MIC2111B Datasheet, PDF (1/35 Pages) Micrel Semiconductor – High-Performance, Multi-Mode, Step-Down Controller

MIC2111B
High-Performance, Multi-Mode,
Step-Down Controller
General Description
Micrel’s MIC2111B is a programmable-frequency, valley-
current/voltage-mode PWM controller that provides the
control and protection features necessary for power
devices and drivers that use current sensing across the
inductor. The MIC2111B can provide single tri-state PWM
logic signal to work with either power-stage modules or
discrete driver and MOSFETs. The device has precision
enable and power-good (PG) functions for sequencing of
multiple power supplies. In addition, the solution is
compatible with intelligent power stages in a high-current,
step-down DC/DC converter.
To optimize system size and system efficiency, the
MIC2111B frequency can be programmed from 200kHz to
2MHz. The device operates in power-saving mode at light
loads by reducing frequency. Optional outside audio range
operation is possible when the power-stage is configured
in light load mode. The solution uses differential current
sensing for better current-limit accuracy and a dedicated
differential amplifier for remote output sensing for accurate
output voltage control. The MIC2111B has a high-gain
transconductance amplifier for loop compensation.
External slope compensation can be added through a
resistor to avoid sub-harmonic oscillations. Other features
include programmable OCP, output OVP, and thermal
OTP protections. The MIC2111B offers Micrel’s proprietary
bi-directional, single wire fault communication for total
system protection.
The MIC2111B is available in a 20-pin 3mm × 3mm TQFN
package and has a junction temperature range of –40°C to
+125°C.
Datasheets and support documentation are available on
Micrel’s web site at: www.micrel.com.
Features
• Single 3.3V or 5V supply
• Supports load currents up to 40A
• Programmable valley-current/voltage-mode PWM
architecture
• 3.3V logic PWM output compatible with power-stage
modules and DrMOS modules
• Single tri-state PWM output
• Programmable switching frequency: 200kHz to 2MHz.
• Differential remote sensing for output voltage and
inductor current
• 0.6V reference voltage with total ±1% accuracy for
output
• Adjustable soft-start/soft-stop and pre-biased safe
startup.
• Supports light load and outside audio modes
• Programmable slope compensation and loop
compensation
• Enable input, power-good (PG) output for sequencing
• Programmable OCP, output OVP, thermal OTP, and
dedicated FAULTb pin for system safe startup/stop
• Internal thermal shutdown and UVLO
• –40°C to +125°C junction temperature range
• Available in 20-pin 3mm × 3mm TQFN package
Applications
• Servers and work stations
• Routers, switches, networking/telecom infrastructure
• Printers, scanners, graphics and video cards
• High current, high-performance POLs
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
October 13, 2015
Revision 2.1