AD680ANZ Analog Devices Inc, AD680ANZ Datasheet - Page 10
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AD680ANZ
Manufacturer Part Number
AD680ANZ
Description
IC VREF PREC 2.5V LP 8-DIP
Manufacturer
Analog Devices Inc
Type
Voltage Referencer
Specifications of AD680ANZ
Temperature Coefficient
20ppm/°C
Reference Type
Series
Voltage - Output
2.5V
Tolerance
±0.2%
Voltage - Input
4.5 ~ 36 V
Number Of Channels
1
Current - Quiescent
250µA
Current - Output
50mA
Operating Temperature
-40°C ~ 85°C
Mounting Type
Through Hole
Package / Case
8-DIP (0.300", 7.62mm)
Topology
Series
Input Voltage
4.5V To 36V
Reference Voltage
2.5V
Reference Voltage Tolerance
5mV
Voltage Reference Case Style
DIP
No. Of Pins
8
Current, Output
0 to 10 mA
Current, Supply
195 μA
Package Type
PDIP-8
Power Dissipation
1 mW
Regulation, Line
40 μV/V
Regulation, Load
80 μV/mA
Regulator Type
Switching
Temperature, Operating, Range
-40 to +85 °C
Voltage, Input
5 V
Voltage, Noise
8 μVp-p
Voltage, Output
2.5 V
Voltage, Supply
4.5 to 5 V
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Current - Cathode
-
Lead Free Status / Rohs Status
RoHS Compliant part
Electrostatic Device
AD680
4.5 V REFERENCE FROM A 5 V SUPPLY
The AD680 can be used to provide a low power, 4.5 V reference,
as shown in Figure 19. In addition to the AD680, the circuit
uses a low power op amp and a transistor in a feedback con-
figuration that provides a regulated 4.5 V output for a power
supply voltage as low as 4.7 V. The high quality tantalum 10 μF
capacitor (C1) in parallel with the ceramic 0.1 μF capacitor (C2)
and the 3.9 Ω resistor (R5) ensure a low output impedance up to
approximately 50 MHz (see Figure 19).
0.1μF
Figure 19. 4.5 V Reference Running from a Single 5 V Supply
AD680
GND
V
IN
V
2.5kΩ
OUT
1%
R2
+IN
–IN
3
2
2kΩ
1%
R1
1kΩ
R3
OP90
7
4
3.3μF
V+
V–
0.1μF
CC
CF
6
OUT
R4
3.57kΩ
2N2907A
+
3.9Ω
R5
4.7V TO 15V
C1
10μF
C2
0.1μF
Rev. H | Page 10 of 12
VOLTAGE REGULATOR FOR PORTABLE
EQUIPMENT
The AD680 is ideal for providing a stable, low cost, low power
reference voltage in portable equipment power supplies.
Figure 20 shows how the AD680 can be used in a voltage
regulator that not only has low output noise (as compared to a
switch mode design) and low power, but it also has a very fast
recovery after current surges. Some caution should be taken in
the selection of the output capacitors. Too high an ESR (effective
series resistance) could endanger the stability of the circuit. A solid
tantalum capacitor, 16 V or higher, and an aluminum electro-
lytic capacitor, 10 V or higher, are recommended for C1 and C2,
respectively. Also, the path from the ground side of C1 and C2
to the ground side of R1 should be kept as short as possible.
CHARGER
LEAD-ACID
BATTERY
INPUT
6V
+
Figure 20. Voltage Regulator for Portable Equipment
0.1μF
AD680
GND
V
TEMP
2
4
V
IN
OUT
6
3
R1
402kΩ 1%
2
3
OP777
–
+
7
4
402kΩ 1%
R2
6
510kΩ
R3
IRF9530
+
C1
68μF
TANT
+
C2
1000μF
ELECT