AiT A7107E6 Schematics
M
ICROPOWER HIGH EFFICIENCY
STEP-UP DC-DC CONVERTER
A7107
Description Features
The A7107 is a micropower, high efficiency,
and low voltage step-up DC/DC converter
intended for use in battery powered wireless
applications. With the low start-up input
voltage below 1V, the device is suitable for
applications with 1 or 2 AA cells, providing up
to 300mA output current at 3.3V output. The
35µA low quiescent current, zero shutdown
current and high efficiency maintains long
battery lifetime. A switching frequency of
450KHz minimizes solution footprint by
allowing the use of small inductors and
ceramic capacitors. The device is offered in a
low profile (1mm) small 6-lead SOT-23
package.
The current mode PWM design is optimized
for stable and high efficiency operations over
a wide range of load currents. With low
resistance internal MOSFET switches, the
Low Start-up voltage: 0.85V (typ)
35µA Quiescent Supply Current in
switch-off mode
<1µA Shutdown Current
90% Efficiency
Excellent load and line regulation
characteristics
300mA, 350mΩ Internal MOSFET
450KHz Fixed Switching Frequency
Small SOT-26 package
Application
Wireless key board and mouse
MP3 Player, PDA, DSC
LCD Panel
RF-Tags
Portable Equipment
Typical Application
A7107 maintains high efficiency over a wide
range of load current. In addition to its high
efficiency at moderate and heavy loads, the
A7107 includes automatic PFM operation that
improves efficiency of the power converter at
light loads.
Ordering Information
E6
SOT-26 PN: A7107E6
AiT provides all lead free parts Note
AiT provides E6 in Tape & Reel
Advanced Innovation Technology Corp.
www.ait-ic.com Rev
Page
1/8
1.0
M
ICROPOWER HIGH EFFICIENCY
STEP-UP DC-DC CONVERTER
A7107
Pin Description
Top View
Pin No.
1 CE
2 EXT Output pin for driving external NMOS
3 GND Ground
4 LX Pin for switching
5 VDD Input positive power pin
6 FB
Description Pin Function
Chip enable
A7107 gets into shutdown mode when CE pin set to low
Feedback input pin
Internal reference voltage for the error amplifier is 1.25V
Absolute Maximum Ratings
Parameter
Supply Voltage -0.3V~6V
LX Pin Switch Voltage -0.3V~6V
Other I/O Pin Voltage -0.3V ~ (VDD+0.3V)
LX Pin Switch Current 2.5A
EXT Pin Driver Current 150mA
Operating Junction Temperature (note1) +125oC
Storage Temperature Range -65oC ~ +155oC
Note1: TJ is caculated from the ambient temperature TA and power dissipation PD according to the following
formula:
DAJ
°×+=
)/220( WCPTT
Advanced Innovation Technology Corp. Page
www.ait-ic.com Rev
2/8
1.0
M
ICROPOWER HIGH EFFICIENCY
STEP-UP DC-DC CONVERTER
A7107
Electrical Characteristics
VIN=1.5V, V
Start-Up Voltage IL=1mA 0.85 1.05
Operating V
Quiescent Current (Shutdown Current) CE Pin=0V, VIN=4.5V 0.01 1 uA
Quiescent Current (Switch-Off Current) VIN=6V 35 50 uA
Quiescent current (No Load Current) 110 uA
Feedback Reference Voltage
Switching Frequency 380 450 520 KHz
Maximum Duty 85 90 %
=3.3V, IL=0mA, TA=25oC, unless otherwise noted.
OUT
Parameter Conditions Min Typ Max
Range VDD Pin Voltage 2 4.2 V
OUT
TA = +25°C 1.195 1.220 1.245
TA= 0°C ≤ TA ≤ 85°C 1.190 1.220 1.250
= -40°C ≤ TA ≤ 85°C 1.183 1.220 1.257
T
A
Unit
V
V
V
V
LX ON Resistance 0.3 1.1 Ω
Current Limit Setting 2 A
EXT ON Resistance to VDD 16 Ω
EXT ON Resistance to GND 18 Ω
Output Voltage
Output Voltage
Line Regulation
Load Regulation
Load Regulation VIN = 3.0, IL = 1 to 300mA
CE Pin Trip Level 0.4 0.8 1.2 V
Temperature Stability for V
Thermal Shutdown 165
Thermal Shutdown Hysteresis 10
110 ppm/oC
OUT
VIN=1.5V, IL = 100mA
TA= -40°C ≤ TA ≤ 85°C
VIN=3.0V, IL = 300mA
TA= -40°C ≤ TA ≤ 85°C
VIN = 1.0 to 3.0V,
IL = 1mA
VIN = 1.5V,
IL = 1 to 100mA
3.200 3.300 3.400
3.200 3.300 3.400
0.3 mV/V
0.4 mV/mA
0.4 mV/mA
V
V
o
C
o
C
Advanced Innovation Technology Corp. Page
www.ait-ic.com Rev
3/8
1.0
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