TMP05 datasheet(16/28 Pages) AD

16 / 28 page

TMP05/TMP06

Rev. 0 | Page 16 of 28

START

PULSE

#1 TEMP MEASUREMENT

#2 TEMP MEASUREMENT

#N TEMP MEASUREMENT

TIME

Figure 28. Daisy-Chain Signal at Input to the Microcontroller

Before the start pulse reaches a TMP05/TMP06 part in the

daisy chain, the device acts as a buffer for the previous tempera-

ture measurement signals. Each part monitors the PWM signal

for the start pulse from the previous part. Once the part detects

the start pulse, it initiates a conversion and inserts the result at

the end of the daisy-chain PWM signal. It then inserts a start

pulse for the next part in the link. The final signal input to the

microcontroller should look like Figure 28. The input signal on

Pin 2 (IN) of the first daisy-chain device must remain low until

the last device has output its start pulse.

If the input on Pin 2 (IN) goes high and remains high, the

TMP05/TMP06 part powers down between 0.3 s and 1.2 s later.

The part, therefore, requires another start pulse to generate

another temperature measurement. Note that, to reduce power

dissipation through the part, it is recommended to keep Pin 2

(IN) at a high state when the part is not converting. If the IN

pin is at 0 V, then the OUT pin is at 0 V (because it is acting as a

buffer when not converting), and drawing current through

either the pull-up MOSFET (TMP05) or the pull-up resistor

(TMP06).

TMP05 OUTPUT

The TMP05 has a push-pull CMOS output (Figure 29) and

provides rail-to-rail output drive for logic interfaces. The rise

and fall times of the TMP05 output are closely matched, so that

errors caused by capacitive loading are minimized. If load

capacitance is large (for example, when driving a long cable), an

external buffer might improve accuracy.

An internal resistor is connected in series with the pull-up

MOSFET when the TMP05 is operating in one shot mode.

TMP05

V+

OUT

Figure 29. TMP05 Digital Output Structure

TMP06 OUTPUT

The TMP06 has an open-drain output. Because the output

source current is set by the pull-up resistor, output capacitance

should be minimized in TMP06 applications. Otherwise,

unequal rise and fall times skew the pulse width and introduce

measurement errors.

OUT

TMP06

Figure 30. TMP06 Digital Output Structure

TMP05 Datenblatt(PDF) 16 Page - Analog Devices

TMP05 Datenblatt(HTML) 16 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Datenblatt Download

Link URL