19-1712; Rev 1; 4/00
Dual Trip SOT Temperature Switches
General Description
The MAX6505–MAX6508 temperature switches have dual
logic outputs that assert when the die temperature cross-
es their trip thresholds. Trip thresholds are factory pro-
grammed to convenient temperatures in 5°C increments.
The MAX6505/MAX6506 have an ALARM output that
asserts when the temperature is above the factory-pro-
grammed thresholds (available from -40°C to +125°C).
They also have a WARN output that asserts when the
temperature is several degrees below the ALARM thresh-
old. The difference between the ALARM and WARN
thresholds (∆T
AW
) is pin selectable to +5°C, +10°C,
+20°C, or +30°C. The MAX6505’s logic outputs are open
drain, while the MAX6506’s logic outputs are push-pull.
The MAX6507 has open-drain outputs (OVER, OK), and
the MAX6508 has push-pull outputs (OVER,
OK),
each
with two factory-programmed threshold temperatures
(TOVER and TUNDER) in the wide range of -40°C to
+125°C. The overtemperature output asserts when the
temperature is above TOVER. When the temperature is in
the desired window (less than TOVER and greater than
TUNDER), OK (OK) asserts.
The MAX6505–MAX6508 are accurate to ±0.5°C (typ),
±5.5°C (max). Operating from a +2.5V to +5.5V supply,
these low-cost devices typically consume 30µA supply
current and require no external components for setting
trip points. The MAX6505–MAX6508 are available in a 6-
pin SOT23 package.
Features
♦
±0.5°C (typ) Threshold Accuracy Over Full
Temperature Range
♦
No External Components Required
♦
Low Cost
♦
30µA (typ) Supply Current
♦
Factory-Programmed Thresholds from -40°C to
+125°C in 5°C Increments
♦
Open-Drain Outputs (MAX6505/MAX6507),
Push-Pull Outputs (MAX6506/MAX6508)
♦
Pin Selectable +2°C, +10°C Hysteresis
(MAX6507/MAX6508)
♦
Pin Selectable +5°C, +10°C, +20°C, +30°C
T
ALARM
- T
WARN
(MAX6505/MAX6506)
♦
SOT23-6 Package
MAX6505–MAX6508
Ordering Information
PART
MAX6505UT_
_ _ _-T*
MAX6506UT_
_ _ _-T*
MAX6507UT_
_ _ _-T**
MAX6508UT_
_ _ _-T**
TEMP. RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-
PACKAGE
6 SOT23-6
6 SOT23-6
6 SOT23-6
6 SOT23-6
________________________Applications
µP Temperature Monitoring in High-Speed
Computers
Temperature Control
Temperature Alarms
Fan Control
*To complete the suffix information for the MAX6505/
MAX6506, add P or N for positive or negative trip tempera-
ture, and select an available trip point in degrees centigrade.
For example, the MAX6505UTP055-T describes a MAX6505 in
a SOT23-6 package with a +55°C threshold (Table 3). Contact
the factory for pricing and availability of temperature versions
(minimum order 10,000 pieces).
**To complete the suffix information for MAX6507/MAX6508,
see Table 4.
Selector Guide appears at end of data sheet.
Typical Operating Circuits appear at end of data sheet.
Pin Configurations
TOP VIEW
WARN
1
(WARN)
6
ALARM
(ALARM)
OK
1
(OK)
6
OVER
(OVER)
GND
2
MAX6505
MAX6506
5
S0
GND
2
MAX6507
MAX6508
5
N.C.
S1
3
( ) ARE FOR MAX6506.
4
V
CC
S0
3
4
V
CC
( ) ARE FOR MAX6508.
SOT23-6
SOT23-6
________________________________________________________________
Maxim Integrated Products
1
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
Dual Trip SOT Temperature Switches
MAX6505–MAX6508
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
CC
to GND) ..................................-0.3V to +6V
S1, S0 to GND ............................................-0.3V to (V
CC
+ 0.3V)
All Other Pins to GND.................................-0.3V to (V
CC
+ 0.3V)
Input/Output Current, All Pins...........................................±20mA
Continuous Power Dissipation (T
A
= +70°C)
6-Pin SOT23 (derate 7.1mW/°C above +70°C)...........571mW
Operating Temperature Range
(T
MIN
to T
MAX
) ..............................................-40°C to +125°C
Thermal Resistance (Θ
JA
)..............................................115°C/W
Storage Temperature Range .............................-65°C to +150°C
Maximum Die Temperature..............................................+150°C
Lead Temperature (soldering, 10s) .................................+300°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
CC
= +2.5V to +5.5V, R
PULLUP
= 100kΩ (MAX6505/MAX6507 only), T
A
= -40°C to +125°C, unless otherwise noted. Typical values
are at T
A
= +25°C and V
CC
= +5V, unless otherwise noted.) (Note 1)
PARAMETER
Supply Voltage Range
SYMBOL
V
CC
S0 = S1 = GND
Supply Current
I
CC
S0 = GND
Temperature Threshold
Accuracy (Note 2)
-40°C to 0
°
C
∆T
TH
0°C to +95
°
C
+95°C to +125
°
C
S1 = GND, S0 = GND
Delta Temperature
(T
ALARM
-T
WARNING
)
MAX6505/MAX6506
∆T
AW
S1 = GND, S0 = V
CC
S1 = V
CC
, S0 = GND
S1 = V
CC
, S0 = V
CC
ALARM (MAX6505/MAX6506)
WARN
(MAX6505/MAX6506)
T
HYST
OK, OVER
(MAX6507/MAX6508)
V
IH
V
IL
Output Voltage High
(MAX6506/MAX6508)
I
SOURCE
= 500µA, V
CC
> 2.5V
V
OH
I
SOURCE
= 800µA,V
CC
> 4.5V
Output Voltage Low
V
OL
I
SINK
= 3.2mA, V
CC
> 2.5V
I
SINK
= 5mA, V
CC
> 4.5V
0.8 x
V
CC
V
CC
-1.5
0.5
0.5
V
∆T
AW
= 5°C or
10°C
∆T
AW
= 20°C or
30°C
S0 = GND
S0 = V
CC
Logic Input Levels (S1, S0)
0.8 x
V
CC
0.8
MAX6505/
MAX6506
MAX6507/
MAX6508
-5.5
-3.5
-4
CONDITIONS
MIN
2.5
40
30
±0.5
±0.5
±0.5
5
10
20
30
2
5
10
2
10
V
°C
°C
TYP
MAX
5.5
80
µA
60
5.5
3.5
4
°C
UNITS
V
Temperature Threshold
Hysteresis (Note 3)
V
2
_______________________________________________________________________________________
Dual Trip SOT Temperature Switches
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +2.5V to +5.5V, R
PULLUP
= 100kΩ (MAX6505/MAX6507 only), T
A
= -40°C to +125°C, unless otherwise noted. Typical values
are at T
A
= +25°C and V
CC
= +5V, unless otherwise noted.) (Note 1)
PARAMETER
Open-Drain Output Leakage
Current
SYMBOL
CONDITIONS
V
CC
= 5.5V, V
ALARM
= 5.5V,
V
WARN
= 5.5V (MAX6505)
V
CC
= 5.5V, V
OK
= 5.5V,
V
OVER
= 5.5V (MAX6507)
MIN
TYP
MAX
1
µA
1
UNITS
MAX6505–MAX6508
Note 1:
100% production tested at T
A
= +25°C. Specifications over temperature limits are guaranteed by design.
Note 2:
T
ALARM
, T
UNDER
, and T
OVER
are factory-programmed temperature trip thresholds from -40°C to +125°C in 5°C increments.
Note 3:
Temperature threshold hysteresis is defined as the difference from positive-going temperature thresholds minus the nega-
tive-going temperature thresholds.
Typical Operating Characteristics
(V
CC
= +5V, unless otherwise noted.)
SUPPLY CURRENT
vs. TEMPERATURE
V
CC
= +5V
R
PULLUP
= 100kΩ
MAX6505/8-01
HYSTERESIS vs. TRIP TEMPERATURE
V
CC
= +5V
R
PULLUP
= 100kΩ
MAX6505/8-02
TRIP-POINT ERROR (%)
vs. SUPPLY VOLTAGE
0
TRIP-POINT ERROR (%)
-0.1
-0.2
-0.3
-0.4
-0.5
-0.6
-0.7
NORMALIZED TO TRIP-POINT
TEMPERATURE AT V
CC
= +5V
2.5
3.0
3.5
4.0
4.5
5.0
5.5
MAX6505/8-03
50
45
SUPPLY CURRENT (µA)
40
35
30
25
20
2.5
0.1
2.0
HYSTERESIS (°C)
1.5
1.0
0.5
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
-0.8
SUPPLY VOLTAGE (V)
MAX6505
STARTUP AND POWER-DOWN
(T < T
TH
)
MAX6505/8-04
MAX6505
STARTUP DELAY
(T > T
TH
)
MAX6505/8-05
A
2V/div
A
2V/div
B
B
100µs/div
A: V
CC
PULSE
B: ALARM VOLTAGE, R
PULLUP
= 100kΩ
100µs/div
A: V
CC
PULSE
B: ALARM VOLTAGE, R
PULLUP
= 100kΩ
_______________________________________________________________________________________
3
Dual Trip SOT Temperature Switches
MAX6505–MAX6508
Pin Description
PIN
MAX6505
MAX6506
MAX6507
MAX6508
WARN
Open-Drain Active-Low Warning Output.
WARN
goes low
when the die temperature exceeds T
WARN
= T
ALARM
-
∆T
AW.
Push-Pull Active-High Warning Output. WARN goes high
when the die temperature exceeds T
WARN
= T
ALARM
-
∆T
AW.
Ground
Delta Temperature Select Input. Connect to V
CC
or GND to
select the difference between T
ALARM
and T
WARN
(Table
1 or see
Electrical Characteristics).
Hysteresis Select Input. Connect to V
CC
for 10°C
hysteresis. Connect to GND for 2°C hysteresis.
Supply Voltage Input. Bypass V
CC
to GND with a 0.1µF
ceramic capacitor.
No Connection. Not internally connected.
Open-Drain Active-Low Overtemperature Output.
OVER
goes low when the die temperature exceeds the factory-
set value of T
OVER
.
Push-Pull Active-High Overtemperature Output. OVER
goes high when the die temperature exceeds the factory-
set value of T
OVER.
Open-Drain Active-High Temperature Sensor Output. OK
goes high impedance when the die temperature is
between the factory-set values of T
OVER
and T
UNDER
.
When the die temperature is above T
OVER
or below
T
UNDER
, OK goes low.
Push-Pull Active-Low Temperature Sensor Output.
OK
goes low when the die temperature is between the factory-
set values of T
OVER
and T
UNDER
. When the die temp-
erature is above T
OVER
or below T
UNDER
,
OK
goes high.
Open-Drain Active-Low Alarm Output.
ALARM
goes low
when the die temperature exceeds the factory-set value of
T
ALARM
.
Push-Pull Active-High Alarm Output. ALARM goes high
when the die temperature exceeds the factory-set value of
T
ALARM
.
NAME
FUNCTION
1
-—
-—
-—
2
3, 5
1
2
3, 5
-—
2
-—
-—
2
-—
WARN
GND
S1, S0
-—
4
-—
-—
-—
4
-—
-—
3
4
5
6
3
4
5
-—
S0
V
CC
N.C.
OVER
-—
-—
_
6
OVER
-—
-—
1
-—
OK
-—
-—
-—
1
OK
6
-—
-—
-—
ALARM
-—
6
-—
-—
ALARM
4
_______________________________________________________________________________________
Dual Trip SOT Temperature Switches
_______________Detailed Description
The MAX6505–MAX6508 fully integrated temperature
switches incorporate two temperature-dependent refer-
ences and a comparator. One reference exhibits a pos-
itive temperature coefficient and the other a negative
temperature coefficient. The temperature at which the
two reference voltages are equal determines the tem-
perature trip point. There are two versions, each of
which has two logic outputs.
The MAX6505/MAX6506 have a main trip point (T
ALARM
)
and a lower, “warning” trip point (T
WARN
). When the die
temperature rises above these trip points, the ALARM
and WARN outputs are asserted (Figure 1). The differ-
ence between the two trip points (∆T
AW
) is pin selec-
table to +5°C, +10°C, +20°C, or +30°C by connecting
the two control pins (S0 and S1) high or low (Table 1).
MAX6505 has open-drain active-low outputs; MAX6506
has push-pull active-high outputs.
The MAX6507/MAX6508 have two factory-programmed
threshold temperatures (T
OVER
and T
UNDER
) and two
outputs (OK and OVER). One output (OK) asserts
when the temperature is between T
OVER
and T
UNDER
.
The other output (OVER) asserts when the temperature
is above T
OVER
. Table 4 shows the hex codes to deter-
mine the part numbers associated with specific values
of T
OVER
and T
UNDER
. The first hex code indicates the
lower trip point (T
UNDER
) and the second indicates the
higher trip point (T
OVER
). For example, a part with T
UN-
DER
= -10°C and T
OVER
= +75°C will have the part
number MAX6508UTA04B (Table 4 and Figure 2).
MAX6507 has open-drain outputs; MAX6508 has push-
pull outputs.
Table 1. MAX6505/MAX6506
∆T
AW
Selection Table
CONTROL PINS
S0
GND
GND
V
CC
V
CC
S1
GND
V
CC
GND
V
CC
DESCRIPTION
∆T
AW
=T
ALARM
– T
WARN
(°C)
5
10
20
30
MAX6505–MAX6508
HYSTERESIS
≈
2°C
65°C
55°C
HYSTERESIS
≈
5°C
WARN
ALARM
Figure 1. Temperature Response—MAX6505UTP065 Outputs,
∆T
AW
= 10°C, and WARN Hysteresis
≈
5°C
Hysteresis Selection
The temperature threshold hysteresis for the ALARM
output of the MAX6505/MAX6506 is 2°C. The hysteresis
for the WARN output depends on the value of
∆T
AW
. If
∆T
AW
is 5°C or 10°C (set by S0 and S1), WARN hys-
teresis is 5°C. If
∆T
AW
is 20°C or 30°C, WARN hystere-
sis is 10°C. MAX6507 and MAX6508 have pin-selectable
hysteresis of 2°C or 10°C for both OVER and OK out-
puts (Table 2).
Applications Information
Thermal Considerations
The MAX6505–MAX6508 supply current is typically
30µA. When used to drive high-impedance loads, the
devices dissipate negligible power. Therefore, the die
temperature is essentially the same as the package
temperature. The key to accurate temperature monitor-
ing is good thermal contact between the MAX6505–
MAX6508 package and the device being monitored. In
some applications, the SOT23-6 packages may be
small enough to fit underneath a socketed micro-
processor (µP), allowing the device to monitor the µP’s
temperature directly. Use the monitor’s output to reset
the µP, assert an interrupt, or trigger an external alarm.
Accurate temperature monitoring depends on the ther-
mal resistance between the device being monitored
and the MAX6505–MAX6508 die.
The rise in die temperature due to self-heating is given
by the following formula:
∆T
J
= P
DISSIPATION
✕
θ
JA
where P
DISSIPATION
is the power dissipated by the
MAX6505–MAX6508, and
θ
JA
is the package’s thermal
resistance. The typical thermal resistance is +115°C/W
for the SOT23-6 package. To limit the effects of self-heat-
ing, minimize the output currents. For example, if the
MAX6505 sinks 5mA, the output voltage is guaranteed to
be less than 0.5V. Therefore, an additional 2.5mW of
5
_______________________________________________________________________________________
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