MAX710CSLASHD datasheet(8/12 Pages) MAXIM

8 / 12 page

3.3V/5V or Adjustable,

Step-Up/Down DC-DC Converters

_______________________________________________________________________________________

MAX710

SHDN

STBY

N/E

LBO

LBI+

LBI-

REF

PGND

0.1

µF

GND

ILIM

OUT

4.7

µF

100

µF

VIN = +1.8V TO +11V

100

µF

3/5

MAX710

SHDN

STBY

N/E

LBO

R5 = R6

(VIN - VREF)

VREF

R5 = R6 (4.08)

WHEN VREF = 1.28V

AND VIN = 6.5V

LBI+

LBI-

REF

PGND

0.1

µF

GND

ILIM

OUT

4.7

µF

100

µF

VIN = +1.8V TO +11V

100

µF

3/5

Figure 2a. High-Efficiency Operating Configuration for

VBATT < VOUT

Figure 2b. High-Efficiency Operating Configuration for

VBATT < 6.5V

In high-efficiency mode (N/E = low), the maximum

input voltage is limited to 7V. This voltage limitation is

easily overcome, however, by configuring the LBO out-

put to change modes based on input voltage, allowing

an 11V maximum input with high-efficiency configura-

tions. Four operating configurations are described in

Table 1 and in the following subsections.

Configuration 1: High Efficiency, 7V Max VIN

With N/E connected to GND, when the IC boosts, the

linear regulator operates only as a switch, with mini-

mum forward drop, until VIN > VOUT (where linear regu-

lation begins). This configuration is limited to no more

than 7V input, but provides best efficiency for battery-

only operation or low-voltage AC adapter usage.

Configuration 2: High Efficiency, VBATT < VOUT

In this configuration, N/E is driven high by LBO when

VIN > VOUT (Figure 2a). When VIN < VOUT, the IC

boosts, and the linear regulator operates as a switch,

with minimum forward drop. When VIN > VOUT, the lin-

ear regulator operates with VFV forward drop, while VPS

increases by VFV so that OUT maintains regulation. VFV

is set inside the IC to approximately 0.5V (at 5V VOUT).

When VIN is only slightly higher than VOUT, conversion

efficiency is poorer than in configuration 1, so configu-

ration 2 is most suitable when the battery voltage is less

than VOUT, but the AC adapter output is greater than

VOUT.

Up to 11V

High efficiency,

VBATT < VOUT

(Figure 2a)

Low noise

High efficiency,

11V, VBATT < 6.5V

(Figure 2b)

DESCRIPTION

High efficiency,

7V max VIN

INPUT

VOLTAGE

Up to 7V

NO.

LBO = N/E

LBI- = VOUT

LBI+ = VIN

N/E = PS

LBO = N/E

LBI- = REF

LBI+ = R5, R6

CONNECTIONS

N/E = GND

Table 1. Operating Configurations

MAX710C/D датащи(PDF) 8 Page - Maxim Integrated Products

MAX710C/D датащи(HTML) 8 Page - Maxim Integrated Products

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12

датащи скачать

ссылки URL