ADP3335ACP-5-REEL Analog Devices Inc, ADP3335ACP-5-REEL Datasheet - Page 10

• Manufacturer Part Number: ADP3335ACP-5-REEL
• Description: IC REG LDO 5V 500MA 8-LFCSP TR
• Manufacturer: Analog Devices Inc
• Series: anyCAP®r

Specifications of ADP3335ACP-5-REEL

• Rohs Status: RoHS non-compliant
• Regulator Topology: Positive Fixed
• Voltage - Output: 5V
• Voltage - Input: Up to 12V
• Voltage - Dropout (typical): 0.2V @ 500mA
• Number Of Regulators: 1
• Current - Output: 500mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-LFCSP
• Current - Limit (min): -

ADP3335
APPLICATIONS INFORMATION
OUTPUT CAPACITOR SELECTION
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.
INPUT BYPASS CAPACITOR
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 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
A noise reduction capacitor (C
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.
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 C
will be delayed. With NR values greater than 1 nF, this delay
may be on the order of several milliseconds.
V
IN
1μF
C
IN
Figure 24. Typical Application Circuit
OFF
+
7
8
ON
IN
IN
SD
ADP3335
6
NR
5
NR
NR
GND
OUT
OUT
OUT
) can be used, as shown in
4
C
increases, the turn-on time
NR
3
2
1
+
C
1μF
V
OUT
OUT
Rev. B | Page 10 of 16
THERMAL OVERLOAD PROTECTION
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.
CALCULATING JUNCTION TEMPERATURE
Device power dissipation is calculated as follows:
Where I
V
Assuming I
3.3 V, device power dissipation is
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, θ
the above example, where the power dissipation is 700 mW, the
temperature rise above ambient will be approximately equal to
To limit the maximum junction temperature to 150°C, the
maximum allowable ambient temperature will be
In this case, the resulting ambient temperature limitation is
above the maximum allowable ambient temperature of 85°C.
IN
and V
P
ΔT
T
P
D
AMAX
D
= (5 V – 3.3 V)400 mA + 5.0 V(4 mA) = 700 mW
JA
LOAD
=
OUT
= 0.700 W × 48°C/W = 33.6°C
(
= 150°C − 33.6°C = 116.4°C
V
LOAD
and I
IN
are input and output voltages, respectively.
−
= 400 mA, I
V
GND
OUT
are load current and ground current, and
)
I
LOAD
GND
+
( )
= 4 mA, V
V
IN
I
GND
IN
= 5.0 V, and V
JA
is 48°C/W. In
OUT
=