ACE ACE709

ACE709
0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter
Description
ACE709, is a high-efficiency, synchronous step-up switching regulators optimized for battery-powered
applications. It supports up to 1A load current and allows the use of small, low cost inductors and MLCC
capacitors.
The ACE709 starts up as low as 0.9V input voltage and it has true-shutoff function (shut off output to zero
voltage when CE pulled low) and real output short-circuit protection. These features make it ideal for USB
interface power supply.
Given its high efficiency, the ACE709 device is ideal for small portable applications powered by battery. It
consumes as low as 40uA (3V input /3.3V output) at zero load. And its current consumption is less than
1uA in shutdown mode.
Features
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Capable of Delivering 1A
High Efficiency: Up to 92%
Compatible with MLCC capacitor
1.8MHz Switching Frequency
Low dropout 100% Duty operation
0.6V Reference for Low Output voltages
True Shutoff and Short-Circuit Protection
Logic Control Shutdown (IQ<1uA)
Thermal shutdown and UVLO
Application
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MID / Tablet PC
Portable Power Bank
Smartphone OTG
Toy
Other portable device
Absolute Maximum Ratings
Parameter
Max
Max Input Voltage
5.5
Unit
V
125
O
C
Ambient Temperature(TA )
-40~85
O
C
Maximum Power Dissipation
800
Storage Temperature(Ts)
-55~150
ESD (HBM)
>2000
Max Operating Junction Temperature(TJ)
mW
O
C
V
Note: Exceed these limits to damage to the device. Exposure to absolute maximum rating conditions may affect device reliability.
VER 1.2
1
ACE709
0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter
Packaging Type
DFN2*2-6
Top View
DFN2*2-6 Description
1
CE
2
FB
3
VOUT
Function
Enable pin for the IC. Drive the pin to high to enable the part, and low to
disable
Feedback input. Connect an external resistor divider from the output to FB and
GND to set the output to a voltage between 0.6V and Vin
Output voltage pin, with 22uF ceramic capacitor closely connected to GND
4
GND
Ground
5
LX
To connect inductor to VIN
6
VIN
Supply voltage, with 4.7uF ceramic capacitor connected to GND
Ordering information
ACE709 XX + H
Halogen - free
Pb - free
KN : DFN2*2-6
Recommended work conditions
Parameter
Input Voltage Range
Max Unit
5
Operating Junction Temperature(TJ) -40~85
V
O
C
VER 1.2
2
ACE709
0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter
Block Diagram
Electrical Characteristics
O
VDD=5V, TA=25 C
Symbol
Parameter
Test Conditions
Min
Typ
Max
Unit
VDD
Input Voltage Range
5
V
Vstart
Startup Voltage
Iout = 0 A
0.9
1.0
V
Vref
Feedback Voltage
Vout = 2.5 to 5V
0.6
0.615
Ifb
Feedback Leakage current
0.1
0.4
Vout
Output Voltage Range
Iq
Quiescent Current
Irev
Reverse current, Vout to Vin
Fsoc
Switching Frequency
1.8
RDS(ON) P
PMOS RDS(ON)
150
300
mΩ
RDS(ON) N
NMOS RDS(ON)
150
300
mΩ
Llimit
Peak Current Limit
1.5
2
A
Ilxlk
LX Leakage Current
10
uA
Icelk
CE Leakage Current
1
uA
Vh_en
EN Input High Voltage
Vl_en
EN Input Low Voltage
TSD
Thermal Shut Down
0.9
0.585
2.1
5
V
Active, Vfb=0.7, No Switching
40
60
uA
Shutdown
1
10
uA
5
uA
CE=0
1.2
LX=5V, CE=0
MHz
0.6
V
0.3
150
V
O
C
VER 1.2
3
ACE709
0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter
Typical Application Circuit
Typical Performance Characteristics
O
Tested under TA=25 C, L=6.8uH, unless otherwise specified
VER 1.2
4
ACE709
0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter
Typical Performance Characteristics
O
Tested under TA=25 C, L=6.8uH, unless otherwise specified
VER 1.2
5
ACE709
0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter
Detailed description
General description
The ACE709 is a high-efficiency, Boost DC/DC converter, with input current limit at 1.5A. It integrates an
150mΩ high side MOSFET and an 150 mΩ low side MOSFET. It employs PWM/PFM auto-switch control
mode.
Short circuit protection
ACE709 employs a “Hiccup” mode of short-circuit protection, which enables output voltage auto recover
when short-circuit is removed.
True shut off function
ACE709 offers a true shut off function, which means it can really shut off output (make output voltage to
zero) when CE is pull low (chip turns off). Normally, there is a schottky diode (or MOSFET body diode)
existed between LX and Vout for a normal boost converter, and thus, when CE is pull low, though the chip
is turned off, the Vin is connected to Vout thru inductor and schottky diode. So we still can detect a voltage
at Vout terminal. ACE709, with its proprietary design skill, can truly shut down the output when chip is
turned off.
Design Procedure
Setting Output Voltages
Output voltages are set by external resistors. The FB_ threshold is 0.6V.
RTOP = RBOTTOM[(VOUT / 0.6) - 1]
Capacitor Selection
A 22uF ceramic capacitor is demanded on output terminal, while 4.7uF is good enough for input.
Higher values, lower cost ceramic capacitors are now becoming available in smaller case sizes. Their
high ripple current, high voltage rating and low ESR make them ideal for switching regulator applications.
Using ceramic capacitors can achieve very low output ripple and small circuit size. When choosing the
input and output ceramic capacitors, choose the X5R or X7R dielectric formulations. These dielectrics
have the best temperature and voltage characteristics of all the ceramics for a given value and size.
Application Information
Layout is critical to achieve clean and stable operation. The switching power stage requires particular
attention. Follow these guidelines for good PC board layout:
1. Place 22uF output capacitors as close to the IC VOUT and GND pins as possible
2. Connect input and output capacitors to the same power ground node with a star ground configuration
then to IC ground.
3. Keep the high-current paths as short and wide as possible. Keep the path of switching current short.
Avoid vias in the switching paths.
4. If possible, connect VIN, SW, and GND separately to a large copper area to help cool the IC to further
improve efficiency and long-term reliability.
5. Ensure all feedback connections are short and direct. Place the feedback resistors as close to the IC
as possible.
6. Route high-speed switching nodes away from sensitive analog areas
VER 1.2
6
ACE709
0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter
Packing Information
DFN2*2-6
VER 1.2
7
ACE709
0.9V startup, 1A True Shut-Off Synchronous Boost DC/DC Converter
Notes
ACE does not assume any responsibility for use as critical components in life support devices or systems
without the express written approval of the president and general counsel of ACE Electronics Co., LTD.
As sued herein:
1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and shoes failure to perform when properly used in
accordance with instructions for use provided in the labeling, can be reasonably expected to result in
a significant injury to the user.
2. A critical component is any component of a life support device or system whose failure to perform can
be reasonably expected to cause the failure of the life support device or system, or to affect its safety
or effectiveness.
ACE Technology Co., LTD.
http://www.ace-ele.com/
VER 1.2
8