MIC23450
3MHz, PWM, 2A Triple Buck Regulator
with HyperLight Load
®
and Power Good
General Description
The MIC23450 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 perfectly
suited 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 5mm x 5mm QFN package
saves board space and requires only five external
components for each channel.
The MIC23450 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, less than 1mm
height.
The MIC23450 has a very-low quiescent current of 23µA
each channel and achieves as high as 81% efficiency at
1mA. At higher loads, the MIC23450 provides a constant
switching frequency around 3MHz while achieving peak
efficiencies up to 93%.
The MIC23450 is available in 32-pin 5mm x 5mm QFN
package with an operating junction temperature range
from –40°C to +125°C.
Datasheets and support documentation can be found on
Micrel’s web site at:
www.micrel.com.
Features
•
•
•
•
•
•
•
•
•
Input voltage: 2.7V to 5.5V
3 independent 2A outputs
Up to 93% peak efficiency
81% typical efficiency at 1mA
Three independent Power Good Indicators
23µA 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
0.01µA shutdown current (per channel)
Thermal-shutdown and current-limit protection
Output voltage as low as 1V
32-pin 5mm x 5mm 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
110513-1.1
Micrel, Inc.
MIC23450
Ordering Information
Part Number
MIC23450-AAAYML
Notes:
1.
2.
3.
Other options available. Contact Micrel for details.
QFN is a Green, RoHS-compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.
QFN
•
= Pin 1 identifier.
Marking
AAA
Nominal Output
Voltage
ADJ/ADJ/ADJ
Junction Temperature
(1)
Range
–40C to +125°C
Package
(2, 3)
Lead Finish
Pb-Free
32-Pin 5mm
×
5mm QFN
Pin Configuration
32-Pin 5mm
×
5mm
QFN (ML)
−
Adjustable
Top View
Pin Description
Pin Number
26, 23, 21
30, 3, 8
31, 4, 9
32, 5, 10
1, 6, 12
2, 7, 11
27, 29, 14
28, 15, 13
24, 22, 18
16, 17, 19, 20, 25
ePAD
Pin Name
SW1, 2, 3
EN1, 2, 3
SNS1, 2, 3
FB1, 2, 3
PG1, 2, 3
AGND1, 2, 3
PVIN1, 2, 3
AVIN1, 2, 3
PGND1, 2, 3
NC
ePad
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, e.g., 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.
No Connect.
Connect to ground plane to ensure good thermal properties.
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Micrel, Inc.
MIC23450
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
32-Pin 5mm
×
5mm QFN (θ
JA
).........................
+30°C/W
32-Pin 5mm
×
5mm 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
)
Notes:
1.
2.
3.
4.
Exceeding the absolute maximum rating may damage the device.
The device is not guaranteed to function outside its operating rating.
Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5kΩ in series with 100pF.
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
69
0.01
Max.
5.5
2.65
120
5
+2.5
Units
V
V
mV
µA
µA
%
V
A
A
%/V
−2.5
.604
0.62
4.5
1.8
0.3
0.2
0.4
0.6
0.3
0.2
.635
I
OUT1
, I
OUT2
, I
OUT3
SNS1, SNS2, SNS3 = 0.9
×
V
OUTNOM
2
%
I
SW1
, I
SW2
, I
SW3
=
+100mA
(PMOS)
I
SW1
, I
SW2
, I
SW3
=
−100mA
(NMOS)
Ω
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Micrel, Inc.
MIC23450
Electrical Characteristics
(4)
(Continued)
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
Maximum Frequency
Soft-Start Time
Power Good Threshold
Power Good Hysteresis
Power Good Pull Down
Enable Threshold
Enable Input Current
Overtemperature Shutdown
Overtemperature Shutdown
Hysteresis
V
SNS
= 90% V
NOM
, I
PG
= 1mA
Turn-On
0.5
0.8
0.1
160
20
Condition
I
OUT1
, I
OUT2
, I
OUT3
= 120mA
V
OUT1
, V
OUT2
, V
OUT3
= 90%
% of V
NOM
83
Min.
Typ.
3
115
90
10
200
1.2
1
96
Max.
Units
MHz
µs
%
%
mV
V
µA
°C
°C
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Micrel, Inc.
MIC23450
Typical Characteristics
Efficiency vs. Output Current
V
OUT
= 1.8V
100%
90%
80%
V
IN
= 3V
100%
90%
80%
V
IN
= 3V
Efficiency vs. Output Current
V
OUT
= 2.5V
8
7
Current Limit
vs. Input Voltage
EFFICIENCY (%)
EFFICIENCY (%)
70%
60%
50%
40%
30%
20%
10%
0%
0.001
0.01
0.1
1
10
V
IN
= 5V
V
IN
= 3.6V
70%
60%
50%
40%
30%
20%
10%
0%
0.001
0.01
0.1
V
IN
= 3.6V
CURRENT LIMIT (A)
6
5
4
3
2
1
0
CH1 = 2.5V
CH2 = 1.8V
CH3 = 1.2V
V
IN
= 5V
1
10
2
3
4
5
6
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
INPUT VOLTAGE (V)
Shutdown Current
vs. Input Voltage
180
160
1.9
Line Regulation
(Low Loads)
1.9
Line Regulation
(High Loads)
SUPPLY CURRENT (nA)
OUTPUT VOLTAGE (V)
1.85
I
OUT
= 120mA
I
OUT
= 20mA
120
100
80
60
40
20
0
2
3
4
5
6
OUTPUT VOLTAGE (V)
140
1.85
1.8
1.8
I
OUT
= 1mA
1.75
I
OUT
= 1A
1.75
I
OUT
= 2A
1.7
1.7
2
2.5
3
3.5
4
4.5
5
5.5
6
1.65
2
2.5
3
3.5
4
4.5
5
5.5
6
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Output Voltage
vs. Output Current (HLL)
1.9
1.88
1.9
1.88
Output Voltage
vs. Output Current (CCM)
1.84
Output Voltage
vs. Temperature
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
1.84
1.82
1.8
1.78
1.76
1.74
1.72
1.7
0
1.84
1.82
1.8
1.78
1.76
1.74
1.72
V
OUT
= 1.8V
0.2
0.4
0.6
0.8
V
IN
= 3V
1
1.2
1.4
1.6
1.8
2
V
IN
= 5V
V
IN
= 3.6V
OUTPUT VOLTAGE (V)
1.86
V
IN
= 5V
V
IN
= 3.6V
1.86
1.82
V
IN
= 5.5V
V
IN
= 3.6V
1.80
V
IN
= 3V
1.78
V
IN
= 2.7V
1.76
V
OUT
= 1.8V
0.03
0.06
0.09
0.12
0.15
0.18
1.7
1.74
-60 -40 -20
0
20
40
60
80 100 120 140
LOAD CURRENT (A)
LOAD CURRENT (A)
TEMPERATURE (°C)
November 5, 2013
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