Document
Advanced Analog Technology, Inc.
AAT1108
Preliminary and Provisional
2-CHANNEL STEP-UP PWM CONTROLLERS WITH ADJUSTABLE LDO
Features www.DataSheet4U.com z z z z z z z Complete PWM Power Control Circuitry Adjustable LDO Regulator Under-voltage Lockout Protection Totem pole Output Output Short Circuit Protection Dead Time Control¡G 0 to 100% Wide Operating Frequency¡G 10kHz to 800kHz General Description The AAT1108 series provides an integrated two-channel pulse-width-modulation (PWM) solution for the power supply of DC-DC system, this device offers the systems engineer the flexibility to tailor the power supply circuitry to a specific application. Each channel contains its own error amplifier, PWM comparator, dead–time control and output driver. The under-voltage protection, oscillator, short circuit protection and voltage reference circuit are common for the two channels. The AAT1108 contains two boost (step-up) exclusive circuits. Dead-time control (DTC) can be set to provide 0% to 100% dead time by resistive divider network. Soft start can be implemented by paralleling the DTC resistor with a capacitor. Two dead time control inputs are assigned for Ch-1 and Ch-2 individually, and dead time control inputs can be used to control on / off operation. The maximum output currents of LDO regulator can be enlarged by connect a N_MOS FET (or NPN bipolar) as a source follow stage at out3 pin.
*Spec is subject to change without notice in this document.
Pin Configuration
TOP VIEW
CT RT INV3 INV1 FB1 DTC1 OUT1 GND 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 Vref SCP OUT3 INV2 FB2 DTC2 OUT2
VDD
(TSSOP-16 PACKAGE)
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V 0.1
Advanced Analog Technology, Inc.
AAT1108
Pin Description Pin # 1 2
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Name CT RT INV3 INV1 FB1 DTC1 OUT1 GND VDD OUT2 DTC2 FB2 INV2 OUT3 SCP Vref
I/O I External timing capacitance I External timing resistance I Negative input for LDO amplifier
Description
3 4 5 6 7 8 9
I Negative input for error amplifier 1 I Output for error amplifier 1 I Output 1 dead time / soft start setting O Output 1 Ground I Power supply O Output 2 I Output 2 dead time / soft start setting I Output for error amplifier 2 I Negative input for error amplifier 2 I LDO output I Timer latch setting O Reference voltage (2.505V) output
10 11 12 13 14 15 16
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V 0.1
Advanced Analog Technology, Inc.
AAT1108
Absolute Maximum Ratings CHARACTERISTICS Supply voltage Input voltage (IN-, DTC) Output voltage
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SYMBOL VDD VI VO
VALUE 7
VDD VDD +0.3 -120/+120 -20 to 85 -65 to 150 500
UNIT V V V
Output current Operating free-air temperature range Storage temperature range Power dissipation
IO
Tope Tstg
mA
o o
C C
Pd
mW
Recommended Operating Conditions
Supply voltage, VDD Input voltage, INV1, INV2, INV3 Output voltage OSC capacitor OSC resistor (Note 1) Oscillator frequency Output current, Iout1, Iout2 Out put current, I.