Micrel, Inc. MIC2199 MIC2199 300kHz 4mm 4mm Synchronous Buck Converter General Description Features The MIC2199 is a high-power 300kHz synchronous buck 4.5V to 32V input range DC-to-DC controller housed in a small 4mm 4mm MLF 4mm 4mm MLF package 12-pin package. The MIC2199 operates from a wide 4.5V 300kHz PWM operation to 32V input and can be programmed for output voltages 95% efficien cy from 0.8V to 6V. The wide input voltage capability makes Output voltage adjustable down to 0.8V the MIC2199 an ideal solution for point-of-load DC-to-DC 20A output current capability conversion in 5V, 12V, 24V, and 28V systems. Drives all N- Channel MOSFETs Logic contro lled micropower shutdown The 300kHz switching frequency allows the use of a small Cycle-by-cycle current limiting inductor and small output capacitors. The current mode PWM Adjustable u ndervoltage lockout control along with the external COMP pin allows for ease of Frequency fo ldback overcurrent protection stability compensation and fast transient response across a wide range of applications. Applications An all N-Channel synchronous architecture and powerful Point-of-load DC-to-DC conversion from 5V, 12V, output drivers allow up to 20A of output current capability. 24V, 28V supplies For smaller external components, refer to the 500kHz Telecom equ ipment MIC2198. Wireless mo dems Servers The MIC2199 is available in a 12-pin 4mm 4mm MLF Base stations package with a junction temperature range from 40C to 125C. Typical Application V IN 4.5V to 24V U1 MIC2199BML SD103BWS 100.0 VIN VDD 4.7F 22F BST 0.1F IRF7821 EN/UVLO HSD V OUT 95.0 2H 0.01 3.3V/7A VSW 220F IRF7821 LSD CSH 90.0 1nF COMP VOUT 10k 2k FB V = 3.3V OUT 6.04k GND 85.0 0 2 4 6 8 2.2nF (A) I LOAD Efficiency for 4.5V24V to 3.3V/7A Converter V = 5V and V = 3.3V IN OUT MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc. Micrel, Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC2199. Ordering Information Part Number Voltage Temperature Range Package Standard Pb-Free MIC2199BML MIC2199YML Adj 40C to +125C 12-Pin 4x4 MLF Pin Configuration 1 12 COMP HSD EN/UVLO 2 11 VSW 3 10 FB BST 4 9 CSH GND 5 8 VOUT LSD VIN 6 7 VDD 12-Pin 44 MLF (ML) Pin Description Pin Number Pin Name Pin Function 1 COMP Compen sation (Output): Internal error amplifier output. Connect to capac itor or series RC network to compensate the regulator control loop. 2 EN/UVLO Enable/U ndervoltage Lockout (Input): Low-level signal powers down the controller. Input below the 2.5V threshold disables switching and functions as an accurate undervoltage lockout (UVLO). Input below the threshold forces complete micropower (<0.1A) shutdown. 3 FB Feedbac k (Input): Regulates FB pin to 0.8V. See Applications Information for resistor divider calculations. 4 CSH Current-Sense High (Input): Current limit comparator non-inverting input. A built-in offset of 100mV between CSH and V pins in conjunction with the OUT current-sense resistor set the current limit threshold level. This is also the non-inverting input to the current sense amplifier. 5 VOUT Current-Sense Low (Input): Output voltage feedback input and inverting input for the current limit comparator and the current sense amplifier. 6 VIN Unregula ted Input (Input): +4.5V to +32V supply input. 7 VDD 5V Internal Linear-Regulator (Output): V is the external MOSFET gate DD drive supply voltage and internal supply bus for the IC. Bypass to GND with 4.7F. 8 LSD Low-Side Drive (Output): High-current driver output for low-side N-Chann el MOSFET. Voltage swing is between ground and V . DD 9 GND Ground (Return). 10 BST Boost (Input): Provides drive voltage for the high-side MOSFET driver. The drive voltage is higher than the input voltage by V minus a diode drop. DD 11 VSW Switch (Return): High-side MOSFET driver return. 12 HSD High-Sid e Drive (Output): High-current driver output for high-side MOSFE T. This node voltage swing is between ground and V +5V minus a diode drop. IN January 2010 2 M9999-011310