MIC2179 1.5A Synchronous Buck Regulator Features General Description Input Voltage Range: +4.5V to +16.5V The MIC2179 is a 200kHz synchronous buck (step-down) switching regulator designed for Dual-Mode Operation for High Efficiency (up to high-efficiency, battery-powered applications. 96%): - PWM Mode for > 150 mA Load Current The MIC2179 operates from a 4.5V to 16.5V input and features internal power MOSFETs that can supply up to - Skip Mode for < 150 mA Load Current 1.5A output current. It can operate with a maximum 150 m Internal Power MOSFETs at 12V Input duty cycle of 100% for use in low-dropout conditions. It 200 kHz Preset Switching Frequency also features a shutdown mode that reduces quiescent Low Quiescent Current current to less than 5 A. - 1.0 mA in PWM Mode The MIC2179 achieves high efficiency over a wide - 600 A in Skip Mode output current range by operating in either PWM or skip -< 5 A in Shutdown Mode mode. The operating mode is externally selected, typically by an intelligent system, which chooses the Current-Mode Control appropriate mode according to operating conditions, - Simplified Loop Compensation efficiency, and noise requirements. The switching - Superior Line Regulation frequency is preset to 200kHz and can be 100% Duty Cycle for Low Dropout Operation synchronized to an external clock signal of up to Current Limit 300 kHz. Thermal Shutdown The MIC2179 uses current-mode control with internal Undervoltage Lockout current sensing. Current-mode control provides superior line regulation and makes the regulator control Applications loop easy to compensate. The output is protected with pulse-by-pulse current limiting and thermal shutdown. High-Efficiency, Battery-Powered Supplies Undervoltage lockout turns the output off when the Buck (Step-Down) DC/DC Converters input voltage is less than 4.5V. Laptop Computers The MIC2179 is packaged in a 20-lead SSOP package Cellular Telephones with an operating temperature range of -40C to +85C. Handheld Instruments Package Type Battery Chargers MIC2179 20-Lead SSOP (SM) (Top View) PGND 1 20 PGND PGND 2 19 PGND SW 3 18 NC NC 4 17 VIN VIN 5 16 PWM 6 15 EN PWRGD FB BIAS 7 14 COMP 8 13 SYNC SGND SGND 9 12 SGND 10 11 SGND 2021 Microchip Technology Inc. DS20006284B-page 1MIC2179 Typical Application Circuit V IN 5.4V to 16.5V C1 10F 16,17 U1 20V R1 L1 VIN 20k 15 22H EN 3,4 V OUT SW 3.3V/600mA Output Good 6 D1 PWRGD 1,2, C2 Output Low MIC 19,20 MBRM120 100F PGND 5 Skip Mode 2179-3.3 6.3V PWM PWM Mode 13 7 SYNC FB COMP SGND BIAS 8 912 14 C3 R5 Pins 4 and 18 are not connected. 0.01F C4 4.02k 6.8nF Pins 3 and 4 can be connected together for a low-impedance connection. Functional Block Diagram V IN 4.5V to 16.5V 100F VIN 16 17 UVLO, R1 V 1.245 1 Thermal OUT R2 Shutdown 150m P-channel I Output SENSE Control L V Amp. OUT SW Logic EN Enable 3.3V 3 Shutdown 15 Regulator D C OUT BIAS 150m 14 PGND N-channel R3 0.01F 1 4.02k Internal 2 I * LIMIT Supply Voltage 19 Comp. 20 * Connect PWM PWM/ S to P GND GND Skip Mode I Skip-Mode PWM Mode LIMIT 5 Select Thresh. Voltage Bold lines indicate high current traces Corrective Ramp Stop SYNC 200kHz 13 Oscillator R1 Skip-Mode Reset Pulse Comp. FB R 7 Q R2 S V IN Power Good 20k Comp. PWM PWRGD Output Good Comp. 6 R C COMP 8 C V 1.245V 1.13V C REF MIC2179 Adjustable 910 11 12 SGND DS20006284B-page 2 2021 Microchip Technology Inc.