PTN78060A
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SLTS245B – APRIL 2005 – REVISED AUGUST 2006
15-W, WIDE-INPUT ADJUSTABLE POSITIVE-TO-NEGATIVE
VOLTAGE REGULATOR MODULE
FEATURES
APPLICATIONS
•
•
•
•
•
•
•
•
•
•
Up to 3-A Output Current
Wide-Input Voltage
(9 V to 29 V)
Wide-Output Voltage Adjust
(–15 V to –3 V)
High Efficiency (Up to 88%)
Undervoltage Lockout
Output Current Limit
Overtemperature Shutdown
Operating Temperature: –40°C to 85°C
Surface-Mount Package Available
General-Purpose, Industrial Controls,
HVAC Systems
Test and Measurement,
Medical Instrumentation
AC/DC Adaptors, Vehicles,
Marine, and Avionics
•
•
DESCRIPTION
The PTN78060A is a series of high-efficiency, buck-boost, integrated switching regulators (ISR), that represent
the third generation in the evolution of the (PT)78NR100 series of products. In new designs, the PTN78060A
series should also be considered in place of the PT6640 series of single in-line pin (SIP) products. In all cases,
the PTN78060A has either similar or improved electrical performance characteristics. The caseless,
double-sided package has excellent thermal characteristics, and is compatible with TI's roadmap for RoHS and
lead-free compliance.
Operating from a wide-input voltage range of 9 V to 29 V, the PTN78060A provides high-efficiency,
positive-to-negative voltage conversion for loads of up to 3 A. The output voltage can be set to any value over a
wide adjustment range using a single external resistor. The adjust range is –15 V to –3 V.
The PTN78060A is suited to a wide variety of general-purpose industrial applications that operate off 12-V, 24-V,
or tightly regulated 28-V dc power.
C4(3)
4.7 µF
Ceramic
(Optional)
1
VO
7
1
PTN78060A
2
6
VI
3
+
N/C
C1(1)
GND
100 µF
Electrolytic
(Required)
C2
3 × 4.7 µF
Ceramic
(Required)
4
5
N/C
RSET (2)
1%, 0.05 W
(Required)
+
C3(1)
100 µF
(Required)
GND
L
O
A
D
UDG−05094
(1)
See the Application Information section for capacitor recommendations
(2)
RSET is required to adjust the output voltage lower than -3 V. See the Application Information section for values.
(3)
For reduced VO ripple and noise, a ceramic capacitor is suggested.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2005–2006, Texas Instruments Incorporated
PTN78060A
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SLTS245B – APRIL 2005 – REVISED AUGUST 2006
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
ORDERING INFORMATION
For the most current package and ordering information, see the Package Option Addendum at the end of this datasheet, or see
the TI website at www.ti.com.
ABSOLUTE MAXIMUM RATINGS
(1)
over operating free-air temperature range unless otherwise noted
all voltages with respect to GND
UNIT
TA
Operating free-air temperature
Over VI range
Wave solder temperature
Surface temperature of module body or pins (5
seconds)
–40°C to 85°C
Solder reflow temperature
Surface temperature of module body or pins
Horizontal TH (suffix AH)
260°C
Horizontal SMD (suffix AS)
235°C
Horizontal SMD (suffix AZ)
Tstg
Storage temperature
PO
Output power
(1)
260°C
–40°C to 125°C
|VO| ≥ 5 V
15 W
Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating
conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
RECOMMENDED OPERATING CONDITIONS
VI
Input voltage
TA
Operating free-air temperature
MIN
MAX
9
32 - |VO|
UNIT
V
–40
85
°C
PACKAGE SPECIFICATIONS
PTN78060x (Suffix AH, AS, and AZ)
Weight
Meets UL 94 V-O
Mechanical shock
Per Mil-STD-883D, Method 2002.3, 1 ms, ½ sine,
mounted
Mechanical vibration
Mil-STD-883D, Method 2007.2, 20-2000 Hz
(1)
2
3.9 grams
Flammability
Qualification limit.
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500 G
(1)
Horizontal T/H (suffix AH)
20 G
(1)
Horizontal SMD (suffix AS & AZ)
20 G
(1)
PTN78060A
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SLTS245B – APRIL 2005 – REVISED AUGUST 2006
ELECTRICAL CHARACTERISTICS
operating at 25°C free-air temperature, VI = 20 V, VO = –5 V, IO = IO (max), C1 = 100 µF, C2 = 3 × 4.7 µF, C3 = 100 µF, and
C4 = 4.7 µF (unless otherwise noted)
PARAMETER
IO
Output current
VI
Input voltage range
VO
TEST CONDITIONS
TA = 85°C, natural convection airflow
Over IO range
η
(1)
VO = –12 V
0.1
1.25
(1)
VO = –5 V
0.1
3
(1)
VO = –3.3 V
0.1
3
(1)
VO = –15 V
9
17
(2)
VO = –12 V
9
20
(2)
VO = –5 V
9
27
(2)
VO = –3.3 V
9
28.7
(2)
–40°C to +85°C
Line regulation
Over VI range
±10
Load regulation
Over IO range
±10
Total output voltage
variation
Includes set point, line, load
–40 < TA < 85°C
∆VO = –50 mV
–15
RSET = 100 Ω, IO = 1 A, VO = –15 V
88%
87%
RSET = 28.7 kΩ, IO = 3 A, VO = –5 V
82%
Recovery time
FS
Switching frequency
Over VI and IO ranges
UVLO
Undervoltage lockout
VI increasing
Ceramic
14.1
(4)
CI
External input
capacitance
Nonceramic
100
(4)
CO
External output
capacitance
100
(5)
14
(6)
VO over/undershoot
(5)
(6)
µs
550
%VO
660
Per Telcordia SR-332, 50% stress,
TA = 40°C, ground benign
8.9
kHz
V
µF
200
Equivalent series resistance (nonceramic)
(4)
A
200
2
440
Ceramic
(1)
(2)
(3)
V(PP)
5.5
5.5
Nonceramic
V
77%
2% VO
1-A/µs load step from 50% to 100%
IOmax
Calculated reliability
mV
(3)
–3
RSET = 2 kΩ, IO = 1.25 A, VO = –12 V
Transient response
MTBF
V
mV
±3%
RSET = 221 kΩ, IO = 3 A, VO = –3.3 V
Current limit threshold
A
±0.5%
9 V ≤ VI ≤ (32 - |VO|) V
20-MHz bandwidth
UNIT
±2% (3)
Temperature variation
Output voltage ripple
MAX
1
TA = 25°C
Efficiency
IO (LIM)
TYP
0.1
Set-point voltage
tolerance
Output voltage adjust
range
VO
MIN
VO = –15 V
1000
µF
mΩ
106 Hr
The maximum output current is 3 A or a maximum output power of 15 W, whichever is less.
The maximum input voltage is limited and defined to be (32 - |VO|).
The set-point voltage tolerance is affected by the tolerance and stability of RSET. The stated limit is unconditionally met if RSET has a
tolerance of 1% with 100 ppm/°C or better temperature stability.
A 100-µF electrolytic capacitor and three 4.7-µF ceramic capacitors are required across the input (VI and GND) for proper operation.
Locate the ceramic capacitors close to the module.
100 µF of output capacitance is required for proper operation. See the application information for further guidance.
This is the typical ESR for all the electrolytic (nonceramic) capacitance. Use 17 mΩ as the minimum when using max-ESR values to
calculate.
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PTN78060A
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SLTS245B – APRIL 2005 – REVISED AUGUST 2006
PIN ASSIGNMENT
1
7
PTN78060A
(Top View)
2
6
3
4
5
TERMINAL FUNCTIONS
TERMINAL
4
I/O
DESCRIPTION
1, 7
O
The negative output voltage power connection. It is also the reference for the VO Adjust control input. For
proper operation, pins 1 and 7 must be connected.
VI
2
I
The positive input voltage power node to the module, which is referenced to common GND.
N/C
3
VO Adjust
4
N/C
5
GND
6
NAME
NO.
VO
This pin is active and must be isolated from any electrical connection.
I
A 1% resistor must be connected between pin 4 and pin 7 to set the output voltage of the module. The
adjust range is –15 V to –3 V. If left open-circuit, the output voltage defaults to –3 V. The temperature
stability of the resistor should be 100 ppm/°C (or better). The standard resistor value for a number of
common output voltages is provided in the application information.
This pin is active and must be isolated from any electrical connection.
I/O
The common ground connection for both VI and VO power connections.
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TYPICAL CHARACTERISTICS (9-V INPUT) (1) (2)
OUTPUT VOLTAGE RIPPLE
vs
OUTPUT CURRENT
75
VO = -12 V
70
VO = -15 V
65
VO = -5 V
60
VO = -3 V
55
50
0
0.5
1
1.5
2
2.5
3
300
4.5
250
VO = -15 V
200
150
100
VO = -5 V
50
VO = -3 V
0
0
1.5
1
VO = -5 V
0.5
3
VO = -3 V
0
0.5
1.5
1
2.5
2
3
IO - Output Current - A
TEMPERATURE DERATING
vs
OUTPUT CURRENT
TEMPERATURE DERATING
vs
OUTPUT CURRENT
TEMPERATURE DERATING
vs
OUTPUT CURRENT
90
70
200 LFM
60
100 LFM
50
Nat conv
40
VO = -5 V
90
80
200 LFM
70
100 LFM
60
Nat conv
50
40
VO = -12 V
30
20
20
0
2
1.5
Figure 3.
80
30
2.5
0
2.5
2
VO = -15 V
Figure 2.
Ambient Temperature - oC
Ambient Temperature - oC
1
VO = -12 V
3
Figure 1.
90
0.5
1
1.5
2
IO - Output Current - A
Figure 4.
(2)
0.5
4
3.5
IO - Output Current - A
IO - Output Current - A
(1)
VO = -12 V
Ambient Temperature - oC
Efficiency - %
80
POWER DISSIPATION
vs
OUTPUT CURRENT
PD - Power Dissipation - W
90
85
VO - Output Voltage Ripple - mVPP
EFFICIENCY
vs
OUTPUT CURRENT
2.5
3
80
200 LFM
70
100 LFM
60
Nat conv
50
40
VO = -15 V
30
20
0
0.25
0.5
0.75
1
1.25
IO - Output Current - A
Figure 5.
0
0.2
0.4
0.6
0.8
1
IO - Output Current - A
Figure 6.
The electrical characteristic data has been developed from actual products tested at 25°C. This data is considered typical for the
converter. Applies to Figure 1, Figure 2, and Figure 3.
The temperature derating curves represent the conditions at which internal components are at or below the manufacturer's maximum
operating temperatures. Derating limits apply to modules soldered directly to a 100 mm x 100 mm, double-sided PCB with 2 oz. copper.
For surface mount packages (AS and AZ suffix), multiple vias (plated through holes) are required to add thermal paths around the power
pins. Please refer to the mechanical specification for more information. Applies to Figure 4, Figure 5, and Figure 6.
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PTN78060A
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TYPICAL CHARACTERISTICS (12-V INPUT) (1) (2)
OUTPUT VOLTAGE RIPPLE
vs
OUTPUT CURRENT
75
VO = -12 V
70
VO = -5 V
VO = -15 V
65
VO = -3 V
60
55
50
0
0.5
1
1.5
2
2.5
3
VO = -15 V
120
80
VO = -5 V
40
VO = -3 V
1.5
2.5
2
2
1.5
1
VO = -5 V
0.5
3
VO = -3 V
0
0.5
1.5
1
2.5
2
3
IO - Output Current - A
Figure 9.
TEMPERATURE DERATING
vs
OUTPUT CURRENT
TEMPERATURE DERATING
vs
OUTPUT CURRENT
TEMPERATURE DERATING
vs
OUTPUT CURRENT
90
70
200 LFM
60
100 LFM
50
Nat conv
40
VO = -5 V
90
80
200 LFM
70
100 LFM
60
Nat conv
50
40
30
VO = -12 V
20
0
2.5
Figure 8.
80
30
VO = -15 V
Figure 7.
Ambient Temperature - oC
Ambient Temperature - oC
1
VO = -12 V
3
IO - Output Current - A
20
0.5
1
1.5
2
IO - Output Current - A
Figure 10.
6
0.5
3.5
0
0
0
90
(2)
VO = -12 V
160
IO - Output Current - A
(1)
4
200
Ambient Temperature - oC
Efficiency - %
80
POWER DISSIPATION
vs
OUTPUT CURRENT
PD - Power Dissipation - W
90
85
VO - Output Voltage Ripple - mVPP
EFFICIENCY
vs
OUTPUT CURRENT
2.5
3
80
200 LFM
70
100 LFM
60
Nat conv
50
40
VO = -15 V
30
20
0
0.25
0.5
0.75
1
1.25
IO - Output Current - A
Figure 11.
0
0.2
0.4
0.6
0.8
1
IO - Output Current - A
Figure 12.
The electrical characteristic data has been developed from actual products tested at 25°C. This data is considered typical for the
converter. Applies to Figure 7, Figure 8, and Figure 9.
The temperature derating curves represent the conditions at which internal components are at or below the manufacturer's maximum
operating temperatures. Derating limits apply to modules soldered directly to a 100 mm x 100 mm, double-sided PCB with 2 oz. copper.
For surface mount packages (AS and AZ suffix), multiple vias (plated through holes) are required to add thermal paths around the power
pins. Please refer to the mechanical specification for more information. Applies to Figure 10, Figure 11, and Figure 12.
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TYPICAL CHARACTERISTICS (24-V INPUT) (1) (2)
EFFICIENCY
vs
OUTPUT CURRENT
OUTPUT VOLTAGE RIPPLE
vs
OUTPUT CURRENT
160
80
75
70
65
VO = -5 V
60
55
VO = -3 V
50
45
40
0
0.5
1
1.5
2
2.5
3
3.5
140
120
PD - Power Dissipation - W
VO - Output Voltage Ripple - mVPP
90
85
Efficiency - %
POWER DISSIPATION
vs
OUTPUT CURRENT
VO = -5 V
100
80
60
40
VO = -3 V
20
0
IO - Output Current - A
0
0.5
1
1.5
2.5
2
3
2.5
VO = -5 V
2
1.5
1
VO = -3 V
0.5
0
3
0
0.5
Figure 13.
Figure 14.
TEMPERATURE DERATING
vs
OUTPUT CURRENT
Ambient Temperature - oC
Ambient Temperature - oC
2
2.5
3
Figure 15.
90
80
70
200
200 LFM
LFM
60
100LFM
LFM
100
50
Nat
Nat conv
conv
40
30
VO = -3.3
-5 V V
20
80
70
200
200 LFM
LFM
60
100LFM
LFM
100
50
Nat conv
Nat
conv
40
VO
VO
==
-5-5
VV
30
20
0
0.5
1
1.5
2
IO - Output Current - A
2.5
3
0
0.5
1
1.5
2
2.5
3
IO - Output Current - A
Figure 16.
(2)
1.5
TEMPERATURE DERATING
vs
OUTPUT CURRENT
90
(1)
1
IO - Output Current - A
IO - Output Current - A
Figure 17.
The electrical characteristic data has been developed from actual products tested at 25°C. This data is considered typical for the
converter. Applies to Figure 13, Figure 14, and Figure 15.
The temperature derating curves represent the conditions at which internal components are at or below the manufacturer's maximum
operating temperatures. Derating limits apply to modules soldered directly to a 100 mm x 100 mm, double-sided PCB with 2 oz. copper.
For surface mount packages (AS and AZ suffix), multiple vias (plated through holes) are required to add thermal paths around the power
pins. Please refer to the mechanical specification for more information. Applies to Figure 16, and Figure 17.
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APPLICATION INFORMATION
Adjusting the Output Voltage of the PTN78060A Wide-Output Adjust Power Modules
General
A resistor must be connected directly between the VO Adjust control (pin 4) and the output voltage (pin 7) to set
the output voltage lower than –3 V. The adjustment range is from –15 V to –3 V. If pin 4 is left open, the output
voltage defaults to the highest value, –3 V.
Table 1 gives the standard resistor value for a number of common voltages, and with the actual output voltage
that the value produces. For other output voltages, the resistor value can either be calculated using the following
formula, or simply selected from the range of values given in Table 2. Figure 18 shows the placement of the
required resistor.
RSET = 54.9 kW ´
1.25 V
- 5.62 kW
|VO| - 3 V
(1)
Input Voltage Considerations
The PTN78060A is a buck-boost switching regulator. In order that the output remains in regulation, the input
voltage must not exceed the output by a maximum differential voltage.
Another consideration is the pulse width modulation (PWM) range of the regulator's internal control circuit. For
stable operation, its operating duty cycle should not be lower than some minimum percentage. This defines the
maximum advisable ratio between the regulator's input and output voltage magnitudes.
For satisfactory performance, the maximum operating input voltage range must be equal to (32 – |VO|) volts.
As an example, Table 1 gives the operating input voltage range for the common output bus voltages. In addition,
the Electrical Characteristics define the available output voltage adjust range for various input voltages.
Table 1. Standard Values of Rset for Common Output
Voltages
VO
(Required)
RSET
(Standard Value)
VO
(Actual)
Operating
VI Range
–15 V
100 Ω
–14.997 V
9 V to 17 V
–12 V
2 kΩ
–12.006 V
9 V to 20 V
–5 V
28.7 kΩ
–5.000 V
9 V to 27 V
–3.3 V
221 kΩ
–3.303 V
9 V to 28.7 V
VI
C1
2
+
PTN78060A
VI
VO
GND
Adj
6
4
VO
1, 7
C2
RSET
0.05 W
1%
C3
+
GND
GND
(1)
A 0.05-W rated resistor may be used. The tolerance should be 1%, with a temperature stability of 100 ppm/°C (or
better). Place the resistor as close to the regulator as possible. Connect the resistor directly between pins 4 and 7
using dedicated PCB traces.
(2)
Never connect capacitors from VO Adjust to either GND or VO. Any capacitance added to the VO Adjust pin affects
the stability of the regulator.
Figure 18. VO Adjust Resistor Placement
8
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Table 2. Output Voltage Set-Point Resistor Values
VO Required
RSET
VO Required
RSET
VO Required
RSET
–15.0 V
99 Ω
–11.9 V
2.09 kΩ
–8.8 V
6.21 kΩ
–14.9 V
147 Ω
–11.8 V
2.18 kΩ
–8.6 V
6.63 kΩ
–14.8 V
196 Ω
–11.7 V
2.27 kΩ
–8.4 V
7.09 kΩ
–14.7 V
245 Ω
–11.6 V
2.36 kΩ
–8.2 V
7.58 kΩ
–14.6 V
296 Ω
–11.5 V
2.45 kΩ
–8.0 V
8.11 kΩ
–14.5 V
347 Ω
–11.4 V
2.55 kΩ
–7.8 V
8.68 kΩ
–14.4 V
400 Ω
–11.3 V
2.65 kΩ
–7.6 V
9.30 kΩ
–14.3 V
453 Ω
–11.2 V
2.75 kΩ
–7.4 V
9.98 kΩ
–14.2 V
507 Ω
–11.1 V
2.82 kΩ
–7.2 V
10.7 kΩ
–14.1 V
562 Ω
–11.0 V
2.96 kΩ
–7.0 V
11.5 kΩ
–14.0 V
619 Ω
–10.9 V
3.07 kΩ
–6.8 V
12.4 kΩ
–13.9 V
676 Ω
–10.8 V
3.18 kΩ
–6.6 V
13.4 kΩ
–13.8 V
734 Ω
–10.7 V
3.29 kΩ
–6.4 V
14.6 kΩ
–13.7 V
794 Ω
–10.6 V
3.41 kΩ
–6.2 V
15.8 kΩ
–13.6 V
854 Ω
–10.5 V
3.53 kΩ
–6.0 V
17.3 kΩ
–13.5 V
916 Ω
–10.4 V
3.65 kΩ
–5.8 V
18.9 kΩ
–13.4 V
979 Ω
–10.3 V
3.78 kΩ
–5.6 V
20.7 kΩ
–13.3 V
1.04 kΩ
–10.2 V
3.91 kΩ
–5.4 V
22.9 kΩ
–13.2 V
1.11 kΩ
–10.1 V
4.04 kΩ
–5.2 V
25.6 kΩ
–13.1 V
1.18 kΩ
–10.0 V
4.18 kΩ
–5.0 V
28.7 kΩ
–13.0 V
1.24 kΩ
–9.9 V
4.33 kΩ
–4.8 V
32.5 kΩ
–12.9 V
1.31 kΩ
–9.8 V
4.47 kΩ
–4.6 V
37.2 kΩ
–12.8 V
1.38 kΩ
–9.7 V
4.62 kΩ
–4.4 V
43.4 kΩ
–12.7 V
1.46 kΩ
–9.6 V
4.78 kΩ
–4.2 V
51.6 kΩ
–12.6 V
1.52 kΩ
–9.5 V
4.94 kΩ
–4.0 V
63.0 kΩ
–12.5 V
1.60 kΩ
–9.4 V
5.10 kΩ
–3.8 V
80.1 kΩ
–12.4 V
1.68 kΩ
–9.3 V
5.27 kΩ
–3.6 V
109 kΩ
–12.3 V
1.76 kΩ
–9.2 V
5.45 kΩ
–3.4 V
166 kΩ
–12.2 V
1.84 kΩ
–9.1 V
5.63 kΩ
–3.2 V
338 kΩ
–12.1 V
1.92 kΩ
–9.0 V
5.82 kΩ
–3.0 V
OPEN
–12.0 V
2.01 kΩ
–8.9 V
6.01 kΩ
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CAPACITOR RECOMMENDATIONS FOR THE PTN78060 WIDE-OUTPUT
ADJUST POWER MODULES
Input Capacitor
The minimum requirement for the input bus is 100 µF of nonceramic capacitance and 14.1 µF (3× 4.7 µF) of
ceramic capacitance, in either an X5R or X7R temperature characteristic. Ceramic capacitors should be located
within 0.5 inch (1,27 cm) of the regulator's input pins. Electrolytic capacitors can be used at the input, but only in
addition to the required ceramic capacitance. The minimum ripple current rating for any nonceramic capacitance
must be 350 mA rms. The ripple current rating of electrolytic capacitors is a major consideration when they are
used at the input. This ripple current requirement can be reduced by placing more ceramic capacitors at the
input, in addition to the minimum required 14.1 µF.
Tantalum capacitors are not recommended for use at the input bus, as none were found to meet the minimum
voltage rating of 2 × (maximum dc voltage + ac ripple). The 2× rating is standard practice for regular tantalum
capacitors to ensure reliability. Polymer-tantalum capacitors are more reliable, and are available with a
maximum rating of typically 20 V. These can be used with input voltages up to 16 V.
Output Capacitor
The minimum capacitance required to ensure stability is a 100-µF capacitor. Either ceramic or electrolytic-type
capacitors can be used. The minimum ripple current rating for the nonceramic capacitance must be at least
200 mA rms. The stability of the module and voltage tolerances is compromised if the capacitor is not placed
near the output bus pins. A high-quality, computer-grade electrolytic capacitor should be adequate. A ceramic
capacitor can be also be located within 0.5 inch (1,27 cm) of the output pin.
For applications with load transients (sudden changes in load current), the regulator response improves with
additional capacitance. Additional electrolytic capacitors should be located close to the load circuit. These
capacitors provide decoupling over the frequency range, 2 kHz to 150 kHz. Aluminum electrolytic capacitors are
suitable for ambient temperatures above 0°C. For operation below 0°C, tantalum or Os-Con-type capacitors are
recommended. When using one or more nonceramic capacitors, the calculated equivalent ESR should be no
lower than 10 mΩ (17 mΩ using the manufacturer's maximum ESR for a single capacitor). A list of
recommended capacitors and vendors are identified in Table 3.
Ceramic Capacitors
Above 150 kHz, the performance of aluminum electrolytic capacitors becomes less effective. To further reduce
the reflected input ripple current, or improve the output transient response, multilayer ceramic capacitors must
be added. Ceramic capacitors have low ESR, and their resonant frequency is higher than the bandwidth of the
regulator. When placed at the output, their combined ESR is not critical as long as the total value of ceramic
capacitance does not exceed 200 µF.
Tantalum Capacitors
Tantalum-type capacitors may be used at the output and are recommended for applications where the ambient
operating temperature can be less than 0°C. The AVX TPS, Sprague 593D/594/595, and Kemet
T495/T510/T520 capacitors series are suggested over many other tantalum types due to their rated surge,
power dissipation, and ripple current capability. As a caution, many general-purpose tantalum capacitors have
considerably higher ESR, reduced power dissipation, and lower ripple current capability. These capacitors are
also less reliable as they have lower power dissipation and surge current ratings. Tantalum capacitors that do
not have a stated ESR or surge current rating are not recommended for power applications. When specifying
Os-Con and polymer-tantalum capacitors for the output, the minimum ESR limit is encountered well before the
maximum capacitance value is reached.
Capacitor Table
The capacitor table, Table 3, identifies the characteristics of capacitors from vendors with acceptable ESR and
ripple current (rms) ratings. The recommended 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 rating and ESR (at 100 kHz)
are critical parameters necessary to ensure both optimum regulator performance and long capacitor life.
10
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Designing for Load Transients
The transient response of the dc/dc converter has been characterized using a load transient with a di/dt of
1 A/µs. The typical voltage deviation for this load transient is given in the data sheet specification table using the
required value of output capacitance. As the di/dt of a transient is increased, the response of a converter's
regulation circuit ultimately depends on its output capacitor decoupling network. This is an inherent limitation of
any dc/dc converter once the speed of the transient exceeds its bandwidth capability. If the target application
specifies a higher di/dt or lower voltage deviation, the requirement can only be met with additional output
capacitor decoupling. In these cases, special attention must be paid to the type, value, and ESR of the
capacitors selected.
If the transient performance requirements exceed those specified in the data sheet, the selection of output
capacitors becomes more important. Review the minimum ESR in the characteristic data sheet for details on the
capacitance maximum.
Table 3. Recommended Input/Output Capacitors
CAPACITOR CHARACTERISTICS
QUANTITY
WORKING
VOLTAGE
(V)
VALUE
(µF)
EQUIVALENT
SERIES
RESISTANCE
(ESR) (Ω)
85°C
MAXIMUM
RIPPLE
CURRENT
(IRMS) (mA)
FC( Radial)
35
100
0.117
555
8 x 11,5
≥1
1
EEUFC1V01
FC (SMD)
35
100
0.015
670
10 x10,2
≥1
1
EEVFC1V101P
United Chemi-Con PXA (SMD)
16
180
0.016
4360
8 x 12
≥1
(1)
≤1
PXA16VC180MF60 (VI, |VO| <
14 V)
PS
25
100
0.020
4300
10 x 12,5
≥1
(1)
≤1
10PS100MJ12 (VI < 22V)
LXZ
50
100
0.22
485
8 x 12,5
≥1
(1)
1
LXZ50VB101M8X12LL
MVY(SMD)
50
100
0.300
500
10 x 10
≥1
1
MVY50VC101M10X10TP
Nichicon UWG (SMD)
50
100
0.300
500
10 x 10
≥1
1
UWG1H101MNR1GS
F550 (Tantalum)
10
100
0.055
2000
7,7 x 4,3
HD
50
120
0.072
979
10 x12,5
Sanyo Os-Con SVP (SMD)
20
100
0.024
2500
8 x 12
≥1
(1)
≤1
20SVP100M (VI ≤ 16 V)
SP
16
100
0.032
2890
10 x 5
≥1
(1)
≤1
16SP100M (VI, |VO| ≤ 14 V)
20
100
0.085
1543
7,3 L x 4,3
W x 4,1 H
N/R
(3)
≤3
TPSV107M020R0085
(|VO| ≤ 10 V)
20
100
0.200
> 817
N/R
(3)
≤3
TPSE107M020R0200
(|VO| ≤ 10 V)
Murata X5R Ceramic
16
47
0.002
>1000
3225
≥3
≤3
GRM32ER61C476M
(VI, |VO| ≤ 13.5 V)
Murata X5R Ceramic
6.3
47
0.002
>1000
3225
N/R
(1)
≤3
GRM42-2X5R476M6.3
(|VO| ≤ 5.5 V)
TDK X7R Ceramic
25
2.2
0.002
>1000
3225
≥6
(4)
1
C3225X7R1E225KT/MT
(VI ≤ 20 V)
Murata X7R Ceramic
25
2.2
0.002
>1000
3225
≥6
(4)
1
GRM32RR71E225K
(VI ≤ 20 V)
Kemet X7R Ceramic
25
2.2
0.002
>1000
3225
≥6
(4)
1
C1210C225K3RAC
(VI ≤ 20 V)
AVX X7R Ceramic
25
2.2
0.002
>1000
3225
≥6
(4)
1
C12103C225KAT2A
(VI ≤ 20 V)
Murata X7R Ceramic
50
4.7
0.002
>1000
3225
≥3
1
GRM32ER71H475KA88L
TDK X7R Ceramic
50
2.2
0.002
>1000
3225
≥6
1
C3225X7R1H225KT
Murata Radial Through-hole
50
2.2
0.004
>1000
10 H x 10 W
x4D
≥6
1
RPER71H2R2KK6F03
CAPACITOR VENDOR/
COMPONENT
SERIES
AVX Tantalum TPS (SMD)
(1)
(2)
(3)
(4)
PHYSICAL
SIZE
(mm)
INPUT OUTPUT
BUS
BUS
(1)
N/R
≥1
≤ 3 (2)
1
(1)
VENDOR
NUMBER
F551A107MN (|VO| ≤ 5 V)
UHD1H151MHR
The voltage rating of the input capacitor must be selected for the desired operating input voltage range of the regulator. To operate the
regulator at a higher input voltage, select a capacitor with the next higher voltage rating.
The maximum voltage rating of the capacitor must be selected for the desired set-point voltage (VO ). To operate at a higher output
voltage, select a capacitor with a higher voltage rating.
Not recommended (N/R). The voltage rating does not meet the minimum operating limits in most applications.
The maximum rating of the ceramic capacitor limits the regulator's operating input voltage to 20 V. Select an alternative ceramic
component to operate at a higher input voltage.
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Power-Up Characteristics
When configured per the standard application, the PTN78060A power module produces a regulated output
voltage following the application of a valid input source voltage. During power up, internal soft-start circuitry
slows the rate that the output voltage rises, thereby limiting the amount of in-rush current that can be drawn from
the input source. The soft-start circuitry introduces a short time delay (typically 5 ms – 10 ms) into the power-up
characteristic. This is from the point that a valid input source is recognized. Figure 19 shows the power-up
waveforms when operating from a 12-V input and with the output voltage adjusted to –5-V. The waveforms were
measured with a 2.8-A resistive load.
VI (5 V/div)
VO (2 V/div)
II (2 A/div)
t - Time = 5 ms/div
Figure 19. Power-Up Waveforms
Undervoltage Lockout
The undervoltage lockout (UVLO) circuit prevents the module from attempting to power up until the input voltage
is above the UVLO threshold. This is to prevent the module from drawing excessive current from the input
source at power up. Below the UVLO threshold, the module is held off.
Current Limit Protection
The module is protected against load faults with a continuous current limit characteristic. Under a load-fault
condition, the output current increases to the current limit threshold. Attempting to draw current that exceeds the
current limit threshold causes the module to progressively reduce its output voltage. Current is continuously
supplied to the fault until the fault is removed. Once it is removed, the output voltage promptly recovers. When
limiting output current, the regulator experiences higher power dissipation, which increases its temperature. If
the temperature increase is excessive, the module's overtemperature protection begins to periodically turn the
output voltage off.
Overtemperature Protection
A thermal shutdown mechanism protects the module's internal circuitry against excessively high temperatures. A
rise in temperature may be the result of a drop in airflow, a high ambient temperature, or a sustained current
limit condition. If the internal temperature rises excessively, the module turns itself off, reducing the output
voltage to zero. The module exercises a soft-start power up when the sensed temperature has decreased by
about 10°C below the trip point.
NOTE: Overtemperature protection is a last-resort mechanism to prevent damage to the module. It should not
be relied on as permanent protection against thermal stress. Always operate the module within its temperature
derated limits, for the worst-case operating conditions of output current, ambient temperature, and airflow.
Operating the module above these limits, albeit below the thermal shutdown temperature, reduces the long-term
reliability of the module.
12
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Optional Input/Output Filters
Power modules include internal input and output ceramic capacitors in all of their designs. However, some
applications require much lower levels of either input reflected or output ripple/noise. This application describes
various filters and design techniques found to be successful in reducing both input and output ripple/noise.
Input/Output Capacitors
The easiest way to reduce output ripple and noise is to add one or more 1-µF ceramic capacitors, such as C5
shown in Figure 20. Ceramic capacitors should be placed close to the output power terminals. A single 4.7-µF
capacitor reduces the output ripple/noise by 10% to 30% for modules with a rated output current of less than 3
A. (Note: C4 is required to improve the regulators transient response, and does not reduce output ripple and
noise.)
Switching regulators draw current from the input line in pulses at their operating frequency. The amount of
reflected (input) ripple/noise generated is directly proportional to the equivalent source impedance of the power
source including the impedance of any input lines. The addition of C1,≥4.7-µF (2 ×2.2 µF) ceramic capacitor,
near the input power pins, reduces reflected conducted ripple/noise by up to 20%.
C6
4.7 µF
Ceramic
2
VI
VI
PTN78060A
GND
+
C1
4.7 mF
Ceramic
C2
100 µF
Electrolytic
(Required)
C3(1)
3 y 4.7 mF
Ceramic
(Required)
Vo
1,7
Vo
Adjust
6
4
RSET
GND
C4 (2)
+ 100 µF
(Required)
C5
4.7 µF
Ceramic
GND
UDG−05092
(1)
See the specifications for required value and type.
(2)
See the Application Information section for suggested value and type.
Figure 20. Adding High-Frequency Bypass Capacitors to the Input and Output
π Filters
If a further reduction in ripple/noise level is required for an application, higher order filters must be used. A π (pi)
filter, employing a ferrite bead (Fair-Rite Pt. No. 2673000701 or equivalent) in series with the input or output
terminals of the regulator reduces the ripple/noise by at least 20 db (see Figure 21 and Figure 22). In order for
the inductor to be effective ceramic capacitors are also required. (See the Capacitor Recommendations for
additional information on vendors and component suggestions.)
These inductors plus ceramic capacitors form an excellent filter because of the rejection at the switching
frequency (650 kHz - 1 MHz). The placement of this filter is critical. It must be located as close as possible to the
input or output pins to be effective. The ferrite bead is small (12,5 mm × 3 mm), easy to use, low cost, and has
low dc resistance. Fair-Rite also manufactures a surface-mount bead (part number 2773021447). It is rated to 5
A, and can be used on the output bus. As an alternative, suitably rated 1-µH to 5-µH wound inductors can be
used in place of the ferrite inductor bead.
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C7
4.7 µF
Ceramic
VI
L1
1 µH − 5 µH
2
1,7
VI
GND
GND
Adjust
6
C2
100 µF
Electrolytic
(Required)
VO
Vo
PTN78060A
+
C1
4.7 µF
Ceramic
L2
1 µH − 5 µH
4
C3
3 × 4.7 µF
50 V
Ceramic
(Required)
+
RSET (2)
+
C4 (2)
100 µF
(Required)
C5
4.7 µF
Ceramic
C6 (3)
GND
UDG−05093
(1)
See the specifications for required value and type.
(2)
See the Application Information section for suggested value and type.
(3)
Recommended when IO > 2 A..
Figure 21. Adding π Filters (IO≤ 3 A)
45
40
Attenuation − dB
35
1 MHz
30
25
20
600 kHz
15
10
0
0.5
1
1.5
2
Load Current − A
2.5
3
Figure 22. π-Filter Attenuation vs. Load Current
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PACKAGE OPTION ADDENDUM
www.ti.com
10-Mar-2022
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
(3)
Device Marking
(4/5)
(6)
PTN78060AAH
ACTIVE
ThroughHole Module
EUW
7
36
RoHS Exempt
& Green
SN
N / A for Pkg Type
-40 to 85
PTN78060AAS
ACTIVE
Surface
Mount Module
EUY
7
36
Non-RoHS
& Green
SNPB
Level-1-235C-UNLIM/
Level-3-260C-168HRS
-40 to 85
PTN78060AAST
ACTIVE
Surface
Mount Module
EUY
7
250
Non-RoHS
& Green
SNPB
Level-1-235C-UNLIM/
Level-3-260C-168HRS
-40 to 85
PTN78060AAZ
ACTIVE
Surface
Mount Module
EUY
7
36
RoHS (In
Work) & Green
SNAGCU
Level-3-260C-168 HR
-40 to 85
PTN78060AAZT
ACTIVE
Surface
Mount Module
EUY
7
250
RoHS (In
Work) & Green
SNAGCU
Level-3-260C-168 HR
-40 to 85
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
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