DC/DC Converter. AAT1162 Datasheet
12V, 1.5A Step-Down DC/DC Converter
The AAT1162 is an 800kHz high efficiency step-
down DC/DC converter. With a wide input voltage
range of 4.0V to 13.2V, the AAT1162 is an ideal
choice for dual-cell Lithium-ion battery-powered
devices and mid-power-range regulated 12V-pow-
ered industrial applications. The internal power
switches are capable of delivering up to 1.5A to the
The AAT1162 is a highly integrated device, simpli-
fying system-level design. Minimum external com-
ponents are required for the converter.
The AAT1162 optimizes efficiency throughout the
entire load range. It operates in a combination
PWM/Light Load mode for improved light-load effi-
ciency. The high switching frequency allows the use
of small external components. The low current shut-
down feature disconnects the load from VIN and
drops shutdown current to less than 1µA.
The AAT1162 is available in a Pb-free, space-sav-
ing, thermally-enhanced 16-pin TDFN34 package-
and is rated over an operating temperature range
of -40°C to +85°C.
• Input Voltage Range: 4.0V to 13.2V
• Up to 1.5A Load Current
• Fixed or Adjustable Output:
— Output Voltage: 0.6V to VIN
• Low 115µA No-Load Operating Current
• Less than 1µA Shutdown Current
• Up to 96% Efficiency
• Integrated Power Switches
• 800kHz Switching Frequency
• Soft Start Function
• Short-Circuit and Over-Temperature Protection
• Minimum External Components
• TDFN34-16 Package
• Temperature Range: -40°C to +85°C
• Distributed Power Systems
• Industrial Applications
• Laptop Computers
• Portable DVD Players
• Portable Media Players
• Set-Top Boxes
• TFT LCD Monitors and HDTVs
4.0V ~ 13.2V
12V, 1.5A Step-Down DC/DC Converter
1, 2, EP2
Power switching node. LX is the drain of the internal P-channel switch and N-channel syn-
chronous rectifier. Connect the output inductor to the two LX pins and to EP2. A large
exposed copper pad under the package should be used for EP2.
Power source input. Connect IN to the input power source. Bypass IN to DGND with a
22µF or greater capacitor. Connect both IN pins together as close to the IC as possible. An
additional 100nF ceramic capacitor should also be connected between the two IN pins and
DGND, pin 6
Exposed Pad 1 Digital Ground, DGND. The exposed thermal pad (EP1) should be connected
to board ground plane and pins 6, 13, and 14. The ground plane should include a large
exposed copper pad under the package for thermal dissipation (see package outline).
Internal analog bias input. AIN supplies internal power to the AAT1162. Connect AIN to the
input source voltage and bypass to AGND with a 0.1µF or greater capacitor. For additional
noise rejection, connect to the input power source through a 10Ω or lower value resistor.
Internal LDO bypass node. The output voltage of the internal LDO is bypassed at LDO. The
internal circuitry of the AAT1162 is powered from LDO. Do not draw external power from LDO.
Bypass LDO to AGND with a 1µF or greater capacitor.
Output voltage feedback input. FB senses the output voltage for regulation control. For fixed
output versions, connect FB to the output voltage. For adjustable versions, drive FB from the
output voltage through a resistive voltage divider. The FB regulation threshold is 0.6V.
Control compensation node. Connect a series RC network from COMP to AGND, R = 51k
and C = 270pF.
Analog signal ground. Connect AGND to PGND at a single point as close to the IC as possible.
Active high enable input. Drive EN high to turn on the AAT1162; drive it low to turn it off. For
automatic startup, connect EN to IN through a 4.7kΩ resistor. EN must be biased high, biased
low, or driven to a logic level by an external source. Do not let the EN pin float when the
device is powered.
Power ground. Connect AGND to PGND at a single point as close to the IC as possible.