ELM95xxxxECMOS PWM step-up DC/DC converter
ELM95xxxxE is CMOS PWM step-up DC/DC converter which consists of reference voltage source, error amplifier, oscillation circuit, start-up circuit, PWM control circuit, switching current limit circuit, switch transistor and output voltage setting resistor. For external parts, coil, diode and capacitor are possible choices; with external parts, are 2.7V, 3.0V, 3.3V and 5.0V; ELM95 series can also be designed as semi-custom IC within the range of 2.5V to 5.5V by 0.1V step. With newly-developed PWM control circuit, ELM95 series is able to modulate switching time smoothly with constant frequency and consequently generates stable output with small ripples. There are two switching frequency and maximum duty ratio available:(Switching frequency, Maximum duty ratio)=(55kHz, 60%) and (100kHz, 77%).
| Output voltage range | 2.5V to 5.5V(by 0.1V) |
|---|---|
| Low voltage operation | Vin>=0.9V(No load) |
| Low power operation | 35μW(ELM9530AxE) |
| High efficiency | Typ.85% |
| High accuracy output voltage | ±2.5% |
| Constant switching frequency | Typ.55kHz(Type A), Typ.100kHz(Type B) |
| Output current(e.g.) | 100mA(Type B, Vin=1.5V, Vout=3.3V) |
| Small ripples | Ceramic capacitor can be used for output capacitor. |
| Package | SOT-89 SOT-23 |
| Datasheet | ELM95series |
- Application
- Constant voltage source for battery-operated devices
- Constant voltage source for cameras
- Portable communications equipments
- Local regulator
Absolute Maximum Ratings
| Parameter | Symbol | Limit | Unit |
|---|---|---|---|
| Apply voltage to LX pin | Vlx | Vss-0.3 to 8.0 | V |
| Apply voltage to VOUT pin | Vout | Vss-0.3 to 8.0 | V |
| Output current of LX pin | Ilx | 500 | mA |
| Power dissipation | Pd | 500 (SOT-89) 250 (SOT-23) | mW |
| Operating temperature | Top | -40 to +85 | °C |
| Storage temperature | Tstg | -55 to +125 | °C |
Block diagram
