voltage. This means linear regulator wastes significant power as heat, while K7803 wastes very little. Benefits include lower power consumption, no heat sink required, cooler operation, and smaller size.
K7803 is superior for most applications. Use linear regulators only for extreme noise-sensitive applications.
Do I need a heat sink with K7803-1000R3?
In most applications, no heat sink is required due to the high 93% efficiency. At 1A output with 5V input, power dissipation is only about 0.2W. The SIP3 package can handle this without additional cooling. For high ambient temperatures or continuous full-load operation, ensure adequate airflow.
No heat sink needed for most applications. Ensure adequate airflow for high temperature environments.
What is the minimum input voltage?
K7803-1000R3 can operate with input voltage as low as 4.75V. This is a significant advantage over linear regulators which require input voltage at least 1-2V above output. The 4.75V minimum allows operation from 5V systems with minimal headroom.
Can operate with input only 1.45V above output. Much better than linear regulators for low headroom applications.
Is the output voltage adjustable?
K7803-1000R3 has fixed 3.3V output and is not adjustable. For other output voltages, consider other K78 series products: K7805 for 5V, K7809 for 9V, K7812 for 12V, K7815 for 15V. Each provides fixed output voltage with same high efficiency and pin compatibility.
Fixed output only. Choose appropriate K78 model for required voltage or use adjustable DC/DC for variable output.