The R1205x series PWM step-up DC/DC converters are optimized for driving white LEDs with constant current and for general use.
The R1205x Series are CMOS-based PWM step-up DC/DC converters designed to drive white LEDs with constant current. The series includes two types: the A versions optimized for general use and the B version optimized for serial drive of white LEDs. Key features include an integrated forward diode, under-voltage lockout, soft-start, over-voltage protection, and thermal shutdown circuits.
| Supply Current (Iop) | Typ. 800nA |
|---|---|
| Standby Current (Iistandby) | Max. 5nA |
| Input Voltage Range (A Version) | +2.3V to 5.5V |
| Input Voltage Range (B Version) | 1.8V to 5.5V |
| Feedback Voltage (B Version) | 0.2V |
| Feedback Voltage Accuracy (A Version) | +/- 1.5% |
| Feedback Voltage Accuracy (B Version) | +/- 10mV |
| Oscillator Frequency | 1.2MHz |
| Oscillator Maximum Duty Cycle | Typ. 91% |
| UVLO Detect Voltage (A Version) | Typ. 2.0V |
| UVLO Detect Voltage (B Version) | Typ. 1.6V |
| Coil-current Limit Circuit (A Version) | Typ. 350mA |
| Coil-current Limit Circuit (B Version) | Typ. 700mA |
| Over Voltage Protection Circuit (OVP) | Typ. 25V |
| Soft Start Time (A Version) | Typ. 2ms |
| Thermal Shutdown Temperature | 150°C |
| Packages | DFN1616-6B, TSOT-23-6 |
The A versions are optimized for general use, and the B version is optimized for the serial drive of white LED with constant current.
The Over Voltage Protection Circuit (OVP) is typically set to 25V.
Yes, the brightness can be adjusted by applying a PWM signal (200Hz to 300kHz) to the CE pin.
In case of 7 lights or more, the R1218x Series is recommended.