Features: Guaranteed full load start-up and operation at
1.8V input
Continuous conduction mode for high output current
Pulse Frequency Modulation and internal synchronous
rectification for high efficiency
Isolates the load from the input during shutdown
Minimum external components
Low ON resistance internal switching FETs
Low supply current
5V and 3.3V output versionsPinout
SpecificationsVOUT...............................................................................................7V
Voltage on any other pin.........................GND - 0.3V to VOUT + 0.3V
Peak Switch Current (IPEAK)............................................................2A
Average Switch Current (IAVG)........................................................1A
Junction Temperature...............................................................150°C
Storage Temperature Range.....................................65°C to 150°C
Lead Temperature (Soldering, 10 sec)......................................260°C
Thermal Resistance (qJA)......................................................160°C/W
Temperature RangeML4870CS-X.....................................0°C to 70°C
ML4870ES-X.................................................................-20°C to 70°C
VINOperating Range..............................................1.8V to VOUT- 0.2V
DescriptionThe ML4870 is a continuous conduction boost regulator designed for DC to DC conversion in multiple cell battery power systems. Continuous conduction allows the regulator to maximize output current for a given inductor. The maximum switching frequency can exceed 200kHz, allowing the use of small, low cost inductors. The ML4870 is capable of start-up with inpuvoltages as low as 1.8V, and is available in 5V and 3.3V output versions with an output voltage accuracy of ±3%.
An integrated synchronous rectifier ML4870 eliminates the need for an external Schottky diode and provides a lower forward voltage drop, resulting in higher conversion efficiency. In addtion, low quiescent current and variable frequency operation result in high efficiency even at light loads. The ML4870 requires only a few external components to build a very small regulator capable of achieving conversion efficiencies approaching 85%.
The SHDN input of ML4870 allows the user to stop the regulator from witching, and provides complete isolation of the load rom the battey.
ML4870 Data Sheet
