MIC23254
4MHz Dual 400mA Synchronous Buck
Regulator with Low Input Voltage and
HyperLight Load™
General Description
Features
The MIC23254 is a low-input voltage, high-efficiency 4MHz
•
Low input voltage range: 2.5V to 5.5V
dual 400mA synchronous buck regulator with HyperLight
•
Dual output current 400mA/400mA
Load™ mode. HyperLight Load™ provides very-high
•
Up to 94% peak efficiency and 85% efficiency at 1mA
efficiency at light loads and ultra-fast transient response
•
33µA dual quiescent current
which is perfectly suited for supplying processor core
•
1µH inductor with a 4.7µF capacitor
voltages. An additional benefit of this proprietary
•
4MHz in PWM operation
architecture is very-low output ripple voltage throughout
the entire load range with the use of small output
•
Ultra-fast transient response
capacitors. MIC23254 operates from an input voltage
•
Low voltage output ripple
down to 2.5V for low battery states. The MIC23254 has a
•
20mVpp in HyperLight Load™ mode
®
tiny 2mm x 2mm Thin MLF package that saves precious
•
3mV output voltage ripple in full PWM mode
board space by requiring only 6 additional external
•
0.01µA shutdown current
components to drive both outputs up to 400mA each.
•
Fixed output:10-pin 2mm x 2mm Thin MLF®
The device is designed for use with a 1µH inductor and a
•
–40°C to +125°C junction temperature range
4.7µF output capacitor that enables a sub-1mm height.
The MIC23254 has a very-low quiescent current of 33µA
with both outputs enabled and can achieve over 85%
Applications
efficiency at 1mA. At higher loads the MIC23254 provides a
•
Mobile handsets
constant switching frequency around 4MHz while providing
•
Portable media players
peak efficiencies over 90%.
•
Portable navigation devices (GPS)
The MIC23254 fixed output voltage option is available in a
•
WiFi/WiMax/WiBro modules
10-pin 2mm x 2mm Thin MLF
®
. The MIC23254 is designed
•
Digital cameras
to operate over the junction operating range from –40°C to
•
Wireless LAN cards
+125°C.
•
USB Powered Devices
Data sheets and support documentation can be found on
Micrel’s web site at:
www.micrel.com.
____________________________________________________________________________________________________________
Typical Application
Efficiency
V
OUT
= 1.8V
100
90
80
V
IN
= 3.0V
EFFICIENCY (%)
70
60
50
40
30
20
10
0
1
10
100
1000
L = 1µH
C
OUT
= 4.7µF
V
IN
= 4.2V
V
IN
= 2.7V
V
IN
= 3.6V
LOAD (mA)
HyperLight Load is a trademark of Micrel, Inc.
MLF and
MicroLeadFrame
are registered trademarks of Amkor Technology, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (
408
) 944-0800 • fax + 1 (408) 474-1000 •
http://www.micrel.com
May 2010
M9999-052510
Micrel, Inc.
MIC23254
Ordering Information
Part Number
MIC23254-GCYMT
Notes:
1. Thin MLF® is GREEN RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.
Marking
Code
GCW
Nominal
Output
Voltage 1
1V
Nominal
Output
Voltage 2
1.8V
Junction
Temperature
Range
–40° to +125°C
Package
10-Pin 2mm x 2mm Thin MLF
®
Lead
Finish
Pb-Free
Pin Configuration
SNS1
EN1
AGND
SW1
PGND
1
2
3
4
5
10 SNS2
9
8
7
6
EN2
AVIN
SW2
VIN
®
10-Pin 2mm x 2mm Thin MLF (MT) Fixed Output
(Top View)
Pin Description
Pin Number
(Fixed)
1
2
3
4
5
6
7
8
9
10
Pin Name
SNS1
EN1
AGND
SW1
PGND
VIN
SW2
AVIN
EN2
SNS2
Pin Function
Sense 1 (Input): Connect to V
OUT1
as close to output capacitor as possible to sense output 1
voltage.
Enable 1 (Input): Logic low will shut down output 1. Logic high powers up output 1. Do not leave
unconnected.
Analog Ground. Must be connected externally to PGND.
Switch Node 1 (Output): Internal power MOSFET output.
Power Ground.
Supply Voltage (Power Input): Requires close bypass capacitor to PGND.
Switch Node 2 (Output): Internal power MOSFET output.
Supply Voltage (Power Input): Analog control circuitry. Connect to VIN.
Enable 2 (Input): Logic low will shut down output 2. Logic high powers up output 2. Do not leave
unconnected.
Sense 2 (Input): Connect to V
OUT2
as close to output capacitor as possible to sense output 2
voltage.
May 2010
2
M9999-052510
Micrel, Inc.
MIC23254
Absolute Maximum Ratings
(1)
Supply Voltage (V
IN
) ........................................
−0.3V
to
+6V
Output Switch Voltage (V
SW
) .............................
−0.3V
to 6V
Sense Input Voltage (V
SNS1
, V
SNS2
) ...................
−0.3V
to V
IN
Logic Input Voltage (V
EN1
, V
EN2
) ........................
−0.3V
to V
IN
Storage Temperature Range (T
s
)..............–65°C to +150°C
ESD Rating
(3)
................................................. ESD Sensitive
Operating Ratings
(2)
Supply Voltage (V
IN
)......................................... 2.5V to 5.5V
Sense Input Voltage (V
SNS1
, V
SNS2
) ........................ 0V to V
IN
Logic Input Voltage (V
EN1
, V
EN2
) ............................. 0V to V
IN
Junction Temperature (T
J
) ..................–40°C
≤
T
J
≤
+125°C
Thermal Resistance
2mm x 2mm Thin MLF-10 (θ
JA
) .........................70°C/W
Electrical Characteristics
(4)
T
A
= 25°C with V
IN
= V
EN1
= V
EN2
= 3.6V; L = 1µH; C
OUT
= 4.7µF; I
OUT
= 20mA; only one channel power is enabled, unless
otherwise specified.
Bold
values indicate –40°C< T
J
< +125°C.
Parameter
Under-Voltage Lockout Threshold
UVLO Hysteresis
Quiescent Current
Shutdown Current
Output Voltage Accuracy
Current Limit in PWM Mode
Output Voltage Line Regulation
Output Voltage Load Regulation
PWM Switch ON-Resistance
Frequency
Soft-Start Time
Enable Threshold
Enable Input Current
Over-Temperature Shutdown
Over-Temperature Shutdown Hysteresis
Condition
(Turn-On)
V
OUT1, 2 (Both Enabled)
, I
OUT1, 2
= 0mA , V
SNS1,2
>1.2
×
V
OUT1, 2
Nominal
V
EN1, 2
= 0V; V
IN
= 5.5V
V
IN
= 3.6V, I
LOAD
= 20mA
SNS = 0.9
×
V
OUT NOM
V
IN
= 3.6V to 5.5V, I
LOAD
= 20mA
20mA < I
LOAD
<
400mA, V
IN
= 3.6V
I
SW
= 100mA PMOS
I
SW
=
−100mA
NMOS
I
LOAD
= 120mA
V
OUT
= 90%
0.5
–2.5
0.410
0.62
0.4
0.5
0.6
0.8
4
260
0.9
0.1
160
20
Min.
2.3
Typ.
2.4
60
33
0.01
Max.
2.485
50
4
+2.5
1
Units
V
mV
µA
µA
%
A
%/V
%
Ω
MHz
µs
V
µA
°C
°C
1.2
2
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. Devices are ESD sensitive. Handling precautions recommended. Human body model: 1.5kΩ in series with 100pF.
4. Specification for packaged product only.
May 2010
3
M9999-052510
嵌入式系统
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