DATASHEET
ISL9305
FN7605
Rev 2.00
February 9, 2015
3MHz Dual Step-Down Converters and Dual Low-Input LDOs with I2C Compatible
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
300mA, General-purpose LDOs
microprocessor or multiple voltage rails with battery as input
sources, such as a single Li-ion or Li-Polymer. ISL9305
integrates two high-efficiency 3MHz synchronous step-down
converters (DCD1 and DCD2) and two low-input, low-dropout
linear regulators (LDO1 and LDO2).
• Input Voltage Range
- DCD1/DCD2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3V to 5.5V
- LDO1/LDO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5V to 5.5V
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
2
• 400kb/s I C-bus Series Interface Transfers the Control Data
Between the Host Controller and the ISL9305
• Adjustable Output Voltage
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
• Fixed Output I C Programmability
2
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
800mA load current. The default output voltage can be set from
2
• LDO1/LDO2 Output Voltage I C Programmability
- 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
options from 0.9V to 3.6V in 50mV step.
• 50μA I (Typ) with DCD1/DCD2 in Skip Mode; 20μA I (Typ)
for each Enabled LDO
Q
Q
2
• On-the-fly I C Programming of DC/DC and LDO Output
Voltages
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.
2
• DCD1/DCD2 I C Programmable Skip Mode Under Light
Load or Forced Fixed Switching Frequency PWM Mode
• Small, Thin, 4mmx4mm TQFN Package
Applications
• Cellular Phones, Smart Phones
The ISL9305 is available in a 4mmx4mm 16 Ld TQFN package.
Related Literature
• PDAs, Portable Media Players, Portable Instruments
• Single Li-ion/Li-Polymer Battery-Powered Equipment
• DSP Core Power
• ISL9305H Data Sheet
• AN1564 “ISL9305 and ISL9305H Evaluation Boards”
L
= 1.5µH
R
1
800mA
PG
SW1
FB1
2.3V TO 5.5V
VINDCD1
*
C
1
4
R
2
VINDCD2
4.7µF
C
10µF
10
L
= 1.5µH
R
2
800mA
SDAT
SCLK
SW2
FB2
ISL9305
*
4
C
5
4.7µF
1.5V TO 5.5V
1.5V TO 5.5V
3
R
VINLDO1
C
1µF
2
300mA
300mA
VOLDO1
VOLDO2
VINLDO2
C
1µF
3
C
1µF
C
7
1µF
6
GNDDCD1 GNDDCD2 GNDLDO
*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
February 9, 2015
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