MAX7503MSA+T - Maxim Integrated

General Description

The MAX7500–MAX7504 temperature sensors accurately

measure temperature and provide an overtemperature

alarm/interrupt/shutdown output. These devices convert

the temperature measurements to digital form using a

high-resolution, sigma-delta, analog-to-digital converter

(ADC). Communication is through an I2C-compatible

2-wire serial interface. The MAX7500/MAX7501/MAX7502

integrate a timeout feature that offers protection against

I2C bus lockups. The MAX7503/MAX7504 do not include

the timeout feature.

The 2-wire serial interface accepts standard write byte,

read byte, send byte, and receive byte commands to read

the temperature data and configure the behavior of the

open-drain overtemperature shutdown output.

The MAX7500 features three address select lines, while

the MAX7501–MAX7504 feature two address select lines

and a RESET input. The MAX7500/MAX7501/MAX7502s’

3.0V to 5.5V supply voltage range, low 250μA supply

current, and a lockup-protected I2C-compatible interface

make them ideal for a wide range of applications, including

personal computers (PCs), electronic test equipment, and

office electronics.

The MAX7500–MAX7504 are available in 8-pin μMAX®

and SO packages and operate over the -55°C to +125°C

temperature range.

Applications

●PCs

●Servers

● Ofce Electronics

● Electronic Test Equipment

●Industrial Process Control

Features

●Timeout Prevents Bus Lockup (MAX7500, MAX7501,

MAX7502)

●Hardware Reset for Added Protection

●I2C Bus Interface

●3.0V to 5.5V Supply Voltage Range

● 250μA (typ) Operating Supply Current

● 3μA (typ) Shutdown Supply Current

●±1.5°C (max) Temperature Accuracy (-25°C to

+100°C, 3-σ)

● μMAX, SO Packages Save Space

●Separate Open-Drain OS Output Operates as

Interrupt or Comparator/Thermostat Input

●Register Readback Capability

●Improved LM75 Second Source

19-3382; Rev 5; 11/16

μMAX is a registered trademark of Maxim Integrated Products, Inc.

Ordering Information/Selector Guide continued at end of

data sheet.

Pin Configurations appear at end of data sheet.

PART TEMP

RANGE

PIN-

PACKAGE RESET TIMEOUT

MAX7500MSA -55°C to

+125°C 8 SO — X

MAX7501

MAX7502

MAX7503

MAX7504

+3.0V TO +5.5V+3.0V TO +5.5V

+VS

RESET

GND

SCL

SDA

TO I2C MASTER

4.7kΩ

+VS

GND

SCL

SDA

TO I2C MASTER

4.7kΩ

MAX7500

MAX7500–MAX7504 Digital Temperature Sensors and Thermal

Watchdog with Bus Lockup Protection

Typical Application Circuits

Ordering Information/

Selector Guide

EVALUATION KIT AVAILABLE

(Note 1)

+VS to GND ............................................................. -0.3V to +6V

OS, SDA, SCL to GND .........................................-0.3V to +6.0V

All Other Pins to GND ...............................-0.3V to (+VS + 0.3V)

Input Current at Any Pin (Note 2) ....................................... +5mA

Package Input Current (Note 2) .......................................+20mA

ESD Protection (all pins, Human Body Model, Note 3) ..±2000V

Continuous Power Dissipation (TA = +70°C)

8-Pin μMAX (derate 4.5mW/°C above +70°C) ............362mW

8-Pin SO (derate 5.9mW/°C above +70°C) ................. 471mW

Operating Temperature Range ......................... -55°C to +125°C

Junction Temperature ...................................................... +150°C

Storage Temperature Range ............................ -65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

Soldering Temperature (reflow)

Lead(Pb)-free...............................................................+260°C

Containing lead(Pb) ..................................................... +240°C

(+VS = +3.0V to +5.5V, TA = -55°C to +125°C, unless otherwise noted. Typical values are at +VS = +3.3V, TA = +25°C.) (Notes 4, 5)

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifica-

tions do not apply when operating the device beyond its rated operating conditions.

Note 2: When the input voltage (VI) at any pin exceeds the power supplies (VI < VGND or VI > + VS), the current at that pin should

be limited to 5mA. The 20mA maximum package input current rating limits the number of pins that can safely exceed the

power supplies with an input current of 5mA to 4.

Note 3: Human Body Model, 100pF discharged through a 1.5kΩ resistor.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Accuracy, 6-σ -25°C ≤ TA ≤ +100°C -2.0 ±2.0 °C

-55°C ≤ TA ≤ +125°C -3.0 ±3.0

Accuracy, 3-σ (Note 5) -25°C ≤ TA ≤ +100°C -1.5 +1.5 °C

-55°C ≤ TA ≤ +125°C -2.0 +2.0

Resolution 9 bits

Conversion Time (Note 6) 100 ms

Quiescent Supply Current

I2C inactive 0.25 0.5 mA

Shutdown mode, +VS = 3V 3 µA

Shutdown mode, +VS = 5V 5

+VS Supply Voltage Range 3.0 5.5 V

OS Output Saturation Voltage IOUT = 4.0mA (Note 7) 0.8 V

OS Delay (Note 8) 1 6 Conver-

sions

TOS Default Temperature (Note 9) 80 °C

THYST Default Temperature (Note 9) 75 °C

LOGIC (SDA, SCL, A0, A1, A2)

Input High Voltage VIH +VS x

0.7 V

Input Low Voltage VIL +VS x

0.3 V

Input High Current IIH VIN = 5V 0.005 1.0 µA

Input Low Current IIL VIN = 0V 0.005 1.0 µA

Input Capacitance All digital inputs 5 pF

Output High Current VIN = 5V 1 µA

Output Low Voltage IOL = 3mA 0.4 V

MAX7500–MAX7504 Digital Temperature Sensors and Thermal

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Absolute Maximum Ratings

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these

or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect

device reliability.

Electrical Characteristics

(+VS = +3.0V to +5.5V, TA = -55°C to +125°C, unless otherwise noted. Typical values are at +VS = +3.3V, TA = +25°C.) (Notes 4, 5)

Note 4: All parameters are measured at +25°C. Values over the temperature range are guaranteed by design.

Note 5: There are no industry-wide standards for temperature accuracy specifications. These values allow comparison to vendors

who use 3-σ limits.

Note 6: This specification indicates how often temperature data is updated. The devices can be read at any time without regard to

conversion state, while yielding the last conversion result.

Note 7: For best accuracy, minimize output loading. Higher sink currents can affect sensor accuracy due to internal heating.

Note 8: OS delay is user programmable up to six “over-limit” conversions before OS is set to minimize false tripping in noisy

environments.

Note 9: Default values set at power-up.

Note 10: All timing specifications are guaranteed by design.

Note 11: A master device must provide a hold time of at least 300ns for the SDA signal to bridge the undefined region of SCL’s fall-

ing edge.

Note 12: CB = total capacitance of one bus line in pF. Tested with CB = 400pF.

Note 13: Input filters on SDA, SCL, and A_ suppress noise spikes less than 50ns.

Note 14: Holding the SDA line low for a time greater than tTIMEOUT causes the devices to reset SDA to the IDLE state of the serial

bus communication (SDA set high).

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

I2C-COMPATIBLE TIMING (Note 10)

Serial Clock Frequency fSCL Bus timeout inactive DC 400 kHz

Minimum RESET Pulse Width 1 µs

Bus Free Time Between STOP

and START Conditions tBUF 1.3 µs

START Condition Hold Time tHD:STA 0.6 µs

STOP Condition Setup Time tSU:STO 90% of SCL to 10% of SDA 100 ns

Clock Low Period tLOW 1.3 µs

Clock High Period tHIGH 0.6 µs

START Condition Setup Time tSU:STA 90% of SCL to 90% of SDA 100 ns

Data Setup Time tSU:DAT 10% of SDA to 10% of SCL 100 ns

Data Hold Time tHD:DAT 10% of SCL to 10% of SDA (Note 11) 0 0.9 µs

Maximum Receive SCL/SDA

Rise Time tR300 ns

Minimum Receive SCL/SDA

Rise Time tR(Note 12)

20 +

0.1 x

Maximum Receive SCL/SDA

Fall Time tF300 ns

Minimum Receive SCL/SDA

Fall Time tF(Note 12)

20 +

0.1 x

Transmit SDA Fall Time tF(Note 12) 20 + 0.1

x CB250 ns

Pulse Width of Suppressed Spike tSP (Note 13) 0 50 ns

SDA Time Low for Reset of Serial

Interface tTIMEOUT MAX7500/MAX7501/MAX7502 (Note 14) 150 300 ms

MAX7500–MAX7504 Digital Temperature Sensors and Thermal

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Electrical Characteristics (continued)

(TA = +25°C, unless otherwise noted.)

Detailed Description

The MAX7500–MAX7504 temperature sensors measure

temperature, convert the data into digital form using

a sigma-delta ADC, and communicate the conversion

results through an I2C-compatible 2-wire serial interface.

These devices accept standard I2C commands to read

the data, set the overtemperature alarm (OS) trip thresh-

olds, and configure other characteristics. The MAX7500

features three address select lines (A0, A1, A2) while the

MAX7501–MAX7504 feature two address select lines

(A0, A1) and a RESET input. The MAX7500–MAX7504

operate from +3.0V to +5.5V supply voltages and con-

sume 250μA of supply current.

NAME FUNCTION

MAX7500 MAX7501–

MAX7504

1 1 SDA Serial Data Input/Output Line. Open drain. Connect SDA to a pullup resistor.

2 2 SCL Serial Data Clock Input. Open drain. Connect SCL to a pullup resistor.

3 3 OS Overtemperature Shutdown Output. Open drain. Connect OS to a pullup resistor.

4 4 GND Ground

5 — A2 2-Wire Interface Address Input. Connect A2 to GND or +VS to set the desired I2C bus

address. Do not leave unconnected (see Table 1).

— 5 RESET Active-Low Reset Input. Pull RESET low for longer than the minimum reset pulse width

to reset the I2C bus and all internal registers to their POR values.

6 6 A1 2-Wire Interface Address Input. Connect A1 to GND or +VS to set the desired I2C bus

address. Do not leave unconnected (see Table 1).

7 7 A0 2-Wire Interface Address Input. Connect A0 to GND or +VS to set the desired I2C bus

address. Do not leave unconnected (see Table 1).

8 8 +VSPositive Supply Voltage Input. Bypass to GND with a 0.1µF bypass capacitor.

SHUTDOWN SUPPLY CURRENT (µA)

SHUTDOWN SUPPLY CURRENT

vs. TEMPERATURE

MAX7500 toc02

TEMPERATURE (°C)

9565355-25-55 125

+VS = +5V

+VS = +3V

ACCURACY vs. TEMPERATURE

ACCURACY (°C)

-1.5

-1.0

-0.5

0.5

1.0

1.5

2.0

-2.0

MAX7500 toc03

TEMPERATURE (°C)

9565355-25-55 125

4 TYPICAL PARTS

QUIESCENT SUPPLY CURRENT

vs. TEMPERATURE

MAX7500 toc01

TEMPERATURE (°C)

QUIESCENT SUPPLY CURRENT (µA)

9565355-25

240

250

260

270

280

290

300

230

-55 125

+VS = +5V

+VS = +3V

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MAX7500–MAX7504 Digital Temperature Sensors and Thermal

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Typical Operating Characteristics

Pin Description

I2C-Compatible Bus Interface

From a software perspective, the MAX7500–MAX7504

appear as a set of byte-wide registers that contain tem-

perature data, alarm threshold values, and control bits. A

standard I2C-compatible 2-wire serial interface reads tem-

perature data and writes control bits and alarm threshold

data. Each device responds to its own I2C slave address,

which is selected using A0, A1, and A2. See Table 1.

The MAX7500–MAX7504 employ four standard I2C pro-

tocols: write byte, read byte, send byte, and receive byte

(Figures 1, 2, and 3). The shorter receive byte protocol

allows quicker transfers, provided that the correct data

tion. Use caution when using the shorter protocols in

multimaster systems, as a second master could overwrite

the command byte without informing the first master. The

MAX7500 has eight different slave addresses available;

therefore, a maximum of eight MAX7500 devices can

share the same bus. The MAX7501–MAX7504 each have

four different slave addresses available.

Figure 1. Serial Bus Timing

DEVICE BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0

MAX7500 1 0 0 1 A2 A1 A0 RD/W

MAX7501 1 0 0 1 1 A1 A0 RD/W

MAX7502 1 0 0 1 0 A1 A0 RD/W

MAX7503 1 0 0 1 1 A1 A0 RD/W

MAX7504 1 0 0 1 0 A1 A0 RD/W

tBUF

tSU:STO

tHD:STA

tSU:STA

tHD:DAT

tHIGH

tLOW

tSU:DAT

tHD:STA

SCL

SDA

ACKNOWLEDGE

(A)

STOP

CONDITION

(P)

START

CONDITION

(S)

START

CONDITION

(S)

REPEATED START

CONDITION

(SR)

PARAMETERS ARE MEASURED FROM 10% TO 90%.

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Table 1. I2C Slave Addresses

Figure 2. I2C-Compatible Timing Diagram (Write)

ADDRESS

BYTE

ADDRESS

BYTE

ADDRESS

BYTE

(a) TYPICAL POINTER SET FOLLOWED BY IMMEDIATE READ FROM CONFIGURATION REGISTER

(b) CONFIGURATION REGISTER WRITE

POINTER

BYTE

POINTER

BYTE

POINTER

BYTE MOST-SIGNIFICANT

DATA BYTE

LEAST-SIGNIFICANT

DATA BYTE

CONFIGURATION

BYTE

ADDRESS

BYTE

DATA

BYTE

ACK BY

MAX7500–

MAX7504

ACK BY

MAX7500–

MAX7504

ACK BY

MAX7500–

MAX7504 ACK BY

MAX7500–

MAX7504

ACK BY

MAX7500–

MAX7504

ACK BY

MAX7500–

MAX7504

ACK BY

MAX7500–

MAX7504

START

MASTER

START

MASTER

START

MASTER

REPEAT

START

MASTER

ACK BY

MASTER

STOP

COND BY

MASTER

ACK BY

MAX7500–

MAX7504

ACK BY

MAX7500–

MAX7504

STOP

COND BY

MASTER

STOP

COND BY

MASTER

ACK BY

MAX7500–

MAX7504

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Figure 3. I2C-Compatible Timing Diagram (Read)

ADDRESS

BYTE

ADDRESS BYTE

ADDRESS

BYTE

ADDRESS

BYTE

DATA

BYTE

(a) TYPICAL 2-BYTE READ FROM PRESET POINTER LOCATION SUCH AS TEMP, THIGH, TLOW.

(b) TYPICAL POINTER SET FOLLOWED BY IMMEDIATE READ FOR 2-BYTE REGISTER SUCH AS TEMP, THIGH, TLOW.

MOST-SIGNIFICANT

DATA BYTE

LEAST-SIGNIFICANT

DATA BYTE

POINTER BYTE

MOST-SIGNIFICANT

DATA BYTE

LEAST-SIGNIFICANT

DATA BYTE

ACK BY

MAX7500–

MAX7504

ACK BY

MASTER

ACK BY

MAX7500–

MAX7504

ACK BY

MAX7500–

MAX7504

ACK BY

MASTER

ACK BY

MAX7500–

MAX7504

ACK BY

MASTER

START

MASTER

START

MASTER

REPEAT

START

MASTER

START

MASTER

STOP

COND BY

MASTER

STOP

COND BY

MASTER

STOP

COND BY

MASTER

NO ACK BY

MASTER

ACK BY

MASTER

ACK BY

MASTER

MAX7500–MAX7504 Digital Temperature Sensors and Thermal

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The MAX7500–MAX7504 have an internal pnp-junction-

based temperature sensor whose analog output is con-

verted to digital form using a 9-bit sigma-delta ADC. The

measured temperature and temperature configurations

are controlled by the temperature, configuration, THYST,

and TOS registers. See Table 2.

Temperature Register

Read the measured temperature through the tempera-

ture register. The temperature data format is 9 bits, two’s

complement, and the register is read out in 2 bytes: an

upper byte and a lower byte. Bit D15 is the sign bit. When

bit D15 is 1, the temperature reading is negative. When

bit D15 is zero, the temperature reading is positive. Bits

D14–D7 contain the temperature data, with the LSB

representing 0.5°C and the MSB representing 64°C (see

Table 3). The MSB is transmitted first. The last 7 bits of the

lower byte, bits D6–D0, are don’t cares. When reading the

temperature register, bits D6–D0 must be ignored. When

the measured temperature is greater than +127.5°C,

the value stored in the temperature register is clipped to

7F8h. When the measured temperature is below -64°C,

the value in the temperature register is clipped to BF8h.

During the time of reading the temperature register, any

changes in temperature are ignored until the read is com-

pleted. The temperature register is updated upon comple-

tion of the next conversion.

Table 3 lists the temperature register definition.

Conguration Register

The 8-bit configuration register sets the fault queue, OS

polarity, shutdown control, and whether the OS output

functions in comparator or interrupt mode. When writing

to the configuration register, set bits D7, D6, and D5 to

zero. See Table 5.

Bits D4 and D3, the fault queue bits, determine the num-

ber of faults necessary to trigger an OS condition. See

Table 6. The number of faults set in the queue must occur

to trip the OS output. The fault queue prevents OS false

tripping in noisy environments.

Set bit D2, the OS polarity bit, to zero to force the OS

output active low. Set bit D2 to 1 to set the OS output

polarity to active high. OS is an open-drain output under

all conditions and requires a pullup resistor to output a

high voltage. See Figure 4.

Set bit D1, the comparator/interrupt bit to zero to run the

overtemperature shutdown block in comparator mode. In

comparator mode, OS is asserted when the temperature

rises above the TOS value. OS is deasserted when the

temperature drops below the THYST value.

X = Don’t care.

(BINARY) POR STATE (°C) READ/

WRITE

Temperature 00 — — — Read only

Conguration 01 00 0000 0000 — R/W

THYST 02 4B0 0100 1011 0 75 R/W

TOS 03 500 0101 0000 0 80 R/W

UPPER BYTE LOWER BYTE

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

Sign bit

1= Negative

0 = Positive

MSB

64°C 32°C 16°C 8°C 4°C 2°C 1°C LSB

0.5°C XXXXXXX

TEMPERATURE (°C) DIGITAL OUTPUT

BINARY hex

+125 0111 1101 0xxx xxxx 7D0x

+25 0001 1001 0xxx xxxx 190x

+0.5 0000 0000 1xxx xxxx 008x

0 0000 0000 0xxx xxxx 000x

-0.5 1111 1111 1xxx xxxx FF8x

-25 1110 0111 0xxx xxxx E70x

-55 1100 1001 0xxx xxxx C90x

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Table 2. Register Functions

Table 3. Temperature Register Definition

Table 4. Temperature Data Output

See Figure 4. Set bit D1 to 1 to run the overtemperature

shutdown block in interrupt mode. OS is asserted in inter-

rupt mode when the temperature rises above the TOS

value or falls below the THYST value. OS is deasserted

only after performing a read operation.

Set bit D0, the shutdown bit, to zero for normal operation.

Set bit D0 to 1 to shut down the MAX7500–MAX7504

internal blocks, dropping the supply current to 3μA. The

I2C interface remains active as long as the shutdown bit is

set. The TOS, THYST, and configuration registers can still

be written to and read from while in shutdown.

TOS and THYST Registers

In comparator mode, the OS output behaves like a ther-

mostat. The output asserts when the temperature rises

above the limit set in the TOS register. The output deas-

serts when the temperature falls below the limit set in the

THYST register. In comparator mode, the OS output can

be used to turn on a cooling fan, initiate an emergency

shutdown signal, or reduce system clock speed.

In interrupt mode, exceeding TOS also asserts OS. OS

remains asserted until a read operation is performed on

any of the registers. Once OS has asserted due to cross-

ing above TOS and is then reset, it is asserted again only

when the temperature drops below THYST. The output

remains asserted until it is reset by a read. Putting the

MAX7500–MAX7504 into shutdown mode also resets OS.

The TOS and THYST registers are accessed with 2 bytes,

with bits D15–D7 containing the data. Bits D6–D0 are

don’t cares when writing to these two registers and read-

back zeros when reading from these registers. The LSB

represents 0.5°C while the MSB represents 64°C. See

Table 7.

X = Don’t care.

Figure 4. OS Timing Diagram

D7 D6 D5 D4 D3 D2 D1 D0

0 0 0 Fault queue Fault queue OS polarity Comparator/

interrupt Shutdown

D4 D3 NO. OF FAULTS

0 0 1 (POR state)

0 1 2

1 0 4

1 1 6

COMMAND UPPER BYTE LOWER BYTE

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

Write

Sign bit

1 = negative

0 = positive

MSB

64°C 32°C 16°C 8°C 4°C 2°C 1°C LSB

0.5°C X X X X X X X

Read

Sign bit

1 = negative

0 = positive

MSB

64°C 32°C 16°C 8°C 4°C 2°C 1°C LSB

0.5°C 0 0 0 0 0 0 0

TOS

THYST

OS OUTPUT

(COMPARATOR MODE)

OS SET ACTIVE LOW

OS OUTPUT

(INTERRUPT MODE)

OS SET ACTIVE LOW READ

OPERATION

READ

OPERATION

READ

OPERATION

TEMPERATURE

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Table 5. Configuration Register Definition

Table 6. Configuration Register Fault

Queue Bits

Table 7. TOS and THYST Register Definitions

Shutdown

Set bit D0 in the configuration register to 1 to place the

MAX7500–MAX7504 in shutdown mode and reduce sup-

ply current to 3μA.

Power-Up and Power-Down

The MAX7500–MAX7504 power up to a known state, as

indicated in Table 2. Some of these settings are summa-

rized below:

●Comparator mode

●TOS = +80°C

●THYST = +75°C

●OS active low

●Pointer = 00

Internal Registers

The MAX7500–MAX7504s’ pointer register selects

between four data registers. See Figure 5. At power-

up, the pointer is set to read the temperature register at

address 00. The pointer register latches the last location

to which it was set. All registers are read and write, except

the temperature register, which is read only.

Write to the configuration register by writing an address

byte, a data pointer byte, and a data byte. If 2 data bytes

are written, the second data byte overrides the first. If

more than 2 data bytes are written, only the first 2 bytes

are recognized while the remaining bytes are ignored.

The TOS and THYST registers require 1 address byte and

1 pointer byte and 2 data bytes. If only 1 data byte is writ-

ten, it is saved in bits D15–D8 of the respective register.

If more than 2 data bytes are written, only the first 2 bytes

are recognized while the remaining bytes are ignored.

Read from the MAX7500–MAX7504 in one of two ways.

If the location latched in the pointer register is set from

the previous read, the new read consists of an address

byte, followed by retrieving the corresponding number of

data bytes. If the pointer register needs to be set to a new

address, perform a read operation by writing an address

byte, pointer byte, repeat start, and another address byte.

An inadvertent 8-bit read from a 16-bit register, with the

D7 bit low, can cause the MAX7500–MAX7504 to stop

in a state where the SDA line is held low. Ordinarily, this

would prevent any further bus communication until the

master sends nine additional clock cycles or SDA goes

high. At that time, a stop condition resets the device. With

the MAX7500/MAX7501/MAX7502, if the additional clock

cycles are not generated by the master, the bus resets

and unlocks after the bus timeout period has elapsed.

The MAX7501–MAX7504 can be reset by pulsing RESET

low.

Bus Timeout

Communication errors sometimes occur due to noise pick-

up on the bus. In the worst case, such errors can cause

the slave device to hold the data line low, thereby pre-

venting other devices from communicating over the bus.

The MAX7500/MAX7501/MAX7502s’ internal bus timeout

circuit resets the bus and releases the data line if the line is

low for more than 250ms. When the bus timeout is active,

the minimum serial clock frequency is limited to 6Hz.

RESET

The RESET input on the MAX7501/MAX7504 provides a

way to reset the I2C bus and all the internal registers to

their initial POR values. To reset, apply a low pulse with a

duration of at least 1μs to the RESET input.

Figure 5. Block Diagram

MAX7504

+VS

A2/RESET

SDA

SCL OS

SMBus

INTERFACE

BLOCK

POINTER REGISTER

(SELECTS REGISTER

FOR COMMUNICATION)

DATA ADDRESS

GND

TEMPERATURE

(READ ONLY)

POINTER = 0000 0000

TOS SET POINT

(READ/WRITE)

POINTER = 0000 0011

THYST SET POINT

(READ/WRITE)

POINTER = 0000 0010

CONFIGURATION

(READ/WRITE)

POINTER = 0000 0001

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Applications Information

Digital Noise

The MAX7500–MAX7504 feature an integrated lowpass

filter on both the SCL and the SDA digital lines to mitigate

the effects of bus noise. Although this filtering makes

communication robust in noisy environments, good layout

practices are always recommended. Minimize noise cou-

pling by keeping digital traces away from switching power

supplies. Ensure that digital lines containing high-speed

data communications cross at right angles to the SDA

and SCL lines.

Excessive noise coupling into the SDA and SCL lines

on the MAX7500–MAX7504—specifically noise with

amplitude greater than 400mVP-P (the MAX7500–

MAX7504s’ typical hysteresis), overshoot greater than

300mV above +VS, and undershoot more than 300mV

below GND—may prevent successful serial communication.

Serial bus no-acknowledge is the most common symptom,

causing unnecessary traffic on the bus.

Care must be taken to ensure proper termination within a

system with long PCB traces or multiple parts on the bus.

Resistance can be added in series with the SDA and SCL

lines to further help filter noise and ringing. If it proves to

be necessary, a 5kΩ resistor should be placed in series

with the SCL line, placed as close as possible to SCL.

This 5kΩ resistor, with the 5pF to 10pF stray capacitance

of the MAX7500–MAX7504 provide a 6MHz to 12MHz

lowpass filter, which is sufficient filtering in most cases.

+Denotes a lead(Pb)-free/RoHS-compliant package.

PART TEMP

RANGE

PIN-

PACKAGE RESET TIMEOUT

MAX7500MSA+ -55°C to

+125°C 8 SO — X

MAX7500MUA -55°C to

+125°C 8 µMAX — X

MAX7500MUA+ -55°C to

+125°C 8 µMAX — X

MAX7501MSA -55°C to

+125°C 8 SO X X

MAX7501MSA+ -55°C to

+125°C 8 SO X X

MAX7501MUA -55°C to

+125°C 8 µMAX X X

MAX7501MUA+ -55°C to

+125°C 8 µMAX X X

MAX7502MSA -55°C to

+125°C 8 SO X X

MAX7502MSA+ -55°C to

+125°C 8 SO X X

MAX7502MUA -55°C to

+125°C 8 µMAX X X

MAX7502MUA+ -55°C to

+125°C 8 µMAX X X

MAX7503MSA -55°C to

+125°C 8 SO X —

MAX7503MSA+ -55°C to

+125°C 8 SO X —

MAX7503MUA -55°C to

+125°C 8 µMAX X —

MAX7503MUA+ -55°C to

+125°C 8 µMAX X —

MAX7504MSA -55°C to

+125°C 8 SO X —

MAX7504MSA+ -55°C to

+125°C 8 SO X —

MAX7504MUA -55°C to

+125°C 8 µMAX X —

MAX7504MUA+ -55°C to

+125°C 8 µMAX X —

+VS

A2GND

SCL

SDA

MAX7500

µMAX, SO

+VS

RESETGND

SCL MAX7501–

MAX7504

µMAX, SO

TOP VIEW

MAX7500–MAX7504 Digital Temperature Sensors and Thermal

Watchdog with Bus Lockup Protection

www.maximintegrated.com Maxim Integrated

│

Ordering Information/

Selector Guide continued

Chip Information

PROCESS: CMOS

Pin Congurations

PACKAGE TYPE PACKAGE CODE DOCUMENT NO. LAND PATTERN NO.

8 SO S8-2 21-0041 90-0096

8 μMAX U8-1 21-0036 90-0092

MAX7500–MAX7504 Digital Temperature Sensors and Thermal

Watchdog with Bus Lockup Protection

www.maximintegrated.com Maxim Integrated

│

Package Information

For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”,

“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing

pertains to the package regardless of RoHS status.

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

0 8/04 Initial release of MAX7500 —

1 10/04 Initial release of MAX7501/MAX7502 All

2 6/05 Initial release of MAX7503/MAX7504 All

3 8/08 Various corrections and edits to clarify specications; added Typical Application

Circuits 1–4, 11, 12, 13

410/10 Removed the UL certied bullet from the Features section as the parts have never

been certied 1

5 11/16 Corrected markings of RESET and TIMEOUT functions in Ordering Information table 1, 10, 11

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses

are implied. Maxim Integrated reserves the right to change the circuitry and specications without notice at any time. The parametric values (min and max limits)

shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

│

MAX7500–MAX7504 Digital Temperature Sensors and Thermal

Watchdog with Bus Lockup Protection

Revision History

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.

Mouser Electronics

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Maxim Integrated:

MAX7500MSA+ MAX7500MUA+ MAX7501MSA+ MAX7501MSA+T MAX7501MUA+ MAX7501MUA+T

MAX7502MSA+ MAX7502MSA+T MAX7502MUA+ MAX7502MUA+T MAX7503MSA+ MAX7503MSA+T

MAX7503MUA+ MAX7503MUA+T MAX7504MSA+ MAX7504MSA+T MAX7504MUA+ MAX7504MUA+T

MAX7500MSA+T MAX7500MUA+T MAX7500MTA+T