MIC23451
3MHz, 2A Triple Synchronous
Buck Regulator with
HyperLight Load and Power Good
General Description Features
The MIC23451 is a high-efficiency, 3MHz, triple 2A,
2.7V to 5.5V input voltage
synchronous buck regulator with HyperLight Load mode.
Three independent 2A outputs
HyperLight Load provides very-high efficiency at light
Up to 93% peak efficiency
loads and ultra-fast transient response, which is ideal for
81% typical efficiency at 1mA
supplying processor core voltages. An additional benefit of
this proprietary architecture is very low output ripple Three independent power good indicators
voltage throughout the entire load range with the use of
24A typical quiescent current (per channel)
small output capacitors. The 4mm x 4mm QFN package
3MHz PWM operation in continuous mode
saves board space and requires only five external
Ultra-fast transient response
components for each channel.
Low voltage output ripple
The MIC23451 is designed for use with a very small
30mV ripple in HyperLight Load mode
PP
inductor, down to 0.47H, and an output capacitor as small
5mV output voltage ripple in full PWM mode
as 2.2F that enables a total solution size that is less than
1mm height.
Fully integrated MOSFET switches
0.1A shutdown current (per channel)
The MIC23451 has a very-low quiescent current of 24A
each channel and achieves as high as 81% efficiency at
Thermal-shutdown and current-limit protection
1mA. At higher loads, the MIC23451 provides a constant
Output voltage as low as 1V
switching frequency around 3MHz while achieving peak
26-pin 4mm 4mm QFN
efficiencies up to 93%.
40C to +125C junction temperature range
The MIC23451 is available in a 26-pin 4mm x 4mm QFN
package with an operating junction temperature range
Applications
from 40C to +125C.
Solid state drives (SSD)
Datasheets and support documentation are available on
C/P, FPGA, and DSP power
Micrels web site at: www.micrel.com.
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 Micrel, Inc. MIC23451
Ordering Information
Nominal Output Junction Temperature (2,3)
Part Number Marking Package Lead Finish
(1)
Voltage Range
MIC23451-AAAYFL AAA Adj./Adj./Adj. 40C to +125C Pb-Free
26-Pin 4mm 4mm QFN
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
Pin Configuration
26-Pin 4mm 4mm QFN (FL) Adjustable
(Top View)
Pin Description
Pin Number Pin Name Pin Function
26, 4, 7 SW1, 2, 3 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
21, 19, 15 EN1, 2, 3
device. Do not leave floating.
22, 18, 12 SNS1, 2, 3 Sense. Connect to V as close to output capacitor as possible to sense output voltage.
OUT1,2,3
23, 17, 14 FB1, 2, 3 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
20, 16, 13 PG1, 2, 3
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
EP1, 24, 11 AGND
for best operation. Must be connected externally to PGND.
Power Input Voltage. Connect a capacitor to PGND to localize loop currents and decouple
25, 5, 8 PVIN1, 2, 3
switching noise.
3, 6, 9 AVIN1, 2, 3 Analog Input Voltage. Connect a capacitor to AGND to decouple noise.
EP2, 10, 2, 1 PGND Power Ground.
Revision 1.2
November 5, 2013 2