Datasheet ADP3307 Datasheet (Analog Devices)

Page 1
High Accuracy anyCAP™
V
OUT
= +3.3V
V
IN
+ –
ADP3307-3.3
NR
OUT
ERR
ON
OFF
SD
GND
R1 330kV
IN
E
OUT
C2
0.47mF
C1
0.47mF
a
FEATURES
0.8% Accuracy Over Line and Load Regulations @ +258C Ultralow Dropout Voltage: 120 mV Typical @ 100 mA Requires only C anyCAP = Stable with All Types of Output Capacitors
(Including MLCC) Current and Thermal Limiting Low Noise Dropout Detector Low Shutdown Current: 1 mA
3.0 V to 12 V Supply Range –208C to +858C Ambient Temperature Range Several Fixed Voltage Options Ultrasmall SOT-23-6 (RT-6) Package Excellent Line and Load Regulations
APPLICATIONS Cellular Telephones Notebook, Palmtop Computers Battery Powered Systems PCMCIA Regulator Bar Code Scanners Camcorders, Cameras
= 0.47 mF for Stability
O
100 mA Low Dropout Linear Regulator
ADP3307
FUNCTIONAL BLOCK DIAGRAM
ADP3307
M
BANDGAP
REF
OUT
R1
NR
R2
ERR
SD
IN
THERMAL
PROTECTION
Q2
Q1
CC
DRIVER G
GND
GENERAL DESCRIPTION
The ADP3307 is a member of the ADP330x family of precision low dropout anyCAP voltage regulators. The ADP3307 stands out from the conventional LDOs with a novel architecture and an enhanced process. Its patented design requires only a 0.47 µF output capacitor for stability. This device is stable with any type of capacitor regardless of its ESR (Equivalent Series Resistance) value, including ceramic types (MLCC) for space restricted applications. The ADP3307 achieves exceptional accuracy of ±0.8% at room temperature and ±1.4% overall accuracy over temperature, line and load regulations. The dropout voltage of the ADP3307 is only 120 mV (typical) at 100 mA.
The ADP3307 operates with a wide input voltage range from
3.0 V to 12 V and delivers a load current in excess of 100 mA. It features an error flag that signals when the device is about to
anyCAP is a trademark of Analog Devices, Inc.
Figure 1. Typical Application Circuit
lose regulation or when the short circuit or thermal overload protection is activated. Other features include shutdown and optional noise reduction capabilities. The ADP330x anyCAP LDO family offers a wide range of output voltages and output current levels from 50 mA to 300 mA:
ADP3300 (50 mA, SOT-6) ADP3307 (100 mA, SOT) ADP3301 (100 mA, SO-8) ADP3302 (100 mA, Dual Output) ADP3303 (200 mA) ADP3306 (300 mA)
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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.
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ADP3307–SPECIFICA TIONS
(@ TA = –208C to +858C, VIN = 7 V, CIN = 0.47 mF, C
= 0.47 mF, unless
OUT
otherwise noted)1 The following specifications apply to all voltage options.
Parameter Symbol Conditions Min Typ Max Units
OUTPUT VOLTAGE ACCURACY V
OUT
VIN = V I T V
OUTNOM
= 0.1 mA to 100 mA
L
= +25°C –0.8 +0.8 %
A
= V
IN
OUTNOM
+ 0.3 V to 12 V
+ 0.3 V to 12 V
IL = 0.1 mA to 100 mA –1.4 +1.4 %
V
V
V
I
GND
O
IN
O L
LINE REGULATION V
LOAD REGULATION I
GROUND CURRENT I
IN
= V
OUTNOM
+ 0.3 V to 12 V
TA = +25°C 0.02 mV/V
= 0.1 mA to 100 mA
L
TA = +25°C 0.06 mV/mA IL = 100 mA 0.76 2.0 mA
IL = 0.1 mA 0.19 0.3 mA
GROUND CURRENT IN DROPOUT I
GND
VIN = 2.5 V IL = 0.1 mA 0.6 1.2 mA
V
DROPOUT VOLTAGE V
DROP
= 98% of V
OUT
OUTNOM
IL = 100 mA 0.126 0.22 V I
= 10 mA 0.025 0.07 V
L
IL = 1 mA 0.004 0.015 V
SHUTDOWN THRESHOLD V
THSD
ON 2.0 0.75 V OFF 0.75 0.3 V
SHUTDOWN PIN INPUT CURRENT I
SDIN
0 < VSD, < 5 V 1 µA 5 < VSD 12 V @ VIN = 12 V 22 µA
GROUND CURRENT IN SHUTDOWN I
Q
MODE T
VSD = 0 V, VIN = 12 V
= +25°C 0.005 1 µA
A
V
= 0 V, VIN = 12 V
SD
TA = +85°C 0.01 3 µA
OUTPUT CURRENT IN SHUTDOWN I
OSD
TA = +25°C @ VIN = 12 V 2 µA
MODE TA = +85°C @ VIN = 12 V 4 µA
ERROR PIN OUTPUT LEAKAGE I
EL
VEO = 5 V 13 µA
ERROR PIN OUTPUT
“LOW” VOLTAGE V PEAK LOAD CURRENT I OUTPUT NOISE @ 3.3 V OUTPUT V
EOL
LDPK
NOISE
I
= 400 µA 0.12 0.3 V
SINK
VIN = V
OUTNOM
+ 1 V 170 mA
f = 10 Hz–100 kHz C
= 0 100 µV rms
NR
CNR = 10 nF, CL = 10 µF30µV rms
NOTES
1
Ambient temperature of +85°C corresponds to a junction temperature of 125°C under typical full load test conditions.
Specifications subject to change without notice.
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ADP3307
ABSOLUTE MAXIMUM RATINGS*
Input Supply Voltage . . . . . . . . . . . . . . . . . . . –0.3 V to +16 V
Shutdown Input Voltage . . . . . . . . . . . . . . . . –0.3 V to +16 V
Error Flag Output Voltage . . . . . . . . . . . . . . . –0.3 V to +16 V
Noise Bypass Pin Voltage . . . . . . . . . . . . . . . . –0.3 V to +5 V
Power Dissipation . . . . . . . . . . . . . . . . . . . .Internally Limited
Operating Ambient Temperature Range . . . –55°C to +125°C Operating Junction Temperature Range . . . –55°C to +125°C
θ
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230°C/W
JA
θ
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92°C/W
JC
Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C
Lead Temperature Range (Soldering 10 s) . . . . . . . . .+300°C
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . .+215°C
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . .+220°C
*This is a stress rating only; operation beyond these limits can cause the device to
be permanently damaged.
ORDERING GUIDE
Output Package Marking
Model Voltage Option Code
ADP3307ART-2.7 2.7 V RT-6 LTC ADP3307ART-3 3.0 V RT-6 LUC ADP3307ART-3.2 3.2 V RT-6 LVC ADP3307ART-3.3 3.3 V RT-6 LWC
Contact the factory for the availability of other output voltage options.
Other Members of anyCAP Family
1
PIN FUNCTION DESCRIPTIONS
Pin Name Function
1 GND Ground Pin. 2 NR Noise Reduction Pin. Used for further reduc-
tion of the output noise. (See text for details.) No connection if not used.
3 SD 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.
4 OUT Output of the Regulator, fixed 2.7 V, 3.0 V,
3.2 V or 3.3 V output voltage. Bypass to
ground with a 0.47 µF or larger capacitor. 5 IN Regulator Input. 6 ERR Open Collector Output that goes low to indi-
cate that the output is about to go out of
regulation.
PIN CONFIGURATION
GND
NR
SD
1
ADP3307
2
TOP VIEW
(Not to Scale)
3
6
ERR
5
IN
4
OUT
Output Package
Model Current Options
2
Comments
ADP3300 50 mA SOT-23-6 High Accuracy ADP3301 100 mA SO-8 High Accuracy ADP3302 100 mA SO-8 Dual Output ADP3303 200 mA SO-8 High Accuracy ADP3306 300 mA SO-8, TSSOP-14 High Accuracy,
High Current
NOTES
1
See individual data sheets for detailed ordering information.
2
SO = Small Outline, SOT-23 = Surface Mount, TSSOP = Thin Shrink Small Outline.
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 ADP3307 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
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ADP3307
TEMPERATURE – 8C
GROUND CURRENT – mA
1000
800
0
–25 –5 135
15 35 55 75 95 115
600
400
200
TIME – ms
INPUT/OUTPUT VOLTAGE – Volts
8.0
5.0
0
0 20 200
40 60 80 100 120 140 160 180
7.0
6.0
3.0
1.0
4.0
2.0
VSD = V
IN
CL = 0.47mF R
L
= 32V
V
OUT
= 3.2V
V
IN
V
OUT
–Typical Performance Characteristics
3.202
3.201
3.200
3.199
3.198
3.197
OUTPUT VOLTAGE – Volts
3.196
3.195
3.3 4 145678910111213
IL = 0mA
IL = 10mA
IL = 50mA
IL = 100mA
INPUT VOLTAGE – Volts
V
= 3.2V
OUT
Figure 2. Line Regulation Output Voltage vs. Supply Voltage
900
750
600
450
GROUND CURRENT – mA
300
IL = 0 TO 100mA
3.202 V
= 3.2V
OUT
V
3.201
3.200
3.199
3.198
3.197
OUTPUT VOLTAGE – Volts
3.196
3.195
20 30 40 50 60 70 80 90
0 10 100
OUTPUT LOAD – mA
IN
= 7V
Figure 3. Output Voltage vs. Load Current Up to 100 mA
0.2
0.1
0.0
–0.1
–0.2
OUTPUT VOLTAGE – %
–0.3
IL = 50mA
IL = 100mA
IL = 0
800
640
480
320
GROUND CURRENT – mA
160
0
0 1.2 12.02.4 3.6 4.8 6.0 7.2 8.4 9.6 10.8
INPUT VOLTAGE – Volts
V
= 3.2V
OUT
= 0
I
L
Figure 4. Quiescent Current vs. Sup­ply Voltage—3.2 V (Both Outputs)
150
0 25 100
50 75
OUTPUT LOAD – mA
Figure 5. Ground Current vs. Load Current
120
96
72
48
24
INPUT/OUTPUT VOLTAGE – mV
0
0 25 10050 75
OUTPUT LOAD – mA
Figure 8. Dropout Voltage vs. Output Current
–0.4
–45 –25 135–5 15 35 75 95 11555
Figure 6. Output Voltage Variation % vs. Temperature
5
4
3
2
1
INPUT/OUTPUT VOLTAGE – Volts
0
01 0
Figure 9. Power-Up/Power-Down
TEMPERATURE – 8C
V
= 3.2V
OUT
R
= 32V
L
234321
INPUT VOLTAGE – Volts
–4–
Figure 7. Quiescent Current vs. Temperature
Figure 10. Power-Up Overshoot
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Page 5
ADP3307
3.220
3.210
3.200
3.190
3.180
VOLTS
7.5
7.0
V
= 3.2V
OUT
RL = 32V C
= 0.47mF
L
V
IN
0 40 400
80 120 160 200 240 280 320 360
TIME – ms
Figure 11. Line Transient Response
3.220 V
= 3.2V
OUT
= 4.7mF
C
3.210
L
3.200
VOLTSmA
3.190
3.180
100
10
3.220
3.210
3.200
3.190
3.180
VOLTS
7.5
7.0
V
= 3.2V
OUT
RL = 3.2kV
= 0.47mF
C
L
V
IN
40 60 80 100 120 140 160 180
0 20 200
TIME – ms
Figure 12. Line Transient Response
300
200
mA
100
0
4
2
VOLTS
0
V
= 3.2V
OUT
I
OUT
V
OUT
3.220 V
= 3.2V
OUT
C
= 0.47mF
L
100
10
0 100 500
200 300 400
TIME – ms
VOLTSmA
3.210
3.200
3.190
3.180
Figure 13. Load Transient
4
CL = 0.47mF
3
2
1
VOLTS
0 3
0
CL = 4.7mF
3V
V
OUT
R
L
V
3.2V
= 3.2V
= 32V
OUT
V
SD
0 100 500
200 300 400
TIME – ms
Figure 14. Load Transient
4
3.2V
3
2
1
VOLTS
0
3
0
010 50
20 30 40
TIME – ms
V
= 3.2V
OUT
R
= 32V
L
CL = 0.47mF
V
SD
Figure 17. Turn Off
01 5234
0.5 4.51.5 2.5 3.5 TIME – sec
Figure 15. Short Circuit Current
0
a. 0.47mF, RL = 33kV
–10
b. 0.47mF, R c. 10mF, RL = 33kV
–20
d. 10mF, R
–30 –40 –50 –60 –70
RIPPLE REJECTION – dB
–80 –90
a
–100
10 100 10M1k 10k 1M
db
c
= 33V
L
= 33V
L
FREQUENCY – Hz
a
100k
V
= 3.3V
OUT
b
d
c
Figure 18. Power Supply Ripple Rejection
0 20 10040 60 80
TIME – ms
Figure 16. Turn On
10
V
= 5V, CL = 0.47mF
OUT
IL = 1mA, CNR = 0
1
V
= 3.3V, CL = 0.47mF
OUT
= 1mA, CNR = 0
I
L
0.1
V
= 2.7– 5.0V, CL = 0.47mF
OUT
IL = 1mA, CNR = 10nF
V
OUT
= 1mA, CNR = 10nF
I
0.01 100 1k 100k10k
VOLTAGE NOISE SPECTRAL DENSITY – mV Hz
L
FREQUENCY – Hz
0.47mF BYPASS PIN 5 TO PIN 1
= 2.7– 5.0V, CL = 4.7mF
Figure 19. Output Noise Density
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Page 6
ADP3307
THEORY OF OPERATION
The ADP3307 anyCAP LDO 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 option. 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
NONINVERTING
WIDEBAND
DRIVER
ADP3307
COMPENSATION CAPACITOR
PTAT
V
G
M
ATTENUATION (V
BANDGAP/VOUT
OS
R4
GND
D1
R3
PTAT
CURRENT
OUTPUT
R1
)
R2
(a)
R
LOAD
C
LOAD
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 gained up temperature proportional offset voltage is combined with the 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 trade-off 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.
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 conventional LDOs more difficult because of their unclear specifications and the depen­dence of ESR over temperature.
This is no longer true with the ADP3307 anyCAP LDO. 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 design scheme include superior line noise rejection and very high regulator gain that lead 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 the standard solu­tions that give warning after the output has lost regulation, the ADP3307 provides improved system performance by enabling the ERR pin to give warning 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.
To reduce the noise gain of the loop, the node of the main di­vider network (a) is made available at the noise reduction (NR) pin which can be bypassed with a small capacitor (10 nF–100 nF).
APPLICATION INFORMATION Capacitor Selection: anyCAP
Output Capacitors: as with any micropower device, output transient response is a function of the output capacitance. The ADP3307 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. However, larger capacitors can be used if high output current surges are anticipated. There is an upper limit on the size of the output capacitor. The ADP3307 is stable with extremely low ESR capacitors (ESR 0), such as multi­layer ceramic capacitors (MLCC) or OSCON.
Input Bypass Capacitor: an input bypass capacitor is not re­quired; however, for applications where the input source is high impedance or far from the input pins, a bypass capacitor is recommended. Connecting a 0.47 µF capacitor from the input to ground reduces the circuit’s sensitivity to PC board layout. If a bigger output capacitor is used, the input capacitor should be 1 µF minimum.
Noise Reduction
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 nF–100 nF range provide the best performance. As the noise reduction capacitor increases the high frequency loop-gain of the regulator, the circuit requires a larger output capacitor if it is used. The recommended value is 4.7 µF, as shown in Figure 21. 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 pick up from external sources. The pad connected to this pin should be as small as possible. Long PC board traces are not recommended.
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Page 7
ADP3307-2.7
ADP3307-3.3
+
OUTIN
SD
GND
+
IN
OUT
SD
GND
C1
1.0mF
C2
0.47mF
V
OUT
= 2.7V/3.3V
V
IN
= 4V TO 12V
OUTPUT SELECT
4V 0V
OFF
NR
OUT
ERR
ON
GND
V
IN
C1
1mF
ADP3307-3.3
IN
+
SD
C
NR
10nF
R1
330k
E
OUT
V
= 3.3V
OUT
+
C2
4.7mF
Figure 21. Noise Reduction Circuit
Thermal Overload Protection
The ADP3307 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. 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 125°C.
Calculating Junction Temperature
Device power dissipation is calculated as follows:
= (VIN – V
P
D
Where I and V
Assuming I V
= 3.3 V, device power dissipation is:
OUT
and I
LOAD
are input and output voltages respectively.
OUT
LOAD
= (5.5 – 3.3) 0.1 + 5.5 × 2 mA = 0.231 W
P
D
T = T
are load current and ground current, V
GND
= 100 mA, I
TA = PD × θJA = 0.231 × 165 = 38°C
J
) I
OUT
GND
+ (VIN) I
LOAD
= 2 mA, VIN = 5.5 V and
GND
With a maximum junction temperature of 125°C, this yields a maximum ambient temperature of ~72°C.
Printed Circuit Board Layout Consideration
Surface mount components rely on the conductive traces or pads to transfer heat away from the device. Appropriate PC board layout techniques should be used to remove heat from the immediate vicinity of the package.
The following general guidelines will be helpful when designing a board layout:
1. PC board traces with larger cross section areas will remove more heat. For optimum results, use PC boards with thicker copper and wider traces.
2. Increase the surface area exposed to open air so heat can be removed by convection or forced air flow.
3. Do not use solder mask or silkscreen on the heat dissipating traces because it will increase the junction-to-ambient ther­mal resistance of the package.
ADP3307
Shutdown Mode
Applying a TTL high signal to the shutdown pin or tying it to the input pin will turn the output ON. Pulling the shutdown pin down to a TTL low level or tying it to ground will turn the output OFF. In shutdown mode, quiescent current is reduced to less than 1 µA.
Error Flag Dropout Detector
The ADP3307 will maintain its output voltage over a wide range of load, input voltage and temperature conditions. If the output is about to lose regulation, for example, by reducing the supply voltage below the combined regulated output and drop­out voltages, the ERR pin will be activated. The ERR output is an open collector that will be driven low.
Once set, the ERRor 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.
APPLICATIONS CIRCUITS Crossover Switch
The circuit in Figure 22 shows that two ADP3307s 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.
IN
Figure 22. Crossover Switch
Higher Output Current
The ADP3307 can source up to 100 mA without any heatsink or pass transistor. If higher current is needed, an appropriate pass transistor can be used, as in Figure 23, to increase the output current to 1 A.
= 4V TO 8V
V
IN
C1
47mF
*AAVID531002 HEAT SINK IS USED
MJE253*
R1
50V
IN
ADP3307-3.3
SD
GND
OUT
ERR
Figure 23. High Output Current Linear Regulator
V
= 3.3V@1A
OUT
+
C2 10mF
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Page 8
ADP3307
Constant Dropout Post Regulator
The circuit in Figure 24 provides high precision with low drop­out for any regulated output voltage. It significantly reduces the ripple from a switching regulator while providing a constant
VIN = 2.5V TO 3.5V
100mF
10V
L1
6.8mH
C1
R1 120V
I
LIM
ADP3000-ADJ
SW2GND
V
IN
SW1
FB
D1 1N5817
C2 100mF 10V
Figure 24. Constant Dropout Post Regulator
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
6-Lead Plastic Surface Mount
(RT-6)
dropout voltage, which limits the power dissipation of the LDO to 30 mW. The ADP3000 used in this circuit is a switching regulator in the step-up configuration.
ADP3307-3.3
+
3.3V@100mA
C3
2.2mF
2N3906
Q1
R2
30.1kV 1%
R3 124kV 1%
IN OUT
SD
GND
Q2 2N3906
R4 274kV
C3234–8–12/97
0.071 (1.80)
0.059 (1.50)
0.051 (1.30)
0.035 (0.90)
PIN 1
0.059 (0.15)
0.000 (0.00)
0.122 (3.10)
0.106 (2.70)
1
0.075 (1.90)
2
BSC
0.020 (0.50)
0.010 (0.25)
4 5 6
0.118 (3.00)
0.098 (2.50)
3
0.037 (0.95) BSC
0.057 (1.45)
0.035 (0.90)
SEATING PLANE
0.009 (0.23)
0.003 (0.08)
10°
0°
0.022 (0.55)
0.014 (0.35)
PRINTED IN U.S.A.
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