Rainbow Electronics MAX1299 User Manual

General Description

The MAX1298/MAX1299 implement local and remote
temperature sensing with 12-bit resolution, using +5V
and +3V supply voltages, respectively. Accuracy is
±1°C from 0 to +70°C, with no calibration needed. The
devices feature an algorithmic switched-capacitor ana­log-to-digital converter (ADC), an on-chip clock, and a
3-wire serial interface compatible with SPI™, QSPI™,
and MICROWIRE™.

The MAX1298/MAX1299 also perform fully differential
voltage measurements with 12-bit resolution and sepa­rate track-and-hold (T/H) for positive and negative
inputs. Both devices accept versatile input modes con­sisting of two 3-channel signal pairs, five 1-channel sig­nals relative to a floating common, or VDD/4 relative to
ground. An external reference may be used for more
accurate voltage measurements.

Typical power consumption is only 1.3mW (MAX1299).
A shutdown mode and two standby modes provide
multiple strategies for prolonging battery life in portable
applications that require limited sampling throughput.

The MAX1298/MAX1299 are available in 16-pin SSOP
packages.

________________________Applications

Temperature/Voltage Supervision of
Workstations and Communications Equipment

Hand-Held Instruments

Medical Equipment

Industrial Process Control

Features

♦ Local and Remote Temperature Sensing

♦ 12-Bit Resolution for Temperature and Voltage

Inputs

♦ ±1°C Accuracy from -40°C to +85°C

♦ Fully Differential Inputs

♦ Single-Supply Operation

+4.75V to +5.25V (MAX1298)
+2.7V to +3.6V (MAX1299)

♦ 3-Wire SPI/QSPI/MICROWIRE-Compatible

Interface

♦ Internal Precision Voltage Reference

2.50V (MAX1298)

1.20V (MAX1299)

♦ Space-Saving 16-Pin SSOP Package

MAX1298/MAX1299

12-Bit Serial-Output Temperature Sensors

with 5-Channel ADC

________________________________________________________________ Maxim Integrated Products 1

16

15

14

13

12

11

10

9

1

2

3

4

5

6

7

8

AIN1 AIN0

AIN5

REF

GND

V

DD

SCLK

DIN

DOUT

TOP VIEW

MAX1298
MAX1299

SSOP

SHO

AIN2

GND

AIN3

AIN4

SSTRB

CS

Pin Configuration

19-1726; Rev 0; 5/00

For free samples and the latest literature, visit www.maxim-ic.com or phone [phone].
For small orders, phone [phone].

Ordering Information

*Future product—contact factory for availability.

Typical Operating Circuit appears at end of data sheet.

SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.

PART

TEMP.

RANGE

PIN-

TEMP. SENSE

ACCURACY

(°C)

MAX1298AEAE

±0.75

MAX1298BEAE*

±1.0

MAX1298CEAE

±4.0

MAX1299AEAE

±0.75

MAX1299BEAE*

±1.0

MAX1299CEAE

±4.0

PACKAGE

-40°C to +85°C 16 SSOP

-40°C to +85°C 16 SSOP

-40°C to +85°C 16 SSOP

-40°C to +85°C 16 SSOP

-40°C to +85°C 16 SSOP

-40°C to +85°C 16 SSOP

MAX1298/MAX1299

12-Bit Serial-Output Temperature Sensors
with 5-Channel ADC

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VDD= 4.75V to 5.25V (MAX1298), VDD= +2.7V to 3.6V (MAX1299), external reference, V

REF

= +2.5V (MAX1298), V

REF

= +1.2V

(MAX1299), f

SCLK

= 2.5MHz, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.)

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.

VDDto GND.……………………………………………-0.3V to +6V

SHO to GND...............................................-0.3V to (V

DD

+ 0.3V)

Analog Inputs to GND

(AIN0, AIN1, AIN2, AIN3, AIN4,

AIN5, REF).............................................-0.3V to (V

DD

+ 0.3V)

Digital Inputs to GND (DIN, SCLK,

CS)......-0.3V to (VDD+ 0.3V)

Digital Outputs to GND (DOUT, SSTRB)....-0.3V to (V

DD

+ 0.3V)

Digital Output Sink Current ..…………………………………25mA

Maximum Current into Any Pin……………………………….50mA
Continuous Power Dissipation (T

A

= +70°C)

16-Pin SSOP (derate 8.00mW/°C above +70°C) ........667mW

Operating Temperature Range

MAX129_ _EAE...............................................-40°C to +85°C

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

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

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

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

DC ACCURACY (Note 1)

Resolution RES 12 Bits

Relative Accuracy (Note 2) INL ±1 LSB

Differential Nonlinearity DNL ±1 LSB

Offset Error Inputs AIN0−AIN5 ±2 LSB

Offset Temperature Coefficient ±10

µV/ °C

Gain Error Inputs AIN0−AIN5, offset nulled ±4 LSB

VDD/4 Absolute Error ±2 LSB

Gain Temperature Coefficient ±2

ppm/ °C

Channel-to-Channel Offset
Matching

LSB

CONVERSION RATE

Voltage measurement 1.1

Conversion Time (Note 3) t

CONV

Temperature measurement 2.2

ms

Track/Hold Acquisition Time t

ACQ

16 µs

Aperture Delay t

APR

30 ns

Internal Clock Frequency f

CLK

kHz

ANALOG INPUTS (AIN0 −AIN5)

Input Voltage Range (Note 4) Measurement with respect to IN-, Figure 1

V

Common-Mode Range 0

V

Input Current (Note 5) 0.1 5 µA

Input Capacitance 16 pF

57.6 62.3 65.5

-2V

±0.5

REF

+2V

REF

V

DD

MAX1298/MAX1299

12-Bit Serial-Output Temperature Sensors

with 5-Channel ADC

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VDD= 4.75V to 5.25V (MAX1298), VDD= +2.7V to 3.6V (MAX1299), external reference, V

REF

= +2.5V (MAX1298), V

REF

= +1.2V

(MAX1299), f

SCLK

= 2.5MHz, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

DIGITAL INPUTS

Input Voltage Low V

IL

0.8 V

Input Voltage High V

IH

V

Input Hysteresis V

HYST

0.2 V

Input Leakage Current I

IN

1 µA

Input Capacitance 16 pF

DIGITAL OUTPUTS V

Output Low Voltage V

OL

I

SINK

= 5mA 0.6 V

Output High Voltage V

OH

I

SOURCE

= 0.5mA

V

Three-State Output Leakage
Current

I

OUT

±10 µA

Three-State Output
Capacitance

15 pF

POWER REQUIREMENTS

MAX1298

Positive Supply Voltage V

DD

MAX1299 2.7 3.6

V

MAX1298 390

i nter nal r efer ence

MAX1299 350

MAX1298 310

Ful l - on, vol tag e m easur em ents,
exter nal r efer ence

MAX1299 280

MAX1298 440 500

Full-on, temperature measure­ments, internal reference

MAX1299 400 500

MAX1298 360

Full-on, temperature measure­ments, exter nal r efer ence

MAX1299 330

Standby, SCLK = GND 120

Standby-plus, SCLK = GND 190

Positive Supply Current (Note 6)

I

DD

Shutdown, SCLK = GND 2 10

µA

Power-Supply Rejection Ratio PSRR (Note 7) 50 65 dB

INTERNAL VOLTAGE REFERENCE CHARACTERISTICS

VDD = 5V MAX1298

Reference Voltage V

REF

VDD = 3V MAX1299

V

Reference Tempco

±20

ppm/°C

Output Short-Circuit Current

mA

Capacitive Bypass at REF 0.1 µF

MAX1298 130

REF Output Noise fN = 10Hz to 10kHz

MAX1299 65

µV

RMS

REF Line Regulation

MAX1299

mV/V

MAX1298 4 10

REF Load Regulation

0 to 100µA output current
(Note 8) MAX1299 2 10

µV/µA

Ful l - on, vol tag e m easur em ents,

TC V

REF

MAX1298 +3.0

V

- 0.8

D D

V

- 0.6

D D

4.75 5.25

2.494 2.50 2.506

1.197 1.20 1.203

+0.2

1.25

MAX1298/MAX1299

12-Bit Serial-Output Temperature Sensors
with 5-Channel ADC

4 _______________________________________________________________________________________

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

EXTERNAL VOLTAGE REFERENCE CHARACTERISTICS

MAX1298 0.8 2.5

Reference Voltage Range V

REF

MAX1299 0.8 1.2

V

Converting 10

REF Input Resistance

Shutdown 25

MΩ

REF Input Capacitance 24 pF

INTERNAL TEMPERATURE MEASUREMENT CHARACTERISTICS

Resolution

°C

MAX129_A

MAX129_B ±1TA = +85°C, PD = 1mW

MAX129_C ±1

MAX129_A

MAX129_B ±1

TA = 0°C to +70°C

MAX129_C ±2

MAX129_A

MAX129_B ±1

Output Error (Notes 1, 9)

T

A

= -40°C to 0°C,

T

A

= +70°C to +85°C

MAX129_C ±4

°C

Power-Supply Rejection Ratio PSRR (Note 7) 0.2

Noise

EXTERNAL TEMPERATURE MEASUREMENT CHARACTERISTICS

Output Error 2N3904 (Note 10) ±2 ±4 °C

Remote Diode Excitation (1X) 10 µA

Remote Diode Excitation (10X) 100 µA

ELECTRICAL CHARACTERISTICS (continued)

(VDD= 4.75V to 5.25V (MAX1298), VDD= +2.7V to 3.6V (MAX1299), external reference, V

REF

= +2.5V (MAX1298), V

REF

= +1.2V

(MAX1299), f

SCLK

= 2.5MHz, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.)

0.13

±0.75

±0.75

±0.75

0.18 °C

°C/V

RMS

MAX1298/MAX1299

12-Bit Serial-Output Temperature Sensors

with 5-Channel ADC

_______________________________________________________________________________________ 5

TIMING CHARACTERISTICS

(VDD= +4.75V to 5.25V (MAX1298), VDD= +2.7V to +3.6V (MAX1299), external reference, V

REF

= +2.5V (MAX1298), V

REF

= +1.2V

(MAX1299), f

SCLK

= 2.5MHz, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Figures 4, 6)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

SCLK Frequency f

SCLK

2.5

MHz

SCLK Pulse Width Low t

CL

ns

SCLK Pulse Width High t

CH

ns

CS Low to SCLK High t

CSS

ns

SCLK High to CS Setup t

CSH

ns

CS Pulse Width t

CS

ns

SCLK High to CS Low Setup t

CS0

50 ns

SCLK High to CS High Setup t

CS1

ns

DIN Setup to SCLK High Time t

DS

ns

DIN Hold Time t

DH

0ns

SCLK Fall to Output Data Valid t

DO

RL = 100kΩ, CL = 50pF

ns

CS Fall to Output Enable t

DV

RL = 100kΩ, CL = 50pF

ns

CS Rise to Output Disable t

TR

RL = 100kΩ, CL = 50pF 50 ns

SSTRB Rise to SCLK Rise t

SCLK

0ns

SCLK Fall to SSTRB Fall

ns

Note 1: Tested at VDD= +5.0V (MAX1298) and VDD= +3.0V (MAX1299).
Note 2: Relative accuracy is the deviation of the analog value at any code from its theoretical value after the full-scale range has

been calibrated.

Note 3: Conversion time is defined as the number of clock cycles (64 for voltage measurements, 125 for temperature measure-

ments) multiplied by the internal clock period.

Note 4: Individual analog input voltages cannot extend beyond the power-supply rails.
Note 5: Input resistance is typically 250MΩ; 5µA limit reflects limitations in production testing.
Note 6: Specifications for full-on status assume continuous conversions. Power modes are software selected (Table 4).
Note 7: Measured at V

FS(+4.75V)

- V

FS(+5.25V)

for the MAX1298 and at V

FS(+2.7V)

- V

FS(+3.6V)

for the MAX1299.

Note 8: External load should not change during conversions for specified accuracy.
Note 9: Excludes noise and self-heating effects. Output error for MAX129_C guaranteed by design.
Note 10: External temperature sensing over -40°C to +85°C range, device at +25°C. Guaranteed by design.

t

SSTRB

200

200

100

100

100

100

100

150

150

200

MAX1298/MAX1299

12-Bit Serial-Output Temperature Sensors
with 5-Channel ADC

6 _______________________________________________________________________________________

Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

-1.0

-0.4

-0.6

-0.8

-0.2

0

0.2

0.4

0.6

0.8

1.0

-2500 -1250 0 1250 2500

MAX1298

INTEGRAL NONLINEARITY

vs. OUTPUT CODE

MAX1298/9-01

OUTPUT CODE

INTEGRAL NONLINEARITY (LSB)

-1.0

-0.4

-0.6

-0.8

-0.2

0

0.2

0.4

0.6

0.8

1.0

-2500 -1250 0 1250 2500

MAX1299

INTEGRAL NONLINEARITY

vs. OUTPUT CODE

MAX1298/9-02

OUTPUT CODE

INTEGRAL NONLINEARITY (LSB)

-1.0

-0.4

-0.6

-0.8

-0.2

0

0.2

0.4

0.6

0.8

1.0

-2500 -1250 0 1250 2500

MAX1298

DIFFERENTIAL NONLINEARITY

vs. OUTPUT CODE

MAX1298/9-03

OUTPUT CODE

DIFFERENTIAL NONLINEARITY (LSB)

-1.0

-0.4

-0.6

-0.8

-0.2

0

0.2

0.4

0.6

0.8

1.0

-2500 -1250 0 1250 2500

MAX1299

DIFFERENTIAL NONLINEARITY

vs. OUTPUT CODE

MAX1298/9-04

OUTPUT CODE

DIFFERENTIAL NONLINEARITY (LSB)

0

150

100

50

200

250

300

350

400

450

500

4.7 4.94.8 5.0 5.1 5.2

MAX1298

SUPPLY CURRENT vs. SUPPLY VOLTAGE

(VOLTAGE MEASUREMENT MODE)

MAX1298/9-05

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (µA)

EXTERNAL REFERENCE

INTERNAL REFERENCE

0

150

100

50

200

250

300

350

400

450

500

2.7 3.12.9 3.3 3.5

MAX1299

SUPPLY CURRENT vs. SUPPLY VOLTAGE

(VOLTAGE MEASUREMENT MODE)

MAX1298/9-06

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (µA)

EXTERNAL REFERENCE

INTERNAL REFERENCE

0

150

100

50

200

250

300

350

400

450

500

4.7 4.94.8 5.0 5.1 5.2

MAX1298

SUPPLY CURRENT vs. SUPPLY VOLTAGE

(TEMPERATURE MEASUREMENT MODE)

MAX1298/9-07

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (µA)

EXTERNAL REFERENCE

INTERNAL REFERENCE

0

150

100

50

200

250

300

350

400

450

500

2.7 3.12.9 3.3 3.5

MAX1299

SUPPLY CURRENT vs. SUPPLY VOLTAGE

(TEMPERATURE MEASUREMENT MODE)

MAX1298/9-08

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (µA)

EXTERNAL REFERENCE

INTERNAL REFERENCE

0

150

100

50

250

200

450

400

350

300

500

-40 -20 0 20 40 60

80

MAX1298

SUPPLY CURRENT vs. TEMPERATURE

(VOLTAGE MEASUREMENT MODE)

MAX1298/9-09

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

EXTERNAL REFERENCE

INTERNAL REFERENCE