PT6703 Datasheet, PDF (6/7 Pages) Texas Instruments – 13-A Low-Voltage Programmable Integrated Switching Regulator

Application Notes
PT6703
Capacitor Recommendations for the Non-Isolated
13-A Excalibur™ Series of Regulators
Input Capacitors
The recommended input capacitance is determined by the
1.0 ampere minimum ripple current rating and 1000µF
minimum capacitance. Capacitors listed below must be
rated for a minimum of 2x the input voltage with +5V
operation. Ripple current and ≤100mΩ Equivalent Series
Resistance (ESR) values are the major considerations along
with temperature when selecting the proper capacitor.
Output Capacitors
The minimum required output capacitance is 330µF with a
maximum ESR less than or equal to 100mΩ. Failure to
observe this requirement may lead to regulator instability
or oscillation. Electrolytic capacitors have poor ripple
performance at frequencies greater than 400kHz, but
excellent low frequency transient response. Above the
ripple frequency ceramic decoupling capacitors are nec-
essary 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 1 below.
Tantalum Characteristics
Tantalum capacitors with a minimum 10V rating are
recommended on the output bus, but only the AVX TPS
Series, Sprague 594/595 Series, or Kemet T495/T510
Series. The AVX TPS Series, Sprague Series or Kemet
Series capacitors are specified over other types due to
their higher surge current, excellent power dissipation and
ripple current ratings. As a caution, the TAJ Series by AVX
is not recommended. This series exhibits considerably higher
ESR, reduced power dissipation and lower ripple current
capability. The TAJ Series is a less reliable compared to the
TPS series when determining power dissipation capability.
Capacitor Table
Table 1 identifies the characteristics of capacitors from a
number of vendors with acceptable ESR and ripple current
(rms) ratings. The suggested minimum quantities per regu-
lator for both the input and output buses are identified.
This is not an extensive capacitor list. The table below is a
suggested selection guide for input and output capacitors. Other
capacitor vendors are available with comparable RMS ripple
current rating and ESR (Equivalent Series Resistance at 100kHz).
These critical parameters are necessary to insure both opti-
mum regulator performance and long capacitor life.
Table 1 Capacitors Characteristic Data
Capacitor
Vendor
Series
Capacitor Characteristics
Quantity
Working Value(µF) (ESR) Equivalent
Voltage
Series Resistance
Panasonic
FC Surface Mtg
FC Radial
United
Chemi -Con
LFZ Radial
FX Surface Mtg
Nichicon
PL Series
PM Series
Oscon SS
SV
AVX
Tanatalum
TPS- Series
Vishay/Sprague
Tantalum
595D/594D
Kemet
Tantalum
T510/T495
Series
Sanyo Poscap
TPB
10V
35V
25V
10V
25V
10V
6.3V
10V
25V
10V
25V
10V
10V
10V
10V
10V
10V
10V
10V
10V
1000
330
330
1200
330
1000
1000
680
330
1000
330
330
330
330
330
0.065Ω
0.065Ω
0.090Ω
0.065Ω
0.090Ω
0.068Ω
0.013Ω
0.015Ω/2=0.007Ω
0.095Ω
0.065Ω
0.095Ω
0.025Ω/3=0.008Ω
0.020Ω/3=0.007Ω
0.100Ω/3=0.034Ω
0.060Ω/3=0.02Ω
330
0.045Ω/3=0.015Ω
680
0.090Ω/4=0.023Ω
330
0.035Ω/3=0.012Ω
220
0.070Ω/5=0.035Ω
220
0.040Ω/5=0.008Ω
85°C Maximum
Ripple
Current(Irms)
1205mA
1205mA
765mA
1205mA
760mA
1050mA
4935mA
>7000mA
750mA
1040mA
750mA
>7000mA
>7000mA
>3500mA
>3500mA
>4600mA
>2500mA
>5000mA
>3000mA
>3000mA
Physical
Size(mm)
12.5x16.5
12.5x16.5
10x12.5
12.5x15
10x12.5
10x16
10x10.5
10X10.5
10x15
12.5x15
10x15
10x10.5
10.3x12.6
7.0Lx
5.97Wx
3.45H
7.2L x
6.0W x
3.5H
4.3Wx7.3L
x4.0H
7.2L x
4.3W x
3.1H
Input Output
Bus
Bus
Vendor Number
1
1 EEVFC1A102LQ
1 EEVFC1V331LQ
1 EEUFA1E331
1
1 EEUFC1A122S
1 LXZ25VB331M10X12LL
1
1 LXZ35VB102M10X16LL
1
1 6FX1000M(Vin 3.3V)
2
1 10FX680M(Os-con)
1 UPL1E331MPH6
1
1 UPL1A102MHH6
1 UPM1E331MPH6
3
1 10SS330M
3
1 10SV330M(Surface Mtg)
3
1 TPSV337M010R0100
3
1 TPSV337M010R0060
3
1 594D337X0010R2T
Surface Mount
2
1 595D687X0010R2T
3
1 T510X337M010AS
5
2 T495X227M010AS
Surface Mount
5
2 10TPB220M
Surface Mount
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