MIC2125/6 28V Synchronous Buck Controllers Featuring Adaptive ON-Time Control Features General Description Hyper Speed Control Architecture Enables: The MIC2125 and MIC2126 are constant-frequency synchronous buck controllers featuring a unique - High delta V operation (V = 28V and V IN OUT adaptive ON-time control architecture. The MIC2125/6 = 0.6V) operate over an input voltage range from 4.5V to 28V - Any Capacitor stable and can be used to supply load current up to 25A. The 4.5V to 28V Input Voltage output voltage is adjustable down to 0.6V with a Adjustable Output Voltage from 0.6V to 24V guaranteed accuracy of 1%. The device operates with 200 kHz to 750 kHz Programmable Switching programmable switching frequency from 200 kHz to Frequency 750 kHz. HyperLight Load (MIC2125) HyperLight Load architecture provides the same high efficiency and ultra-fast transient response as the Hyper Speed Control (MIC2126) Hyper Speed Control architecture under medium to Enable Input and Power Good Output heavy loads. It also maintains high efficiency under Built-in 5V Regulator for Single-Supply Operation light load conditions by transitioning to variable Programmable current limit and hiccup mode frequency, discontinuous conduction mode operation. short-circuit protection The MIC2125/6 offer a full suite of features to ensure 7 ms internal soft-start, internal compensation, protection of the IC during fault conditions. These and thermal shutdown include undervoltage lockout to ensure proper Supports Safe Start-Up into a Prebiased Output operation under power-sag conditions, internal 40C to +125C Junction Temperature Range soft-start to reduce inrush current, hiccup mode Available in 16-pin, 3 mm 3 mm QFN Package short-circuit protection, and thermal shutdown. Applications Package Type Networking/Telecom Equipment MIC2125/6 Base Stations, Servers 16-Pin 3 mm x 3 mm QFN (ML) Distributed Power Systems Industrial Power Supplies 16 15 14 13 1 12 AGND VDD 2 11 PVDD NC EP 17 10 3 ILIM OVP 9 DL 4 BST 56 7 8 2015 Microchip Technology Inc. DS20005459B-page 1 PGND VIN FREQ EN DH PG SW FBILIM MIC2125/6 Typical Application Circuit MIC2125/6 3x3 QFN V IN 4.5V TO 28V FREQ PVDD 2.2F 220F VIN 3 VDD BST MIC2125/6 4.7F AGND 0.1F DH V OUT 0.72H 3.3V/20A EN EN SW 90.9k PG PG 10k 470pF 100F 470F DL V OUT 56.2k 0.1F OVP PGND 10k 2.26k FB ILIM 1.2k Functional Block Diagram MIC2125/26 PVDD V IN 4.5V TO 28V VDD VIN LDO R19 2.2F 220F 4.7F FIXED T FREQ 2 ON ESTIMATE VDD R20 BST MODIFIED V IN T OFF UVLO DH Q1 HSD 0.1F V OUT 0.72H 100k 3.3V/20A SW CONTROL PVDD EN LOGIC EN 470pF TIMER R1 90.9k DL 10k 470F SOFTSTART Q3 LSD 100F 1.2k 0.1F PGND SOFT START CL R2 DETECTION 2.26k THERMAL SHUTDOWN OVP COMPENSATION V g EA m FB REF COMP 0.6V VDD 49.9k V 8% REF PG 0.6V PG AGND 92% DS20005459B-page 2 2015 Microchip Technology Inc.