ADP3335ARMZ-3.3-RL2 [ADI]

IC VREG 3.3 V FIXED POSITIVE LDO REGULATOR, 0.37 V DROPOUT, PDSO8, LEAD FREE, MO-187AA, MSOP-8, Fixed Positive Single Output LDO Regulator;
ADP3335ARMZ-3.3-RL2
型号: ADP3335ARMZ-3.3-RL2
厂家: ADI    ADI
描述:

IC VREG 3.3 V FIXED POSITIVE LDO REGULATOR, 0.37 V DROPOUT, PDSO8, LEAD FREE, 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:257K)
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  
Data Sheet  
ADP3335  
FEATURES  
FUNCTIONAL BLOCK DIAGRAM  
High accuracy over line and load: 0.9% at 25°C, 1.8% over  
temperature  
Ultralow dropout voltage: 200 mV (typical) at 500 mA  
Requires only CO = 1.0 µF for stability  
anyCAP® = stable with any type of capacitor (including MLCC)  
Current and thermal limiting  
Q1  
OUT  
NR  
IN  
ADP3335  
R1  
R2  
THERMAL  
PROTECTION  
CC  
DRIVER  
gm  
SD  
+
BANDGAP  
REF  
Low noise  
Low shutdown current: < 10 nA (typical)  
2.6 V to 12 V supply range  
–40°C to +85°C ambient temperature range  
GND  
Figure 1.  
APPLICATIONS  
5
PCMCIA cards  
NR  
Cellular phones  
ADP3335  
Camcorders, cameras  
Networking systems, DSL/cable modems  
Cable set-top box  
3
2
1
OUT  
IN  
7
8
OUT  
OUT  
V
V
OUT  
IN  
SD  
IN  
+
+
C
IN  
1µF  
C
OUT  
1µF  
GND  
4
MP3/CD players  
6
DSP supplies  
ON  
OFF  
Figure 2. Typical Application Circuit  
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 1.8% 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 80 µA (typical) in light load situations.  
Rev. C  
Document Feedback  
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Tel: 781.329.4700 ©2000–2012 Analog Devices, Inc. All rights reserved.  
Technical Support  
www.analog.com  
 
 
 
 
ADP3335  
Data Sheet  
TABLE OF CONTENTS  
Features .............................................................................................. 1  
Applications Information .............................................................. 10  
Output Capacitor Selection....................................................... 10  
Input Bypass Capacitor.............................................................. 10  
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  
Applications....................................................................................... 1  
Functional Block Diagram .............................................................. 1  
General Description ......................................................................... 1  
Revision History ............................................................................... 2  
Specifications..................................................................................... 3  
Absolute Maximum Ratings............................................................ 4  
ESD Caution.................................................................................. 4  
Pin Configuration and Function Descriptions............................. 5  
Typical Performance Characteristics ............................................. 6  
Theory of Operation ........................................................................ 9  
REVISION HISTORY  
12/12—Rev. B to Rev. C  
Changes to Figure 14 and Figure 16............................................... 7  
Updated Outline Dimensions....................................................... 12  
Changes to Ordering Guide .......................................................... 13  
1/04—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  
6/10—Rev. A to Rev. B  
Added Exposed Pad Notation to Figure 4 and Table 3................ 5  
Added Exposed Pad Notation to Outline Dimensions ............. 12  
Changes to Ordering Guide .......................................................... 13  
Rev. C | Page 2 of 16  
 
Data Sheet  
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. C | Page 3 of 16  
 
 
 
ADP3335  
Data Sheet  
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 indicated in the operational  
section 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  
θJA, 2-layer LFCSP-8  
158°C/W  
62°C/W  
ESD CAUTION  
θJA, 4-layer LFCSP-8  
48°C/W  
Storage Temperature Range  
Lead Temperature Range (Soldering 10 sec)  
Vapor Phase (60 sec)  
–65°C to +150°C  
300°C  
215°C  
Infrared (15 sec)  
220°C  
Rev. C | Page 4 of 16  
 
 
Data Sheet  
ADP3335  
PIN CONFIGURATION AND FUNCTION 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  
1
8 IN  
ADP3335  
TOP VIEW  
(Not to Scale)  
2
3
4
7
OUT  
IN  
6 SD  
NR  
OUT  
GND  
5
NOTES  
1. THE EXPOSED PAD ON THE BOTTOM OF THE PACKAGE  
ENHANCES THE THERMAL PERFORMANCE AND IS  
ELECTRICALLY CONNECTED TO DIE SUBSTRATE.  
THERMAL VIAS MUST BE ISOLATED OR CONNECTED  
TO IN. DO NOT CONNECT THE THERMAL PAD TO  
GROUND.  
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  
Exposed  
Pad  
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.  
The exposed pad on the bottom of the LFCSP package enhances thermal performance and is electrically  
connected to the die substrate, which is electrically common with the input pins, IN (Pin 7 and Pin 8), inside the  
package.  
7, 8  
EP  
Rev. C | Page 5 of 16  
 
ADP3335  
Data Sheet  
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  
0
100  
200  
300  
400  
500  
–40  
–15  
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. C | Page 6 of 16  
 
Data Sheet  
ADP3335  
250  
200  
150  
100  
50  
2.210  
2.200  
2.190  
2.180  
2.170  
3.500  
3.000  
V
R
C
= 2.2V  
= 4.4  
= 1µF  
OUT  
L
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  
2.210  
2.200  
2.190  
2.189  
2.179  
3.500  
3.000  
3.0  
2.5  
2.0  
1.5  
1.0  
0.5  
0
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  
3
2
1
0
4
2
0
C
OUT  
= 1µF  
2.1  
C
OUT  
= 10µF  
V
= 4V  
IN  
R
C
= 2.2  
= 1µF  
L
L
400  
200  
V
= 2.2V  
OUT  
SD = V  
IN  
0
R
L
= 4.4Ω  
200  
400  
TIME (µs)  
600  
800  
200  
400  
600  
TIME (µs)  
800  
Figure 13. Power-Up Response  
Figure 16. Load Transient Response  
Rev. C | Page 7 of 16  
ADP3335  
Data Sheet  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
V
= 2.2V  
OUT  
2.3  
2.2  
C
= 10µF  
L
I
L
= 500mA  
C
= 1µF  
L
I
L
= 500mA  
2.1  
C
= 1µF  
= 50µA  
L
V
R
C
= 4V  
= 4.4  
= 10µF  
IN  
I
L
L
L
400  
200  
C
= 10µF  
= 50µA  
L
0
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
L
= 0mA WITH NOISE REDUCTION  
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  
= 2.2V  
IN  
OUT  
= 4.4  
V
OUT  
= 2.2V  
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. C | Page 8 of 16  
 
Data Sheet  
ADP3335  
THEORY OF OPERATION  
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.  
R4, the values can be chosen to produce a 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 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.  
OUTPUT  
INPUT  
COMPENSATION  
CAPACITOR  
ATTENUATION  
R1  
Q1  
(V  
/V  
)
BANDGAP OUT  
C
D1  
R3  
LOAD  
PTAT  
(a)  
R2  
NONINVERTING  
WIDEBAND  
DRIVER  
g
m
V
OS  
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.  
PTAT  
R
LOAD  
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.  
Additional features of the circuit include current limit, thermal  
shutdown, and noise reduction.  
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 divider—R3 and  
Rev. C | Page 9 of 16  
 
ADP3335  
Data Sheet  
APPLICATIONS 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  
An input bypass capacitor is not strictly required, but is advisable  
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.  
CALCULATING JUNCTION TEMPERATURE  
Device power dissipation is calculated as follows:  
PD = (VIN VOUT)ILOAD + (VIN)IGND  
Where ILOAD and IGND are load current and ground current, and  
VIN and VOUT are input and output voltages, respectively.  
Assuming ILOAD = 400 mA, IGND = 4 mA, VIN = 5.0 V, and VOUT  
=
NOISE REDUCTION  
3.3 V, device power dissipation is  
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 connection 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.  
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.  
TJA = 0.700 W × 48°C/W = 33.6°C  
To limit the maximum junction temperature to 150°C, the  
maximum allowable ambient temperature will be  
C
NR  
T
AMAX = 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. C | Page 10 of 16  
 
 
 
 
 
 
 
Data Sheet  
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 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.  
5. Use additional copper layers or planes to reduce the thermal  
resistance. When connecting to other layers, use multiple  
vias, if 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  
SHUTDOWN MODE  
1.40  
1.90  
SD  
Applying a TTL high signal to the shutdown ( ) pin or tying it  
SD  
to the input pin, turns the output ON. Pulling  
down to 0.4 V  
3.36  
or below, or tying it to ground, turns the output OFF. In shutdown  
mode, quiescent current is reduced to a typical value of 10 nA.  
Figure 25. 3 mm × 3 mm LFCSP Pad Pattern  
(Dimensions shown in millimeters)  
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. C | Page 11 of 16  
 
 
 
 
ADP3335  
Data Sheet  
OUTLINE DIMENSIONS  
3.25  
3.00 SQ  
2.75  
0.60 MAX  
5
0.50  
BSC  
0.60 MAX  
8
2.95  
2.75 SQ  
2.55  
1.60  
1.45  
1.30  
EXPOSED  
PAD  
TOP  
VIEW  
PIN 1  
INDICATOR  
(BOTTOM VIEW)  
4
1
PIN 1  
INDICATOR  
0.50  
0.40  
0.30  
1.89  
1.74  
1.59  
12° MAX  
0.70 MAX  
0.65TYP  
0.90 MAX  
0.85 NOM  
0.05 MAX  
0.01 NOM  
FOR PROPER CONNECTION OF  
THE EXPOSED PAD, REFER TO  
THE PIN CONFIGURATION AND  
FUNCTION DESCRIPTIONS  
0.30  
0.23  
0.18  
SEATING  
PLANE  
0.20 REF  
SECTION OF THIS DATA SHEET.  
Figure 26. 8-Lead Lead Frame Chip Scale Package [LFCSP_VD]  
3 mm × 3 mm Body, Very Thin, Dual Lead  
(CP-8-2)  
Dimensions shown in millimeters  
3.20  
3.00  
2.80  
8
1
5
4
5.15  
4.90  
4.65  
3.20  
3.00  
2.80  
PIN 1  
IDENTIFIER  
0.65 BSC  
0.95  
0.85  
0.75  
15° MAX  
1.10 MAX  
0.80  
0.55  
0.40  
0.15  
0.05  
0.23  
0.09  
6°  
0°  
0.40  
0.25  
COPLANARITY  
0.10  
COMPLIANT TO JEDEC STANDARDS MO-187-AA  
Figure 27. 8-Lead Mini Small Outline Package [MSOP]  
(RM-8)  
Dimensions shown in millimeters  
Rev. C | Page 12 of 16  
 
Data Sheet  
ADP3335  
ORDERING GUIDE  
Model1  
Output Voltage (V)2  
Temperature Range  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
–40°C to +85°C  
Package Description  
8-Lead LFCSP_VD  
8-Lead LFCSP_VD  
8-Lead LFCSP_VD  
8-Lead LFCSP_VD  
8-Lead LFCSP_VD  
8-Lead LFCSP_VD  
8-Lead MSOP  
8-Lead MSOP  
8-Lead MSOP  
8-Lead MSOP  
8-Lead MSOP  
Package Option  
CP-8-2  
CP-8-2  
CP-8-2  
CP-8-2  
CP-8-2  
CP-8-2  
RM-8  
RM-8  
RM-8  
RM-8  
RM-8  
Branding3  
L1G  
L1H  
L1J  
L1K  
L1K  
L1L  
LFA  
LFA  
LFC  
LFC  
LFD  
LFD  
LFE  
LFE  
LFF  
LFF  
ADP3335ACPZ-1.8-R7  
ADP3335ACPZ-2.5-R7  
ADP3335ACPZ-2.85R7  
ADP3335ACPZ-3.3-R7  
ADP3335ACPZ-3.3-RL  
ADP3335ACPZ-5-R7  
ADP3335ARMZ-1.8-R7  
ADP3335ARMZ-1.8-RL  
ADP3335ARMZ-2.5-RL  
ADP3335ARMZ-2.5RL7  
ADP3335ARMZ-2.85R7  
ADP3335ARMZ-2.85RL  
ADP3335ARMZ-3.3-RL  
ADP3335ARMZ-3.3RL7  
ADP3335ARMZ-5-R7  
ADP3335ARMZ-5-REEL  
1.8  
2.5  
2.85  
3.3  
3.3  
5
1.8  
1.8  
2.5  
2.5  
2.85  
2.85  
3.3  
3.3  
5
8-Lead MSOP  
8-Lead MSOP  
8-Lead MSOP  
8-Lead MSOP  
RM-8  
RM-8  
RM-8  
RM-8  
5
8-Lead MSOP  
RM-8  
1 Z = RoHS Compliant Part.  
2 For additional voltage options, contact a local sales or distribution representative.  
3 Z = RoHS Compliant Parts have a "#" marked on the device preceding the date code.  
Rev. C | Page 13 of 16  
 
 
ADP3335  
NOTES  
Data Sheet  
Rev. C | Page 14 of 16  
Data Sheet  
NOTES  
ADP3335  
Rev. C | Page 15 of 16  
ADP3335  
NOTES  
Data Sheet  
©2000–2012 Analog Devices, Inc. All rights reserved. Trademarks and  
registered trademarks are the property of their respective owners.  
D00147-0-12/12(C)  
Rev. C | Page 16 of 16  

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