/a>Power Management” title=”Power Management”>Power Management” title=”Power Management”>Power Management IC (mini-PMIC), which integrates two high-efficiency 3MHz synchronous step-down converters (DCD1 and DCD2) and Two low-input low-dropout line regulators (LDO1 and LDO2), DCD1 and DCD2 can provide 1.5A current, LDO1 and LDO2 can provide 300A current, mainly used in mobile phones and smart phones, PDA, PMP and handheld meters, DSP Core power supply and equipment powered by a single-cell lithium battery. This article introduces the main features of ISL9305H, block diagram, typical application circuit diagram, and ISL9305IRTZEVAL1Z evaluation board circuit diagram, bill of materials and PCB layout diagram.

ISL9305H is an integrated mini Power Management IC (mini-PMIC) for powering low-voltage microprocessor, or applications using a single Li-Ion or Li-Polymer cell battery to power multiple voltage rails. ISL9305H integrates two high-efficiency 3MHz synchronous step- down converters (DCD1 and DCD2) and two low-input, low-dropout linear regulators (LDO1 and LDO2).

The 3MHz PWM switching frequency allows the use of very small external inductors and apacitors. 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 I2C interface to operate in forced PWM mode regardless of the load current condition. The I2C 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 1.5A load current. The default output voltage can be set from 0.8V to VIN using external feedback resistors on the adjustable version, or the ISL9305H can be ordered in factory pre-set power-up default voltages in increments of 100mV from 0.9V to 3.6V.

ISL9305H 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 output comes with factory pre-set fixed output voltage options between 0.9V to 3.3V. ISL9305H is available in a 4mmx4mm 16 Ld TQFN package.

Main features of ISL9305H:

• Dual 1.5A, Synchronous Step-down Converters and Dual 300mA, General-purpose LDOs

• Input Voltage Range

– DCD1/DCD2……………………… 2.5V 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 ISL9305H

• Adjustable Output Voltage

– DCD1/DCD2………………………. 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 3.3V

• 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

ISL9305H application:

• Cellular Phones, Smart Phones

• PDAs, Portable Media Players, Portable Instruments

• Single Li-Ion/Li-Polymer Battery-Powered Equipment

• DSP Core Power

Figure 1. Block diagram of ISL9305H

Figure 2. ISL9305H typical application circuit diagram

ISL9305IRTZEVAL1Z and ISL9305HIRTZEVAL1Z evaluation boards

• Input voltage rating from 2.3V to 5.5V

• Two 800mA buck converters for ISL9305 and two 1.5A buck converters for ISL9305H

• Two 300mA LDOs

• Output voltages are programmable with I2C

• 3MHz switching frequency

• Connector, test point and Jumper

Figure 3. ISL9305HIRTZEVAL1Z evaluation board circuit diagram

ISL9305HIRTZEVAL1Z Evaluation Board Bill of Materials:

Figure 4. PCB layout of ISL9305HIRTZEVAL1Z evaluation board

For details, see:
http://www.intersil.com/data/fn/fn7724.pdf
and
http://www.intersil.com/data/an/an1564.pdf

Link to this article：IntersilISL9305H3MHz microprocessor power solution