MAX6629MTT+T - Maxim Integrated

General Description

The MAX6629–MAX6632 are local digital temperature

sensors with an SPI-compatible serial interface. The

temperature is converted to a 12-bit + sign word with a

resolution of 0.0625°C/LSB. An extended temperature

range provides useful readings up to +150°C.

These sensors are 3-wire serial interface SPI compatible,

allowing the MAX6629–MAX6632 to be readily connected

to a variety of microcontrollers (μCs). The MAX6629–

MAX6632 are read-only devices, simplifying their use in

systems where only temperature data is required.

All four digital temperature sensors require very little

supply current, making them ideal for portable systems.

The MAX6631/MAX6632 perform a temperature-to-digital

conversion once every 8s and require minimal average

supply current, 32μA (typ). The MAX6629/MAX6630

perform a conversion once every 0.5s and require only

200μA (typ) supply current. Any of these temperature

sensors can perform conversions more often—up to

approximately four conversions per second by reading the

conversion results more often.

Applications

Features

●Low Power Consumption

• 32μA typ (MAX6631/MAX6632)

• 200μA typ (MAX6629/MAX6630)

●12-Bit + Sign Resolution with 0.0625°C/LSB

●Accuracy

• ±1°C (max) from 0°C to +70°C

●+150°C Extended Temperature Range

●SPI-Compatible Serial Interface

●+3.0V to +5.5V Supply Range

●6-Pin TDFN and SOT23 Packages

● Lead-Free Version Available (TDFN Package)

19-2047; Rev 6; 11/16

●Cellular

●Hard Disk Drive

●HVACs

●Industrial Control

●Systems

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

*EP = Exposed pad.

PART TEMP RANGE PIN-PACKAGE

MAX6629MTT+ -55°C to +125°C 6 TDFN-EP*

MAX6629MUT#G16 -55°C to +125°C 6 SOT23

MAX6630MTT+ -55°C to +125°C 6 TDFN-EP*

MAX6630MUT#G16 -55°C to +125°C 6 SOT23

MAX6631MTT+ -55°C to +125°C 6 TDFN-EP*

MAX6632MTT+ -55°C to +125°C 6 TDFN-EP*

MAX6632MUT#G16 -55°C to +125°C 6 SOT23

GND

SCKVCC

1 6 SO

N.C.

MAX6629

MAX6631

SOT23

TDFN

TOP VIEW

3 4

CS N.C.

SCKVCC

1 6 SO

GND

MAX6630

MAX6632

SOT23

TDFN

3 4

VCC

GND SCK

µC

+3V TO +5.5V

0.1µF

MAX6629

MAX6630

MAX6631

MAX6632

MAX6629–MAX6632 12-Bit + Sign Digital Temperature Sensors

with Serial Interface

Ordering Information

Typical Application Circuit

Pin Congurations

All voltages referenced to GND.

VCC.............................................................

....

..........-0.3V, +6.0V

SO, SCK, CS....................................................-0.3V, VCC + 0.3V

SO .......................................................................-1mA to +50mA

Current into Any Pin ............................................................10mA

Continuous Power Dissipation (TA = +70°C)

6-Pin SOT23 (derate 9.10mW/°C above +70°C)

.........

727mW

6-Pin TDFN (derate 24.4mW/°C above +70°C

).........

1951mW

Junction Temperature.........

..........................................

...+150°C

Operating Temperature Range (Note 1)

...........

-55°C to +150°C

Storage Temperature Range

.............................

-65°C to +150°C

Lead Temperature (soldering, 10s)

.................................

+300°C

Soldering Temperature (reflow)

TDFN................................................

.............

...............+260°C

SOT23 (Ordering Information contains “#”)

.................

+245°C

SOT23 (Ordering Information contains “-”).

.................

+240°C

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

2 and 3)

Note 1: It is not recommended to operate the device above +125°C for extended periods of time.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

TEMPERATURE

Accuracy

TA = room temp, VCC = +3.3V -0.8 ±0.2 +0.8

0°C ≤ TA ≤ +70°C, VCC = +3.3V -1.0 ±0.2 +1.0

-20°C ≤ TA ≤ +85°C, VCC = +3.3V -1.6 +0.3 +1.6

-20°C ≤ TA ≤ +100°C, VCC = +3.3V -2.3 +0.5 +2.3 °C

-40°C ≤ TA ≤ +125°C, VCC = +3.3V -3.2 +0.8 +3.2

TA ≥ -55°C, VCC = +3.3V -1.0 +1.5 +3.5

TA = +150°C, VCC = +3.3V -5.0 +1.5 +6.5

Power-Supply Sensitivity PSS 0.2 0.6 °C/V

Resolution 0.0625 °C

Time Between Conversion

Starts tSAMPLE

MAX6629, MAX6630, CS high 0.37 0.5 0.65 s

MAX6631, MAX6632, CS high 5.9 8 10.5

Conversion Time tCONV 180 250 320 ms

POWER SUPPLY

Supply Voltage Range VCC 3.0 5.5 V

Supply Current, SCK Idle

ISD Shutdown (Note 3), VCC = +0.8V 5

µAIIDLE ADC idle (Figure 2), CS = low 6 20

ICONV ADC converting (Figure 2) 360 650

Average Operating Current ICC

MAX6629, MAX6630 200 400 µA

MAX6631, MAX6632 32 50

Power-On Reset (POR)

Threshold VCC falling 1.6 V

MAX6629–MAX6632 12-Bit + Sign Digital Temperature Sensors

with Serial Interface

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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

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

2 and 3)

Note 2: Tested at a single temperature. Specifications over temperature are guaranteed by design.

Note 3: The MAX6629–MAX6632 are not specifically equipped with a shutdown function. Their low supply current permits powering

them from the output of a logic gate. This specification is given to ensure that the MAX6629–MAX6632 do not draw exces-

sive currents at low supply voltages, ensuring reliable operation from a gate output.

Note 4: Timing characteristics are guaranteed by design and are not production tested.

Note 5: CLOAD = total capacitance of one bus line in picofarads.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

LOGIC INPUTS (CS, SCK)

Logic Input Low Voltage VIL

0.3 x

VCC

Logic Input High Voltage VIH 0.7 x

VCC

Input Leakage Current ILEAK VIN = VGND or +5.5V ±1 ±5 µA

LOGIC OUTPUTS (SO)

Output Low Voltage VOL ISINK = 1.6mA 0.4 V

Output High Voltage VOH ISOURCE = 1.6mA VCC - 0.4 V

TIMING CHARACTERISTICS (Notes 4 and 5)

Serial Clock Frequency fSCL 5 MHz

SCK Pulse Width High tCH 100 ns

SCK Pulse Width Low tCL 100 ns

CS Fall to SCK Rise tCSS CLOAD = 10pF 80 ns

CS Fall to Output Enable tDV CLOAD = 10pF 80 ns

CS Rise to Output Disable tTR CLOAD = 10pF 50 ns

SCK Fall to Output Data Valid tDO CLOAD = 10pF 80 ns

MAX6629–MAX6632 12-Bit + Sign Digital Temperature Sensors

with Serial Interface

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Electrical Characteristics (continued)

(VCC = +3.3V, TA = +25°C, unless otherwise noted.)

NAME FUNCTION

MAX6629

MAX6631

MAX6630

MAX6632

1 2 N.C. No Connect. Connect to ground plane for better thermal performance to the PC board.

2 1 GND Ground

3 3 VCC

Supply Voltage Input. Bypass VCC to GND with a 0.1µF capacitor. VCC can also be

powered from a logic output as long as the voltage level is greater than 3.0V and the logic

output is not noisy. Setting the logic output low provides a hardware shutdown mode.

4 4 SCK Serial Clock Input

5 5 CS Chip-Select Input. Enables the interface. A rising edge off CS initiates the next conversion.

Pulling CS low initiates an idle state.

6 6 SO Serial Data Output

— — EP Exposed Pad (TDFN only). Connect to GND or leave unconnected.

0.6

1.0

0.8

1.4

1.2

1.8

1.6

2.0

2.4

2.2

2.6

-55 -5 20 45-30 70 95 120 145

POWER-ON RESET (POR)

THRESHOLD vs.TEMPERATURE

MAX6629-32 toc02

TEMPERATURE (°C)

POWER-ON RESET THRESHOLD (V)

-4

-2

-3

-1

-55 -5 20 45-30 70 95 120 145

TEMPERATURE ERROR

vs. TEMPERATURE

MAX6629-32 toc03

TEMPERATURE (°C)

TEMPERATURE ERROR (∞C)

MAX6629

10 100k 10M1k100 10k 1M 100M

TEMPERATURE ERROR

vs. POWER-SUPPLY NOISE FREQUENCY

MAX6629-32 toc04

FREQUENCY (Hz)

TEMPERATURE ERROR (°C)

12 VIN = SQUARE WAVE

APPLIED TO VCC WITH NO

0.1µF CAPACITOR

VIN = 250mVP-P

100

125

-2 20 4 6 8 10 12 14

RESPONSE TO THERMAL SHOCK

MAX6629-32 toc05

TIME (s)

TEMPERATURE (°C)

100

200

150

300

250

400

350

-55 -5 20 45-30 70 95 120 145

OPERATING SUPPLY CURRENT

vs. TEMPERATURE

MAX6629-32 toc01

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

MAX6629

VCC = +5.5V VCC = +4.5V VCC = +5.0V

VCC = +3.0V

VCC = +3.3V

VCC = +3.6V

MAX6629–MAX6632 12-Bit + Sign Digital Temperature Sensors

with Serial Interface

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Typical Operating Characteristics

Pin Description

Detailed Description

The MAX6629–MAX6632 are local digital temperature

sensors with a serial bus. The MAX6629–MAX6632 are

typically interfaced to a μC in temperature sensing and

control applications. The MAX6629–MAX6632 convert

temperature to a 12-bit + sign word with a 0.0625°C LSB.

The data is communicated through a simple serial inter-

face with a CS (chip select) line, SO (data) line, and SCK

(clock) line. This interface can be directly connected to,

and is fully compatible with, SPI interfaces. This interface

can also be connected to virtually any processor, which

has at least three general-purpose input/output (GPIO)

lines available to implement software “bit banging.”

The high resolution of the MAX6629–MAX6632 makes

them especially useful in thermal control loops, HVAC

systems, or in any system where quick anticipation of

temperature trends is useful. The MAX6629–MAX6632

can produce temperature data in excess of +150°C,

although they are specified for a maximum operating

temperature of +150°C. The low power consumption is

also ideal in battery-operated and portable applications.

The MAX6631/MAX6632 are optimized for minimum

power consumption with their 8s conversions. The

MAX6629/MAX6630 provide faster conversions, 0.5s, at

the expense of power consumption. The low quiescent

supply current enables the device to be powered from

a logic line or the output of a gate where the high level

exceeds 3V, as shown in Figure 1. While the MAX6629–

MAX6632 are not specifically equipped with a software

shutdown mode, the hardware shutdown can easily be

implemented by setting the gate output to low. Pulling

CS low without a clock also puts the device in idle mode.

Take care to ensure that the logic output is not noisy, as

excessive noise on VCC can affect temperature measure-

ment accuracy.

ADC Conversion Sequence

The MAX6629–MAX6632 continuously convert tempera-

ture to digital data. Setting CS low stops any conversion

in progress, places the device in idle mode, and makes

data available for reading. Setting CS high starts a new

conversion. CS must remain high for at least 0.3s to allow

for the conversion to be completed. Figure 2 shows the

timing relationship between conversion time and conver-

sion rate.

SPI Digital Interface

The MAX6629–MAX6632 are compatible with SPI serial-

interface standards (Figure 3) and are designed to be

read-only devices. CS’s rising edge always starts a new

conversion and resets the interface. CS must stay high

for a minimum of 300ms to allow the conversion to finish.

CS’s falling edge stops any conversion in progress, and

data is latched into the shift register. Then the data clocks

Figure 1. Powering the Sensor from a Logic Gate

Figure 2. Conversion Time and Rate Relationships

LOGIC LINE WHERE VLOGIC > 3V

MAX6629

MAX6630

MAX6631

MAX6632

VCC

GND

SCK

MAX6629

MAX6630

MAX6631

MAX6632

0.25s ADC

CONVERSION TIME

MAX6631

MAX6632

CONVERSION PERIOD

MAX6629

MAX6630

CONVERSION PERIOD

0.5s

0.25s ADC

CONVERSION TIME

MAX6629–MAX6632 12-Bit + Sign Digital Temperature Sensors

with Serial Interface

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out at SO on SCK’s falling edge with the sign bit (D15)

first, followed by the MSB. Data is sent in one 16-bit word,

and CS must remain low until all 16 bits are transferred. If

CS goes high in the middle of a transmission, it is neces-

sary to wait the conversion time (less than 300ms) before

attempting a new read. The serial data is composed of 12

+ 1 data bits (D15–D3) and 3 trailing bits (D2–D0). D2 is

always low, serving as the confirmation bit that the device

has been communicated with. The last 2 bits, D0 and D1,

are undefined and are always in high-impedance mode

(Table 1). The power-up state for SO is high impedance.

Figure 3 shows the detailed serial timing specifications

for the SPI port. The temperature data format is in two’s

complement format (Table 2).

Power Shutdown Mode

The MAX6629–MAX6632 do not have a built-in power

software shutdown mode. However, a power shutdown

mode is easily implemented utilizing an unused logic

gate. A typical CMOS or TTL logic output has enough

drive capability to serve as the power source if its output

voltage level exceeds 3V, as shown in Figure 1. Drive the

logic output low to provide a hardware shutdown mode.

Idle Mode

The MAX6629–MAX6632 can be put into idle mode by

pulling CS low. Data can be clocked out when the device

is in idle mode.

Power-On Reset (POR)

The POR supply voltage of the MAX6629–MAX6632 is

typically 1.6V. Below this supply voltage, the interface is

inactive and the data register is set to the POR state, 0°C.

When power is first applied and VCC rises above 1.6V

(typ), the device starts to convert, although temperature

reading is not recommended at VCC levels below 3.0V.

Table 2. Temperature Data Format

(Two’s Complement)

Table 1. Data Output Format

Figure 3. SPI Timing Diagram

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

Sign MSB

Data

LSB

Data Low High-Z High-Z

TEMPERATURE

(°C)

DIGITAL OUTPUT (BINARY)

D15–D3 D2 D1, D0

150 0,1001,0110,0000 0 XX

125 0,0111,1101,0000 0 XX

25 0,0001,1001,0000 0 XX

0.0625 0,0000,0000,0001 0 XX

0 0,0000,0000,0000 0 XX

-0.0625 1,1111,1111,1111 0 XX

-25 1,1110,0111,0000 0 XX

-55 1,1100,1001,0000 0 XX

D15 D0D1D2D3

SCK

tDV

tCSS

tDO

tTR

MAX6629–MAX6632 12-Bit + Sign Digital Temperature Sensors

with Serial Interface

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Applications Information

Thermal Considerations

The key to accurate temperature monitoring is good ther-

mal contact between the MAX6629–MAX6632 package

and the object being monitored. In some applications, the

6-pin SOT23 package is small enough to fit underneath

a socketed μP, allowing the device to monitor the μP’s

temperature directly. Accurate temperature monitoring

depends on the thermal resistance between the object

being monitored and the MAX6629–MAX6632 die. Heat

flows in and out of plastic packages primarily through

the leads. If the sensor is intended to measure the tem-

perature of a heat-generating component on the circuit

board, it should be mounted as close as possible to that

component and should share supply and ground traces (if

they are not noisy) with that component where possible.

This maximizes the heat transfer from the component to

the sensor.

The MAX6629/MAX6630 supply current is typically

200μA, and the MAX6631/MAX6632 supply current is

typically 32μA. When used to drive high-impedance

loads, the device dissipates negligible power. Therefore,

the die temperature is essentially the same as the pack-

age temperature.

The rise in die temperature due to self-heating is given by

the following formula:

ΔTJ = PDISSIPATION x θJA

where PDISSIPATION is the power dissipated by the

MAX6629–MAX6632, and θJA is the package’s thermal

resistance.

The typical thermal resistance is +110°C/W for the 6-pin

SOT23 package. To limit the effects of self-heating, mini-

mize the output currents. For example, if the MAX6629–

MAX6632 sink 1mA, the output voltage is guaranteed

to be less than 0.4V. Therefore, an additional 0.4mW of

power is dissipated within the IC. This corresponds to a

0.044°C shift in the die temperature in the 6-pin SOT23.

PACKAGE

TYPE

PACKAGE

CODE

DOCUMENT

NO.

LAND

PATTERN NO.

6 SOT23 U6FH-6 21-0058 90-0175

6 TDFN-EP T633+2 21-0137 90-0058

VOLTAGE

REFERENCE

SPI-COMPATIBLE

INTERFACE

TEMPERATURE

SENSOR

12-BIT + SIGN

∑∆ ADC

MAX6629

MAX6630

MAX6631

MAX6632

SCK

MAX6629–MAX6632 12-Bit + Sign Digital Temperature Sensors

with Serial Interface

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│

Functional Diagram

Chip Information

PROCESS: BiCMOS

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 5/01 Initial release of MAX6629 —

17/01 Initial release of MAX3360, MAX3361, and MAX3362; changed ICONV from 600µA (max) to

650µA (max) in the Electrical Characteristics table 1, 2

2 4/04

Changed the lead temperature in the Absolute Maximum Ratings section, replacing Note

2 with +300°C (removed the JEDEC solder reow boiler plating due to high temp solder

paste for ip chips now in production)

3 8/05 Added the TDFN package 1, 2, 9

4 5/10

Added “+” to TDFN packages in the Ordering Information table 1

Added soldering information to the Absolute Maximum Ratings section 2

Added the TDFN exposed pad information to the Pin Description table 4

5 10/14 Removed automotive reference from data sheet 1, 5

6 11/16 Removed MAX6631MUT from Ordering Information table, changed non lead-free parts to

lead-free parts 1

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.

Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.

MAX6629–MAX6632 12-Bit + Sign Digital Temperature Sensors

with Serial Interface

│

Revision History

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