LP5521TMEV National Semiconductor, LP5521TMEV Datasheet - Page 27

• Manufacturer Part Number: LP5521TMEV
• Description: EVAL BOARD FOR LP5521
• Manufacturer: National Semiconductor

Specifications of LP5521TMEV

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: Q5109809

1 μF for C
470 nF for C
LEDs
Recommended External Components
CAPACITOR SELECTION
The LP5521 requires 4 external capacitors for proper opera-
tion (C
mount multi-layer ceramic capacitors are recommended.
These capacitors are small, inexpensive and have very low
equivalent series resistance (ESR < 20 mΩ typ.). Tantalum
capacitors, OS-CON capacitors, and aluminum electrolytic
capacitors are not recommended for use with the LP5521 due
to their high ESR, as compared to ceramic capacitors.
For most applications, ceramic capacitors with X7R or X5R
temperature characteristic are preferred for use with the
LP5521. These capacitors have tight capacitance tolerance
(as good as ±10%) and hold their value over temperature
(X7R: ±15% over -55°C to 125°C; X5R: ±15% over -55°C to
85°C).
Capacitors with Y5V or Z5U temperature characteristic are
generally not recommended for use with the LP5521. Capac-
itors with these temperature characteristics typically have
List of Recommended External Components
C1005X5R1A105K
C1005X5R1A474K
ECJUVBPA105M
ECJ0EB1A105M
ECJ0EB0J474K
IN
Model
OUT
= C
FLY1-2
and C
OUT
= 1 μF, C
IN
Ceramic X5R, array of two
FLY1
= C
Ceramic X5R
Ceramic X5R
Ceramic X5R
Ceramic X5R
FLY2
Type
= 470 nF). Surface-
Panasonic
Panasonic
Panasonic
Vendor
27
TDK
TDK
wide capacitance tolerance (+80%, -20%) and vary signifi-
cantly over temperature (Y5V: +22%, -82% over -30°C to
+85°C range; Z5U: +22%, -56% over +10°C to +85°C range).
Under some conditions, a nominal 1 μF Y5V or Z5U capacitor
could have a capacitance of only 0.1 μF. Such detrimental
deviation is likely to cause Y5V and Z5U capacitors to fail to
meet the minimum capacitance requirements of the LP5521.
The minimum voltage rating acceptable for all capacitors is
6.3V. The recommended voltage rating of the output capaci-
tor is 10V to account for DC bias capacitance losses.
Some ceramic capacitors, especially those in small pack-
ages, exhibit a strong capacitance reduction with the
increased applied voltage (DC bias effect). The capaci-
tance value can fall below half of the nominal capaci-
tance. Choose output and input capacitor with DC bias
voltage effect better than –50% at 5V voltage (0.5 μF at
5V).
User Defined
Voltage Rating
10 V
10 V
10 V
10 V
10 V
Size inch (mm)
0402 (1005)
0402 (1005)
0402 (1005)
0402 (1005)
0504
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