MAX8893A_10 Datasheet, PDF(46/51 Page) Maxim Integrated Products – μPMICs for Multimedia Application Processors in a 3.0mm x 2.5mm WLP

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FPMIC for Multimedia Application Processor

in 2.5mm x 3.0mm WLP

Table 16. SVER

This register contains the MAX8893A/MAX8893B/MAX8893C version number.

Reset Value

Type

Special Features

SVER

0x46

N/A

Read

BIT

B7 (MSB)

B0 (LSB)

NAME

SVER

DESCRIPTION

Reserved for future use

00 = MAX8893A

01 = MAX8893B

10 = MAX8893C

DEFAULT VALUE

Applications Information

Step-Down Converter

Input Capacitor

The input capacitor, CIN1, reduces the current peaks

drawn from the battery or input power source and reduc-

es switching noise in the IC. The impedance of CIN1 at

the switching frequency should be kept very low. Ceramic

capacitors with X5R or X7R temperature characteristics

are highly recommended due to their small size, low ESR,

and small temperature coefficients. Due to the step-down

converterâs fast soft-start, the input capacitance can be

very low. For most applications, a 2.2FF capacitor is suf-

ficient. Connect CIN1 as close as possible to the IC to

minimize the impact of PCB trace inductance.

For other input capacitors, use a 2.2FF ceramic capaci-

tor from IN2 to ground and a 2.2FF ceramic capacitor

from BATT to ground.

Output Capacitor

The output capacitor, CBUCK, is required to keep the

output voltage ripple small and to ensure regulation loop

stability. CBUCK must have low impedance at the switch-

ing frequency. Ceramic capacitors with X5R or X7R

temperature characteristics are highly recommended

due to their small size, low ESR, and small temperature

coefficients. Due to the unique feedback network, the

output capacitance can be very low. For most applica-

tions a 2.2FF capacitor is sufficient. For optimum load-

transient performance and very low output ripple, the

output capacitor value in FF should be equal to or larger

than the inductor value in FH.

Inductor Selection

The recommended inductor for the step-down converter

is from 1.0FH and 4.7FH. Low inductance values are

physically smaller, but require faster switching, resulting

in some efficiency loss. The inductorâs DC current rating

needs to be only 100mA greater than the applicationâs

maximum load current because the step-down converter

features zero current overshoot during startup and load

transients.

For output voltages above 2.0V, when light load efficien-

cy is important, the minimum recommended inductor is

2.2FH. For optimum voltage-positioning load transients,

choose an inductor with DC series resistance in the

50mÏ to 150mÏ range. To achieve higher efficiency at

heavy loads (above 200mA) or minimum load regulation

(but some transient overshoot), the inductor resistance

should be kept below 100mÏ. For light -oad applications

up to 200mA, much higher resistance is acceptable with

very little impact on performance. See Table 17 for some

suggested inductors.

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