MIC23451
3MHz, 2A Triple Synchronous
Buck Regulator with
HyperLight Load
®
and Power Good
General Description
The MIC23451 is a high-efficiency, 3MHz, triple 2A,
®
synchronous buck regulator with HyperLight Load mode.
HyperLight Load provides very-high efficiency at light
loads and ultra-fast transient response, which is ideal for
supplying processor core voltages. An additional benefit of
this proprietary architecture is very low output ripple
voltage throughout the entire load range with the use of
small output capacitors. The 4mm x 4mm QFN package
saves board space and requires only five external
components for each channel.
The MIC23451 is designed for use with a very small
inductor, down to 0.47µH, and an output capacitor as small
as 2.2µF that enables a total solution size that is less than
1mm height.
The MIC23451 has a very-low quiescent current of 24µA
each channel and achieves as high as 81% efficiency at
1mA. At higher loads, the MIC23451 provides a constant
switching frequency around 3MHz while achieving peak
efficiencies up to 93%.
The MIC23451 is available in a 26-pin 4mm x 4mm QFN
package with an operating junction temperature range
from –40°C to +125°C.
Datasheets and support documentation are available on
Micrel’s web site at:
www.micrel.com.
Features
•
•
•
•
•
•
•
•
•
2.7V to 5.5V input voltage
Three independent 2A outputs
Up to 93% peak efficiency
81% typical efficiency at 1mA
Three independent power good indicators
24µA typical quiescent current (per channel)
3MHz PWM operation in continuous mode
Ultra-fast transient response
Low voltage output ripple
−
30mV
PP
ripple in HyperLight Load mode
−
5mV output voltage ripple in full PWM mode
Fully integrated MOSFET switches
0.1µA shutdown current (per channel)
Thermal-shutdown and current-limit protection
Output voltage as low as 1V
26-pin 4mm × 4mm QFN
–40°C to +125°C junction temperature range
•
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Applications
•
•
•
•
•
•
•
Solid state drives (SSD)
µC/µP, FPGA, and DSP power
Test and measurement systems
Set-top boxes and DTV
High-performance servers
Security/surveillance cameras
5V POL applications
Typical Application
HyperLight Load is a registered trademark of Micrel, 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
November 5, 2013
Revision 1.2
Micrel, Inc.
MIC23451
Ordering Information
Part Number
MIC23451-AAAYFL
Notes:
1. Other options are available. Contact Micrel for details.
2. QFN is a Green, RoHS-compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.
3. QFN
•
= Pin 1 identifier
Marking
AAA
Nominal Output
Voltage
Adj./Adj./Adj.
Junction Temperature
(1)
Range
–40°C to +125°C
Package
(2,3)
Lead Finish
Pb-Free
26-Pin 4mm
×
4mm QFN
Pin Configuration
26-Pin 4mm
×
4mm QFN (FL)
−
Adjustable
(Top View)
Pin Description
Pin Number
26, 4, 7
21, 19, 15
22, 18, 12
23, 17, 14
20, 16, 13
EP1, 24, 11
25, 5, 8
3, 6, 9
EP2, 10, 2, 1
Pin Name
SW1, 2, 3
EN1, 2, 3
SNS1, 2, 3
FB1, 2, 3
PG1, 2, 3
AGND
PVIN1, 2, 3
AVIN1, 2, 3
PGND
Pin Function
Switch (Output). Internal power MOSFET output switches for output 1/2/3.
Enable (Input). Logic high enables operation of regulator 1/2/3. Logic low will shut down the
device. Do not leave floating.
Sense. Connect to V
OUT1,2,3
as close to output capacitor as possible to sense output voltage.
Feedback. Connect a resistor divider from output 1/2/3 to ground to set the output voltage.
Power Good. Open-drain output for the power good indicator for output 1/2/3. Place a resistor
between this pin and a voltage source to detect a power good condition.
Analog Ground. Connect to quiet ground point away from high-current paths, for example, C
OUT
,
for best operation. Must be connected externally to PGND.
Power Input Voltage. Connect a capacitor to PGND to localize loop currents and decouple
switching noise.
Analog Input Voltage. Connect a capacitor to AGND to decouple noise.
Power Ground.
November 5, 2013
2
Revision 1.2
Micrel, Inc.
MIC23451
Absolute Maximum Ratings
(1)
Supply Voltage (PV
IN,
AV
IN
) ..................................
−0.3
to 6V
Sense (V
SNS1
, V
SNS2
, V
SNS3
). .................................
−0.3
to 6V
Power Good (PG1, PG2, PG3) ............................
−0.3
to 6V
Output Switch Voltage (V
SW1
, V
SW2
, V
SW3
).........
−0.3V
to 6V
Enable Input Voltage (V
EN1
, V
EN2
, V
EN3
) ............
−0.3V
to V
IN
Storage Temperature Range ....................
−65°C
to
+150°C
(3)
ESD Rating ................................................. ESD Sensitive
Operating Ratings
(2)
Supply Voltage (V
IN
) ..................................... +2.7V to +5.5V
Enable Input Voltage (V
EN1
, V
EN2
, V
EN3
) ................. 0V to V
IN
Output Voltage Range (V
SNS1
, V
SNS2
, V
SNS3
) ...
+1V
to
+3.3V
Junction Voltage Range (T
J
) ...............
−40°C ≤
T
J
≤ +125°C
Thermal Resistance
26-Pin 4mm
×
4mm QFN (θ
JA
).........................
+20°C/W
26-Pin 4mm
×
4mm QFN (θ
JC
) ........................
+10°C/W
Electrical Characteristics
(4)
T
A
=
+25°C;
V
IN
= V
EN1
, V
EN2
, V
EN3
= 3.6V; L1 = L2 = L3 = 1µH; C
OUT1
, C
OUT2
, C
OUT3
= 4.7µF, unless otherwise specified.
Bold
values indicate –40°C
≤
T
J
≤
+125°C, unless noted.
Parameter
Supply Voltage Range
Undervoltage Lockout Threshold
Undervoltage Lockout Hysteresis
Quiescent Current
Per Channel Shutdown Current
Output Voltage Accuracy
Feedback Voltage
(V
FB1
, V
FB2
, V
FB3
)
Peak Current Limit
Foldback Current Limit
Output Voltage Line Regulation
(V
OUT1
, V
OUT2
, V
OUT3
)
V
IN
= 3.6V to 5.5V if V
OUTNOM1, 2, 3
<
2.5V, I
LOAD
= 20mA
V
IN
= 4.5V to 5.5V if V
OUTNOM1, 2, 3
≥
2.5V, I
LOAD
= 20mA
DCM: 20mA
<
I
LOAD
<
130mA, V
IN
= 3.6V if V
OUTNOM
<
2.5V
Output Voltage Load Regulation
(V
OUT1
, V
OUT2
, V
OUT3
)
DCM: 20mA
<
I
LOAD
<
130mA, V
IN
= 5.0V if V
OUTNOM
>
2.5V
CCM: 200mA
<
I
LOAD
<
500mA, V
IN
= 3.6V if V
OUTNOM
<
2.5V
CCM: 200mA
<
I
LOAD
<
1A, V
IN
= 5.0V if V
OUTNOM
>
2.5V
PWM Switch ON-Resistance
(R
SW1
, R
SW2
, R
SW3
)
Maximum Frequency
Soft-Start Time
Power Good Threshold
Power Good Hysteresis
Power Good Pull Down
Notes:
1. Exceeding the absolute maximum ratings may damage the device.
2. The device is not guaranteed to function outside its operating ratings.
3. Devices are ESD sensitive. Handling precautions are recommended. Human body model, 1.5kΩ in series with 100pF.
4. Specification for packaged product only.
Condition
Turn-On
I
OUT
= 0mA, SNS
>
1.2
×
V
OUTNOM
V
EN1
, V
EN2
, V
EN3
= 0V; V
IN
= 5.5V
V
IN
= 3.6V if V
OUT(NOM)
<
2.5V, I
LOAD
= 20mA
V
IN
= 4.5V if V
OUT(NOM)
≥
2.5V, I
LOAD
= 20mA
Min.
2.7
2.45
Typ.
2.55
75
65
0.1
Max.
5.5
2.65
120
5
+2.5
Units
V
V
mV
µA
µA
%
V
A
A
%/V
−2.5
0.604
0.62
4.1
2.3
0.3
0.2
0.4
0.6
0.3
0.217
3
150
83
90
10
0.635
I
OUT1
, I
OUT2
, I
OUT3
SNS1, SNS2, SNS3 = 0.9
×
V
OUTNOM
2.2
%
I
SW1
, I
SW2
, I
SW3
=
+100mA
(PMOS)
I
OUT1
, I
OUT2
, I
OUT3
= 120mA
V
OUT1
, V
OUT2
, V
OUT3
= 90%
% of V
NOM
V
SNS
= 90% V
NOM
, I
PG
= 1mA
Ω
MHz
µs
96
200
%
%
mV
November 5, 2013
3
Revision 1.2
Analog electronics
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