1.4MHz high efficiency synchronous PWM step up DC/DC converter

ELM620BA is synchronous PWM step-up DC/DC converter with high efficiency and 1.4MHz fixed frequency; by adopting synchronous switch, ELM620BA is able to provide high efficiency without external Schottky diode. ELM620BA is able to activate within the range from 0.6V to 5V of input voltage and 2.5V to 6V of output one. For 3V or 3.3V output, ELM620BA can provide current up to 260mA by a single AA cell, or to 600mA by 2 serial-connected AA cells. With 1.4MHz switching frequency, small coils and capacitors can be adopted; therefore, ELM620BA is possible to be assembled within small areas on the board .

Current mode control
Output voltage drop protection
Thermal shutdown protection and short circuit protection
Input voltage0.6V to 5.0V
Output voltage2.5V to 6.0V
Low current consumptionTyp.300µA
Shutdown current<1µA
Low start-up voltageTyp.0.9V
Low switch on (internal switch) resistance0.35Ω
Constant frequencyTyp.1.4MHz
High efficiency96%
Cellular phone
Digital camera
MP3 player
Portable machine
Wireless handset

Absolute Maximum Ratings

VIN power supply voltageVin-0.3 to +6.0V
Apply voltage to SWVswGND-0.3 to Vout+0.3V
Apply voltage to FBVfbGND-0.3 to Vout+0.3V
Apply voltage to ENVenGND-0.3 to Vout+0.3V
Apply voltage to VOUTVout-0.3 to +6.0V
Power dissipationPd250mW
Operating temperature rangeTop-30 to +85°C
Storage temperature rangeTstg-65 to +125°C

Block diagram