Document
Advanced Analog Technology, Inc.
AAT1500
Product information presented is current as of publication date. Details are subject to change without notice
CONSTANT CURRENT BOOST CONVERTER FOR 1 TO 4 WHITE LEDS
Features
z z z z z z z z z Up to 4 LEDs at 2.8V Supply High Efficiency (85%) Output Over Voltage Protection HV Internal Switch 1 MHz PWM Switching Frequency Uses Tiny 1 mm Height Inductor 2.6V to 6V Input Range 0.1µA Shutdown Current SOT-25, SOT-26 & VQFN-8 Package Available
General Description
The AAT1500 is a step-up converter that provides a solution to drive 1 to 4 white LEDs with a constant current from a Lithium Ion cell, and its switching frequency is fixed at 1 MHz. The AAT1500 offers a low 0.25V reference, which minimizes power loss in the current setting resistor and improves efficiency. Except in SOT-25 package, protection features include output over voltage protections. The AAT1500 consists of a 0.1µA shutdown current, and HV internal switch. Input supple range allows operation from 2.6V to 6V.
Pin Configuration
TOP VIEW
SW GND IE
1 2 3
5
VDD
SW
GND
4
EN
SOT - 25 PACKAGE
w
1 3 4
w
IE
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8 7 6 5
1 2 3
.D
4
SW
TOP VIEW
t a
OVP EN
S a
e h
t e
U 4
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m o
The AAT1500 is available in 5-pin SOT-25, 6-pin SOT-26 and 8-pin VQFN-8 package.
6 5
VDD
Applications
z z z z z z Palmtops MP3 Player Digital Still Cameras Portable Media Player Cell Phones and Smart Phones Electronic Information Organizers
SOT - 26 PACKAGE
TOP VIEW
OVP
VDD 2 EN GND
GND1 IE NC
VQFN-8 PACKAGE
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Advanced Analog Technology, Inc.
AAT1500
Pin Description
PIN NO SOT-25 1 2 3 4 5 PIN NO SOT-26 1 2 3 4 5 6 PIN NO VQFN-8 8 4 6 3 1 2 7 5 NAME SW GND IE EN OVP VDD GND1 NC I/O O I I I Switch Pin Ground Inverting Input Pin of Error Amplifier Chip Enable/Disable(Active High) Over Voltage Protection Supply Voltage SW MOS Ground NC DESCRIPTION
Absolute Maximum Ratings (Note 1)
CHARACTERISTICS Supply Voltage SYMBOL VDD VALUE
− 0.3 to 7 − 0.3 to 21 − 0.3 to 6
UNIT
V V V
o o o o
SW, OVP to GND Other I/O Pin Voltage Junction Temperature Storage Temperature Range Operating Temperature Range Lead Temperature
Tstorage
125
− 45 to 125 − 40 to 85
C C C C
TC TL
260
Recommended Operating Conditions
CHARACTERISTICS
Supply Voltage
SYMBOL VDD
VALUE
UNIT
2.6 to 6
V
Dissipation Ratings
CHARACTERISTICS PACKAGE SYMBOL VALUE UNIT
o o
Package Thermal Resistance Power Dissipation, TC = 25 oC
SOT-26 VQFN-8 SOT-26 VQFN-8
θ JA θ JA
Pd Pd
208 50 0.48 2
C/W C/W W W
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Advanced Analog Technology, Inc.
AAT1500
Electrical Characteristics, VDD = 3.6 V, TC = 25 oC (Unless Otherwise Specified)
Operating Condition PARAMETER SYMBOL TEST CONDITION MIN TYP MAX UNIT
Supply Voltage Under Voltage Lockout Operating Current Quiescent Current Shutdown Current
Osci.