The R1232D series is a CMOS-based PWM step-down DC/DC converter with synchronous rectifier and low supply current. A 10μF or greater ceramic capacitor can be used as the output capacitor with the R1232D. Each of these ICs consists of an oscillator, a PWM control circuit, a voltage reference unit, an error amplifier, a soft-start circuit, protection circuits, a protection against miss operation under low voltage (UVLO), a chip enable circuit, a synchronous rectifier, Nch. driver transistor, and so on. A low ripple, high efficiency step-down DC/DC converter can be easily composed of this IC with only a few kinds of external components, or an inductor and capacitors. (As for R1232D001x type, divider resistors are also necessary.) In terms of the output voltage, it is fixed internally in the R1232Dxx1x types. While in the R1232D001x types, the output voltage is adjustable with external divider resistors. As protection circuits, current limit circuit which limits peak current of LX at each clock cycle, and latch type protection circuit exist. The latch protection works if the term of the over-current condition keeps on a certain time. Latch-type protection circuit works to latch an internal driver with keeping it disable. To release the condition of protection, after disable this IC with a chip enable circuit, enable it again, or restart this IC with power-on or make the supply voltage at U1 less than 3V.
The R1232D Series are CMOS-based PWM step-down DC/DC converters featuring a built-in synchronous rectifier and low supply current. These ICs include an oscillator, PWM control circuit, voltage reference unit, error amplifier, soft-start circuit, and various protection circuits such as UVLO and latch-type over-current protection.
The series offers two choices of oscillator frequency (1MHz or 2.25MHz) and supports output voltages from 0.9V to 3.3V for fixed types, while adjustable types support a range from 0.8V to Vin. The devices are available in an SON-8 package with lead-free and halogen-free options.
| Operating Temperature Range | -40 to 85 °C |
|---|---|
| Power Dissipation (SON-8) | 480 mW |
| Oscillator Frequency Options | 1MHz or 2.25MHz |
The typical soft-start time is 1.0ms at an oscillator frequency of 1MHz.
A ceramic capacitor with a capacitance of 10u.F or more can be used as the output capacitor.
The device operates within a temperature range of -40 to 85 °C.
The maximum power dissipation for the SON-8 package is 480 mW.