MIC33263/4
4MHz, 2A Buck Regulator with Integrated
Inductor and HyperLight Load
General Description Features
The MIC33263/4 is a highly-efficient synchronous buck Integrated MOSFETs, inductor
regulator with an integrated inductor which provides the
100% duty cycle
optimal trade-off between footprint and efficiency. The
4MHz PWM operation in continuous mode
MIC33263/4 operates at 4MHz switching frequency and
2A output current
provides up to 2A output current. In addition, the 100%
duty cycle and HyperLight Load (HLL) mode-of-operation Low output voltage ripple
delivers very-high efficiency at light loads and ultra-fast
85% typical efficiency at 1mA and up to 93% peak
transient response which makes the MIC33263/4 perfectly
efficiency
suited for any space-constrained application and great
Ultra-fast transient response
alternative for low dropout regulators. An additional benefit
Advanced copper lead frame design provides superior
of this proprietary architecture is very low output ripple
thermal performance
voltage throughout the entire load range with the use of
Thermal-shutdown and current-limit protection
small output capacitors.
Low-radiated emission (EMI) per EN55022, class B
The MIC33263/4 provides small compact total solution
Adjustable output voltage 0.7V to 5V
size of 4.6mm 7mm with very few tiny external
components.
Configurable soft-start with pre-bias start-up capability
Auto discharge of 180 (MIC33264 only)
At higher loads, the MIC33263/4 provides a constant
switching frequency around 4MHz while achieving peak
Low profile 2.5mm 3.0mm 1.9mm QFN packages
efficiencies up to 93%. It also includes under-voltage
0.1A shutdown current
lockout to ensure proper operation under power-sag
33A quiescent current
conditions, internal soft-start to reduce inrush current,
foldback current limit, power good (PG) indicator, and
Applications
thermal shutdown. The MIC33263/4 is available in a 20-pin
5V point-of-load (POL)
2.5mm 3.0mm 1.9mm QFN package with an operating
junction temperature range from 40C to +125C. Low voltage distributed power systems
Space-constrained applications
Datasheets and support documentation are available on
Micrels website at: www.micrel.com. Portable devices
SSD storage systems
Digital cameras
Typical Application
Efficiency
vs. Output Current
100
90
80
70
V = 1.2V
V = 1.8V OUT
OUT
V = 2.5V
OUT
60
50
40
30
20
VIN = 3.3V
10
0
10 100 1000
OUTPUT CURRENT (mA)
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. MIC33263/4
Ordering Information
(1, 2)
Part Number Output Voltage Auto Discharge Junction Temperature Range Package
MIC33263YGK ADJ No 20-Pin 2.5mm 3mm QFN
40 C to +125 C
MIC33264YGK ADJ Yes 40 C to +125 C 20-Pin 2.5mm 3mm QFN
Note:
1. QFN is a GREEN, RoHS-compliant package. Mold compound is Halogen Free.
2. Pb-free. Lead finish is matte tin.
Pin Configuration
2.5mm 3mm QFN (GK)
(Top View)
Pin Description
Pin Number Pin Name Pin Function
1, 20 PVIN Power Input Voltage: Connect a capacitor to PGND to decouple the noise.
2, 8, 9 PGND Power Ground.
Switch (Output): Internal power MOSFET output switches. Disable pull down 180 Ohms
3, 4, 5, 6, 7 SW
(MIC33264 only).
10, 11, 12, 13 VOUT Inductor Output. Connect a capacitor to PGND to filter the switcher output voltage.
Analog Ground: Connect to central ground point where all high current paths meet (CIN, COUT,
14 AGND
PGND) for best operation.
15 AVIN Analog Input Voltage: Connect a capacitor to ground to decouple the noise.
16 SS Soft-Start: Place a capacitor from SS pin to ground to program the soft-start time
Power Good: Open Drain output for the power good indicator. Place a resistor between this pin
17 PG
and a voltage source to detect a power good condition.
18 FB Feedback: Connect a resistor divider from the output to ground to set the output voltage.
Enable (Input): Logic high enables operation of the regulator. Logic low will shut down the device.
19 EN
Do not leave floating.
Revision 2.1
January 28, 2015 2