MIC33030 datasheet(13/24 Pages) MICROCHIP

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2018 - 2022 Microchip Technology Inc.

DS20006026B-page 13

MIC33030

5.0

APPLICATION INFORMATION

The MIC33030 is a high-performance DC/DC step

down regulator that offers a small solution size.

Supporting an output current up to 400 mA inside a tiny

2.5 mm x 2.0 mm HJDFN package and requiring only

two external components, the MIC33030 meets today’s

miniature portable electronic device needs. Using the

HyperLight Load® switching scheme, the MIC33030 is

able to maintain high efficiency throughout the entire

load range while providing ultra-fast load transient

response. The following sections provide additional

device application information.

5.1

Input Capacitor

A 2.2 µF ceramic capacitor or greater should be placed

close to the VIN pin and PGND pin for bypassing. A

TDK C1608X5R0J475K, size 0603, 4.7 µF ceramic

capacitor is recommended based upon performance,

size and cost. A X5R or X7R temperature rating is

recommended for the input capacitor. Y5V temperature

rating capacitors, aside from losing most of their

capacitance over temperature, can also become

resistive at high frequencies. This reduces their ability

to filter out high frequency noise.

5.2

Output Capacitor

The MIC33030 is designed for use with a 2.2 µF or

greater ceramic output capacitor. Increasing the output

capacitance will lower output ripple and improve load

transient response but could increase solution size or

cost. A low equivalent series resistance (ESR) ceramic

output capacitor such as the TDK C1608X5R0J475K,

size 0603, 4.7 µF ceramic capacitor is recommended

based upon performance, size and cost. Both the X7R

X5R

temperature

rating

capacitors

are

recommended. The Y5V and Z5U temperature rating

capacitors are not recommended due to their wide

variation in capacitance over temperature and

increased resistance at high frequencies.

5.3

Compensation

The MIC33030 is designed to be stable with a minimum

of 2.2 µF ceramic (X5R) output capacitor.

5.4

Duty Cycle

The typical maximum duty cycle of the MIC33030 is

90%.

5.5

Efficiency Considerations

Efficiency is defined as the amount of useful output

power, divided by the amount of power supplied.

EQUATION 5-1:

Maintaining high efficiency serves two purposes. It

reduces power dissipation in the power supply,

reducing the need for heat sinks and thermal design

considerations and it reduces consumption of current

for battery powered applications. Reduced current

draw from a battery increases the devices operating

time which is critical in hand held devices.

There are two types of losses in switching converters;

DC losses and switching losses. DC losses are simply

the power dissipation of I2R. Power is dissipated in the

high-side switch during the on cycle. Power loss is

equal to the high-side MOSFET RDS(ON) multiplied by

the switch current squared. During the off cycle, the

low-side

N-channel

MOSFET

conducts,

also

dissipating power. Device operating current also

reduces efficiency. The product of the quiescent

(operating) current and the supply voltage represents

another DC loss. The current required driving the gates

on and off at a constant 8 MHz frequency and the

switching transitions make up the switching losses.

FIGURE 5-1:

Efficiency under Load.

Figure 5-1 shows an efficiency curve. From no load to

100 mA, efficiency losses are dominated by quiescent

current losses, gate drive and transition losses. By

using the HyperLight Load® mode, the MIC33030 is

able to maintain high efficiency at low output currents.

Over 100 mA, efficiency loss is dominated by MOSFET

RDS(ON) and inductor losses. Higher input supply

voltages will increase the gate to source threshold on

the internal MOSFETs, thereby reducing the internal



VOUT IOUT



VIN IIN



--------------------------------







 100



0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100

1000

LOAD CURRENT (mA)

VIN = 3.6V

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