DATASHEET ISL9305 FN7605 Rev 2.00 3MHz Dual Step-Down Converters and Dual Low-Input LDOs with I2C Compatible February 9, 2015 Interface The ISL9305 is an integrated mini Power Management IC Features (mini-PMIC) ideal for applications of powering low-voltage Dual 800mA, Synchronous Step-down Converters and Dual microprocessor or multiple voltage rails with battery as input 300mA, General-purpose LDOs sources, such as a single Li-ion or Li-Polymer. ISL9305 integrates two high-efficiency 3MHz synchronous step-down Input Voltage Range converters (DCD1 and DCD2) and two low-input, low-dropout - DCD1/DCD2 2.3V to 5.5V linear regulators (LDO1 and LDO2). - LDO1/LDO2 1.5V to 5.5V The 3MHz PWM switching frequency allows the use of very small 2 400kb/s I C-bus Series Interface Transfers the Control Data external inductors and capacitors. Both step-down converters can Between the Host Controller and the ISL9305 enter skip mode under light load conditions to further improve the Adjustable Output Voltage efficiency and maximize the battery life. For noise sensitive 2 applications, they can also be programmed through I C interface - VODCD1/VODCD2 0.8V to V IN to operate in forced PWM mode regardless of the load current 2 2 Fixed Output I C Programmability condition. The I C interface supports on-the-fly slew rate control of - At 25mV/Step 0.825V to 3.6V 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 2 LDO1/LDO2 Output Voltage I C Programmability 800mA load current. The default output voltage can be set from - At 50mV/Step 0.9V to 3.6V 0.8V to V using external feedback resistors on the adjustable IN version, or the ISL9305 can be ordered in factory pre-set voltage 50 A I (Typ) with DCD1/DCD2 in Skip Mode 20A I (Typ) Q Q options from 0.9V to 3.6V in 50mV step. for each Enabled LDO 2 On-the-fly I C Programming of DC/DC and LDO Output The ISL9305 also provides two 300mA low dropout (LDO) Voltages regulators. The input voltage range is 1.5V to 5.5V allowing 2 them to be powered from one of the on-chip step-down DCD1/DCD2 I C Programmable Skip Mode Under Light converters or directly from the battery. The default LDO Load or Forced Fixed Switching Frequency PWM Mode power-up output comes with factory pre-set fixed output Small, Thin, 4mmx4mm TQFN Package voltage options between 0.9V to 3.3V. Applications The ISL9305 is available in a 4mmx4mm 16 Ld TQFN package. Cellular Phones, Smart Phones Related Literature PDAs, Portable Media Players, Portable Instruments ISL9305H Data Sheet Single Li-ion/Li-Polymer Battery-Powered Equipment AN1564 ISL9305 and ISL9305H Evaluation Boards DSP Core Power L = 1.5H 1 800mA PG SW1 2.3V TO 5.5V * VINDCD1 R C 1 4 R 2 VINDCD2 FB1 C 4.7F 10 10F L = 1.5H 2 800mA SDAT SW2 SCLK ISL9305 * R 1.5V TO 5.5V C 3 5 FB2 R VINLDO1 4 4.7F C 2 1F 300mA 1.5V TO 5.5V VOLDO1 VINLDO2 300mA VOLDO2 C 3 C C 1F 6 7 GNDDCD1 GNDDCD2 GNDLDO 1F 1F *Only for adjustable output version. For fixed output version, directly connect the FB pin to the output of the buck converter. FIGURE 1. TYPICAL APPLICATION DIAGRAM FN7605 Rev 2.00 Page 1 of 17 February 9, 2015ISL9305 TABLE 1. TYPICAL APPLICATION PART LIST PARTS DESCRIPTION MANUFACTURER PART NUMBER SPECIFICATIONS SIZE L1, L2 Inductor Sumida CDRH2D14NP-1R5 1.5H/1.80A/50m 3.0mmx3.0mmx1.55mm C1 Input capacitor Murata GRM21BR60J106KE19L 10F/6.3V 0805 C2, C3 Input capacitor Murata GRM185R60J105KE26D 1F/6.3V 0603 C4, C5 Output capacitor Murata GRM219R60J475KE01D 4.7F/6.3V 0805 C6, C7 Output capacitor Murata GRM185R60J105KE26D 1F/6.3V 0603 R1, R2, Resistor Various 1%, SMD, 0.1 0603 R3, R4 NOTE: 1. C4 and C5 are 10F/6.3V for VODCD less than 1V. Block Diagram ANALOG/LOGIC CIRCUIT INPUT SHORT VINDCD1 DCDPG CIRCUIT 10F PROTECTION 1.5H SW1 DCD1 4.7F FB1 BUCK CONVERTER GNDDCD1 PGOOD WITH 1~200MS DELAY TIME VINDCD2 OVERCURRENT PROTECTION 10F 1.5H SW2 4.7F DCD2 FB2 UVLO VREF BUCK CONVERTER GNDDCD2 OSC VINLDO1 THERMAL 1F SHUTDOWN VOLDO1 LDO1 300mA 1F SDAT 2 I C VINLDO2 INTERFACE 1F SCLK LDO2 VOLDO2 300mA 1F GNDLDO FN7605 Rev 2.00 Page 2 of 17 February 9, 2015