aoz1605 Alpha & Omega Semiconductor, aoz1605 Datasheet - Page 8

• Manufacturer Part Number: aoz1605
• Description: 500 Ma / 3 Mhz Ezbuck Regulator
• Manufacturer: Alpha & Omega Semiconductor

Block Diagram
Operation
The AOZ1605 has a patented light load mode
architecture allowing up to 85% efficiency at 1 mA load
currents, enabling longer standby times in battery
operated systems.
The AOZ1605 is a high efficiency step down DC-DC buck
converter that operates typically at 3 MHz fixed Pulse
Width Modulation (PWM) at medium to heavy load
currents. The AOZ1605 can deliver a constant voltage
from a single Li-Ion battery with an input voltage rail from
2.5 Volts to 5.5 Volts. Using a voltage mode architecture
with synchronous rectification, the AOZ1605 has the
ability to deliver up 500 mA of continuous current
ENABLE
Rev. 1.0 March 2011
Shutdown
Oscillator
Thermal
3 MHz
UVLO
PWM
PFM
Control
Output
Logic
Comp
Ilimit
+
–
www.aosmd.com
+
–
Master
Logic
depending on the input voltage, output voltage, ambient
temperature and inductor chosen.
There are two modes of operations depending on the
current consumption, PFM (Pulse Frequency
Modulation) and PWM (Pulse Width Modulation).
For ultra-low current the device operates in the PFM
mode to obtain high efficiency that is characteristic of
the PFM mode. The device operates in the PWM mode
when the output current exceed the load current of
approximately 100 mA or higher.
Additional feature include under voltage lockout,
over current protection, thermal shutdown and soft-start.
Threshold
Isense
Amp
lmin
+
–
Error
Amp
600mV
+
VREF
–
VIN
+
–
LX
PGND
FB
COUT
L1
C1
AOZ1605
Page 8 of 15
VOUT
R2
R1