Rainbow-electronics MAX8724 Manual do Utilizador descarregar pdf

General Description

The MAX1908/MAX8724 highly integrated, multichemistry

battery-charger control ICs simplify the construction of

accurate and efficient chargers. These devices use ana-

log inputs to control charge current and voltage, and can

be programmed by the host or hardwired. The MAX1908/

MAX8724 achieve high efficiency using a buck topology

with synchronous rectification.

The MAX1908/MAX8724 feature input current limiting.

This feature reduces battery charge current when the

input current limit is reached to avoid overloading the AC

adapter when supplying the load and the battery charger

simultaneously. The MAX1908/MAX8724 provide outputs

to monitor current drawn from the AC adapter (DC input

source), battery-charging current, and the presence of

an AC adapter. The MAX1908’s conditioning charge fea-

ture provides 300mA to safely charge deeply discharged

lithium-ion (Li+) battery packs.

The MAX1908 includes a conditioning charge feature

while the MAX8724 does not.

The MAX1908/MAX8724 charge two to four series Li+

cells, providing more than 5A, and are available in a

space-saving 28-pin thin QFN package (5mm × 5mm).

An evaluation kit is available to speed designs.

Applications

Notebook and Subnotebook Computers

Personal Digital Assistants

Hand-Held Terminals

Features

♦ ±0.5% Output Voltage Accuracy Using Internal

Reference (0°C to +85°C)

♦ ±4% Accurate Input Current Limiting

♦ ±5% Accurate Charge Current

♦ Analog Inputs Control Charge Current and

Charge Voltage

♦ Outputs for Monitoring

Current Drawn from AC Adapter

Charging Current

AC Adapter Presence

♦ Up to 17.6V Battery-Voltage Set Point

♦ Maximum 28V Input Voltage

♦ >95% Efficiency

♦ Shutdown Control Input

♦ Charges Any Battery Chemistry

Li+, NiCd, NiMH, Lead Acid, etc.

MAX1908/MAX8724

Low-Cost Multichemistry Battery Chargers

________________________________________________________________ Maxim Integrated Products 1

28 27 26 25 24 23 22

IINP

CSSP

CSSN

DHI

BST

DLOV

89101112 13 14

SHDN

ICHG

ACIN

ACOK

REFIN

ICTL

GND

VCTL

BATT

CELLS

CSIN

CSIP

PGND

DLO

CCV

CCI

CCS

REF

CLS

LDO

DCIN

MAX1908

MAX8724

THIN QFN

TOP VIEW

Pin Configuration

Ordering Information

MAX1908

MAX8724

AC ADAPTER

INPUT

TO EXTERNAL

LOAD

LDO

FROM HOST µP

10µH

0.015Ω

BATT+

DCIN

REFIN

VCTL

ICTL

ACIN

ACOK

SHDN

ICHG

IINP

CCV

CCI

CCS

CELLS

LDO

BST

DLOV

DHI

DLO

PGND

CSIP

CSIN

BATT

REF CLS

GND

CSSP CSSN

0.01Ω

Minimum Operating Circuit

19-2764; Rev 1; 1/04

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

EVALUATION KIT

AVAILABLE

PART TEMP RANGE PIN-PACKAGE

MAX1908ETI -40°C to +85°C 28 Thin QFN

MAX8724ETI -40°C to +85°C 28 Thin QFN

1 2 3 4 5 6 ... 26 27

MAX1908/MAX8724 1
Package Information 27

Resumo do Conteúdo

Página 1 - MAX1908/MAX8724

General DescriptionThe MAX1908/MAX8724 highly integrated, multichemistrybattery-charger control ICs simplify the construction ofaccurate and efficient

Página 2

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers10 ______________________________________________________________________________________-11032

Página 3

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers______________________________________________________________________________________ 11Pin De

Página 4

MAX1908/MAX8724Detailed DescriptionThe MAX1908/MAX8724 include all the functions neces-sary to charge Li+ batteries. A high-efficiency synchro-nous-re

Página 5

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers______________________________________________________________________________________ 13DCINLD

Página 6

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers14 ______________________________________________________________________________________TO EXT

Página 7

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers______________________________________________________________________________________ 15MAX190

Página 8

MAX1908/MAX8724Setting the Charging-Current LimitThe ICTL input sets the maximum charging current. Thecurrent is set by current-sense resistor RS2, co

Página 9

Current MeasurementUse ICHG to monitor the battery charging current beingsensed across CSIP and CSIN. The ICHG voltage isproportional to the output cu

Página 10

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers18 ______________________________________________________________________________________IMAXRE

Página 11

In normal operation, the controller starts a new cycle byturning on the high-side N-channel MOSFET and turning off the low-side N-channel MOSFET. When

Página 12

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers2 _______________________________________________________________________________________ABSOLU

Página 13

MAX1908/MAX8724CCV Loop DefinitionsCompensation of the CCV loop depends on the para-meters and components shown in Figure 5. CCVandRCVare the CCV loop

Página 14

The 22µF ceramic capacitor has a typical ESR of0.003Ω, which sets the output zero at 2.412MHz.The output pole is set at:where:Set the compensation zer

Página 15

MAX1908/MAX8724The crossover frequency is given by:The CCI loop dominant compensation pole:where the GMI amplifier output impedance, ROGMI=10MΩ.To cal

Página 16

the charge-current amplifier transconductance = 1µA/mV.GMINis the DC-DC converter transconductance =3.3A/V. The CCS loop is a single-pole system with

Página 17

MAX1908/MAX8724Choose crossover frequency fCO_CSto be 1/5th theMAX1908/MAX8724 switching frequency:Solving for CCS, CCS= 2nF.To be conservative, set C

Página 18

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers______________________________________________________________________________________ 25where

Página 19

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers26 ______________________________________________________________________________________Table

Página 20

MAX1908/MAX8724Low-Cost Multichemistry Battery ChargersMaxim cannot assume responsibility for use of any circuitry other than circuitry entirely embod

Página 21

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers_______________________________________________________________________________________ 3ELECTR

Página 22

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers4 _______________________________________________________________________________________ELECTR

Página 23

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers_______________________________________________________________________________________ 5ELECTR

Página 24

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers6 _______________________________________________________________________________________ELECTR

Página 25

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers_______________________________________________________________________________________ 7ELECTR

Página 26

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers8 _______________________________________________________________________________________ELECTR

Página 27 - Package Information

MAX1908/MAX8724Low-Cost Multichemistry Battery Chargers_______________________________________________________________________________________ 9INDUCT

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Rainbow-electronics MAX8724 Manual do Utilizador

Consulte online ou descarregue Manual do Utilizador para Sensores Rainbow-electronics MAX8724. Rainbow Electronics MAX8724 User Manual Manual do Utilizador

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