The 3MHz PWM switching frequency allows the use of very small external inductors and capacitors. Both step-down converters can enter skip mode under light load conditions to further improve the efficiency and maximize the battery life. For noise sensitive applications, they can also be programmed through I2 C interface to operate in forced PWM mode regardless of the load current condition. The I2 C interface supports on-the-fly slew rate control of the output voltage from 0.825V to 3.6V at 25mV/step size for dynamic power saving. Each step-down converter can supply up to 800mA load current. The default output voltage can be set from 0.8V to VIN using external feedback resistors on the adjustable version, or the ISL9305 can be ordered in factory pre-set voltage options from 0.9V to 3.6V in 50mV step.
The ISL9305 also provides two 300mA low dropout (LDO) regulators. The input voltage range is 1.5V to 5.5V allowing them to be powered from one of the on-chip step-down converters or directly from the battery. The default LDO power-up output comes with factory pre-set fixed output voltage options between 0.9V to 3.3V.
The ISL9305 is available in a 4mmx4mm 16 Ld TQFN package.
- Dual 800mA, Synchronous Step-down Converters and Dual 300mA, General-purpose LDOs
- Input Voltage Range
- DCD1/DCD2: 2.3V to 5.5V
- LDO1/LDO2: 1.5V to 5.5V
- 400kb/s I2C-bus Series Interface Transfers the Control Data Between the Host Controller and the ISL9305
- Adjustable Output Voltage
- VODCD1/VODCD2: 0.8V to VIN
- Fixed Output I2C Programmability
- At 25mV/Step: 0.825V to 3.6V
- LDO1/LDO2 Output Voltage I2C Programmability
- At 50mV/Step: 0.9V to 3.6V
- 50μA IQ (Typ) with DCD1/DCD2 in Skip Mode; 20μA IQ (Typ) for each Enabled LDO
- On-the-fly I2C Programming of DC/DC and LDO Output Voltages
- DCD1/DCD2 I2C Programmable Skip Mode Under Light Load or Forced Fixed Switching Frequency PWM Mode
- Small, Thin, 4mmx4mm TQFN Package
Design Resources and Tools