PT6470 Datasheet, PDF (6/14 Pages) Texas Instruments – 14-A 3.3-V Input Adjustable Integrated Switching Regulator

Application Notes
PT6460 & PT6470 Series
Capacitor Recommendations for the
PT6460 & PT6470 Regulator Series
Input Capacitor:
The recommended input capacitor is determined by a
minimum of 470 µF capacitance and 700 mA minimum
ripple current rating.
Ripple current and <100 mΩ equivalent series resistance
(ESR) values are the major considerations, along with
temperature, when when designing with different types
of capacitors. Tantalum capacitors have a recommended
minimum voltage rating of 2× (maximum DC voltage +
AC ripple). This is necessary to insure reliability for
input voltage bus applications.
Output Capacitors (Optional):
The ESR of the capacitors should be less than 150 mΩ.
Electrolytic capacitors have marginal ripple performance at
frequencies greater than 400 kHz but excellent low fre-
quency transient response. Above the ripple frequency,
ceramic capacitors are necessary to improve the transient
response and reduce any high frequency noise components
apparent during higher current excursions. Preferred low
ESR type capacitor part numbers are identified in Table 2-1.
Tantalum Capacitors( Optional Output Capacitors)
Tantalum type capacitors can be used for the output but
only the AVX TPS, Sprague 593D/594/595, or Kemet
T495/T510 series. These capacitors are recommended
over many other tantalum types due to their higher rated
surge, power dissipation, and ripple current capability.
As a caution the TAJ series by AVX is not recommended.
This series has considerably higher ESR, reduced power
dissipation, and lower ripple current capability. The TAJ
series is less reliable than the AVX TPS series when deter-
mining power dissipation capability. Tantalum or Oscon®
types are recommended for applications where ambient
temperatures fall below 0 °C.
Capacitor Table
Table 2-1 identifies the characteristics of capacitors from
a number of vendors with acceptable ESR and ripple
current (rms) ratings. The number of capacitors required
at both the input and output buses is identified for each
capacitor type.
This is not an extensive capacitor list. Capacitors from other
vendors are available with comparable specifications. Those listed
are for guidance. The RMS ripple current rating and ESR
(at 100kHz) are critical parameters necessary to insure both
optimum regulator performance and long capacitor life.
Table 2-1: Input/Output Capacitors
Capacitor Vendor/
Series
Capacitor Characteristics
Quantity
Panasonic
FC (Radial)
FK (SMT)
United Chemi-con
LXZ/LXV
FX
Nichicon PL/PM
NX Series (SMT)
Sanyo-Os-con SP
SVP (SMT)
AVX Tantalum
TPS (SMT)
Kemet Polymer
Tantalum
T520/T530 (SMT)
Sprague Tantalum
594D (SMT)
Working Value(µF) (ESR) Equivalent
Voltage
Series Resistance
16 V
470
10 V
560
25 V
470
35 V
470
0.09 Ω
0.09 Ω
0.08 Ω
0.06 Ω
Maximum Ripple
Current @105°C
(Irms)
755 mA
755 mA
850 mA
1100 mA
Physical Size
(mm)
Input
Bus
10x12.5
1
10×12.5
1
10x10.2
1
12.5×13.5
1
Output
Bus
Vendor Part Number
1 EEUFC1C471
1 EEUFC1A561
1 EEVFK1E471P
1 EEVFK1V471Q
16 V
10 V
10 V
16 V
16 V
470
0.090 Ω
680
0.090 Ω
680
0.015 Ω
330
0.12÷2=0.06 Ω
470
0.09 Ω
10 V
330
10 V
470
10 V
560
10 V
470
10 V
470
10 V
330
10 V
330
0.024 Ω
0.015 Ω
0.013 Ω
0.045 Ω
0.060 Ω
0.040 Ω
0.015 Ω
760 mA
770 mA
4735 mA
745 mA
770 mA
3770 mA
>4500 mA
>5200 mA
1723 mA
1826 mA
1800 mA
>3800 mA
10x12.5
1
10x12.5
1
10×10.5
1
10x12.5
2
10x15
1
10x8
2
10×10.5
1
11×12.7
1
7.3L×5.7W
1
×4.1H
1
4.3W×7.3L
2
×4.0H
2
1 LXZ16VB471M10X12LL
1 LXZ10VB681M10X12LL
1 10FX680M
1 UPM1C331MPH6
1 UPM1C 471MPH6
1 PNX1A330MCAR1GS
1 10SP470M
1 10SVP560M
1 TPSE477M010R0045
1 TPSV477M010R0060
1 T520X337M010AS
1 T530X337M010AS
10 V
680
0.090 Ω
1660 mA
7.2L×6W
1
×4.1H
1 595D687X0010R2T
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