OUTLINE

The R1224N Series are CMOS-based PWM step-down DC/DC Converter controllers with low supply current. Each of these ICs consists of an oscillator, a PWM control circuit, a reference voltage unit, an error amplifier, a phase compensation circuit, a soft-start circuit, a protection circuit, a PWM/VFM alternative circuit, a chip enable circuit, resistors for output voltage detect, and input voltage detect circuit. A low ripple, high efficiency step-down DC/DC converter can be easily composed of this IC with only several external components, or a power-transistor, an inductor, a diode and capacitors. Output Voltage is fixed or can be adjusted with external resistors (Adjustable types are without PWM/VFM alternative circuit).

FEATURES

• Supply Current .............................................Typ. 20µA (R1224Nxx2E/F/M/L, R1224N102M)

Typ. 30µA (R1224Nxx2G, R1224N102G)

Typ. 40µA (R1224Nxx2H, R1224N102H)

• Standby Current ...........................................Typ. 0µA

• Input Voltage Range ....................................2.3V~18.5V

• Output Voltage Range..................................1.2V to 6.0V (R1224Nxx2x)

1.0V to VIN (R1224N102x)

• Output Voltage Accuracy............................±2.0

• Oscillator Frequency...................................Typ. 180kHz (R1224Nxx2M, R1224N102M)

Typ. 300kHz (R1224Nxx2E/G, R1224N102G)

Typ. 500kHz (R1224Nxx2F/H, R1224N102H)

• Efficiency.........................................................................Typ. 90

• Low Temperature-Drift Coefficient of Output Voltage......Typ. ±100ppm/°C

• Package .......................................................................... SOT-23-5

• Built-in Soft-start Function............................................... Typ. 10ms

• Built-in Current Limit Circuit

APPLICATIONS

• Power source for hand-held communication equipment, cameras, video instruments such as VCRs, camcorders.

• Power source for battery-powered equipment.

• Power source for household electrical appliances.