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FEATURES High Accuracy Over Line and Load: 0.7% @ +25 C, 1.4% Over Temperature Ultralow Dropout Voltage: 140 mV (Typ) @ 200 mA Requires Only CO = 0.47 F for Stability anyCAP = Stable with Any Type of Capacitor (Including MLCC) Current and Thermal Limiting Low Noise Low Shutdown Current: <2 A 2.9 V to 12 V Supply Range -40 C to +85 C Ambient Temperature Range Ultrasmall Thermally Enhanced Chip-on-LeadTM SOT-23-6 6-Lead Package APPLICATIONS Cellular Telephones Notebook, Palmtop Computers Battery Powered Systems PCMCIA Regulator Bar Code Scanners Camcorders, Cameras
IN ERR
High Accuracy Ultralow IQ, 200 mA, SOT-23, anyCAPTM Low Dropout Regulator ADP3330
FUNCTIONAL BLOCK DIAGRAM
Q1 THERMAL PROTECTION OUT
ADP3330
CC gm
R1
DRIVER SD
R2 BANDGAP REF
GND
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 F 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 A. The ADP3330 has ultralow quiescent current 34 A (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 CIN 0.47 F + - IN SD OUT GND ON OFF + - VOUT C OUT 0.47 F
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 (c) Analog Devices, Inc., 1999
(@ TA = -40 C to +85 C, VIN = +7 V, CIN = 0.47 F, COUT = 0.47 F, unless otherwise noted).1, 2 The following specifications apply to all voltage options except -2.5.
Parameter OUTPUT VOLTAGE ACCURACY Symbol VOUT Conditions VIN = VOUTNOM +0.25 V to +12 V IL = 0.1 mA to 200 mA TA = +25C VIN = VOUTNOM +0.25 V to +12 V IL = 0.1 mA to 150 mA TA = -40C to +85C VIN = VOUTNOM +0.25 V to +12 V IL = 0.1 mA to 200 mA TA = -20C to +85C VIN = VOUTNOM +0.25 V to +12 V TA = +25C IL = 0.1 mA to 200 mA TA = +25C IL = 200 mA, TA = -20C to +85C IL = 150 mA IL = 50 mA IL = 0.1 mA VIN = VOUTNOM - 100 mV IL = 0.1 mA VOUT = 98% of VOUTNOM IL = 200 mA, TA = -20C to +85C IL = 150 mA IL = 10 mA IL = 1 mA VIN = VOUTNOM + 1 V f = 10 Hz-100 kHz, CL = 10 F IL = 200 mA, CNR = 10 nF, VOUT = 3 V f = 10 Hz-100 kHz, CL = 10 F IL = 200 mA, CNR = 0 nF, VOUT = 3 V ON OFF VIN = 12 V, 0 < SD, 12 V 0 < SD, 5 V SD = 0 V, VIN = 12 V TA = +25C @ VIN = 12 V TA = +85C @ VIN = 12 V VEO = 5 V ISINK = 400 A 0.19 2.0 0.4 1.9 1.4 0.01 9 6 2 1 2 1 0.40 Min Typ Max Units
ADP3330-xx-SPECIFICATIONS
-0.7
+0.7
%
-1.4
+1.4
%
-1.4 0.04 0.04 1.6 1.2 0.4 34 37 0.14 0.11 0.042 0.025 300 47 95
+1.4
% mV/V mV/mA
LINE REGULATION LOAD REGULATION GROUND CURRENT
V O V IN VO I L
IGND
4.0 3.1 1.1 50 55 0.23 0.17 0.06 0.052
mA mA mA A A V V V V mA V rms V rms V V A A A A A A V
GROUND CURRENT IN DROPOUT DROPOUT VOLTAGE
IGND VDROP
PEAK LOAD CURRENT OUTPUT NOISE
3
ILDPK VNOISE
SHUTDOWN THRESHOLD SHUTDOWN PIN INPUT CURRENT GROUND CURRENT IN SHUTDOWN MODE OUTPUT CURRENT IN SHUTDOWN MODE ERROR PIN OUTPUT LEAKAGE ERROR PIN OUTPUT "LOW" VOLTAGE
VTHSD ISD
IGNDSD IOSD IEL VEOL
NOTES 1 Ambient temperature of +85C corresponds to a junction temperature of +125C 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
unless otherwise noted).1, 2
Parameter OUTPUT VOLTAGE ACCURACY
ADP3330-2.5-SPECIFICATIONS
Symbol VOUT
(@ TA = -40 C to +85 C, VIN = +7 V ,CIN = 0.47 F, COUT = 0.47 F,
Min Typ Max Units
Conditions VIN = +2.9 V to +12 V IL = 0.1 mA to 200 mA TA = +25C VIN = +2.9 V to +12 V IL = 0.1 mA to 150 mA TA = -40C to +85C VIN = +2.9 V to +12 V IL = 0.1 mA to 200 mA TA = -20C to +85C VIN = +2.9 V to +12 V TA = +25C IL = 0.1 mA to 200 mA TA = +25C IL = 200 mA, TA = -20C to +85C IL = 150 mA IL = 50 mA IL = 0.1 mA VIN = VOUTNOM - 100 mV IL = 0.1 mA VOUT = 98% of VOUTNOM IL = 200 mA, TA = -20C to +85C IL = 150 mA IL = 10 mA IL = 1 mA VIN = VOUTNOM + 1 V f = 10 Hz-100 kHz, CL = 10 F IL = 200 mA, CNR = 10 nF, VOUT = 3 V f = 10 Hz-100 kHz, CL = 10 F IL = 200 mA, CNR = 0 nF, VOUT = 3 V ON OFF VIN = 12 V, 0 < SD, 12 V 0 < SD, 5 V SD = 0 V, VIN = 12 V TA = +25C @ VIN = 12 V TA = +85C @ VIN = 12 V VEO = 5 V ISINK = 400 A
-0.7
+0.7
%
-1.4
+1.4
%
-1.4 0.04 0.04 1.6 1.2 0.4 34 37 0.14 0.11 0.042 0.025 300 47 95 2.0
+1.4
% mV/V mV/mA
LINE REGULATION LOAD REGULATION GROUND CURRENT
V O V IN VO I L
IGND
4.0 3.1 1.1 50 55 0.4 0.3 0.06 0.052
mA mA mA A A V V V V mA V rms V rms
GROUND CURRENT IN DROPOUT DROPOUT VOLTAGE
IGND VDROP
PEAK LOAD CURRENT OUTPUT NOISE
3
ILDPK VNOISE
SHUTDOWN THRESHOLD SHUTDOWN PIN INPUT CURRENT GROUND CURRENT IN SHUTDOWN MODE OUTPUT CURRENT IN SHUTDOWN MODE ERROR PIN OUTPUT LEAKAGE ERROR PIN OUTPUT "LOW" VOLTAGE
VTHSD ISD
0.4 1.9 1.4 0.01 9 6 2 1 2 1 0.19 0.40
V V A A A A A A V
IGNDSD IOSD IEL VEOL
NOTES 1 Ambient temperature of +85C corresponds to a junction temperature of +125C 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-
ADP3330
ABSOLUTE MAXIMUM RATINGS* PIN FUNCTION DESCRIPTIONS
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 . . . . . -40C to +85C Operating Junction Temperature Range . . . . -40C to +125C JA (4-Layer Board) . . . . . . . . . . . . . . . . . . . . . . . +165C/W JA (2-Layer Board) . . . . . . . . . . . . . . . . . . . . . . . +190C/W Storage Temperature Range . . . . . . . . . . . . . -65C to +150C Lead Temperature Range (Soldering 10 sec) . . . . . . . . +300C Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . . +215C Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . +220C
*This is a stress rating only; operation beyond these limits can cause the device to be permanently damaged.
Pin 1 2 3
Name OUT IN ERR
Function Output of the Regulator. Bypass to ground with a 0.47 F 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.
PIN CONFIGURATION
4 5
GND NR
ORDERING GUIDE
6 Marking Code L1B L2B L3B L4B L5B L6B L8B
SD
Model ADP3330ART-2.5 ADP3330ART-2.75 ADP3330ART-2.85 ADP3330ART-3 ADP3330ART-3.3 ADP3330ART-3.6 ADP3330ART-5
Voltage Output 2.5 V 2.75 V 2.85 V 3.0 V 3.3 V 3.6 V 5.0 V
Package Option* 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)
OUT
1
ADP3330
6 5
SD NR
TOP VIEW ERR 3 (Not to Scale) 4 GND
IN 2
*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.
WARNING!
ESD SENSITIVE DEVICE
-4-
REV. A
Typical Performance Characteristics-ADP3330
3.010 3.008 VOUT = 3.0V
3.005 3.004
OUTPUT VOLTAGE - Volts
45
VOUT = 3.0V VIN = 7V
GROUND CURRENT - A
VOUT = 3V 40 IL = 100 A 35 30 25 20 15 10 5 0 IL = 0 A
OUTPUT VOLTAGE - Volts
3.006 3.004 3.002 3.000 2.998 2.996 2.994 2.992 2.990 3.25 4 5 6 7 8 9 10 INPUT VOLTAGE - Volts 11 12 IL = 0mA IL = 10mA IL = 50mA IL = 100mA IL = 150mA
3.003 3.002 3.001 3.000 2.999 2.998 2.997 2.996 2.995 2.994 0 25 50 75 100 125 150 175 200 OUTPUT LOAD - mA
IL = 200mA
0
2
4 6 8 10 INPUT VOLTAGE - Volts
12
Figure 2. Line Regulation Output Voltage vs. Supply Voltage
Figure 3. Output Voltage vs. Load Current
Figure 4. Ground Current vs. Supply Voltage
1.6 VIN = 7V 1.4
0.4 IL = 0mA
GROUND CURRENT - mA
GROUND CURRENT - mA
1.0 0.8 0.6 0.4 0.2 0 0 50 100 150 OUTPUT LOAD - mA 200
OUTPUT VOLTAGE - %
1.2
0.3
IL = 50mA
0.2 IL = 150mA 0.1 IL = 200mA 0.0
-0.1 -45 -25 -5 15 35 55 75 95 115 135 JUNCTION TEMPERATURE - C
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 - C
Figure 5. Ground Current vs. Load Current
Figure 6. Output Voltage Variation % vs. Junction Temperature
Figure 7. Ground Current vs. Junction Temperature
250 INPUT/OUTPUT VOLTAGE - Volts
3.5 3.0 2.5 2.0 1.5 VIN - Volts 1.0 0.5 0 0 1.0 2.0 3.0 TIME - Sec 4.0 5.0 VOUT - Volts VOUT = 3V SD = VIN RL = 15 CL = 0.47 F 3 2 1 0 10 5 0 0 100 200 300 TIME - s 400 500 CL = 10 F VIN = 7V VOUT = 3V SD = VIN RL = 15
INPUT/OUTPUT VOLTAGE - mV
200
150
100
50
0
0
25
50 75 100 125 150 175 200 OUTPUT LOAD - mA
Figure 8. Dropout Voltage vs. Output Current
Figure 9. Power-Up/Power-Down
Figure 10. Power-Up Response
REV. A
-5-
ADP3330
3.100 3.020 3.020 3.050
VOUT - Volts
VOUT - Volts
3.000 2.980 2.960 2.940 VOUT = 3V RL = 15 CL = 0.47 F
3.000 2.980 2.960 2.940 VOUT = 3V RL = 15 CL = 10 F
Volts
3.000 2.950 2.900 200 VIN = 7V VOUT = 3V CL = 0.47 F
VIN - Volts
VIN - Volts
mA
7.5 7.0 0 100 200 300 TIME - s 400 500
7.5 7.0 0 100 200 300 TIME - s 400 500
100 20mA 0
0
200
400
600
800
1000
TIME - s
Figure 11. Line Transient Response
Figure 12. Line Transient Response
Figure 13. Load Transient Response
Volts
3.100 3.050
Volts
3 0 500
VOUT
3 2 VOUT 1
IOUT
Volts
3.000 2.950 2.900 200 VIN = 7V VOUT = 3V CL = 10 F
mA
VIN = 7V VOUT = 3V CL = 10 F RL = 15
400 300 200 100
0 VERR 3 0 2
mA
100 20mA 0
VIN = 7V 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 TIME - Sec
VSD 0
0
200
400
600
800
1000
0
200
TIME - s
400 600 TIME - s
800
1000
Figure 14. Load Transient Response
Figure 15. Short Circuit Current
Figure 16. Turn On-Turn Off Response
0 VOUT = 3.0V -10 RIPPLE REJECTION - dB -20 -30 -40 -50 -60 -70 -80 -90 -100 10 100 CL = 0.47 F IL = 200mA CL = 0.47 F IL = 0.1mA
RMS NOISE - V
160 140
1 CL = 0.47 F CNR = 0 VOLTAGE NOISE SPECTRAL DENSITY - V/ Hz CL = 10 F CNR = 0 CL = 0.47 F CNR = 10nF 0.1 CL = 10 F CNR = 10nF
120
IL = 200mA
100 80 60 40
IL = 0mA IL = 200mA WITH NOISE REDUCTION
CL = 10 F IL = 200mA CL = 10 F IL = 0.1mA 1k 10k 100k FREQUENCY - Hz 1M 10M
20 0 0
IL = 0mA WITH NOISE REDUCTION
VOUT = 3.0V IL = 200mA
40 50
10
20 CL -
30 F
0.01 10
100
1k 10k FREQUENCY - Hz
100k
1M
Figure 17. Power Supply Ripple Rejection
Figure 18. RMS Noise vs. CL (10 Hz-100 kHz)
Figure 19. Output Noise Density
-6-
REV. A
ADP3330
THEORY OF OPERATION
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 Q1 OUTPUT COMPENSATION ATTENUATION R1 CAPACITOR (VBANDGAP/VOUT) PTAT VOS R4 R3 D1 (a) PTAT CURRENT CLOAD RLOAD R2
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. 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. 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 F 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. 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 +165C, the circuit activates a soft thermal shutdown, indicated by a signal low on the ERR pin, to reduce the current to a safe level.
NONINVERTING WIDEBAND DRIVER
gm
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. 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 F 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 F at minimum temperature. 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 F 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.
Noise Reduction
SILICON DIE
a. Normal SOT-23-6 Package
SILICON DIE WITH ELECTRICALLY ISOLATED DIE ATTACH
b. Thermally Enhanced Chip-on-Lead Package Figure 22.
Thermal Overload Protection
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. When adding a noise reduction capacitor, use the following guidelines: * Maintain a minimum load current of 1 mA when not in shutdown. * For CNR values greater than 500 pF, add a 100 k series resistor (RNR). 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.
NR
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 +165C. Under extreme conditions (i.e., high ambient temperature and power dissipation) where die temperature starts to rise above +165C, 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. 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 +125C.
Calculating Junction Temperature
Device power dissipation is calculated as follows: PD = (V IN - VOUT) ILOAD +(VIN) IGND Where ILOAD and IGND are load current and ground current, VIN and VOUT are input and output voltages respectively. Assuming ILOAD = 200 mA, IGND = 4 mA, VIN = 4.2 V and VOUT = 3.0 V, device power dissipation is:
ADP3330-3
VIN C1 + 0.47 F - SD IN OUT R1 ERR GND
CNR RNR 330k VOUT = +3.3V + C2 - 0.47 F
PD = (4.2 - 3) 200 mA + 4.2 (4 mA) = 257 mW The proprietary package used in the ADP3330 has a thermal resistance of 165C/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: TJA = 0.257 W x 165C/W = 42.4C To limit the maximum junction temperature to +125C, maximum allowable ambient temperature will be: TA MAX = 125C - 42.4C = 82.6C
Figure 21. Noise Reduction Circuit
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 190C/W on a 2-layer board as compared to >230C/W for a standard SOT-23 leadframe. Figure 22 shows the difference between the standard SOT-23 and the Chip-on-Lead leadframes.
-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. 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. 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 165C/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. 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.
Error Flag Dropout Detector
ADP3330 is well suited for applications such as cellular phone handsets that require low quiescent current and low dropout voltage features. ADP3330 draws 34 A typical under light load situations (i.e., load current = 100 A), which results in low power consumption when the cell phone is in standby mode. 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.
END OF DISCHARGE VOLTAGE OF 3 CELL NiCd OR 1 CELL Li-Ion BATTERY
MINIMUM BATTERY VOLTAGE 3.0V
250mV MAXIMUM INPUT-OUTPUT OVERHEAD FOR 200mA OUTPUT CURRENT NOMINAL OUTPUT VOLTAGE 2.75V -1.4% OUTPUT VOLTAGE ACCURACY 2.712V ABSOLUTE MINIMUM OUTPUT VOLTAGE 2.700V 12mV TRANSIENT, LINE AND LOAD RESPECTIVE MARGIN
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. 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.
Shutdown Mode
Figure 23. LDO Budgeting for a 3 Cell NiCd/1 Cell Li-Ion Supply
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 A.
REV. A
-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.
VIN = 3.85V TO 12V IN OUT VOUT = 3.6V/2.5V
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.
VIN = 4.5V TO 8V C1 100 F R1 50 MJE253* VOUT = 3V@1A
OUTPUT SELECT 3V 0V
ADP3330-3.6
SD GND
IN OUT + C2 100 F
ADP3330-3
SD GND ERR
C1+ 1.0 F LOGIC SUPPLY
IN
OUT
+
ADP3330-2.5
SD GND
C2 0.47 F
*AAVID531002 HEAT SINK IS USED
Figure 25. High Output Current Linear Regulator
Figure 24. Crossover Switch
-10-
REV. A
ADP3330
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
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) PIN 1
6 1
5 2
4 3
0.118 (3.00) 0.098 (2.50)
0.037 (0.95) BSC 0.075 (1.90) BSC 0.051 (1.30) 0.035 (0.90) 0.059 (0.15) 0.000 (0.00) 0.057 (1.45) 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)
REV. A
-11-
PRINTED IN U.S.A.
C3455a-0-8/99
-12-
C3455a-0-8/99
PRINTED IN U.S.A.

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Price & Availability of ADP3330

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