AD ADP3330ART-5 High accuracy ultralow iq, 200 ma, sot-23, anycap low dropout regulator Datasheet

High Accuracy Ultralow IQ,
200 mA, SOT-23, anyCAP™
Low Dropout Regulator
ADP3330
a
FEATURES
High Accuracy Over Line and Load: 60.7% @ +258C,
61.4% Over Temperature
Ultralow Dropout Voltage: 140 mV (Typ) @ 200 mA
Requires Only CO = 0.47 mF for Stability
anyCAP = Stable with Any Type of Capacitor
(Including MLCC)
Current and Thermal Limiting
Low Noise
Low Shutdown Current: <2 mA
2.9 V to 12 V Supply Range
–408C to +858C Ambient Temperature Range
Ultrasmall Thermally Enhanced Chip-on-Lead™
SOT-23-6 6-Lead Package
FUNCTIONAL BLOCK DIAGRAM
Q1
IN
OUT
ADP3330
THERMAL
PROTECTION
R1
CC
ERR
gm
DRIVER
R2
SD
BANDGAP
REF
GND
APPLICATIONS
Cellular Telephones
Notebook, Palmtop Computers
Battery Powered Systems
PCMCIA Regulator
Bar Code Scanners
Camcorders, Cameras
GENERAL DESCRIPTION
The ADP3330 is a member of the ADP330x family of precision
low dropout anyCAP voltage regulators. The ADP3330 operates
with an input voltage range of 2.9 V to 12 V and delivers a load
current up to 200 mA. The ADP3330 stands out from the conventional LDOs with a novel architecture and an enhanced
process that enables it to offer performance advantages and
higher output current than its competition. Its patented design
requires only a 0.47 µF output capacitor for stability. This
device is insensitive to output capacitor Equivalent Series
Resistance (ESR), and is stable with any good quality capacitor, including ceramic (MLCC) types for space-restricted
applications. The ADP3330 achieves exceptional accuracy of
± 0.7% at room temperature and ± 1.4% over temperature, line
and load variations. The dropout voltage of the ADP3330 is
only 140 mV (typical) at 200 mA. This device also includes a
safety current limit, thermal overload protection and a shutdown
feature. In shutdown mode, the ground current is reduced to
less than 2 µA. The ADP3330 has ultralow quiescent current
34 µA (typ) in light load situations.
The SOT-23-6 package has been thermally enhanced using
Analog Devices’ proprietary Chip-on-Lead feature to maximize
power dissipation.
ERR
NR
ADP3330
VIN
IN
CIN
0.47mF
+
–
OUT
SD
GND
VOUT
+
–
C OUT
0.47mF
ON
OFF
Figure 1. Typical Application Circuit
anyCAP and Chip-on-Lead are trademarks of Analog Devices, Inc.
REV. A
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 1999
ADP3330-xx–SPECIFICATIONS
(@ TA = –408C to +858C, VIN = +7 V, CIN = 0.47 mF, COUT = 0.47 mF,
unless otherwise noted).1, 2 The following specifications apply to all voltage options except –2.5.
Parameter
Symbol
Conditions
OUTPUT VOLTAGE ACCURACY
VOUT
VIN = VOUTNOM +0.25 V to +12 V
IL = 0.1 mA to 200 mA
TA = +25°C
VIN = VOUTNOM +0.25 V to +12 V
IL = 0.1 mA to 150 mA
TA = –40°C to +85°C
VIN = VOUTNOM +0.25 V to +12 V
IL = 0.1 mA to 200 mA
TA = –20°C to +85°C
Min
Typ
Max
Units
–0.7
+0.7
%
–1.4
+1.4
%
–1.4
+1.4
%
∆V O
∆V IN
∆VO
∆I L
VIN = VOUTNOM +0.25 V to +12 V
TA = +25°C
0.04
mV/V
IL = 0.1 mA to 200 mA
TA = +25°C
0.04
mV/mA
GROUND CURRENT
IGND
IL = 200 mA, TA = –20°C to +85°C
IL = 150 mA
IL = 50 mA
IL = 0.1 mA
1.6
1.2
0.4
34
4.0
3.1
1.1
50
mA
mA
mA
µA
GROUND CURRENT IN DROPOUT
IGND
VIN = VOUTNOM – 100 mV
IL = 0.1 mA
37
55
µA
VOUT = 98% of VOUTNOM
IL = 200 mA, TA = –20°C to +85°C
IL = 150 mA
IL = 10 mA
IL = 1 mA
0.14
0.11
0.042
0.025
0.23
0.17
0.06
0.052
V
V
V
V
ILDPK
VIN = VOUTNOM + 1 V
300
mA
VNOISE
f = 10 Hz–100 kHz, CL = 10 µF
IL = 200 mA, CNR = 10 nF, VOUT = 3 V
f = 10 Hz–100 kHz, CL = 10 µF
IL = 200 mA, CNR = 0 nF, VOUT = 3 V
47
µV rms
95
µV rms
LINE REGULATION
LOAD REGULATION
DROPOUT VOLTAGE
PEAK LOAD CURRENT
OUTPUT NOISE
3
SHUTDOWN THRESHOLD
VDROP
VTHSD
ON
OFF
2.0
0.4
V
V
SHUTDOWN PIN INPUT CURRENT
ISD
VIN = 12 V, 0 < SD, ≤ 12 V
0 < SD, ≤ 5 V
1.9
1.4
9
6
µA
µA
GROUND CURRENT IN SHUTDOWN
MODE
IGNDSD
SD = 0 V, VIN = 12 V
0.01
2
µA
OUTPUT CURRENT IN SHUTDOWN
MODE
IOSD
TA = +25°C @ VIN = 12 V
TA = +85°C @ VIN = 12 V
1
2
µA
µA
ERROR PIN OUTPUT LEAKAGE
IEL
VEO = 5 V
1
µA
ERROR PIN OUTPUT “LOW”
VOLTAGE
VEOL
ISINK = 400 µA
0.40
V
0.19
NOTES
1
Ambient temperature of +85°C corresponds to a junction temperature of +125°C under typical full load test conditions.
2
Application stable with no load.
3
See detail in Figure 19 and Application section of data sheet.
Specifications subject to change without notice.
–2–
REV. A
ADP3330
ADP3330-2.5–SPECIFICATIONS
unless otherwise noted).1, 2
(@ TA = –408C to +858C, VIN = +7 V ,CIN = 0.47 mF, COUT = 0.47 mF,
Parameter
Symbol
Conditions
OUTPUT VOLTAGE ACCURACY
VOUT
VIN = +2.9 V to +12 V
IL = 0.1 mA to 200 mA
TA = +25°C
VIN = +2.9 V to +12 V
IL = 0.1 mA to 150 mA
TA = –40°C to +85°C
VIN = +2.9 V to +12 V
IL = 0.1 mA to 200 mA
TA = –20°C to +85°C
Min
Typ
Max
Units
–0.7
+0.7
%
–1.4
+1.4
%
–1.4
+1.4
%
∆V O
∆V IN
∆VO
∆I L
VIN = +2.9 V to +12 V
TA = +25°C
0.04
mV/V
IL = 0.1 mA to 200 mA
TA = +25°C
0.04
mV/mA
GROUND CURRENT
IGND
IL = 200 mA, TA = –20°C to +85°C
IL = 150 mA
IL = 50 mA
IL = 0.1 mA
1.6
1.2
0.4
34
4.0
3.1
1.1
50
mA
mA
mA
µA
GROUND CURRENT IN DROPOUT
IGND
VIN = VOUTNOM – 100 mV
IL = 0.1 mA
37
55
µA
VOUT = 98% of VOUTNOM
IL = 200 mA, TA = –20°C to +85°C
IL = 150 mA
IL = 10 mA
IL = 1 mA
0.14
0.11
0.042
0.025
0.4
0.3
0.06
0.052
V
V
V
V
ILDPK
VIN = VOUTNOM + 1 V
300
mA
VNOISE
f = 10 Hz–100 kHz, CL = 10 µF
IL = 200 mA, CNR = 10 nF, VOUT = 3 V
f = 10 Hz–100 kHz, CL = 10 µF
IL = 200 mA, CNR = 0 nF, VOUT = 3 V
47
µV rms
95
µV rms
LINE REGULATION
LOAD REGULATION
DROPOUT VOLTAGE
PEAK LOAD CURRENT
OUTPUT NOISE
3
SHUTDOWN THRESHOLD
VDROP
VTHSD
ON
OFF
2.0
0.4
V
V
SHUTDOWN PIN INPUT CURRENT
ISD
VIN = 12 V, 0 < SD, ≤ 12 V
0 < SD, ≤ 5 V
1.9
1.4
9
6
µA
µA
GROUND CURRENT IN SHUTDOWN
MODE
IGNDSD
SD = 0 V, VIN = 12 V
0.01
2
µA
OUTPUT CURRENT IN SHUTDOWN
MODE
IOSD
TA = +25°C @ VIN = 12 V
TA = +85°C @ VIN = 12 V
1
2
µA
µA
ERROR PIN OUTPUT LEAKAGE
IEL
VEO = 5 V
1
µA
ERROR PIN OUTPUT “LOW”
VOLTAGE
VEOL
ISINK = 400 µA
0.40
V
NOTES
1
Ambient temperature of +85°C corresponds to a junction temperature of +125°C under typical full load test conditions.
2
Application stable with no load.
3
See detail in Figure 19 and Application section of data sheet.
Specifications subject to change without notice.
REV. A
–3–
0.19
ADP3330
PIN FUNCTION DESCRIPTIONS
ABSOLUTE MAXIMUM RATINGS*
Input Supply Voltage . . . . . . . . . . . . . . . . . . . . –0.3 V to +16 V
Shutdown Input Voltage . . . . . . . . . . . . . . . . . –0.3 V to +16 V
Power Dissipation . . . . . . . . . . . . . . . . . . . . Internally Limited
Operating Ambient Temperature Range . . . . . –40°C to +85°C
Operating Junction Temperature Range . . . . –40°C to +125°C
θJA (4-Layer Board) . . . . . . . . . . . . . . . . . . . . . . . +165°C/W
θJA (2-Layer Board) . . . . . . . . . . . . . . . . . . . . . . . +190°C/W
Storage Temperature Range . . . . . . . . . . . . . –65°C to +150°C
Lead Temperature Range (Soldering 10 sec) . . . . . . . . +300°C
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . . +215°C
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . +220°C
Pin
Name
Function
1
OUT
2
3
IN
ERR
4
5
GND
NR
6
SD
Output of the Regulator. Bypass to ground
with a 0.47 µF or larger capacitor.
Regulator Input.
Open Collector Output that goes low to
indicate that the output is about to go out
of regulation.
Ground Pin.
Noise Reduction Pin. Used for further
reduction of output noise (see text for
detail). No connection if not used.
Active Low Shutdown Pin. Connect to
ground to disable the regulator output.
When shutdown is not used, this pin
should be connected to the input pin.
*This is a stress rating only; operation beyond these limits can cause the device to
be permanently damaged.
ORDERING GUIDE
Model
Voltage
Output
Package
Option*
Marking
Code
ADP3330ART-2.5
ADP3330ART-2.75
ADP3330ART-2.85
ADP3330ART-3
ADP3330ART-3.3
ADP3330ART-3.6
ADP3330ART-5
2.5 V
2.75 V
2.85 V
3.0 V
3.3 V
3.6 V
5.0 V
RT-6 (SOT-23-6)
RT-6 (SOT-23-6)
RT-6 (SOT-23-6)
RT-6 (SOT-23-6)
RT-6 (SOT-23-6)
RT-6 (SOT-23-6)
RT-6 (SOT-23-6)
L1B
L2B
L3B
L4B
L5B
L6B
L8B
PIN CONFIGURATION
OUT
1
IN 2
ADP3330
6
SD
5
NR
TOP VIEW
ERR 3 (Not to Scale) 4 GND
*Contact the factory for the availability of other output voltage options.
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the ADP3330 features proprietary ESD protection circuitry, permanent damage may
occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD
precautions are recommended to avoid performance degradation or loss of functionality.
–4–
WARNING!
ESD SENSITIVE DEVICE
REV. A
Typical Performance Characteristics–ADP3330
3.010
IL = 0mA
3.004
IL = 10mA
3.002
IL = 50mA
3.000
IL = 100mA
2.998
IL = 150mA
2.996
2.994
3.003
40
IL = 100mA
GROUND CURRENT – mA
3.006
VOUT = 3V
VOUT = 3.0V
VIN = 7V
3.004
OUTPUT VOLTAGE – Volts
OUTPUT VOLTAGE – Volts
3.008
45
3.005
VOUT = 3.0V
3.002
3.001
3.000
2.999
2.998
2.997
2.992
6
7
8
9
10
INPUT VOLTAGE – Volts
11
12
Figure 2. Line Regulation Output
Voltage vs. Supply Voltage
0
25
Figure 3. Output Voltage vs. Load
Current
IL = 0mA
1.0
0.8
0.6
0.4
IL = 50mA
0.2
IL = 150mA
0.1
IL = 200mA
0.0
GROUND CURRENT – mA
0.3
OUTPUT VOLTAGE – %
GROUND CURRENT – mA
1.4
0.2
50
100
150
OUTPUT LOAD – mA
–0.1
–45 –25 –5 15 35 55 75 95 115 135
JUNCTION TEMPERATURE – 8C
200
Figure 5. Ground Current vs. Load
Current
Figure 6. Output Voltage Variation %
vs. Junction Temperature
0
2
4
6
8
10
INPUT VOLTAGE – Volts
12
3.0
VIN = 7V
2.8
IL = 200mA
2.6
2.4
2.2
IL = 150mA
2.0
1.8
IL = 100mA
1.6
1.4
1.2
1.0
0.8
0.6
0.4 IL = 50mA
0.2
IL = 0mA
0
–45 –25 –5 15 35 55 75 95 115 135
JUNCTION TEMPERATURE – 8C
Figure 7. Ground Current vs. Junction
Temperature
3.5
150
100
50
0
25
50
75 100 125 150 175 200
OUTPUT LOAD – mA
Figure 8. Dropout Voltage vs.
Output Current
REV. A
CL = 0.47mF
VOUT – Volts
200
VOUT = 3V
SD = VIN
RL = 15V
3.0
2.5
2.0
3
2
0
1.0
10
0.5
0
0
1.0
2.0
3.0
TIME – Sec
4.0
5.0
Figure 9. Power-Up/Power-Down
–5–
CL = 10mF
1
1.5
VIN – Volts
INPUT/OUTPUT VOLTAGE – Volts
250
INPUT/OUTPUT VOLTAGE – mV
10
Figure 4. Ground Current vs. Supply
Voltage
0.4
1.2
0
15
50 75 100 125 150 175 200
OUTPUT LOAD – mA
VIN = 7V
0
20
0
2.994
1.6
0
25
5
2.995
5
IL = 0mA
30
2.996
IL = 200mA
2.990
3.25 4
35
VIN = 7V
VOUT = 3V
SD = VIN
RL = 15V
5
0
0
100
200
300
TIME – ms
400
500
Figure 10. Power-Up Response
ADP3330
3.100
3.020
VOUT = 3V
RL = 15V
CL = 0.47mF
2.980
3.000
VOUT = 3V
RL = 15V
CL = 10mF
2.980
3.000
2.940
2.940
200
7.0
100
200
300
TIME – ms
400
3.050
20mA
0
100
200
300
TIME – ms
400
500
3
0
0
2
400
IOUT
mA
200
0
VERR 3
0
2
100
100
20mA
VSD
VIN = 7V
0
0
0
200
400
600
800
0
1000
TIME – ms
Figure 14. Load Transient Response
400
600
TIME – ms
RMS NOISE – mV
–60
CL = 0.47mF
CNR = 0
CL = 10mF
IL = 200mA
–70
IL = 200mA
100
80
60
IL = 0mA
IL = 200mA
WITH NOISE REDUCTION
40
–80
CL = 10mF
IL = 0.1mA
–90
100
1k
10k
100k
FREQUENCY – Hz
20
1M
10M
Figure 17. Power Supply Ripple
Rejection
0
0
1000
1
120
CL = 0.47mF
IL = 200mA
800
Figure 16. Turn On–Turn Off Response
VOLTAGE NOISE SPECTRAL
DENSITY – mV/ Hz
CL = 0.47mF
IL = 0.1mA
–30
–100
10
200
140
–20
–50
0
160
VOUT = 3.0V
–10
–40
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
TIME – Sec
Figure 15. Short Circuit Current
0
1000
1
300
200
800
VIN = 7V
VOUT = 3V
CL = 10mF
RL = 15V
3
VOUT
2.900
0
600
VOUT
Volts
2.950
400
Figure 13. Load Transient Response
500
VIN = 7V
VOUT = 3V
CL = 10mF
200
TIME – ms
Figure 12. Line Transient Response
3.000
RIPPLE REJECTION – dB
100
7.0
0
Volts
3.100
mA
7.5
500
Figure 11. Line Transient Response
mA
2.900
VIN – Volts
2.960
7.5
VIN = 7V
VOUT = 3V
CL = 0.47mF
2.950
2.960
0
Volts
3.050
Volts
VOUT – Volts
3.000
VIN – Volts
VOUT – Volts
3.020
CL = 10mF
CNR = 0
CL = 0.47mF
CNR = 10nF
0.1
CL = 10mF
CNR = 10nF
VOUT = 3.0V
IL = 200mA
IL = 0mA WITH NOISE REDUCTION
10
20
30
CL – mF
40
Figure 18. RMS Noise vs. CL
(10 Hz–100 kHz)
–6–
50
0.01
10
100
1k
10k
FREQUENCY – Hz
100k
1M
Figure 19. Output Noise Density
REV. A
ADP3330
THEORY OF OPERATION
The patented amplifier controls a new and unique noninverting
driver that drives the pass transistor, Q1. The use of this special
noninverting driver enables the frequency compensation to
include the load capacitor in a pole splitting arrangement to
achieve reduced sensitivity to the value, type and ESR of the
load capacitance.
The new anyCAP LDO ADP3330 uses a single control loop for
regulation and reference functions. The output voltage is sensed
by a resistive voltage divider consisting of R1 and R2 which is
varied to provide the available output voltage options. Feedback
is taken from this network by way of a series diode (D1) and a
second resistor divider (R3 and R4) to the input of an amplifier.
INPUT
Most LDOs place strict requirements on the range of ESR
values for the output capacitor because they are difficult to
stabilize due to the uncertainty of load capacitance and resistance. Moreover, the ESR value, required to keep conventional
LDOs stable, changes depending on load and temperature.
These ESR limitations make designing with LDOs more
difficult because of their unclear specifications and extreme
variations over temperature.
OUTPUT
COMPENSATION
ATTENUATION R1
CAPACITOR
(VBANDGAP/VOUT)
Q1
NONINVERTING
WIDEBAND
DRIVER
gm
R3
PTAT
VOS
D1
(a)
R4
PTAT
CURRENT
CLOAD
RLOAD
R2
With the ADP3330 anyCAP LDO, this is no longer true. It
can be used with virtually any good quality capacitor, with no
constraint on the minimum ESR. The innovative design allows
the circuit to be stable with just a small 0.47 µF capacitor on the
output. Additional advantages of the pole splitting scheme
include superior line noise rejection and very high regulator gain
which leads to excellent line and load regulation. An impressive
± 1.4% accuracy is guaranteed over line, load and temperature.
ADP3330
GND
Figure 20.␣ Functional Block Diagram
A very high gain error amplifier is used to control this loop.
The amplifier is constructed in such a way that at equilibrium it
produces a large, temperature-proportional input “offset voltage”
that is repeatable and very well controlled. The temperatureproportional offset voltage is combined with the complementary
diode voltage to form a “virtual bandgap” voltage, implicit in
the network, although it never appears explicitly in the circuit.
Ultimately, this patented design makes it possible to control the
loop with only one amplifier. This technique also improves the
noise characteristics of the amplifier by providing more flexibility on the tradeoff of noise sources that leads to a low noise
design.
Additional features of the circuit include current limit, thermal
shutdown and noise reduction. Compared to standard solutions
that give warning after the output has lost regulation, the
ADP3330 provides improved system performance by enabling the
ERR pin to give warning just before the device loses regulation.
As the chip’s temperature rises above +165°C, the circuit
activates a soft thermal shutdown, indicated by a signal low on
the ERR pin, to reduce the current to a safe level.
The R1, R2 divider is chosen in the same ratio as the bandgap
voltage to the output voltage. Although the R1, R2 resistor
divider is loaded by the diode D1, and a second divider consisting of R3 and R4, the values are chosen to produce a temperature stable output. This unique arrangement specifically
corrects for the loading of the divider so that the error resulting
from base current loading in conventional circuits is avoided.
REV. A
–7–
ADP3330
APPLICATION INFORMATION
Capacitor Selection
Output Capacitors: as with any micropower device, output
transient response is a function of the output capacitance. The
ADP3330 is stable with a wide range of capacitor values, types
and ESR (anyCAP). A capacitor as low as 0.47 µF is all that is
needed for stability; larger capacitors can be used if high output
current surges are anticipated. The ADP3330 is stable with
extremely low ESR capacitors (ESR ≈ 0), such as Multilayer
Ceramic Capacitors (MLCC) or OSCON. Note that the
effective capacitance of some capacitor types may fall below the
minimum at cold temperature. Ensure that the capacitor
provides more than 0.47 µF at minimum temperature.
SILICON
DIE
a. Normal SOT-23-6 Package
SILICON DIE WITH
ELECTRICALLY
ISOLATED
DIE ATTACH
Input Bypass Capacitor: an input bypass capacitor is not strictly
required but it is advisable in any application involving long
input wires or high source impedance. Connecting a 0.47 µF
capacitor from IN to ground reduces the circuit’s sensitivity to
PC board layout. If a larger value output capacitor is used, then
a larger value input capacitor is also recommended.
b. Thermally Enhanced Chip-on-Lead Package
Figure 22.
Thermal Overload Protection
Noise Reduction
The ADP3330 is protected against damage due to excessive
power dissipation by its thermal overload protection circuit
which limits the die temperature to a maximum of +165°C.
Under extreme conditions (i.e., high ambient temperature and
power dissipation) where die temperature starts to rise above
+165°C, the output current is reduced until the die temperature
has dropped to a safe level. The output current is restored when
the die temperature is reduced.
A noise reduction capacitor (CNR) can be used to further reduce
the noise by 6 dB–10 dB (Figure 21). Low leakage capacitors in
10 pF–500 pF range provide the best performance. Since the
noise reduction pin (NR) is internally connected to a high impedance node, any connection to this node should be carefully done
to avoid noise pickup from external sources. The pad connected
to this pin should be as small as possible and long PC board
traces are not recommended.
Current and thermal limit protections are intended to protect
the device against accidental overload conditions. For normal
operation, device power dissipation should be externally limited
so that junction temperatures will not exceed +125°C.
When adding a noise reduction capacitor, use the following
guidelines:
• Maintain a minimum load current of 1 mA when not in
shutdown.
Calculating Junction Temperature
• For CNR values greater than 500 pF, add a 100 kΩ series
resistor (RNR).
Device power dissipation is calculated as follows:
It is important to note that as CNR increases, the turn-on time
will be delayed. With CNR values greater than 1 nF, this delay
may be on the order of several milliseconds.
Where ILOAD and IGND are load current and ground current, VIN
and VOUT are input and output voltages respectively.
PD = (V IN – VOUT) ILOAD +(VIN) IGND
Assuming ILOAD = 200 mA, IGND = 4 mA, VIN = 4.2 V and
VOUT = 3.0 V, device power dissipation is:
NR
VIN
IN
C1 +
0.47mF –
OUT
R1
ERR
SD
PD = (4.2 – 3) 200 mA + 4.2 (4 mA) = 257 mW
CNR
RNR
ADP3330-3
330kV
The proprietary package used in the ADP3330 has a thermal
resistance of 165°C/W, significantly lower than a standard
6-lead SOT-23 package. Assuming a 4-layer board, the junction
temperature rise above ambient temperature will be approximately equal to:
VOUT = +3.3V
+ C2
– 0.47mF
GND
∆TJA = 0.257 W × 165°C/W = 42.4°C
Figure 21.␣ Noise Reduction Circuit
To limit the maximum junction temperature to +125°C,
maximum allowable ambient temperature will be:
Chip-on-Lead Package
The ADP3330 uses a patented Chip-on-Lead package design to
ensure the best thermal performance in an SOT-23 footprint. In
a standard SOT-23, the majority of the heat flows out of the
ground pin. This new package uses an electrically isolated die
attach that allows all pins to contribute to heat conduction.
This technique reduces the thermal resistance to 190°C/W on a
2-layer board as compared to >230°C/W for a standard SOT-23
leadframe. Figure 22 shows the difference between the standard
SOT-23 and the Chip-on-Lead leadframes.
TA MAX = 125°C – 42.4°C = 82.6°C
–8–
REV. A
ADP3330
Printed Circuit Board Layout Considerations
Low Power, Low Dropout Applications
All surface mount packages rely on the traces of the PC board
to conduct heat away from the package.
ADP3330 is well suited for applications such as cellular phone
handsets that require low quiescent current and low dropout
voltage features. ADP3330 draws 34 µA typical under light load
situations (i.e., load current = 100 µA), which results in low
power consumption when the cell phone is in standby mode.
In standard packages the dominant component of the heat
resistance path is the plastic between the die attach pad and the
individual leads. In typical thermally enhanced packages one or
more of the leads are fused to the die attach pad, significantly
decreasing this component. To make the improvement meaningful, however, a significant copper area on the PCB must be
attached to these fused pins.
Figure 23 shows an application in which the ADP3330 is used
in a handset to provide 2.75 V nominal output voltage. The cell
phone is powered from 3 cell NiCd or 1 cell Li-Ion battery.
ADP3330 guarantees an accuracy of 1.4%, even when the input/
output differential is merely 250 mV (worst case). This implies
that the output is regulated and within specification even when
the battery voltage has reached its end-of-discharge voltage of
3 V. The output voltage never falls below 2.7 V, even under
worst case load and temperature conditions. The low dropout
feature coupled with the high accuracy of the ADP3330 ensures
that the system is reliably powered until the end of the life of the
battery, which results in increased system talk time.
The patented chip-on-lead frame design of the ADP3330
uniformly minimizes the value of the dominant portion of the
thermal resistance. It ensures that heat is conducted away by all
pins of the package. This yields a very low 165°C/W thermal
resistance for an SOT-23-6 package, without any special board
layout requirements, just relying on the normal traces connected to the leads. This yields a 17% improvement in heat
dissipation capability as compared to a standard SOT-23-6
package. The thermal resistance can be decreased by, approximately, an additional 10% by attaching a few square cm of
copper area to the VIN pin of the ADP3303 package.
MINIMUM BATTERY
VOLTAGE 3.0V
It is not recommended to use solder mask or silkscreen on the
PCB traces adjacent to the ADP3330’s pins since it will increase
the junction to ambient thermal resistance of the package.
250mV MAXIMUM INPUT-OUTPUT
OVERHEAD FOR 200mA OUTPUT
CURRENT
Error Flag Dropout Detector
NOMINAL OUTPUT
VOLTAGE 2.75V
The ADP3330 will maintain its output voltage over a wide
range of load, input voltage and temperature conditions. If the
output is about to lose regulation by reducing the supply voltage
below the combined regulated output and dropout voltages,
the ERR flag will be activated. The ERR output is an open
collector, which will be driven low.
–1.4% OUTPUT
VOLTAGE ACCURACY
2.712V
ABSOLUTE MINIMUM
OUTPUT VOLTAGE
2.700V
Once set, the ERR flag’s hysteresis will keep the output low
until a small margin of operating range is restored either by
raising the supply voltage or reducing the load.
12mV TRANSIENT, LINE AND
LOAD RESPECTIVE MARGIN
Figure 23.␣ LDO Budgeting for a 3 Cell NiCd/1 Cell
Li-Ion Supply
Shutdown Mode
Applying a TTL high signal to the shutdown (SD) pin, or tying
it to the input pin, will turn the output ON. Pulling SD down to
0.4 V or below, or tying it to ground, will turn the output OFF.
In shutdown mode, quiescent current is reduced to much less
than 1 µA.
REV. A
END OF DISCHARGE VOLTAGE
OF 3 CELL NiCd OR 1 CELL
Li-Ion BATTERY
–9–
ADP3330
APPLICATION CIRCUITS
Crossover Switch
Higher Output Current
The circuit in Figure 24 shows how two ADP3330s can be used to
form a mixed supply voltage system. The output switches between
two different levels selected by an external digital input. Output
voltages can be any combination of voltages from the Ordering
Guide of the data sheet.
The ADP3330 can source up to 200 mA at room temperature
without any heatsink or pass transistor. If higher current is
needed, an appropriate pass transistor can be used, as in Figure
25, to increase the output current to 1 A.
C1
100mF
VIN = 3.85V TO 12V
IN
VOUT = 3.6V/2.5V
OUT
MJE253*
VIN = 4.5V TO 8V
IN
ADP3330-3.6
OUTPUT SELECT
3V
0V
VOUT = 3V@1A
R1
50V
OUT
+
SD
ADP3330-3
GND
SD
C2
100mF
ERR
GND
C1+
1.0mF
OUT
IN
ADP3330-2.5
+
C2
0.47mF
*AAVID531002 HEAT SINK IS USED
Figure 25.␣ High Output Current Linear Regulator
LOGIC SUPPLY
SD
GND
Figure 24.␣ Crossover Switch
–10–
REV. A
ADP3330
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
C3455a–0–8/99
6-Lead Surface Mount
RT-6 (SOT-23-6)
0.122 (3.10)
0.106 (2.70)
0.071 (1.80)
0.059 (1.50)
6
5
4
1
2
3
0.118 (3.00)
0.098 (2.50)
PIN 1
0.037 (0.95) BSC
0.075 (1.90)
BSC
0.051 (1.30)
0.035 (0.90)
0.020 (0.50) SEATING
0.010 (0.25) PLANE
10°
0.009 (0.23) 0°
0.003 (0.08)
0.022 (0.55)
0.014 (0.35)
PRINTED IN U.S.A.
0.059 (0.15)
0.000 (0.00)
0.057 (1.45)
0.035 (0.90)
REV. A
–11–
–12–
PRINTED IN U.S.A.
C3455a–0–8/99