Rainbow-electronics MAX1865 Bedienungsanleitung PDF herunterladen

General Description

The MAX1864/MAX1865 power-supply controllers are

designed to address cost-conscious applications such

as cable modem Consumer Premise Equipment (CPE),

xDSL CPE, and set-top boxes. Operating off a low-cost,

unregulated DC supply (such as a wall adapter output),

the MAX1864 generates three positive outputs, and the

MAX1865 generates four positive outputs and one neg-

ative output to provide a cost-effective system power

supply.

The MAX1864 includes a current-mode synchronous

step-down controller and two positive regulator gain

blocks. The MAX1865 has one additional positive gain

block and one negative regulator gain block. The main

synchronous step-down controller generates a

high-current output that is preset to 3.3V or adjustable

from 1.236V to 0.8 ✕ V

with an external resistive-

divider. The 100kHz/200kHz operating frequency

allows the use of low-cost aluminum-electrolytic capaci-

tors and low-cost power magnetics. Additionally, the

MAX1864/MAX1865 step-down controllers sense the

voltage across the low-side MOSFET’s on-resistance to

efficiently provide the current-limit signal, eliminating

the need for costly current-sense resistors.

The MAX1864/MAX1865 generate additional supply

rails at low cost. The positive regulator gain blocks use

an external PNP pass transistor to generate low-voltage

rails directly from the main step-down converter (such

as 2.5V or 1.8V from the main 3.3V output) or higher

voltages using coupled windings from the step-down

converter (such as 5V, 12V, or 15V). The MAX1865’s

negative gain block uses an external NPN pass transis-

tor in conjunction with a coupled winding to generate

-5V, -12V, or -15V.

All output voltages are externally adjustable, providing

maximum flexibility. Additionally, the MAX1864/

MAX1865 feature soft-start for the step-down converter

and all the positive linear regulators, and have a power-

good output that monitors all of the output voltages.

Applications

xDSL, Cable, and ISDN Modems

Set-Top Boxes

Wireless Local Loop

Features

♦ 4.5V to 28V Input Voltage Range

♦ Master DC-DC Step-Down Converter

Preset 3.3V or Adjustable (1.236V to 0.8 ✕ V

)

Output Voltage

Fixed-Frequency (100kHz/200kHz) PWM

Controller

No Current-Sense Resistor

Adjustable Current Limit

95% Efficient

♦ Two (MAX1864)/Four (MAX1865) Analog

Gain Blocks

Positive Analog Blocks Drive Low-Cost PNP

Pass Transistors to Build Positive Linear

Regulators

Negative Analog Block (MAX1865) Drives a

Low-Cost NPN Pass Transistor to Build a

Negative Linear Regulator

♦ Power-Good Indicator

♦ Soft-Start Ramp for All Positive Regulators

MAX1864/MAX1865

xDSL/Cable Modem Triple/Quintuple Output

Power Supplies

________________________________________________________________ Maxim Integrated Products 1

POK IN

BST

GND

ILIM

TOP VIEW

MAX1864

16 QSOP

COMP

OUT

FB2

FB3

Pin Configurations

Ordering Information

19-2030; Rev 0; 4/01

PART

TEMP.

RANGE

PIN-

PACKAGE

OSC

(kHz)

MAX1864TEEE -40°C to +85°C 16 QSOP 200

MAX1864UEEE -40°C to +85°C 16 QSOP 100

MAX1865TEEP -40°C to +85°C 20 QSOP 200

MAX1865UEEP -40°C to +85°C 20 QSOP 100

Pin Configurations continued at end of data sheet.

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.

1 2 3 4 5 6 ... 24 25

MAX1864/MAX1865 1
Power Supplies 1

Inhaltsverzeichnis

Seite 1 - Power Supplies

General DescriptionThe MAX1864/MAX1865 power-supply controllers aredesigned to address cost-conscious applications suchas cable modem Consumer Premise

Seite 2

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies10 ______________________________________________________________________________

Seite 3

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies_________________________________________________________________________________

Seite 4

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies12 ______________________________________________________________________________

Seite 5

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies_________________________________________________________________________________

Seite 6

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies14 ______________________________________________________________________________

Seite 7

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies_________________________________________________________________________________

Seite 8

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies16 ______________________________________________________________________________

Seite 9

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies_________________________________________________________________________________

Seite 10

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies18 ______________________________________________________________________________

Seite 11

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies_________________________________________________________________________________

Seite 12

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies2 _______________________________________________________________________________

Seite 13

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies20 ______________________________________________________________________________

Seite 14

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies_________________________________________________________________________________

Seite 15

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies22 ______________________________________________________________________________

Seite 16

5) Ensure all feedback connections are short anddirect. Place the feedback resistors as close to theMAX1864/MAX1865 as possible.6) When trade-offs in

Seite 17

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies24 ______________________________________________________________________________

Seite 18

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower SuppliesMaxim cannot assume responsibility for use of any circuitry other than circuitry

Seite 19

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies_________________________________________________________________________________

Seite 20

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies4 _______________________________________________________________________________

Seite 21

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies_________________________________________________________________________________

Seite 22

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies6 _______________________________________________________________________________

Seite 23

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies_________________________________________________________________________________

Seite 24

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies8 _______________________________________________________________________________

Seite 25

MAX1864/MAX1865xDSL/Cable Modem Triple/Quintuple OutputPower Supplies_________________________________________________________________________________

Kommentare zu diesen Handbüchern

Keine Kommentare

Rainbow-electronics MAX1865 Bedienungsanleitung

Stöbern Sie online oder laden Sie Bedienungsanleitung nach Sensoren Rainbow-electronics MAX1865 herunter. Rainbow Electronics MAX1865 User Manual Benutzerhandbuch

Inhaltsverzeichnis

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Sensoren Rainbow-electronics MAX1865