PT6653E Datasheet, PDF (4/16 Pages) Texas Instruments – Single Device: 5-A Output Input Voltage Range: 9 V to 28 V 12 V / 24 V Input Compatible

Application Notes
PT6650 Series
Capacitor Recommendations for the
PT6650 Regulator Series
Input Capacitor:
The required input capacitor is determined by 560 µF
capacitance value, and a minimum ripple current rating of
1.2 Arms. The ripple current rating and less than 120 mΩ
equivalent series resistance (ESR) are the major consid-
erations, along with operating temperature, when selecting
input capacitors.
Tantalum/Os-Con capacitors are not recommended due
to a minimum voltage rating of 2× (the max. DC voltage
+ AC ripple). This is standard practice to ensure reliability.
Output Capacitors:
The ESR specification of the output capacitor should be
a minimum of 50 mΩ ^*. Electrolytic capacitors have
marginal ripple performance at frequencies greater than
400 kHz but excellent low frequency 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. Electrolytic capacitors with
appropriate ESR values are identified in Table 1-1. In low-
temperature applications (<0 °C), a higher capacitance
with lower ESR will improve performance.
* Os-Con and ultra low ESR type capacitors are not recom-
mended on the output bus as they degrade regulator stability.
Tantalum Capacitors (For V_o <5.1 V)
Tantalum type capacitors can be used on the output bus for
output voltages less than 5.1 V. Voltages higher than this
will exceed the capacitor’s published surge voltage limits.
If tantalum capacitors are located on the output bus, an
appropriate fuse with I²t current derating is recommended
along with an external clamp component. An Output
Over-voltage Clamp (OOVC) will fault the output fuse
to protect the capacitors in event of an over-voltage con-
dition. The OOVC can be a simple zener high power
diode, 3 W to 5 W, located on the load side of the output
bus. The zener diode should be rated to 1.3 times the
normal output voltage.
Capacitor Table
Table 1-1 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
(Equivalent Series Resistance at 100 kHz) are critical param-
eters necessary to insure both optimum regulator performance
and long capacitor life.
Table 1-1: Input/Output Capacitors
Capacitor Vendor/
Series
Panasonic
FC (Radial)
FC/FK (SMT)
United Chemi-con
LXZ/LXV Series
MVY (SMT)
Nichicon
PM Series
AVX Tantalum
TPS (SMT)
Kemet Tantalum
T496 /T495 Series
(SMT)
Sprague Tantalum
594D Series
(SMT)
Capacitor Characteristics
Quantity
Working Value (µF) (ESR) Equivalent
Voltage
Series Resistance
50 V
50 V
50 V
63 V
35 V
50 V
50 V
35 V
35 V
50 V
63 V
50 V
10 V
10 V
560
390
390
680
330
1000
680
330
220
560
560
330
330
330
0.068 Ω
0.080 Ω
0.080 Ω
0080 Ω
0.080 Ω
0.073 Ω
0.048 Ω
0.068 Ω
0.150 Ω
0.044 Ω
0.039 Ω
0.060 Ω
0.10 Ω
0.06 Ω
Max. Ripple
Current @85°C
(Irms)
1900 mA
1610 mA
1610 mA
1690 mA
850 mA
1610 mA
1840 mA
1050 mA
670 mA
1550 mA
1400 mA
1210 mA
>2500 mA
>3000 mA
10 V
220
10 V
220
0.500 Ω
0.070 Ω
500 mA
>2000 mA
10 V
330
0.130 Ω
1393 mA
Physical
Size (mm)
Input
Bus
Output
Bus
Vendor Part Number
18×15
16×15
16×15
18×16.5
10×10.2
16×16.5
16×20
10×16
10×10.3
16×20
18×20
16×15
7.3L
×5.7W
×4.1H
4.3W
×7.3L
×4.0H
7.2L
×6W
×4.1H
1
2
2
1
N/R ^[1]
1
1
N/R ^[1]
N/R ^[1]
1
1
2
N/R ^[1]
N/R ^[1]
N/R ^[1]
N/R ^[1]
N/R ^[1]
1 EEUFC1H561
1 EEUFC1H391S
1 EEUFC1H391S
1 EEVFK1J681M
1 EEVFK1V331P
1 EEVFK1H102M
1 LXZ50VB681M16X20LL
1 LXV35VB331M10X16LL
2
MVY35VC2211M10X10TP
1 UPM1H561MHH6
1 UPM1J561MHH6
1 UPM1H331MHH6
1 ^[2] TPSE337M010R0100 (V_o <5.1V)
1 ^[2] TPSV337M010R0060 (V_o <5.1V)
2 ^[2] T496X227M010AS (V_o <5.1V)
2 ^[2] T495X227M0100AS (V_o <5.1V)
1 ^[2] 595D337X0010R2T (V_o <5.1V)
Notes: [1] N/R –Not recommended. The voltage rating does not meet the minimum operating limits.
[2] A fused input bus is recommended when tantalum capacitors are used on the output bus.
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