MIC3172

The MIC2172 and MIC3172 are complete 100kHz SMPS current-mode controllers with internal 65V 1.25A power switches. The MIC2172 features external frequency synchronization or frequency adjustment, while the MIC3172 features an enable/shutdown control input.

Although primarily intended for voltage step-up applications, the floating switch architecture of the MIC2172/3172 makes it practical for step-down, inverting, and Cuk configurations as well as isolated topologies.

Operating from 3V to 40V, the MIC2172/3172 draws only 7mA of quiescent current making it attractive for battery operated supplies.

The MIC3172 is for applications that require on/off control of the regulator. The MIC3172 is externally shutdown by applying a TTL low signal to EN (enable). When disabled, the MIC3172 draws only leakage current (typically less than 1µA). EN must be high for normal operation. For applications not requiring control, EN must be tied to VIN or TTL high.

The MIC2172 is for applications requiring two or more SMPS regulators that operate from the same input supply. The MIC2172 features a SYNC input which allows locking of its internal oscillator to an external reference. This makes it possible to avoid the audible beat frequencies that result from the unequal oscillator frequencies of independent SMPS regulators.

A reference signal can be supplied by one MIC2172 designated as a master. To insure locking of the slave's oscillators, the reference oscillator frequency must be higher than the slave's. The master MIC2172's oscillator frequency is increased up to 135kHz by connecting a resistor from SYNC to ground (see applications information).

The MIC2172/3172 is available in an 8-pin plastic DIP or SOIC for -40°C to +85°C operation.

Features
  • 1.25A, 65V internal switch rating
  • 3V to 40V input voltage range
  • Current-mode operation
  • Internal cycle-by-cycle current limit
  • Thermal shutdown
  • Low external parts count
  • Operates in most switching topologies
  • 7mA quiescent current (operating)
  • <1µA quiescent current, shutdown mode (MIC3172)
  • TTL shutdown compatibility (MIC3172)
  • External frequency synchronization (MIC2172)
  • External frequency trim (MIC2172)
  • Fits most LT1172 sockets (see applications info)
Parameter
Parameter Name Value Value
Regulator Type Step Up (Boost) Step Up (Boost)
Input Voltage Range Min (V) 3 3
Input Voltage Range Max (V) 40 40
Output Voltage Range Min (V) 3.6 3.6
Output Voltage Range Max (V) 65 65
Quiescent Current (mA) typ 7 7
Switching Frequency (kHz) 100 100
Operating Temp Range -40 to 85 -40 to 85
Vfb (V) 1.24 1.24
Duty Cycle Max (%) 95 95
SHUTDOWN Current (µA) (Typ) 0.1 0.1
Switch current (A) typ 1.25 1.25
Alternative Topology SEPIC, CUK, Flyback SEPIC, CUK, Flyback
Documents
MIC2172/3172 - 100kHz 1.25A Switching RegulatorsData Sheets11/05/2015906KB
MIC2172/3172 - 100kHz 1.25A Switching RegulatorsData Sheets11/09/2015158KB
Micrel AN 80 - Photoflash High-Voltage Power SupplyAppNote10/02/201548KB
Ordering Information
Part NumberLeadsPackage TypeTemp RangePacking1+26+100+1000+5000+
MIC3172YM8SOIC-40C to +85CTUBE2.642.202.001.671.54
MIC3172YM-TR8SOIC-40C to +85CT/R2.642.202.001.671.54
RoHS Information
PartNumberDeviceWeightShippingWeightLeadCountPackageTypePackageWidthSolderCompositionJEDECIndicatorRoHSChinaEFUP
MIC3172YN0.4867000.9000008PDIP.300inMatte Tine3
MIC3172YM0.0750000.1632658SOIC3.90mm(.150in)NiPdAue4
MIC3172YM-TR0.0750000.2500008SOIC3.90mm(.150in)NiPdAue4
MIC2172/3172 - 100kHz 1.25A Switching Regulators MIC3172
MIC2172/3172 - 100kHz 1.25A Switching Regulators MIC3172
Micrel AN 80 MIC3172
Products 产品服务
Manufacturers 生产厂家
Sales 联系购买
©1993 - 2024 BDTIC