ELM91xxxxACMOS PFM Step-up DC/DC converter and controller
ELM91xx1xA is CMOS PFM control step-up DC-DC converter; ELM91xx3xA is CMOS PFM control step-up DC-DC controller, which has large output current capacity by using an external FET switch. ELM91 series consists of reference voltage source, error amplifier, oscillation circuit, start-up circuit, PFM-control circuit, switching current limit circuit (ELM91xx1xA only), switching transistor (ELM91xx1xA only) and output voltage setting resistor. For external parts, coil, diode, MOSFET and capacitor are possible choices. The standard output voltages are 1.8V,3.0V,3.3V,5.0V; ELM91 series can also be designed as semi-custom IC within the range of 1.8V to 5.5V by 0.1V step.
| Output voltage range | 1.8V to 5.5V(by 0.1V) |
|---|---|
| Low voltage operation | 0.9V(ELM91xx1xA: Iout=1mA) |
| Oscillating frequency | Typ.100kHz |
| Low power operation | Typ.40µW(ELM91301xA: Typ.100kHz) |
| High efficiency | 85%(ELM9130xxA: Vin=1.5V, Iout=10mA) |
| Output current(e.g.) | 100mA(Vin=1.5V, Vout=3.0V) |
| Package | SOT-89 SOT-23 SC-70-5(SOT-353) |
| Datasheet | ELM91series |
- Application
- Constant voltage source for battery-operated devices
- Portable communication equipments and video recorders
Absolute Maximum Ratings
| Parameter | Symbol | Limit | Unit |
|---|---|---|---|
| Apply voltage to LX pin | Vlx | Vss-0.3 to 7.0 | V |
| Apply voltage to VOUT pin | Vout | Vss-0.3 to 7.0 | V |
| Output current of LX pin | Ilx | 500 | mA |
| Output current of EXT pin | Iext | 20 | mA |
| Power dissipation | Pd | 500(SOT-89), 250(SOT-23), 150(SC-70-5)(SOT-353) | mW |
| Operating temperature | Top | -40 to +85 | °C |
| Storage temperature | Tstg | -55 to +125 | °C |
Block diagram
ELM91xx1xA
ELM91xx3xA
