1.2 V Ultralow Power
High PSRR Voltage Reference
ADR280
FEATURES
1.2 V precision output
Excellent line regulation: 2 ppm/V typical
High power supply ripple rejection: –80 dB at 220 Hz
Ultralow power supply current: 16 μA maximum
Temperature coefficient: 40 ppm/°C maximum
Low noise, 12.5 nV/√Hz typical
Operating supply range, 2.4 V to 5.5 V
Compact 3-lead SOT-23 and SC70 packages
PIN CONFIGURATIONS
V+
1
ADR280
V
OUT 2
3
V–
03065-001
Figure 1. 3-Lead SOT-23
(RT Suffix)
V
OUT 1
APPLICATIONS
List GSM, GPRS, 3G mobile stations
Portable battery-operated electronics
Low voltage converter references
Wireless devices
ADR280
V+
2
3
V–
03065-002
GENERAL DESCRIPTION
The ADR280 is a 1.2 V band gap core reference with excellent
line regulation and power supply rejection designed specifically
for applications experiencing heavy dynamic supply variations,
such as data converter references in GSM, GPRS, and 3G
mobile station applications. Devices such as the AD6535 that
have an analog baseband IC with on-board baseband, audio
codecs, voltage regulators, and battery chargers rely on the
ability of the ADR280 to reject input battery voltage variations
during RF power amplifier activity.
In addition to mobile stations, the ADR280 is suitable for a
variety of general-purpose applications. Most band gap refer-
ences include internal gain for specific outputs, which simplifies
the user’s design, but compromises on the cost, form factor, and
flexibility. The ADR280, on the other hand, optimizes the band
gap core voltage and allows users to tailor the voltage, current,
or transient response by simply adding their preferred op amps.
The ADR280 operates on a wide supply voltage range from
2.4 V to 5.5 V. It is available in compact 3-lead SOT-23 and
SC70 packages. The device is specified over the extended indus-
trial temperature range of −40°C to +85°C.
15
Figure 2. 3-Lead SC70
(KS Suffix)
10
LINE REGULATION (ppm/V)
5
3V TO 5V
0
–5
–10
–20
0
20
40
TEMPERATURE (°C)
60
80
100
Figure 3. Line Regulation vs. Temperature
Rev. C
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113 ©2002–2007 Analog Devices, Inc. All rights reserved.
03065-003
–15
–40
ADR280
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
General Description ......................................................................... 1
Pin Configurations ........................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Electrical Characteristics............................................................. 3
Absolute Maximum Ratings............................................................ 4
Thermal Resistance .......................................................................4
ESD Caution...................................................................................4
Typical Performance Characteristics ..............................................5
Theory of Operation .........................................................................7
Applications Information .................................................................8
Low Cost, Low Power Current Source .......................................8
Outline Dimensions ....................................................................... 10
Ordering Guide .......................................................................... 11
REVISION HISTORY
4/07—Rev.
B to Rev. C
Updated Format..................................................................Universal
Changes to Figure 1, Figure 2.......................................................... 1
Deleted Pin Function Descriptions Section and Pin
Configurations Section .................................................................... 2
Changes to Figure 20 and Figure 21............................................... 9
Updated Outline Dimensions ....................................................... 10
10/04—Rev. A to Rev. B
Changes to Pin Configurations.........................................Universal
Changes to Ordering Guide ............................................................ 2
Changes to Outline Dimensions..................................................... 7
6/03—Rev. 0 to Rev. A
Added SC70 package..........................................................Universal
Changes to Features ..........................................................................1
Changes to General Description .....................................................1
Changes to Specifications.................................................................2
Changes to Ordering Guide .............................................................2
Changes to TPCs 4, 6, and 7 ............................................................3
Updated SOT-23 Outline Dimensions ...........................................7
11/02—Revision 0: Initial Version
Rev. C | Page 2 of 12
ADR280
SPECIFICATIONS
ELECTRICAL CHARACTERISTICS
V
IN
= 2.55 V to 5.5 V, T
A
= 25°C, unless otherwise noted.
Table 1.
Parameter
Output Voltage
Temperature Coefficient
Line Regulation
Supply Current
Ground Current
Input Voltage Range
Operating Temperature Range
Nominal Load Capacitance
Output Noise Voltage
Voltage Noise Density
Power Supply Ripple Rejection
2
Start-Up Time
1
2
Symbol
V
OUT
TCV
O
ΔV
OUT
/ΔV
IN
I
IN
I
GND
V
IN
T
A
C
OUT
V
N
rms
e
N
PSRR
t
ON
Conditions
2.4 V < V
IN
< 5.5 V, 0 μA < I
OUT
< 10 μA, −40°C < T
A
< +85°C
0°C < T
A
< 50°C
–40°C < T
A
< +85°C
2.55 V < V
IN
< 5.5 V, no load
2.4 V < V
IN
< 5.5 V, no load
V– grounded, I
LOAD
= 10 μA
Min
1.195
Typ
1
1.200
5
10
2
10
12
2.4
−40
1
f = 10 Hz to 10 kHz
f = 400 kHz
I
LOAD
= 10 μA
12.5
12.5
−80
2
Max
1.205
20
40
12
16
20
5.5
+85
Unit
V
ppm/°C
ppm/°C
ppm/V
μA
μA
V
°C
μF
μV rms
nV/√Hz
dB
ms
Typical values represent average readings taken at room temperature.
Power supply ripple rejection measurement applies to a changing input voltage (V
IN
) waveform with a nominal 3.6 V baseline that drops to a 3 V value for 380 μs at a
4.6 ms repetition rate.
Rev. C | Page 3 of 12
ADR280
ABSOLUTE MAXIMUM RATINGS
T
A
= 25°C, unless otherwise noted.
Table 2.
Parameter
Supply Voltage
Storage Temperature Range
Operating Temperature Range
Junction Temperature Range
Lead Temperature Range (Soldering, 60 Sec)
Rating
6V
−65°C to +150°C
−40°C to +85°C
−65°C to +150°C
300°C
THERMAL RESISTANCE
θ
JA
is specified for the worst-case conditions, that is, θ
JA
is
specified for a device soldered in circuit board for surface-
mount packages.
Table 3.
Package Type
SOT-23
SC70
θ
JA
230
376
θ
JC
146
102
Unit
°C/W
°C/W
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
ESD CAUTION
Rev. C | Page 4 of 12
ADR280
TYPICAL PERFORMANCE CHARACTERISTICS
15
1.20225
1.20200
1.20175
V
OUT
(V)
10
LINE REGULATION (ppm/V)
NO LOAD
5
3V TO 5V
0
1.20150
1.20125
1.20100
1.20075
1.20050
1.20025
03065-006
–5
–10
–20
0
20
40
60
TEMPERATURE (°C)
80
100
–20
0
20
40
TEMPERATURE (°C)
60
80
100
Figure 4. V
OUT
vs. Temperature
15
Figure 6. Line Regulation vs. Temperature
14
13
V
IN
= 5V
I
IN
(µA)
12
V
IN
= 3V
11
1
10
03065-009
–20
0
20
40
60
TEMPERATURE (°C)
80
100
03065-007
9
–40
CH1
50.0µV
M 1.00s
Figure 5. Supply Current vs. Temperature
Figure 7. Noise Voltage Peak-to-Peak, 10 Hz to 10 kHz
Rev. C | Page 5 of 12
03065-008
1.20000
–40
–15
–40
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