Datasheet

Detailed Description
The MAX6576/MAX6577 low-cost, low-current (140μA
typ) temperature sensors are ideal for interfacing with
microcontrollers (μCs) or microprocessors (μPs). The
MAX6576 converts ambient temperature into a 50%
dutycycle square wave with a period proportional to
absolute temperature. The MAX6577 converts ambient
temperature into a 50% duty-cycle square wave with a
frequency proportional to absolute temperature. Time-
select pins (TS1, TS0) permit the internal temperature-
controlled oscillator (TCO) to be scaled by four preset
multipliers. The MAX6576/MAX6577 feature a single-wire
interface to minimize the number of port pins necessary
for interfacing with a μP.
MAX6576 Characteristics
The MAX6576 temperature sensor converts temperature
to period. The output of the device is a free-running, 50%
duty-cycle square wave with a period that is proportional
to the absolute temperature (°K) of the device (Figure 1).
The MAX6576 has a push/pull CMOS output with sharp
edges. The speed of the output square wave can be
selected by hard-wiring TS1 and TS0 as shown in Table 1.
One of four scaled output periods can be selected using
TS1 and TS0.
MAX6577 Characteristics
The MAX6577 temperature sensor converts temperature
to frequency. The output of the device is a free-running,
50% duty-cycle square wave with a frequency that is pro-
portional to the absolute temperature (°K) of the device
(Figure 2). The MAX6577 has a push/pull CMOS output
with sharp edges. The speed of the output square wave
can be selected by hard-wiring TS1 and TS0 as shown
in Table 2. One of four scaled output frequencies can be
selected using TS1 and TS0.
Table 1. MAX6576 Time-Select Pin
Configuration
Table 2. MAX6577 Time-Select Pin
Configuration
PIN NAME FUNCTION
1 V
DD
Positive Supply Voltage
2 GND Ground
3
N.C.
No Connection. Connect pin to GND or leave open.
4, 5 TS1, TS0
Time-Select Pins. TS1 and TS0 set the temperature scale factor by connecting TS1 and TS0 to either V
DD
or GND. See Tables 1 and 2.
6 OUT
Square-Wave Output with a Clock Period Proportional to Absolute Temperature (°K) (MAX6576)
Square-Wave Output with a Clock Frequency Proportional to Absolute Temperature (°K) (MAX6577)
TS1 TS0 SCALAR MULTIPLIER (μs/°K)
GND GND 10
GND V
DD
40
V
DD
GND 160
V
DD
V
DD
640
TS1 TS0 SCALAR MULTIPLIER (Hz/°K)
GND GND 4
GND V
DD
1
V
DD
GND 1/4
V
DD
V
DD
1/16
Note: The temperature, in °C, may be calculated as follows:
PERIOD(µs)
T( C) 273.15 K
SCALAR MULTIPLIER(µs/ K)
°= − °
°
FREQUENCY(µs)
T( C) 273.15 K
SCALAR MULTIPLIER(µs/ K)
°= − °
°
Note: The temperature, in °C, may be calculated as follows:
MAX6576/MAX6577 SOT Temperature Sensors with
Period/Frequency Output
www.maximintegrated.com
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Pin Description