MIC38150 HELDO 1.5A High Efficiency Low Dropout Regulator General Description The MIC38150 is a 1.5A continuous output current step HELDO down converter. This is a follow on product in the new Features HELDO (High Efficiency Low DropOut Regulators) family, that provide the benefits of an LDO with respect to ease of Output current up to 1.5A use, fast transient performance, high PSRR and low noise Input voltage range: 3.0V to 5.5V while offering the efficiency of a switching regulator. Adjustable output voltage down to 1.0V As output voltages move lower, the output noise and Output noise less than 5mV transient response of a switching regulator become an increasing challenge for designers. By combining a Ultra fast transient performance switcher whose output is slaved to the input of a high Unique switcher plus LDO architecture performance LDO, high efficiency is achieved with a clean Fully integrated MOSFET switches low noise output. The MIC38150 is designed to provide Micro-power shutdown less than 5mV of peak-to-peak noise and over 70dB of Easy upgrade from LDO as power dissipation PSRR at 1kHz. Furthermore, the architecture of the becomes an issue MIC38150 is optimized for fast load transients allowing the output to maintain less than 30mV of output voltage Thermal shutdown and current limit protection deviation even during ultra fast load steps. This makes the 4mm 6mm 0.9mm MLF package MIC38150 an ideal choice for low voltage ASICs and other digital ICs. Applications The MIC38150 features a fully integrated switching regulator and LDO combination, operates with input Point-of-load applications voltages from 3.0V to 5.5V input and offers adjustable Networking, server, industrial power output voltages down to 1.0V. Wireless base-stations The MIC38150 is offered in the small 28-pin 4mm 6mm Sensitive RF applications 0.9mm MLF package and can operate from 40C to +125C. Data sheets and support documentation can be found on Micrels web site at: www.micrel.com Typical Application HELDO is a registered trademark of Micrel, Inc. MLF and MicroLeadFrame are registered trademark of Amkor Technologies Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC38150 Ordering Information Output Junction (1) Part Number Current Voltage Temperature Range Package MIC38150HYHL 1.5A ADJ -40C to +125C PB-Free 28-Pin 4x6 MLF Note: For additional voltage options, contact Micrel. Pin Configuration 28-Pin 4mm x 6mm MLF (ML) (Top View) Pin Description Pin Number Pin Name Pin Name 1, 2, 3, 4, 5 SWO Switch (Output): This is the output of the PFM Switcher. 6, 23, 24, 25, SW Switch Node: Attach external resistor from LPF to increase hysteretic 26, 27, 28 frequency. 7, 22 ePAD Exposed heat-sink pad. Connect externally to PGND. 8 AVIN Analog Supply Voltage: Supply for the analog control circuitry. Requires bypass capacitor to ground. Nominal bypass capacitor is 1F. 9 LPF Low Pass Filter: Attach external resistor from SW to increase hysteretic frequency. 10 AGND Analog Ground. 11 FB Feedback: Input to the error amplifier. Connect to the external resistor divider network to set the output voltage. 12, 13 LDOOUT LDO Output: Output of voltage regulator. Place capacitor to ground to bypass the output voltage. Nominal bypass capacitor is 10F. 14, 15 LDOIN LDO Input: Connect to SW output. Requires a bypass capacitor to ground. Nominal bypass capacitor is 10F. 16, 17 PVIN Input Supply Voltage (Input): Requires bypass capacitor to GND. Nominal bypass capacitor is 10F. 18 EN Enable (Input): Logic low will shut down the device, reducing the quiescent current to less than 50A. This pin can also be used as an under-voltage lockout function by connecting a resistor divider from EN pin-to-VIN and GND. It should be not left open. 19, 20, 21 PGND Power Ground. M9999-061010-C June 2010 2