MIC23250: 4 MHz Dual 400 mA Synchronous Buck Regulator with HyperLight Load™
Features
- Input Voltage: 2.7V to 5.5V
- Dual Output Current: 400 mA/400 mA
- Up to 94% Peak Efficiency and 85% Efficiency at 1 mA
- 33 μA Dual Quiescent Current
- 1 μH Inductor with a 4.7 µF Capacitor
- 4 MHz in PWM Operation
- Ultra Fast Transient Response
- Low Voltage Output Ripple
- 20 mVpp in HyperLight Load™ Mode
- 3 mV Output Voltage Ripple in Full PWM Mode
- 0.01 μΑ Shutdown Current
- Fixed Output: 10-lead 2 mm x 2 mm UDFN
- Adjustable Output: 12-Lead 2.5 mm x 2.5 mm UDFN
- -40°C to +125°C Junction Temperature Range
Applications
- Mobile Handsets
- Portable Media Players
- Portable Navigation Devices (GPS)
- Digital Cameras
- Wireless LAN Cards
- USB Powered Devices
- WiFi/WiMax/WiBro Modules
General Description
The MIC23250 is a high efficiency 4 MHz dual 400 mA synchronous buck regulator with HyperLight Load™ mode. HyperLight Load™ provides very high efficiency at light loads and ultra-fast transient response, making it suitable for processor core voltages. Its architecture offers very low output ripple voltage across the entire load range, using small output capacitors. The fixed output MIC23250 is available in a compact 2 mm x 2 mm UDFN package, requiring only six external components for both outputs up to 400 mA each. The device is designed for use with a 1 μH inductor and a 4.7 µF output capacitor, enabling a sub-1 mm height. The MIC23250 features a low quiescent current of 33 μΑ with both outputs enabled, achieving over 85% efficiency at 1 mA. At higher loads, it maintains a constant switching frequency around 4 MHz, with peak efficiencies up to 94%. The MIC23250 is designed to operate within a junction temperature range of -40°C to +125°C.
Package Types
The MIC23250 is available in two package types:
- 10-Lead Fixed Output (Top View): Pins include SNS1, EN1, AGND, SW1, PGND, SNS2, EN2, AVIN, SW2, VIN.
- 12-Lead Adjustable Output (Top View): Pins include FB1, SNS1, EN1, AGND, SW1, PGND, FB2, SNS2, EN2, AVIN, SW2, VIN.
Electrical Characteristics
Key electrical characteristics include:
| Parameter | Symbol | Min. | Typ. | Max. | Units | Conditions |
|---|---|---|---|---|---|---|
| Supply Voltage (VIN) | 2.7V | 5.5V | V | |||
| Output Switch Voltage (VSW) | 6V | |||||
| Logic Input Voltage (VEN1, VEN2) | -0.3V | VIN | V | |||
| Quiescent Current | IQ | 33 | 50 | μΑ | VOUT1, 2 (both Enabled), IOUT1, 2 = 0 mA, VSNS1, 2 > 1.2 * VOUT1, 2 | |
| Shutdown Current | ISHDN | 0.01 | 4 | μΑ | VEN1, 2 = 0V; VIN = 5.5V | |
| Output Voltage Accuracy | ACC_OUT | -2.5 | +2.5 | % | VIN = 3.6V if VOUTNOM < 2.5V, ILOAD = 20 mA | |
| Feedback Voltage (Adj only) | VFB | 0.720 | V | |||
| Current Limit in PWM Mode | LIM PWM | 0.410 | 0.65 | 1 | A | SNS = 0.9*VOUT NOM |
| PWM Switch ON-Resistance | RDS(ON) | 0.6 | 0.8 | Ω | ISW = 100 mA PMOS | |
| Frequency | fsw | 4 | MHz | ILOAD = 120 mA | ||
| Operating Junction Temperature Range | TJ | -40 | +125 | °C |
Typical Performance Curves
The document includes various performance curves illustrating:
- Quiescent Current vs. Input Voltage
- Switching Frequency vs. Output Current
- Frequency vs. Temperature
- Output Voltage vs. Output Current
- Output Voltage vs. Input Voltage
- Enable Threshold vs. Temperature
- Enable Threshold vs. Input Voltage
- Efficiency curves for various output voltages and input conditions.
- Switching waveforms in discontinuous and continuous modes.
- Start-up and load transient waveforms.
- Line transient waveforms.
Bill of Materials
Recommended component values are provided for both fixed and adjustable output configurations, including capacitors, resistors, and inductors from manufacturers like TDK, Vishay, Murata, FDK, and Coilcraft.
PCB Layout Recommendations
Layout recommendations are provided for both top and bottom layers for fixed and adjustable output configurations, including placement of components and land patterns.
Package Marking Information
Details on package marking for 10-Lead and 12-Lead UDFN packages are provided, including examples and a legend for interpreting the markings.
Product Identification System
A system for identifying Microchip products is described, detailing how to interpret part numbers based on device, output voltage, junction temperature range, package, and media type.
Microchip Information
Includes information on Microchip trademarks, legal notices, and code protection features.
