19-1726; Rev 1; 3/12
12-Bit Serial-Output Temperature Sensors
with 5-Channel ADC
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 ana-
log-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 sepa-
rate track-and-hold (T/H) for positive and negative
inputs. Both devices accept versatile input modes con-
sisting of two 3-channel signal pairs, five 1-channel sig-
nals relative to an AIN5, or V
DD
/4 relative to ground. An
external reference may be used for more accurate volt-
age 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.
Features
o
Local and Remote Temperature Sensing
o
12-Bit Resolution for Temperature and Voltage
Inputs
o
±1°C Accuracy from -40°C to +85°C
o
Fully Differential Inputs
o
Single-Supply Operation
+4.75V to +5.25V (MAX1298)
+2.7V to +3.6V (MAX1299)
o
3-Wire SPI/QSPI/MICROWIRE-Compatible
Interface
o
Internal Precision Voltage Reference
2.50V (MAX1298)
1.20V (MAX1299)
o
Space-Saving 16-Pin SSOP Package
MAX1298/MAX1299
Ordering Information
PART
MAX1298CEAE+
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
16 SSOP
________________________Applications
Temperature/Voltage Supervision of
Workstations and Communications Equipment
Hand-Held Instruments
Medical Equipment
Industrial Process Control
MAX1299CEAE+
-40°C to +85°C
16 SSOP
+Denotes
a lead(Pb)-free/RoHS-compliant package.
Pin Configuration
TOP VIEW
AIN1 1
SHO 2
AIN2 3
AIN3 4
AIN4 5
GND 6
SSTRB 7
CS 8
+
16 AIN0
15 AIN5
14 REF
MAX1298
MAX1299
13 GND
12 V
DD
11 SCLK
10 DIN
9
DOUT
Typical Operating Circuit appears at end of data sheet.
SSOP
QSPI is a trademark of Motorola, Inc.
MICROWIRE is a registered trademark of National Semiconductor Corp.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
12-Bit Serial-Output Temperature Sensors
with 5-Channel ADC
MAX1298/MAX1299
ABSOLUTE MAXIMUM RATINGS
V
DD
to 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 (V
DD
+ 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 7.1mW/°C above +70°C) .......571.4mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature....……………………………………+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) ....……………………+300°C
Soldering Temperature (reflow) ..........……………………+260°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.
ELECTRICAL CHARACTERISTICS
(V
DD
= 4.75V to 5.25V (MAX1298), V
DD
= +2.7V to 3.6V (MAX1299), external reference, V
REF
= +2.5V (MAX1298), V
REF
= +1.2V
(MAX1299), f
SCLK
= 2.5MHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
DC ACCURACY
(Note 1)
Resolution
Relative Accuracy (Note 2)
Differential Nonlinearity
Offset Error
Offset Temperature Coefficient
Gain Error
V
DD
/4 Absolute Error
Gain Temperature Coefficient
Channel-to-Channel Offset
Matching
CONVERSION RATE
Conversion Time (Note 3)
Track/Hold Acquisition Time
Aperture Delay
Internal Clock Frequency
ANALOG INPUTS
(AIN0−AIN5)
Input Voltage Range (Note 4)
Common-Mode Range
Input Current (Note 5)
Input Capacitance
Measurement with respect to IN-, Figure 1
-2V
REF
0
0.1
16
+2V
REF
V
DD
5
V
V
µA
pF
t
CONV
t
ACQ
t
APR
f
CLK
57.6
Voltage measurement
Temperature measurement
16
30
62.3
65.5
1.1
2.2
ms
µs
ns
kHz
±2
±0.5
Inputs AIN0−AIN5, offset nulled
RES
INL
DNL
Inputs AIN0−AIN5
±10
±4
±2
12
±1
±1
±2
Bits
LSB
LSB
LSB
µV/°C
LSB
LSB
ppm/°C
LSB
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
12-Bit Serial-Output Temperature Sensors
with 5-Channel ADC
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= 4.75V to 5.25V (MAX1298), V
DD
= +2.7V to 3.6V (MAX1299), external reference, V
REF
= +2.5V (MAX1298), V
REF
= +1.2V
(MAX1299), f
SCLK
= 2.5MHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
DIGITAL INPUTS
Input Voltage Low
Input Voltage High
Input Hysteresis
Input Leakage Current
Input Capacitance
DIGITAL OUTPUTS
Output Low Voltage
Output High Voltage
Three-State Output Leakage
Current
Three-State Output
Capacitance
POWER REQUIREMENTS
Positive Supply Voltage
V
DD
MAX1298
MAX1299
Full-on, voltage measurements,
internal reference
Full-on, voltage measurements,
external reference
Positive Supply Current (Note 6)
I
DD
Full-on, temperature measure-
ments, internal reference
Full-on, temperature measure-
ments, external reference
Standby, SCLK = GND
Standby-plus, SCLK = GND
Shutdown, SCLK = GND
Power-Supply Rejection Ratio
PSRR
(Note 7)
MAX1298
MAX1299
50
2.494
1.197
INTERNAL VOLTAGE REFERENCE CHARACTERISTICS
V
DD
= 5V
Reference Voltage
V
REF
V
DD
= 3V
Reference Tempco
Output Short-Circuit Current
Capacitive Bypass at REF
REF Output Noise
f
N
= 10Hz to 10kHz
MAX1298
MAX1299
0.1
130
65
TC V
REF
MAX1298
MAX1299
MAX1298
MAX1299
MAX1298
MAX1299
MAX1298
MAX1299
4.75
2.7
390
350
310
280
440
400
360
330
120
190
2
65
2.50
1.20
±20
1.25
2.506
1.203
500
500
µA
5.25
3.6
V
V
OL
V
OH
I
OUT
15
I
SINK
= 5mA
I
SOURCE
= 0.5mA
0.6
V
DD
- 0.6
±10
V
IL
V
IH
V
HYST
I
IN
16
V
DD
- 0.8
0.2
1
0.8
V
V
V
µA
pF
V
V
V
µA
pF
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX1298/MAX1299
10
dB
V
ppm/°C
mA
µF
µV
RMS
_______________________________________________________________________________________
3
12-Bit Serial-Output Temperature Sensors
with 5-Channel ADC
MAX1298/MAX1299
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= 4.75V to 5.25V (MAX1298), V
DD
= +2.7V to 3.6V (MAX1299), external reference, V
REF
= +2.5V (MAX1298), V
REF
= +1.2V
(MAX1299), f
SCLK
= 2.5MHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
REF Line Regulation
REF Load Regulation
0 to 100µA output current
(Note 8)
MAX1298
MAX1299
Converting
Shutdown
SYMBOL
CONDITIONS
MAX1298
MAX1299
MAX1298
MAX1299
0.8
0.8
10
25
24
0.13
T
A
= +85°C, P
D
= 1mW
Output Error (Notes 1, 9)
T
A
= 0°C to +70°C
T
A
= -40°C to 0°C,
T
A
= +70°C to +85°C
Power-Supply Rejection Ratio
Noise
EXTERNAL TEMPERATURE MEASUREMENT CHARACTERISTICS
Output Error
Remote Diode Excitation (1X)
Remote Diode Excitation (10X)
2N3904 (Note 10)
±2
10
100
±4
°C
µA
µA
PSRR
(Note 7)
MAX129_C
MAX129_C
MAX129_C
0.2
0.18
±1
±2
±4
°C/V
°C
RMS
°C
MIN
TYP
+3.0
+0.2
4
2
10
10
2.5
1.2
MAX
UNITS
mV/V
µV/µA
EXTERNAL VOLTAGE REFERENCE CHARACTERISTICS
Reference Voltage Range
REF Input Resistance
REF Input Capacitance
INTERNAL TEMPERATURE MEASUREMENT CHARACTERISTICS
Resolution
°C
V
REF
V
MΩ
pF
4
_______________________________________________________________________________________
12-Bit Serial-Output Temperature Sensors
with 5-Channel ADC
TIMING CHARACTERISTICS
(V
DD
= +4.75V to 5.25V (MAX1298), V
DD
= +2.7V to +3.6V (MAX1299), external reference, V
REF
= +2.5V (MAX1298), V
REF
= +1.2V
(MAX1299), f
SCLK
= 2.5MHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Figures 4, 6)
PARAMETER
SCLK Frequency
SCLK Pulse Width Low
SCLK Pulse Width High
CS
Low to SCLK High
SCLK High to
CS
Setup
CS
Pulse Width
SCLK High to
CS
Low Setup
SCLK High to
CS
High Setup
DIN Setup to SCLK High Time
DIN Hold Time
SCLK Fall to Output Data Valid
CS
Fall to Output Enable
CS
Rise to Output Disable
SSTRB Rise to SCLK Rise
SCLK Fall to SSTRB Fall
SYMBOL
f
SCLK
t
CL
t
CH
t
CSS
t
CSH
t
CS
t
CS0
t
CS1
t
DS
t
DH
t
DO
t
DV
t
TR
t
SCLK
t
SSTRB
R
L
= 100kΩ, C
L
= 50pF
R
L
= 100kΩ, C
L
= 50pF
R
L
= 100kΩ, C
L
= 50pF
0
200
CONDITIONS
MIN
200
200
100
100
100
50
100
100
0
150
150
50
TYP
MAX
2.5
UNITS
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
MAX1298/MAX1299
Note 1:
Tested at V
DD
= +5.0V (MAX1298) and V
DD
= +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.
_______________________________________________________________________________________
5