ELM92xxxBCMOS 600kHz High output current PWM step-up DC/DC converter

ELM92xxxB is CMOS PWM step-up DC/DC converter which consists of reference voltage source, error amplifier, oscillation circuit, start-up circuit, output voltage setting resistor, LX transistor and switching current limiter. For external parts, coil, diode and capacitor are possible choices; with external parts, ELM92 series is able to acquire constant output voltage higher than input voltage. The standard output voltages are 2.7V, 3.0V, 3.3V, and 5.0V; ELM92 series can also be designed as semi-custom IC within the range of 2.5V to 5.5V by 0.1V step. Meanwhile, 600kHz high frequency PWM control scheme makes it easy to design DC/DC converter which can generate large output current with high stability and small ripples by only using small external inductor. With newly developed intermittent operation control scheme, ELM92 series is able to work with high efficiency under wide range of load conditions.

Output voltage range2.5V to 5.5V(by 0.1V)
Low voltage operationVin>=0.9V
Oscillating frequencyTyp.600kHz
Output current(e.g.)250mA(Vin=1.5V, Vout=3.0V)
CE(Chip-enable pin) availableMax.0.5µA(ELM92xx2B Iss at shutdown)
High efficiencyTyp.85%
Switching current limiter
PackageSOT-89
SOT-89-5
DatasheetELM92series
Application
Constant voltage source for battery-operated devices
Constant voltage source for PDAs, cameras, portable communications equipments and videos
Local regulator

Absolute Maximum Ratings

ParameterSymbolLimitUnit
Apply voltage to LX pinVlxVss-0.3 to 8.0V
Apply voltage to VOUT pinVoutVss-0.3 to 8.0V
Apply voltage to CE pinVceVss-0.3 to 8.0V
Power dissipationPd500(SOT-89), 500(SOT-89-5)mW
Operating temperatureTop-40 to +85°C
Storage temperatureTstg-55 to +125°C

Block diagram

block-diagram