General Description
The MIC33050 is a 600mA 4MHz switching regulator
featuring HyperLight Load™ mode. The MIC33050 is
highly efficient throughout the entire output current
range, drawing just 20µA of quiescent current in
operation. The tiny 3mm x 3mm MLF
combination with the 4MHz switching frequency, enables
a compact sub-1mm height solution with only three
external components. The MIC33050 provides accurate
output voltage regulation under the most demanding
conditions and responds extremely quickly to a load
transient with exceptionally small output voltage ripple.
Factoring in the output current, the internal circuitry of
the MIC33050 automatically selects between two modes
of operation for optimum efficiency. Under light load
conditions, the MIC33050 goes into HyperLight Load™
mode. HyperLight Load™ uses a Pulse-Frequency
Modulation (PFM) control scheme that controls the off
time at light load. This proprietary architecture reduces
the amount of switching needed at light load, thereby
increasing operating efficiency. The MIC33050 attains
up to 83% efficiency at 1mA output load. As the load
current increases beyond approximately 100mA, the
device operates using the Pulse-Width Modulation
(PWM) method for up to 93% efficiency at higher load.
The two modes of operation ensure the highest
efficiency across the entire load range.
The MIC33050 operates from an input voltage range of
2.7V to 5.5V and features internal power MOSFETs that
deliver up to 600mA of output current. This step-down
regulator provides an output voltage accuracy of ±2.5%
across the junction temperature range of -40ºC to
+125ºC. The MIC33050 is available in fixed output
versions supporting an output voltage as low as 0.72V.
Requirements
The MIC33050 evaluation board requires an input power
source that is able to deliver greater than 650mA at
2.7V. The output load can either be an active (electronic)
or passive (resistive) load.
HyperLight Load is a trademark of Micrel, Inc.
February 2009
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (
®
package, in
1
408
Getting Started
Output Voltage
The MIC33050 evaluation board is available with the
following output voltage options listed below:
Ordering Information
Note: Other voltage options available on request. Contact Micrel.
MIC33050-GYHL EV
MIC33050-4YHL EV
MIC33050-SYHL EV
) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
MIC33050 Evaluation Board
1. Connect an external supply to the V
2. Connect a load to the V
3. Enable
4MHz Internal Inductor PWM Buck
Regulator with HyperLight Load™
Part Number
terminal. Apply the desired input voltage to V
(J1) and ground (J2) terminals of the evaluation
board, paying careful attention to polarity and
supply voltage (2.7V ≤ V
may be placed between the input supply and the
V
voltage at the V
ammeter and/or power lead resistance can
reduce the voltage supplied to the device.
terminal (J4). The load can be either passive
(resistive)
ammeter may be placed between the load and
the output terminal. Ensure the output voltage is
monitored at the V
evaluation board has a pull-up resistor to V
disable the device, apply a voltage below 0.5V
to the EN terminal. In the absence of the pull-up
resistor, the device is enabled by applying a
voltage greater than 1.2V to the EN terminal.
The enable pin must be either pulled high or low
for proper operation. Removing the pull-up
resistor and leaving the pin floating will cause
the regulator to operate in an unknown state.
IN
(J1) terminal. Be sure to monitor the supply
the
or
1.2V Fixed Output Evaluation Board
1.8V Fixed Output Evaluation Board
3.3V Fixed Output Evaluation Board
active
MIC33050.
OUT
IN
(J3) terminal.
(J1) terminal, since the
(electronic
IN
Description
OUT
≤ 5.5V). An ammeter
(J3) and ground
The
M9999-022409-C
load).
MIC33050
IN
IN
(J1)
. To
An
IN