MAX1617A Просмотр технического описания (PDF) - Maxim Integrated

Номер в каталоге

Компоненты Описание

Список матч

MAX1617A

Remote/Local Temperature Sensor with SMBus Serial Interface

Maxim Integrated 

MAX1617A

Remote/Local Temperature Sensor

with SMBus Serial Interface

Pin Description

PIN

1, 5, 9,

13, 16

2

3

NAME

N.C.

VCC

DXP

FUNCTION

No Connection. Not internally connected. May be used for PC board trace routing.

Supply Voltage Input, 3V to 5.5V. Bypass to GND with a 0.1μF capacitor.

Combined Current Source and A/D Positive Input for Remote-Diode Channel. Do not leave DXP

unconnected; tie DXP to DXN if no remote diode is used. Place a 2200pF capacitor between DXP and

DXN for noise filtering.

4

DXN

Combined Current Sink and A/D Negative Input. DXN is normally biased to a diode voltage above ground.

6

ADD1

SMBus Address Select Pin (Table 8). ADD0 and ADD1 are sampled upon power-up. Excess capacitance

(>50pF) at the address pins when unconnected may cause address-recognition problems.

7, 8

GND

Ground

10

ADD0 SMBus Slave Address Select Pin

11

ALERT SMBus Alert (interrupt) Output, Open Drain

12

SMBDATA SMBus Serial-Data Input/Output, Open Drain

14

SMBCLK SMBus Serial-Clock Input

15

STBY

Hardware Standby Input. Temperature and comparison threshold data are retained in standby mode.

Low = standby mode, high = operate mode.

General Description

The MAX1617A is a temperature sensor designed to

work in conjunction with an external microcontroller (μC)

or other intelligence in thermostatic, process-control, or

monitoring applications. The μC is typically a power-man-

agement or keyboard controller, generating SMBus serial

commands by “bit-banging” general-purpose input/output

(GPIO) pins or via a dedicated SMBus interface block.

Essentially an 8-bit serial analog-to-digital converter

(ADC) with a sophisticated front end, the MAX1617A

contains a switched current source, a multiplexer, an

ADC, an SMBus interface, and associated control logic

(Figure 1). Temperature data from the ADC is loaded into

two data registers, where it is automatically compared

with data previously stored in four over/under-tempera-

ture alarm registers.

ADC and Multiplexer

The ADC is an averaging type that integrates over a

60ms period (each channel, typical) with excellent noise

rejection.

The multiplexer automatically steers bias currents through

the remote and local diodes, measures their forward

voltages, and computes their temperatures. Both chan-

nels are automatically converted once the conversion

process has started, either in free-running or single-shot

mode. If one of the two channels is not used, the device

still performs both measurements, and the user can

simply ignore the results of the unused channel. If the

remote diode channel is unused, tie DXP to DXN rather

than leaving the pins open.

The DXN input is biased at 0.65V(typ) above ground by

an internal diode to set up the analog-to-digital (A/D)

inputs for a differential measurement. The typical DXP–

DXN differential input voltage range is 0.25V to 0.95V.

To ensure proper operation over full temperature range,

ensure VDXP ≤ (0.78 x VCC - 1.1) volts.

www.maximintegrated.com

Maxim Integrated │  6

Share Link: