Summary of Step-down switching regulator minimizes EMI/EMC
The article describes a high-efficiency, low-EMI step-down switching regulator featuring Silent Switcher Architecture, spread spectrum modulation, wide input range, and ultralow quiescent burst mode. It delivers up to 5A continuous (7A peak transient), very low output ripple, fast switching (40 ns), and adjustable synchronization from 200 kHz to 3 MHz, packaged in an 18-lead 3×4 mm QFN.
Parts used in the Step-down switching regulator:
- Step-down switching regulator IC (Silent Switcher Architecture)
- Inductor (rated for up to 7A peak transient)
- Input capacitors suitable for 3.4V to 42V input range
- Output capacitors delivering <10mVP-P ripple
- Gate/driving circuitry internal to IC (peak current mode operation)
- Soft-start and tracking components (internal/configurable)
- Synchronization clock source (200kHz to 3MHz) or external sync input
- PCB with low EMI layout and shielding considerations
- 18-lead 3mm × 4mm QFN footprint
Features
- Silent Switcher® Architecture
- Ultralow EMI/EMC Emissions
- Spread Spectrum Frequency Modulation
- High Efficiency at High Frequency
- Up to 96% Efficiency at 1MHz
- Up to 95% Efficiency at 2MHz
- Wide Input Voltage Range: 3.4V to 42V
- 5A Maximum Continuous Output, 7A Peak Transient Output
- Ultralow Quiescent Current Burst Mode® Operation
- 2.5μA IQ Regulating 12VIN to 3.3VOUT
- Output Ripple < 10mVP-P
- Fast Minimum Switch-On Time: 40ns
- Low Dropout Under All Conditions: 100mV at 1A
- Safely Tolerates Inductor Saturation in Overload
- Adjustable and Synchronizable: 200kHz to 3MHz
- Peak Current Mode Operation
- Output Soft-Start and Tracking
- Small 18-Lead 3mm × 4mm QFN
For more detail: Step-down switching regulator minimizes EMI/EMC
- What is the input voltage range for this regulator?
The input voltage range is 3.4V to 42V. - How much continuous and peak transient output current does it support?
It supports up to 5A continuous output and 7A peak transient output. - What efficiency can be expected at high switching frequencies?
Efficiency can reach up to 96% at 1MHz and up to 95% at 2MHz. - Does the regulator minimize EMI and EMC emissions?
Yes, it uses Silent Switcher Architecture and spread spectrum frequency modulation to minimize EMI/EMC emissions. - What is the quiescent current in Burst Mode operation?
The quiescent current is 2.5 microamperes when regulating 12VIN to 3.3VOUT. - What is the output ripple specification?
The output ripple is less than 10 millivolts peak-to-peak. - Can the switching frequency be adjusted or synchronized?
Yes, the switching frequency is adjustable and synchronizable from 200kHz to 3MHz. - What is the minimum switch-on time?
The minimum switch-on time is 40 nanoseconds. - How low is the dropout under load?
The low dropout is 100 millivolts at 1 ampere. - What package does the regulator come in?
It comes in a small 18-lead 3mm × 4mm QFN package.
