AD590JRZ Analog Devices Inc, AD590JRZ Datasheet - Page 11

• Manufacturer Part Number: AD590JRZ
• Description: IC,TEMPERATURE SENSOR,BIPOLAR/JFET,SOP,8PIN,PLASTIC
• Manufacturer: Analog Devices Inc

Specifications of AD590JRZ

• Rohs Compliant: YES
• Sensing Temperature: -55°C ~ 150°C
• Output Type: Current
• Voltage - Supply: 4 V ~ 30 V
• Accuracy: ±5°C
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Ic Output Type: Current
• Supply Voltage Range: 4V To 30V
• Resolution (bits): 8bit
• Sensor Case Style: SOIC
• No. Of Pins: 8
• Peak Reflow Compatible (260 C): Yes
• Supply Voltage Max: 30V
• Supply Voltage Min: 4V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 20 is an example of a current transmitter designed to be
used with 40 V, 1 kΩ systems; it uses its full current range of 4
to 20 mA for a narrow span of measured temperatures. In this
example, the 1 μA/K output of the AD590 is amplified to
1 mA/°C and offset so that 4 mA is equivalent to 17°C and
20 mA is equivalent to 33°C. R
at an intermediate reference temperature. With a suitable choice
of resistors, any temperature range within the operating limits
of the AD590 can be chosen.
Figure 21 is an example of a variable temperature control circuit
(thermostat) using the AD590. R
high and low limits for R
calibrated multiturn pot, or a switched resistive divider. Powering
the AD590 from the 10 V reference isolates the AD590 from
supply variations while maintaining a reasonable voltage (~7 V)
across it. Capacitor C1 is often needed to filter extraneous noise
from remote sensors. R
transistor and the current requirements of the load.
Figure 22 shows that the AD590 can be configured with an 8-bit
DAC to produce a digitally controlled setpoint. This particular
circuit operates from 0°C (all inputs high) to 51.0°C (all inputs
low) in 0.2°C steps. The comparator is shown with 1.0°C
hysteresis, which is usually necessary to guard-band for extraneous
noise. Omitting the 5.1 MΩ resistor results in no hysteresis.
V+
V–
4mA = 17°C
12mA = 25°C
20mA = 33°C
0.01µF
AD581
OUT
AD590
R
SET
R
R
H
L
Figure 21. Simple Temperature Control Circuit
Figure 20. 4 to 20 mA Current Transmitter
AD590
+
–
10V
10kΩ
+
–
C1
AD581
V
OUT
B
+
–
is determined by the β of the power
SET
10kΩ
2
3
. R
–
+
35.7kΩ
12.7kΩ
LM311
SET
T
5kΩ
10Ω
R
7
4
is trimmed for proper reading
H
could be a simple pot, a
T
V–
V+
and R
1
GND
R
V+
B
–
+
AD707A
L
are selected to set the
30pF
5kΩ
500Ω
HEATING
ELEMENTS
Rev. E | Page 11 of 16
The voltage compliance and the reverse blocking characteristic
of the AD590 allow it to be powered directly from 5 V CMOS
logic. This permits easy multiplexing, switching, or pulsing for
minimum internal heat dissipation. In Figure 23, any AD590
connected to a logic high passes a signal current through the
current measuring circuitry, while those connected to a logic
zero pass insignificant current. The outputs used to drive the
AD590s can be employed for other purposes, but the additional
capacitance due to the AD590 should be taken into account.
–15V
DAC OUT
+
–
6.98kΩ
1kΩ, 15T
AD590
BIT 1
BIT 2
BIT 3
BIT 4
–15V
Figure 23. AD590 Driven from CMOS Logic
GATES
CMOS
5V
3
2
6.8kΩ
1408/1508
LM311
–15V
Figure 22. DAC Setpoint
+5V
20pF
4
MC
8
1
+
–
7
+5V
1kΩ
5.1MΩ
OUTPUT HIGH-
TEMPERATURE ABOVE SETPOINT
OUTPUT LOW-
TEMPERATURE BELOW SETPOINT
+
–
1kΩ
REF
+5V
BIT 8
BIT 7
BIT 6
BIT 5
+
–
(0.1%)
1.25kΩ
+
–
1.15kΩ
200Ω
200Ω, 15T
+2.5V
AD590
+5V
AD580
AD590