Rainbow-electronics MAX6656 Manual do Utilizador descarregar pdf (Página 1)

General Description

The MAX6655/MAX6656 are precise voltage and tem-

perature monitors. The digital thermometer reports the

temperature of two remote sensors and its own die tem-

perature. The remote sensors are diode-connected

transistors—typically a low-cost, easily mounted

2N3906 PNP type—that replace conventional thermis-

tors or thermocouples. Remote accuracy is ±1°C for

multiple transistor manufacturers with no calibration

necessary. The remote channels can also measure the

die temperature of other ICs, such as microprocessors,

that contain a substrate-connected PNP with its collec-

tor grounded and its base and emitter available for tem-

perature-sensing purposes. The temperature is

digitized with 11-bit resolution.

The MAX6655/MAX6656 also measure their own supply

voltage and three external voltages with 8-bit resolution.

Each voltage input’s sensitivity is set to give approxi-

mately 3/4-scale output code when the input voltage is

at its nominal value. The MAX6655 operates at +5V

supply and its second voltage monitor is 3.3V. The

MAX6656 operates on a +3.3V supply and its second

voltage monitor is 5V.

The 2-wire serial interface accepts standard SMBus™

Write Byte, Read Byte, Send Byte, and Receive Byte

commands to program the alarm thresholds and to

read data. The MAX6655/MAX6656 also provide

SMBus alert response and timeout functions. The

MAX6655/MAX6656 measure automatically and

autonomously, with the conversion rate programmable.

The adjustable rate allows the user to control the supply

current.

In addition to the SMBus ALERT output, the MAX6655/

MAX6656 feature an OVERT output, which is used as a

temperature reset that remains active only while the

temperature is above the maximum temperature limit.

The OVERT output is optimal for fan control or for sys-

tem shutdown.

Applications

Notebooks

Thin Clients

Servers

Workstations

Communication Equipment

Desktop PC

Features

♦ Three Temperature Channels

Two Remote PN Junctions

One Local Sensor

♦ Four Voltage Channels

+12V, +5V, +3.3V, +2.5V

Three External Monitors

One Internal Supply Monitor

♦ 11-Bit, 0.125°C Resolution

♦ High Accuracy: ±1°C Over +60°C to +100°C

Temperature Range

♦ Programmable Under/Over-Threshold Alarms

♦ Programmable Power-Saving Mode

♦ No Calibration Required

♦ SMBus/I

C™-Compatible Interface

♦ OVERT Output for Fan Control and System

Shutdown

MAX6655/MAX6656

Dual Remote/Local Temperature Sensors and

Four-Channel Voltage Monitors

________________________________________________________________ Maxim Integrated Products 1

STBY

SMBCLK

OVERT

SMBDATA

ALERT

IN2

IN1

IN3

TOP VIEW

MAX6655

MAX6656

QSOP

DXP1

DXN1

DXP2

ADD0

ADD1

DXN2

GND

Pin Configuration

Ordering Information

19-2117; Rev 0; 7/01

PART TEMP. RANGE PIN-PACKAGE

MAX6655MEE -55°C to +125°C 16 QSOP

MAX6656MEE -55°C to +125°C 16 QSOP

SMBus is a trademark of Intel Corp.

C is a trademark of Philips Corp.

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.

Typical Application Circuit appears at end of data sheet.

1 2 3 4 5 6 ... 17 18

Resumo do Conteúdo

Página 1 - Four-Channel Voltage Monitors

General DescriptionThe MAX6655/MAX6656 are precise voltage and tem-perature monitors. The digital thermometer reports thetemperature of two remote sen

Página 2

MAX6655/MAX6656places constraints on high-frequency noise rejection.Lay out the PC board carefully with proper externalnoise filtering for high-accura

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