ADP3335ARM-1.8-RL [ADI]

IC VREG 1.8 V FIXED POSITIVE LDO REGULATOR, 0.37 V DROPOUT, PDSO8, MO-187AA, MSOP-8, Fixed Positive Single Output LDO Regulator;
ADP3335ARM-1.8-RL
型号: ADP3335ARM-1.8-RL
厂家: ADI    ADI
描述:

IC VREG 1.8 V FIXED POSITIVE LDO REGULATOR, 0.37 V DROPOUT, PDSO8, MO-187AA, MSOP-8, Fixed Positive Single Output LDO Regulator

光电二极管 输出元件 调节器
文件: 总16页 (文件大小:233K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
High Accuracy, Ultralow IQ, 500 mA,  
anyCAP® Low Dropout Regulator  
ADP3335  
FUNCTIONAL BLOCK DIAGRAM  
FEATURES  
High accuracy over line and load: 0.9ꢀ @ 25°C,  
1.8ꢀ over temperature  
Ultralow dropout voltage: 200 mV (typ) @ 500 mA  
Requires only CO = 1.0 µF for stability  
anyCAP = stable with any type of capacitor  
(Including MLCC)  
Q1  
OUT  
NR  
IN  
ADP3335  
R1  
R2  
THERMAL  
PROTECTION  
CC  
DRIVER  
gm  
SD  
+
BANDGAP  
REF  
Current and thermal limiting  
Low noise  
Low shutdown current: < 10 nA (typ)  
2.6 V to 12 V supply range  
–40°C to +85°C ambient temperature range  
GND  
Figure 1.  
5
NR  
APPLICATIONS  
PCMCIA cards  
Cellular phones  
Camcorders, cameras  
Networking systems, DSL/cable modems  
Cable set-top box  
ADP3335  
3
2
1
OUT  
IN  
7
8
OUT  
OUT  
V
V
OUT  
IN  
SD  
IN  
+
+
C
IN  
1µF  
C
OUT  
1µF  
GND  
4
6
ON  
OFF  
MP3/CD players  
Figure 2. Typical Application Circuit  
DSP supplies  
GENERAL DESCRIPTION  
The ADP3335 is a member of the ADP333x family of precision,  
low dropout, anyCAP voltage regulators. It operates with an  
input voltage range of 2.6 V to 12 V, and delivers a continuous  
load current up to 500 mA. The ADP3335 stands out from  
conventional low dropout regulators (LDOs) by using an  
enhanced process enabling it to offer performance advantages  
beyond its competition. Its patented design requires only a  
1.0 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 ADP3335 achieves  
exceptional accuracy of 0.ꢀ9 at room temperature and 1.ꢁ9  
over temperature, line, and load.  
The dropout voltage of the ADP3335 is only 200 mV (typical) at  
500 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 1 µA. The  
ADP3335 has a low quiescent current of ꢁ0 µA (typical) in light  
load situations.  
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 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  
Fax: 781.326.8703  
www.analog.com  
© 2004 Analog Devices, Inc. All rights reserved.  
ADP3335  
TABLE OF CONTENTS  
Specifications..................................................................................... 3  
Noise Reduction ......................................................................... 10  
Thermal Overload Protection .................................................. 10  
Calculating Junction Temperature........................................... 10  
Printed Circuit Board Layout Considerations........................ 11  
LFCSP Layout Considerations.................................................. 11  
Shutdown Mode ......................................................................... 11  
Outline Dimensions....................................................................... 12  
Ordering Guide .......................................................................... 13  
Absolute Maximum Ratings............................................................ 4  
Pin Configuration and Function Descriptions............................. 5  
Typical Performance Characteristics ............................................. 6  
Theory of Operation ........................................................................ 9  
Application Information................................................................ 10  
Output Capacitor Selection....................................................... 10  
Input Bypass Capacitor.............................................................. 10  
REVISION HISTORY  
1/04 changed from Rev. 0 to Rev. A  
Format updated...............................................................Universal  
Renumbered figures .......................................................Universal  
Removed Figure 22....................................................................... 6  
Change to Printed Circuit Board  
Layout Considerations section.................................................. 11  
Added LFCSP Layout Considerations section........................ 11  
Added Package Drawing................................................Universal  
Changes to Ordering Guide ...................................................... 16  
Rev. A | Page 2 of 16  
ADP3335  
SPECIFICATIONS  
All limits at temperature extremes are guaranteed via correlation using standard statistical quality control (SQC) methods. Ambient  
temperature of 85°C corresponds to a junction temperature of 125°C under pulsed full-load test conditions. Application stable with no  
load. VIN = 6.0 V, CIN = COUT = 1.0 µF, TA = –40°C to +85°C, unless otherwise noted.  
Table 1.  
Parameter  
Symbol  
Conditions  
Min  
Typ  
Max  
Unit  
OUTPUT  
Voltage Accuracy1  
VOUT  
VIN = VOUT(NOM) + 0.4 V to 12 V  
IL = 0.1 mA to 500 mA  
TA = 25°C  
–0.9  
+0.9  
%
VIN = VOUT(NOM) + 0.4 V to 12 V  
IL = 0.1 mA to 500 mA  
TA = 85°C  
VIN = VOUT(NOM) + 0.4 V to 12 V  
IL = 0.1 mA to 500 mA  
TJ = 150°C  
–1.8  
–2.3  
+1.8  
+2.3  
%
%
Line Regulation1  
VIN = VOUT(NOM) + 0.4 V to 12 V  
IL = 0.1 mA  
TA = 25°C  
IL = 0.1 mA to 500 mA  
TA = 25°C  
VOUT = 98% of VOUT(NOM)  
IL = 500 mA  
IL = 300 mA  
IL = 50 mA  
IL = 0.1 mA  
0.04  
0.04  
mV/V  
mV/mA  
Load Regulation  
Dropout Voltage  
VDROP  
200  
140  
30  
370  
230  
110  
40  
mV  
mV  
mV  
mV  
10  
Peak Load Current  
Output Noise  
ILDPK  
VNOISE  
VIN = VOUT(NOM) + 1 V  
f = 10 Hz to 100 kHz, CL = 10 µF  
IL = 500 mA, CNR = 10 nF  
f = 10 Hz to 100 kHz, CL = 10 µF  
IL = 500 mA, CNR = 0 nF  
800  
47  
mA  
µV rms  
95  
µV rms  
GROUND CURRENT  
In Regulation  
IGND  
IL = 500 mA  
IL = 300 mA  
IL = 50 mA  
IL = 0.1 mA  
VIN = VOUT(NOM) – 100 mV  
IL = 0.1 mA  
4.5  
2.6  
0.5  
80  
10  
6
2.5  
110  
400  
mA  
mA  
mA  
µA  
In Dropout  
IGND  
120  
µA  
IGNDSD  
SD  
In Shutdown  
SHUTDOWN  
0.01  
1
µA  
= 0 V, VIN = 12 V  
VTHSD  
Threshold Voltage  
ON  
OFF  
SD  
2.0  
V
0.4  
3
V
ISD  
SD  
1.2  
µA  
µA  
Input Current  
0 ≤  
≤ 5 V  
IOSD  
Output Current in Shutdown  
VIN = 12 V, VOUT = 0 V  
0.01  
5
1 VIN = 2.6 V to 12 V for models with VOUT(NOM) ≤ 2.2 V.  
Rev. A | Page 3 of 16  
 
 
ADP3335  
ABSOLUTE MAXIMUM RATINGS  
Table 2.  
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 listed in the operational sections  
of this specification is not implied. Exposure to absolute  
maximum rating conditions for extended periods may affect  
device reliability.  
Parameter  
Rating  
Input Supply Voltage  
Shutdown Input Voltage  
Power Dissipation  
Operating Ambient Temperature Range  
Operating Junction Temperature Range  
θJA, 2-layer MSOP-8  
–0.3 V to +16 V  
–0.3 V to +16 V  
Internally Limited  
–40°C to +85°C  
–40°C to +150°C  
220°C/W  
θJA, 4-layer MSOP-8  
158°C/W  
θJA, 2-layer LFCSP-8  
62°C/W  
θJA, 4-layer LFCSP-8  
48°C/W  
Storage Temperature Range  
–65°C to +150°C  
Lead Temperature Range (Soldering 10 sec) 300°C  
Vapor Phase (60 sec)  
Infrared (15 sec)  
215°C  
220°C  
ESD 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 this product 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.  
Rev. A | Page 4 of 16  
 
ADP3335  
PIN CONFIGURATIONS AND FUNCTIONAL DESCRIPTIONS  
OUT  
OUT  
OUT  
GND  
1
2
3
4
8
7
6
5
IN  
ADP3335  
TOP VIEW  
(Not to Scale)  
IN  
SD  
NR  
Figure 3. 8-Lead MSOP  
OUT  
OUT  
OUT  
GND  
1
2
3
4
8
7
6
5
IN  
ADP3335  
TOP VIEW  
(Not to Scale)  
IN  
SD  
NR  
Figure 4. 8-Lead LFCSP  
Table 3. Pin Function Descriptions  
Pin No. Mnemonic Function  
1, 2, 3  
OUT  
Output of the Regulator. Bypass to ground with a 1.0 µF or larger capacitor. All pins must be connected together  
for proper operation.  
4
5
GND  
NR  
Ground Pin.  
Noise Reduction Pin. Used for further reduction of output noise (see the Noise Reduction section for further  
details).  
6
SD  
IN  
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.  
Regulator Input. All pins must be connected together for proper operation.  
7, 8  
Rev. A | Page 5 of 16  
 
ADP3335  
TYPICAL PERFORMANCE CHARACTERISTICS  
TA = 25°C, unless otherwise noted  
2.202  
5.0  
4.0  
3.0  
2.0  
1.0  
0
V
= 2.2V  
OUT  
2.201  
2.200  
2.199  
2.198  
2.197  
2.196  
2.195  
2.194  
I = 0  
L
150mA  
300mA  
500mA  
2
4
6
8
10  
12  
0
100  
200  
300  
400  
500  
INPUT VOLTAGE (V)  
LOAD CURRENT (mA)  
Figure 5. Line Regulation Output Voltage vs. Supply Voltage  
Figure 8. Ground Current vs. Load Current  
2.201  
2.200  
2.199  
2.198  
2.197  
2.196  
2.195  
2.194  
2.193  
1.0  
0.9  
0.8  
0.7  
0.6  
0.5  
0.4  
0.3  
0.2  
0.1  
0
V
V
= 2.2V  
OUT  
= 6V  
IN  
0
300mA  
500mA  
–0.1  
–0.2  
–0.3  
–0.4  
500mA  
–15  
0
100  
200  
300  
400  
500  
–40  
5
25  
45  
65  
85  
105  
125  
LOAD CURRENT (mA)  
JUNCTION TEMPERATURE (°C)  
Figure 6. Output Voltage vs. Load Current  
Figure 9. Output Voltage Variation vs. Junction Temperature  
140  
120  
100  
80  
8
V
= 2.2V  
OUT  
I
= 500mA  
L
I
= 100µA  
L
7
6
5
4
3
2
1
0
300mA  
I
= 0  
L
60  
40  
100mA  
20  
50mA  
0
0
0
2
4
6
8
10  
12  
–40  
–15  
5
25  
45  
65  
85  
105  
125  
INPUT VOLTAGE (V)  
JUNCTION TEMPERATURE (°C)  
Figure 7. Ground Current vs. Supply Voltage  
Figure 10. Ground Current vs. Junction Temperature  
Rev. A | Page 6 of 16  
 
ADP3335  
250  
200  
150  
100  
50  
2.210  
2.200  
2.190  
2.189  
2.179  
3.500  
3.000  
V
= 2.2V  
OUT  
R
C
= 4.4  
L
= 1µF  
L
0
0
100  
200  
OUTPUT (mA)  
300  
400  
500  
40  
80  
140  
TIME (µs)  
180  
Figure 11. Dropout Voltage vs. Output Current  
Figure 14. Line Transient Response  
V
= 2.2V  
OUT  
SD = V  
IN  
3.0  
2.5  
2.0  
1.5  
1.0  
0.5  
0
2.210  
2.200  
2.190  
2.189  
2.179  
3.500  
3.000  
R
L
= 4.4Ω  
V
= 2.2V  
OUT  
R
= 4.4  
L
L
C
= 10µF  
40  
80  
140  
TIME (µs)  
180  
1
2
3
4
TIME (sec)  
Figure 12. Power-Up/Power-Down  
Figure 15. Line Transient Response  
2.3  
2.2  
2.1  
3
2
1
0
4
2
0
C
OUT  
= 1µF  
V
V
C
= 4V  
= 2.2  
IN  
OUT  
= 1µF  
C
OUT  
= 10µF  
L
400  
200  
0
V
= 2.2V  
OUT  
SD = V  
IN  
R
L
= 4.4Ω  
200  
400  
TIME (µs)  
600  
800  
200  
400  
TIME (µs)  
600  
800  
Figure 13. Power-Up Response  
Figure 16. Load Transient Response  
Rev. A | Page 7 of 16  
ADP3335  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
V
= 2.2V  
OUT  
2.3  
2.2  
C
= 10µF  
L
I
= 500mA  
L
C
= 1µF  
L
I
= 500mA  
L
2.1  
C
= 1µF  
= 50µA  
L
V
R
C
= 4V  
= 4.4  
= 10µF  
IN  
I
L
L
L
400  
200  
C
= 10µF  
= 50µA  
0
L
I
L
10  
100  
1k  
10k  
100k  
1M  
10M  
200  
400  
600  
TIME (µs)  
800  
FREQUENCY (Hz)  
Figure 20. Power Supply Ripple Rejection  
Figure 17. Load Transient Response  
160  
140  
120  
100  
80  
C
= 10nF  
NR  
2.2  
0
I
= 500mA WITHOUT  
L
NOISE REDUCTION  
800mΩ  
SHORT  
FULL SHORT  
I
= 500mA WITH  
L
3
2
1
0
NOISE REDUCTION  
60  
I
L
= 0mA WITHOUT  
NOISE REDUCTION  
V
= 4V  
IN  
40  
20  
I
= 0mA WITH NOISE REDUCTION  
L
0
200  
400  
TIME (µs)  
600  
800  
0
10  
20  
30  
40  
50  
C
(µF)  
L
Figure 18. Short-Circuit Current  
Figure 21. RMS Noise versus CL (10 Hz to 100 kHz)  
100  
V
V
R
= 4V  
IN  
V
= 2.2V  
OUT  
= 2.2V  
= 4.4  
OUT  
I
= 1mA  
3
2
1
0
L
1µF  
L
10  
1
C
C
= 10µF  
NR  
L
C
C
= 10µF  
NR  
L
= 0nF  
= 10nF  
C
C
= 1µF  
= 0nF  
L
10µF  
10µF  
NR  
1µF  
0.1  
C
C
= 1µF  
NR  
L
= 10nF  
2
1
0.01  
0.001  
200  
400  
TIME (µs)  
600  
800  
10  
100  
1k  
10k  
100k  
1M  
FREQUENCY (Hz)  
Figure 19. Turn On/Turn Off Response  
Figure 22. Output Noise Density  
Rev. A | Page 8 of 16  
 
ADP3335  
THEORY OF OPERATION  
divider—R3 and R4, the values can be chosen to produce a  
The ADP3335 uses a single control loop for regulation and  
reference functions. The output voltage is sensed by a resistive  
voltage divider, 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.  
temperature stable output. This unique arrangement specifically  
corrects for the loading of the divider, thus avoiding the error  
resulting from base current loading in conventional circuits.  
The patented amplifier controls a new and unique noninverting  
driver that drives the pass transistor, Q1. This special nonin-  
verting 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.  
OUTPUT  
ATTENUATION  
INPUT  
Q1  
COMPENSATION  
CAPACITOR  
R1  
(V  
/V  
)
BANDGAP OUT  
C
D1  
R3  
LOAD  
PTAT  
(a)  
R2  
NONINVERTING  
WIDEBAND  
DRIVER  
g
m
V
OS  
PTAT  
R
LOAD  
Most LDOs place very 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. The ESR value required to keep conventional LDOs  
stable, moreover, 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.  
R4  
CURRENT  
ADP3335  
GND  
Figure 23. Functional Block Diagram  
A very high gain error amplifier is used to control this loop. The  
amplifier is constructed in such a way that equilibrium  
produces a large, temperature proportional input offset voltage  
that is repeatable and very well controlled. The temperature  
proportional offset voltage combines with the complementary  
diode voltage to form a virtual band gap voltage implicit in the  
network, although it never appears explicitly in the circuit.  
With the ADP3335, ESR limitations are no longer a source of  
design constraints. The ADP3335 can be used with virtually any  
good quality capacitor and with no constraint on the minimum  
ESR. This innovative design allows the circuit to be stable with  
just a small 1 µF capacitor on the output. Additional advantages  
of the pole-splitting scheme include superior line noise reject-  
tion and very high regulator gain, which lead to excellent line  
and load regulation. Impressive 1.8% accuracy is guaranteed  
over line, load, and temperature.  
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 in  
the trade-off of noise sources that leads to a low noise design.  
The R1 and R2 divider is chosen in the same ratio as the band  
gap voltage to the output voltage. Although the R1 and R2  
resistor divider is loaded by the D1 diode and a second  
Additional features of the circuit include current limit, thermal  
shutdown, and noise reduction.  
Rev. A | Page 9 of 16  
 
ADP3335  
APPLICATION INFORMATION  
OUTPUT CAPACITOR SELECTION  
THERMAL OVERLOAD PROTECTION  
As with any micropower device, output transient response is a  
function of the output capacitance. The ADP3335 is stable over  
a wide range of capacitor values, types, and ESR (anyCAP). A  
capacitor as low as 1 µF is all that is needed for stability; larger  
capacitors can be used if high output current surges are  
anticipated. The ADP3335 is stable with extremely low ESR  
capacitors (ESR ≈ 0), such as multilayer ceramic capacitors  
(MLCC) or organic semiconductor electrolytic capacitors  
(OSCON). Note that the effective capacitance of some capacitor  
types may fall below the minimum at extreme temperatures.  
Ensure that the capacitor provides more than 1 µF over the  
entire temperature range.  
The ADP3335 is protected against damage from 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.  
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 150°C.  
INPUT BYPASS CAPACITOR  
CALCULATING JUNCTION TEMPERATURE  
An input bypass capacitor is not strictly required, but is advi-  
sable in any application involving long input wires or high  
source impedance. Connecting a 1 µF capacitor from IN to  
ground reduces the circuits sensitivity to PC board layout. If a  
larger value output capacitor is used, then a larger value input  
capacitor is also recommended.  
Device power dissipation is calculated as follows:  
PD =  
(
VIN VOUT  
)
ILOAD  
+
(
VIN IGND  
)
Where ILOAD and IGND are load current and ground current, and  
IN and VOUT are input and output voltages, respectively.  
V
Assuming ILOAD = 400 mA, IGND = 4 mA, VIN = 5.0 V, and VOUT  
3.3 V, device power dissipation is  
=
NOISE REDUCTION  
A noise reduction capacitor (CNR) can be used, as shown in  
Figure 24, to further reduce the noise by 6 dB to 10 dB  
(Figure 22). Low leakage capacitors in the 100 pF to 1 nF range  
provide the best performance. Since the noise reduction pin,  
NR, is internally connected to a high impedance node, any con-  
nection to this node should be made carefully 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.  
PD = (5 V – 3.3 V)400 mA + 5.0 V(4 mA) = 700 mW  
The junction temperature can be calculated from the power  
dissipation, ambient temperature, and package thermal  
resistance. The thermal resistance is a function not only of the  
package, but also of the circuit board layout. Standard test  
conditions are used to determine the values published in this  
data sheet, but actual performance will vary. For an LFCSP-8  
package mounted on a standard 4-layer board, θJA is 48°C/W. In  
the above example, where the power dissipation is 700 mW, the  
temperature rise above ambient will be approximately equal to  
When adding a noise reduction capacitor, maintain a minimum  
load current of 1 mA when not in shutdown.  
TJA = 0.700 W × 48°C/W = 33.6°C  
It is important to note that as CNR increases, the turn-on time  
will be delayed. With NR values greater than 1 nF, this delay  
may be on the order of several milliseconds.  
To limit the maximum junction temperature to 150°C, the  
maximum allowable ambient temperature will be  
C
NR  
TAMAX = 150°C − 33.6°C = 116.4°C  
5
NR  
3
2
1
OUT  
In this case, the resulting ambient temperature limitation is  
above the maximum allowable ambient temperature of 85°C.  
ADP3335  
OUT  
7
8
IN  
V
OUT  
V
OUT  
C
OUT  
1µF  
IN  
IN  
+
+
C
IN  
1µF  
GND  
4
SD  
6
ON  
OFF  
Figure 24. Typical Application Circuit  
Rev. A | Page 10 of 16  
 
 
ADP3335  
2. The thermal pad of the LFCSP package provides a low  
PRINTED CIRCUIT BOARD LAYOUT  
CONSIDERATIONS  
thermal impedance path (approximately 20°C/W) to the  
PCB. Therefore, the PCB must be properly designed to  
effectively conduct heat away from the package. This is  
achieved by adding thermal vias to the PCB, which provide  
a thermal path to the inner or bottom layers. See Figure 25  
for the recommended via pattern. Note that the via  
diameter is small to prevent the solder from flowing  
through the via and leaving voids in the thermal pad solder  
joint.  
All surface-mount packages rely on the traces of the PC board  
to conduct heat away from the package. Use the following  
general guidelines when designing printed circuit boards to  
improve both electrical and thermal performance.  
1. Keep the output capacitor as close as possible to the output  
and ground pins.  
2. Keep the input capacitor as close as possible to the input  
and ground pins.  
Also, note that the thermal pad is attached to the die  
substrate, so the thermal planes to which the thermal vias  
connect must be electrically isolated or tied to VIN. Do  
NOT connect the thermal pad to ground.  
3. PC board traces with larger cross sectional areas will  
remove more heat from the ADP3335. For optimum heat  
transfer, specify thick copper and use wide traces.  
3. The solder mask opening should be about 120 µ (4.7 mils)  
larger than the pad size, resulting in a minimum 60 µm  
(2.4 mils) clearance between the pad and the solder mask.  
4. It is not recommended to use solder mask or silkscreen on  
the PCB traces adjacent to the ADP3335s pins, since doing  
so will increase the junction-to-ambient thermal resistance  
of the package.  
4. The paste mask opening is typically designed to match the  
pad size used on the peripheral pads of the LFCSP package.  
This should provide a reliable solder joint as long as the  
stencil thickness is about 0.125 mm. The paste mask for the  
thermal pad needs to be designed for the maximum  
5. Use additional copper layers or planes to reduce the  
thermal resistance. When connecting to other layers, use  
multiple vias, if possible.  
coverage to effectively remove the heat from the package.  
However, due to the presence of thermal vias and the size  
of the thermal pad, eliminating voids may not be possible.  
LFCSP LAYOUT CONSIDERATIONS  
The LFCSP package has an exposed die paddle on the bottom,  
which efficiently conducts heat to the PCB. In order to achieve  
the optimum performance from the LFCSP package, special  
consideration must be given to the layout of the PCB. Use the  
following layout guidelines for the LFCSP package.  
5. The recommended paste mask stencil thickness is  
0.125 mm. A laser cut stainless steel stencil with  
trapezoidal walls should be used. A “No Clean” Type 3  
solder paste should be used for mounting the LFCSP  
package. Also, a nitrogen purge during the reflow process is  
recommended.  
2× VIAS, 0.250∅  
35µm PLATING  
0.73  
0.30  
6. The package manufacturer recommends that the reflow  
temperature should not exceed 220°C and the time above  
liquidus is less than 75 seconds. The preheat ramp should  
be 3°C/second or lower. The actual temperature profile  
depends on the board density and must be determined by  
the assembly house as to what works best.  
1.80  
0.90  
2.36  
0.50  
1.40  
1.90  
SHUTDOWN MODE  
3.36  
SD  
Applying a TTL high signal to the shutdown ( ) pin or tying it  
Figure 25. 3 mm × 3 mm LFCSP Pad Pattern  
(Dimensions shown in millimeters)  
SD  
to the input pin, turns the output ON. Pulling  
down to 0.4 V  
or below, or tying it to ground, turns the output OFF. In shut-  
down mode, quiescent current is reduced to a typical value of  
10 nA.  
1. The pad pattern is given in Figure 25. The pad dimension  
should be followed closely for reliable solder joints, while  
maintaining reasonable clearances to prevent solder  
bridging.  
Rev. A | Page 11 of 16  
 
 
ADP3335  
OUTLINE DIMENSIONS  
0.50  
0.40  
0.30  
3.00  
BSC SQ  
0.60 MAX  
8
PIN 1  
INDICATOR  
0.45  
1
PIN 1  
INDICATOR  
1.90  
1.75  
1.60  
2.75  
BSC SQ  
TOP  
VIEW  
1.50  
REF  
BOTTOM  
VIEW  
0.50  
BSC  
4
5
0.25  
MIN  
1.60  
1.45  
1.30  
0.80 MAX  
0.65TYP  
0.90  
0.85  
0.80  
12° MAX  
0.05 MAX  
0.02 NOM  
SEATING  
PLANE  
0.30  
0.23  
0.18  
0.20 REF  
Figure 26. 8-Lead Frame Chip Scale Package [LFCSP]  
(CP-8)  
Dimensions shown in millimeters  
3.00  
BSC  
8
5
4
4.90  
BSC  
3.00  
BSC  
PIN 1  
0.65 BSC  
1.10 MAX  
0.15  
0.00  
0.80  
0.60  
0.40  
8°  
0°  
0.38  
0.22  
0.23  
0.08  
COPLANARITY  
0.10  
SEATING  
PLANE  
COMPLIANT TO JEDEC STANDARDS MO-187AA  
Figure 27. 8-Lead Mini Small Outline Package [MSOP]  
(RM-8)  
Dimensions shown in millimeters  
Rev. A | Page 12 of 16  
 
ADP3335  
ORDERING GUIDE  
Model  
Output Voltage1  
1.8 V  
1.8 V  
2.5 V  
2.5 V  
2.5 V  
2.85 V  
2.85 V  
2.85 V  
3.3 V  
3.3 V  
3.3 V  
5 V  
Package Option  
RM-8 (MSOP-8)  
RM-8 (MSOP-8)  
RM-8 (MSOP-8)  
RM-8 (MSOP-8)  
RM-8 (MSOP-8)  
RM-8 (MSOP-8)  
RM-8 (MSOP-8)  
RM-8 (MSOP-8)  
RM-8 (MSOP-8)  
RM-8 (MSOP-8)  
RM-8 (MSOP-8)  
RM-8 (MSOP-8)  
RM-8 (MSOP-8)  
CP-8 (LFCSP-8)  
CP-8 (LFCSP-8)  
CP-8 (LFCSP-8)  
CP-8 (LFCSP-8)  
CP-8 (LFCSP-8)  
CP-8 (LFCSP-8)  
CP-8 (LFCSP-8)  
CP-8 (LFCSP-8)  
CP-8 (LFCSP-8)  
Branding Information  
ADP3335ARM-1.8–RL  
ADP3335ARM-1.8–RL7  
ADP3335ARM-2.5–RL  
ADP3335ARM-2.5–RL7  
ADP3335ARMZ-2.5–RL72  
ADP3335ARM-2.85–RL  
ADP3335ARM-2.85–R7  
ADP3335ARMZ-2.85–R72  
ADP3335ARM-3.3–RL  
ADP3335ARMZ-3.3–RL2  
ADP3335ARM-3.3–RL7  
ADP3335ARM-5–REEL  
ADP3335ARM-5–REEL7  
ADP3335ACP-1.8–RL  
ADP3335ACP-1.8–RL7  
ADP3335ACP-2.5–RL  
ADP3335ACP-2.5–RL7  
ADP3335ACP-2.85–R7  
ADP3335ACP-3.3–RL  
ADP3335ACP-3.3–RL7  
ADP3335ACP-5–REEL  
ADP3335ACP-5–REEL7  
LFA  
LFA  
LFC  
LFC  
LFC3  
LFD  
LFD  
LFD3  
LFE  
LFE3  
LFE  
LFF  
LFF  
LFA  
LFA  
LFC  
LFC  
LFD  
LFE  
LFE  
LFF  
LFF  
5 V  
1.8 V  
1.8 V  
2.5 V  
2.5 V  
2.85 V  
3.3 V  
3.3 V  
5 V  
5 V  
1 Contact the factory for other output voltage options.  
2 Z = Pb-free part.  
3 Pb-free devices have a "#" marked on the device.  
Rev. A | Page 13 of 16  
 
 
 
 
 
 
ADP3335  
NOTES  
Rev. A | Page 14 of 16  
ADP3335  
NOTES  
Rev. A | Page 15 of 16  
ADP3335  
NOTES  
© 2004 Analog Devices, Inc. All rights reserved. Trademarks and  
registered trademarks are the property of their respective owners  
C00147-0-1/04(A)  
Rev. A | Page 16 of 16  

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