TEXAS INSTRUMENTS PTN78020A Technical data

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C2* 4x 4.7 F Ceramic (Required)

C1* 100 F Electrolytic (Required)

C3* 100 F (Required)

GND GND

PTN78020A

(Top View)

*See the for capacitor recommendation.Application Information

SET

is required to adjust the output voltage lower than -3 V. See the for values.Application Information

STANDARD APPLICATION

4 5

SET

1 %, 0.05 W

(Required)

L O A D

查询PTN78020A供应商

25-W, WIDE-INPUT ADJUSTABLE POSITIVE-TO-NEGATIVE VOLTAGE

FEATURES APPLICATIONS

• 4-A Output Current

• Wide-Input Voltage

(9 V to 29 V)

• Wide-Output Voltage Adjust

(–15 V to –3 V)

• High Efficiency (Up to 87%)

• Output Current Limit

• Overtemperature Shutdown

• Undervoltage Lockout

• Operating Temperature: –40°C to 85°C

• Surface-Mount Package Available

PTN78020A

SLTS244A – APRIL 2005 – REVISED MAY 2005

REGULATOR MODULE

• General-Purpose, Industrial Controls,

HVAC Systems, Test and Measurement, Medical Instrumentation, AC/DC Adaptors, Vehicles, Marine, and Avionics

DESCRIPTION

The PTN78020A is a series of high-efficiency buck-boost-integrated switching regulators (ISR), that represent the third generation in the evolution of high-performance power modules designed for industrial use. The wide-input voltage range makes these modules suitable for a variety of applications that operate off 12–V, 24–V, and tightly-regulated 28–V dc power. In new designs, they should be considered in place of the PT6640 and PT78NR100 series of single in-line pin (SIP) products. The PTN78020A is smaller and lighter than its predecessors, and 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.

The PTN78020A operates over an input voltage range of 9 V to 29 V, and provides high-efficiency, positive-to-negative voltage conversion for loads of up to 4 A. The output voltage is set using a single external resistor, and may be adjusted to any value within the range, –15 V to –3 V.

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.

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.

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PTN78020A

SLTS244A – APRIL 2005 – REVISED MAY 2005

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

PTN78020 (Basic Model)

Output Voltage Part Number Description Package Designator

PTN78020AAH Horizontal T/H (Pb-free) EUK-7

–15 V to –3 V PTN78020AAS

PTN78020AAZ

(1) Add a T suffix for tape and reel option on SMD packages. (2) Standard option specifies Sn/Pb solder ball material. (3) Lead (Pb) - free option specifies Sn/Ag solder ball material.

(1) (2) (1) (3)

Horizontal SMD (standard) EUL-7

Horizontal SMD (Pb-free) EUL-7

ABSOLUTE MAXIMUM RATINGS

(1)

over operating free-air temperature range unless otherwise noted all voltages with respect to GND

(1) Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings

Operating free-air temperature Over VIrange –40°C to 85°C

Solder reflow temperature

Surface temperature of module body or pins

Horizontal SMD (suffix AS) 235°C

Horizontal SMD (suffix AZ) 260 ° C Storage temperature –40°C to 125°C Output power |V

| ≥ 12 V 25 W

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

MIN MAX UNIT

Input voltage 9 32 – |VO| V Operating free-air temperature -40 85 °C

PACKAGE SPECIFICATIONS

PTN78020x (Suffix AH, AS, & AZ)

Weight 7.3 grams Flammability 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) Qualification limit.

Horizontal T/H (suffix AH) 250 Gs

Horizontal SMD (suffix AS and AZ) 125 Gs

Horizontal T/H (suffix AH) 20 Gs

Horizontal SMD (suffix AS and AZ) 10 Gs

UNIT

(1)

(1) (1) (1)

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PTN78020A

SLTS244A – APRIL 2005 – REVISED MAY 2005

ELECTRICAL CHARACTERISTICS

operating at 25°C free-air temperature, VI= 20 V, VO= –5 V, IO= IO(max), CI= 100 µF and 4x 4.7 µF, C otherwise noted)

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

VO= -3 V 0.1 4

Output current A

Input voltage range Over IOrange V

TA= 25 ° C, natural convection airflow

Set-point voltage tolerance TA= 25°C ±2% Temperature variation -40°C to +85°C -0.5%

Line regulation Over VIrange -10 mV Load regulation Over IOrange -10 mV

Total output voltage variation -3%

Includes set point, line, load

-40 < TA< 85°C

VO(adj) Output voltage adjust range 9 V ≤ VI≤ (32 – |VO|) V -15 - 3 V

η Efficiency

VI= 12 V, R

VI= 20 V, R

VI= 24 V, R

= 100 Ω, VO= –15 V 87%

SET

= 2 k Ω, VO= –12 V 86%

SET

= 28.7 k Ω, VO= –5 V 82%

SET

= 221 k Ω, VO= –3.3 V 77%

SET

Output voltage ripple 20-MHz bandwidth 1% V

O (LIM)

Current limit threshold ∆ VO= –50 mV 8.5 A

1 A/µs load step from 50% to 100% IOmax

Transient response

VOover/undershoot 5 %V

Switching frequency Over VIand IOranges 440 550 660 kHz

UVLO Undervoltage lockout VIincreasing 5.5 V

External input capacitance µF

Ceramic 18.8 Nonceramic 100 Ceramic 200

External output capacitance Nonceramic 100

Equivalent series resistance (nonceramic) 10

MTBF Calculated reliability 5.6

Per Telcordia SR-332, 50% stress, TA= 40°C, ground benign

VO= -5 V 0.1 4

VO= -12 V 0.1 2.1

VO= -15 V 0.1 1.67

VO= -3 V 9 29

VO= -5 V 9 27

VO= -12 V 9 20

VO= -15 V 9 17

Recovery time 200 µs

(4) (4)

(5) (6)

= 100 µF (unless

(1) (1) (1) (1) (2) (2) (2) (2) (3)

(3)

2,000

(PP)

µF

m Ω

Hrs

(1) The maximum output current is 4 A, or a maximum output power of 25 W, whichever is less. (2) The maximum input voltage is limited and defined to be (32 – |VO|) volts. (3) The set-point voltage tolerance is affected by the tolerance and stability of R

tolerance of 1% with 100 ppm/°C or better temperature stability.

(4) A minimum 100-µF electrolytic and four 4.7-µF ceramic capacitors are required across the input (V

Locate the ceramic capacitors close to the module.

. The stated limit is unconditionally met if R

SET

and GND) for proper operation.

SET

(5) 100 µF of output capacitance is required for proper operation. See the application information for further guidance. (6) This is the typical ESR for all the electrolytic (nonceramic) capacitance. Use 17 m Ω as the minimum when using max-ESR values to

calculate.

has a

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PTN78020A

(Top View)

543

PTN78020A

SLTS244A – APRIL 2005 – REVISED MAY 2005

PIN ASSIGNMENT

TERMINAL FUNCTIONS

TERMINAL

NAME NO.

N/C 3 This pin is active and must be isolated from any electrical connection.

VOAdjust 4 I

N/C 5 This pin is active and must be isolated from any electrical connection. GND 6 I/O The common ground connection for VIand VOpower connections.

1, 7 O

2 I The positive input voltage power node to the module, which is referenced to common GND.

I/O DESCRIPTION

The negative output voltage power connection. It is also the reference for the VOAdjust control input. For proper operation, pins 1 and 7 must be connected.

A 1% resistor must be connected between pin 4 and pin 7 to set the output voltage of the module lower than -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 set-point range is -15 V to -3 V. The standard resistor value for a number of common output voltages is provided in the application information.

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1 2

100

V = -5 V

V = -3 V

V = -12 V

V = -15 V

Efficiency - %

I - Output Current - A

1 2

I - Output Current - A

100

150

250

200

300

V = -5 V

V = -3 V

V = -12 V

V = -15 V

V - Output Voltage Ripple - mV

O PP

0 1 2 3 4

I - Output Current - A

0.5

1.5

2.5

3.5

4.5

V = -5 V

V = -3 V

V = -12 V

V = -15 V

P - Power Dissipation - W

0 0.4 0.8 1.2 1.6

I - Output Current - A

V = -15 V

200 LFM

100 LFM

Nat conv

Ambient Temperature - C

0 0.3 0.6 0.9 1.51.2 1.8 2.1

I - Output Current - A

Ambient Temperature - C

200 LFM

100 LFM

Nat conv

V = -12 V

1 2

I - Output Current - A

V = -5 V

200 LFM

100 LFM

Nat conv

Ambient Temperature - C

SLTS244A – APRIL 2005 – REVISED MAY 2005

TYPICAL CHARACTERISTICS (9-V INPUT)

(1) (2)

EFFICIENCY OUTPUT VOLTAGE RIPPLE POWER DISSIPATION

vs vs vs

OUTPUT CURRENT OUTPUT CURRENT OUTPUT CURRENT

Figure 1. Figure 2. Figure 3.

PTN78020A

TEMPERATURE DERATING TEMPERATURE DERATING TEMPERATURE DERATING

vs vs vs

OUTPUT CURRENT OUTPUT CURRENT OUTPUT CURRENT

Figure 4. Figure 5. Figure 6.

(1) 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 .

(2) 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. Applies to Figure 4 , Figure 5 , and Figure 6 .

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0 1 2 3 4

100

V = -5 V

V = -3 V

V = -12 V

V = -15 V

Efficiency - %

I - Output Current - A

1 2

I - Output Current - A

100

150

250

200

300

V = -5 V

V = -3 V

V = -12 V

V = -15 V

V - Output Voltage Ripple - mV

O PP

0 1 2 3 4

I - Output Current - A

0.5

1.5

2.5

3.5

4.5

V = -5 V

V = -3 V

V = -12 V

V = -15 V

P - Power Dissipation - W

0 0.3 0.6 0.9 1.51.2 1.8 2.1

I - Output Current - A

V = -12 V

200 LFM

100 LFM

Nat conv

Ambient Temperature - C

0 0.4 0.8 1.2 1.6

I - Output Current - A

V = -15 V

200 LFM

100 LFM

Nat conv

Ambient Temperature - C

0 1 2 3 4

I - Output Current - A

V = -5 V

200 LFM

100 LFM

Nat conv

Ambient Temperature - C

PTN78020A

SLTS244A – APRIL 2005 – REVISED MAY 2005

EFFICIENCY OUTPUT VOLTAGE RIPPLE POWER DISSIPATION

vs vs vs

OUTPUT CURRENT OUTPUT CURRENT OUTPUT CURRENT

Figure 7. Figure 8. Figure 9.

TYPICAL CHARACTERISTICS (12-V INPUT)

(1) (2)

TEMPERATURE DERATING TEMPERATURE DERATING TEMPERATURE DERATING

vs vs vs

OUTPUT CURRENT OUTPUT CURRENT OUTPUT CURRENT

Figure 10. Figure 11. Figure 12.

(1) 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 .

(2) 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. Applies to Figure 10 , Figure 11 , and Figure 12 .

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TYPICAL CHARACTERISTICS (24-V INPUT)

0 1 2 3 4

V = -5 V

V = -3 V

Efficiency - %

I - Output Current - A

1 2

I - Output Current - A

100

120

140

V = -5 V

V = -3 V

V - Output Voltage Ripple - mV

O PP

0 1 2 3 4

I - Output Current - A

0.5

1.5

2.5

3.5

4.5

V = -5 V

V = -3 V

P - Power Dissipation - W

0 1 2 3 4

I - Output Current - A

V = -5 V

200 LFM

100 LFM

Nat conv

Ambient Temperature - C

EFFICIENCY OUTPUT VOLTAGE RIPPLE

vs vs

OUTPUT CURRENT OUTPUT CURRENT

Figure 13. Figure 14.

PTN78020A

SLTS244A – APRIL 2005 – REVISED MAY 2005

(1) (2)

POWER DISSIPATION TEMPERATURE DERATING

vs vs

OUTPUT CURRENT OUTPUT CURRENT

Figure 15. Figure 16.

(1) 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 .

(2) 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. Applies to Figure 16 .

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R = 54.9 k

SET

W ´

1.25 V

| |V - 3 V

- 5.62 kW

GND GND

PTN78020A

1, 72

Adj

GND

C2C1

SET

0.05 W

PTN78020A

SLTS244A – APRIL 2005 – REVISED MAY 2005

APPLICATION INFORMATION

Adjusting the Output Voltage of the PTN78020A Wide-Output Adjust Power Modules

General

A resistor must be connected directly between the V 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 17 shows the placement of the required resistor.

Input Voltage Considerations

The PTN78020A 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 - |V

Adjust control (pin 4) and the output voltage (pin 7) to set

|) 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 R

(Required) (Standard Value) (Actual) VIRange

–15 V 100 Ω –14.997 V 9 V to 17 V –12 V 2 k Ω –12.006 V 9 V to 20 V

–5 V 28.7 k Ω –5.000 V 9 V to 27 V

–3.3 V 221 k Ω –3.303 V 9 V to 28.7 V

(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 1 using dedicated PCB traces.

(2) Never connect capacitors from VOAdjust to either GND or V

the stability of the regulator.

Figure 17. V

SET

Voltages

Adjust Resistor Placement

for Common Output

set

. Any capacitance added to the VOAdjust pin affects

out

Operating

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SLTS244A – APRIL 2005 – REVISED MAY 2005

Table 2. Output Voltage Set-Point Resistor Values

VORequired R

–15.0 V 99 Ω –11.9 V 2.09 k Ω –8.8 V 6.21 k Ω –14.9 V 147 Ω –11.8 V 2.18 k Ω –8.6 V 6.63 k Ω –14.8 V 196 Ω –11.7 V 2.27 k Ω –8.4 V 7.09 k Ω –14.7 V 245 Ω –11.6 V 2.36 k Ω –8.2 V 7.58 k Ω –14.6 V 296 Ω –11.5 V 2.45 k Ω –8.0 V 8.11 k Ω –14.5 V 347 Ω –11.4 V 2.55 k Ω –7.8 V 8.68 k Ω –14.4 V 400 Ω –11.3 V 2.65 k Ω –7.6 V 9.30 k Ω –14.3 V 453 Ω –11.2 V 2.75 k Ω –7.4 V 9.98 k Ω –14.2 V 507 Ω –11.1 V 2.82 k Ω –7.2 V 10.7 k Ω –14.1 V 562 Ω –11.0 V 2.96 k Ω –7.0 V 11.5 k Ω –14.0 V 619 Ω –10.9 V 3.07 k Ω –6.8 V 12.4 k Ω –13.9 V 676 Ω –10.8 V 3.18 k Ω –6.6 V 13.4 k Ω –13.8 V 734 Ω –10.7 V 3.29 k Ω –6.4 V 14.6 k Ω –13.7 V 794 Ω –10.6 V 3.41 k Ω –6.2 V 15.8 k Ω –13.6 V 854 Ω –10.5 V 3.53 k Ω –6.0 V 17.3 k Ω –13.5 V 916 Ω –10.4 V 3.65 k Ω –5.8 V 18.9 k Ω –13.4 V 979 Ω –10.3 V 3.78 k Ω –5.6 V 20.7 k Ω –13.3 V 1.04 k Ω –10.2 V 3.91 k Ω –5.4 V 22.9 k Ω –13.2 V 1.11 k Ω –10.1 V 4.04 k Ω –5.2 V 25.6 k Ω –13.1 V 1.18 k Ω –10.0 V 4.18 k Ω –5.0 V 28.7 k Ω –13.0 V 1.24 k Ω –9.9 V 4.33 k Ω –4.8 V 32.5 k Ω –12.9 V 1.31 k Ω –9.8 V 4.47 k Ω –4.6 V 37.2 k Ω –12.8 V 1.38 k Ω –9.7 V 4.62 k Ω –4.4 V 43.4 k Ω –12.7 V 1.46 k Ω –9.6 V 4.78 k Ω –4.2 V 51.6 k Ω –12.6 V 1.52 k Ω –9.5 V 4.94 k Ω –4.0 V 63.0 k Ω –12.5 V 1.60 k Ω –9.4 V 5.10 k Ω –3.8 V 80.1 k Ω –12.4 V 1.68 k Ω –9.3 V 5.27 k Ω –3.6 V 109 k Ω –12.3 V 1.76 k Ω –9.2 V 5.45 k Ω –3.4 V 166 k Ω –12.2 V 1.84 k Ω –9.1 V 5.63 k Ω –3.2 V 338 k Ω –12.1 V 1.92 k Ω –9.0 V 5.82 k Ω –3.0 V OPEN –12.0 V 2.01 k Ω –8.9 V 6.01 k Ω

SET

VORequired R

SET

VORequired R

PTN78020A

SET

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PTN78020A

SLTS244A – APRIL 2005 – REVISED MAY 2005

CAPACITOR RECOMMENDATIONS FOR THE PTN78020 WIDE-OUTPUT ADJUST POWER MODULES

Input Capacitor

The minimum requirement for the input capacitance is 18.8-µF (4× 4.7-µF) ceramic capacitance, in either a X5R or X7R temperature characteristic, and 100-µF of nonceramic capacitance. Ceramic capacitors should be located within 0.5 inch (1,27 cm) of the regulator's input pins. Electrolytic capacitors must be used at the input in addition to the required ceramic capacitance. The minimum ripple current rating for any nonceramic capacitance must be at least 750 mA rms for output currents of 3 A or less. 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 18.8-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). This voltage derating 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 electrolytic 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 250 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 m Ω 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 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.

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PTN78020A

SLTS244A – APRIL 2005 – REVISED MAY 2005

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.

Table 3. Recommended Input/Output Capacitors

CAPACITOR CHARACTERISTICS QUANTITY

CAPACITOR VENDOR/

COMPONENT

SERIES

WORKING MAXIMUM PHYSICAL VOLTAGE RIPPLE SIZE

VALUE SERIES INPUT OUTPUT

(V) CURRENT (mm)

EQUIVALENT

(µF) RESISTANCE BUS BUS

(ESR) ( Ω )

FC( Radial) 35 180 0.090 755 10 × 16 1 1 EEUFC1V331 (VI< 30 V) FK (SMD) 50 330 0.12 900 12,5 × 13,5 1 United Chemi-Con PXA (SMD) 16 150 0.026 3430 10 × 12,2 ≤ 1 PXA16VC151MJ80TP (VI, |VO|

PS 25 100 0.020 4320 10 × 12,5 1 LXZ 35 220 0.090 760 10 × 12,5 1 MVZ (SMD) 25 470 0.090 670 10 × 10 1 1 MVZ25VC471MJ10TP (VI< 20

Nichicon UWG (SMD) 35 330 0.15 670 10 × 10 1 1 UWG1V331MNR1GS F550 (Tantalum) 10 100 0.055 2000 7,7 × 4,3 N/R HD 50 150 0.061 979 10 × 12,5 1 1 UHD1H151MHR Sanyo Os-Con SVP (SMD) 20 150 0.020 4300 10 × 12,7 1 SP 20 120 0.024 3110 8 × 10,5 1

20 100 0.085 1543 7,3 L × 4,3 N/R

AVX Tantalum TPS (SMD)

20 100 0.200 > 817 3225 N/R

Murata X5R Ceramic 6.3 100 0.002 >1000 3225 N/R

TDK X5R Ceramic 6.3 100 0.002 >1000 3225 N/R

Murata X5R Ceramic 16 47 0.002 >1000 3225 4

Kemet X5R Ceramic 6.3 47 0.002 >1000 3225 N/R

TDK X5R Ceramic 6.3 47 0.002 >1000 3225 N/R

Murata X5R Ceramic 6.3 47 0.002 >1000 3225 N/R

TDK X7R Ceramic 25 2.2 0.002 >1000 3225 ≥ 8

Murata X7R Ceramic 25 2.2 0.002 >1000 3225 ≥ 8

Kemet X7R Ceramic 25 2.2 0.002 >1000 3225 ≥ 8

AVX X7R Ceramic 25 2.2 0.002 >1000 3225 ≥ 8

85°C

VENDOR

NUMBER

(mArms)

(1)

1 EEVFK1H181Q

(1)

(1) (1)

< 14 V)

≤ 1 25PS100M J12 (VI< 20 V)

1 LXZ35VB221M10X12LL

(2)

(1) (1)

(2)

W × 4,1 H (|V

(2)

(1)

(2)

(4)

(3)

≤ 3

F551A107MN (VO≤ 5 V)

≤ 1 20SVP150M (VI≤ 16 V) ≤ 1 20SP180M (VI≤ 16 V) ≤ 3 TPSV107M020R0085

| ≤ 10 V)

≤ 3 TPSE107M020R0200

(|V

| ≤ 10 V)

≤ 2 GRM32ER60J107M

(|V

| ≤ 5.5 V)

≤ 2 C3225X5R0J107MT

(|V

| ≤ 5.5 V)

≤ 4 GRM32ER61C476M

(|V

| ~ VI≤ 13.5 V)

≤ 4 C1210C476K9PAC

(|V

| ≤ 5.5 V)

≤ 4 C3225X5R0J476MT

(|V

| ≤ 5.5 V)

≤ 4 GRM42-2X5R476M6.3

(|V

| ≤ 5.5 V)

1 C3225X7R1E225KT/MT

(|V

| ≤ 20 V)

1 GRM32RR71E225K

(|V

| ≤ 20 V)

1 C1210C225K3RAC

(VI, |VO| ≤ 20 V)

(4)

1 C12103C225KAT2A

(VI, |VO| ≤ 20 V)

(1) 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. (2) Not recommended (N/R). The voltage rating does not meet the minimum operating limits in most applications. (3) The maximum voltage rating of the capacitor must be selected for the desired set-point voltage (V

voltage, select a capacitor with a higher voltage rating.

). To operate at a higher output

(4) The maximum rating of the ceramic capacitor limits the regulator operating input voltage to 20 V. Select a alternative ceramic

component to operate at a higher input voltage.

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PTN78020A

SLTS244A – APRIL 2005 – REVISED MAY 2005

Table 3. Recommended Input/Output Capacitors (continued)

CAPACITOR CHARACTERISTICS QUANTITY

CAPACITOR VENDOR/

COMPONENT

SERIES

Kemet X7R Ceramic 50 1.0 0.002 >1000 3225 N/R Murata X7R Ceramic 50 4.7 0.002 >1000 3225 ≥ 4 1 GRM32ER71H475KA88L TDK X7R Ceramic 50 2.2 0.002 >1000 3225 ≥ 8 1 C3225X7R1H225KT Murata X7R Ceramic 50 1.0 0.002 >1000 3225 N/R TDK X7R Ceramic 50 1.0 0.002 >1000 3225 N/R Kemet Radial Through-hole 50 1.0 0.002 >1000 5,08 × 7,62 N/R

Murata Radial Through-hole 50 2.2 0.004 >1000 10 H × 10 ≥ 8 1 RPER71H2R2KK6F03

WORKING MAXIMUM PHYSICAL VOLTAGE RIPPLE SIZE

(V) CURRENT (mm)

VALUE SERIES INPUT OUTPUT

EQUIVALENT

(µF) RESISTANCE BUS BUS

(ESR) ( Ω )

85°C

(mArms)

× 9,14 H

W × 4 D

VENDOR NUMBER

(2)

1 C1210C105K5RAC

(2)

1 GRM32RR71H105KA01L

(2)

1 C3225X7R1H105KT

(2)

1 C330C105K5R5CA

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t - Time = 5 ms/div

VI(5 V/div)

VO(2 V/div)

II(2 A/div)

PTN78020A

SLTS244A – APRIL 2005 – REVISED MAY 2005

Power-Up Characteristics

When configured per the standard application, the PTN78020A 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 18 shows the power-up waveforms for a PTN78020A, operating from a 12-V input and with the output voltage adjusted to –5-V. The waveforms were measured with a 3-A resistive load.

Figure 18. 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 prevents 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 PTN78020 modules protect against load faults with a continuous current limit characteristic. Under a load fault condition, the output current cannot exceed the current limit value. Attempting to draw current that exceeds the current limit value causes the module to progressively reduce its output voltage. Current is continuously supplied to the fault until it is removed. On removal of the fault, 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 overtemperature protection begins to periodically turn the output voltage completely 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 junction temperature of the internal control IC rises excessively the module turns itself off, reducing the output voltage to zero. The module instantly restarts when the sensed temperature decreases by a few degrees.

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.

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C4 100 F (Required)

C3* 4 x 4.7 F Ceramic (Required)

C2 100 F Electrolytic

C1 1 F 50 V

SET

C5 1 F Ceramic

GND

PTN78020A

1, 72

GND

Adjust

* See the specifications for required value and type.

# See the for suggested value and type.Application Information

PTN78020A

SLTS244A – APRIL 2005 – REVISED MAY 2005

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 19 . Ceramic capacitors should be placed close to the output power terminals. A single 1-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 regulator 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, minimum 1-µF ceramic capacitor, near the input power pins, reduces reflected conducted ripple/noise by 10% to 30%.

Figure 19. 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 20 and Figure 21 ). In order for the inductor to be effective in reduction of ripple and noise-ceramic capacitors are required. (See Capacitor Recommendations for the PTN78020A 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), through hole (part number 2673000701) rated to 5 A. 1-µH to 5-µH inductors can be used in place of the ferrite inductor bead.

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GND

†

L1 1 - 5 Hm

L2 1 - 5 Hm

PTN78020A

1, 72

GND

Adjust

C4 100 F (Required)

C3*

18.8 F Ceramic (Required)

C2 100 F Electrolytic (Required)

C1 1 F Ceramic

C5 1 F Ceramic

SET

* See the specifications for required value and type.

# See the for suggested value and type. † Recommended for applications with load transients.

Application Information

0 0.5 1 1.5 2 2.5 3

1 MHz

600 kHz

Attenuation − dB

Load Current − A

PTN78020A

SLTS244A – APRIL 2005 – REVISED MAY 2005

Figure 20. Adding π Filters (I

Figure 21. π -Filter Attenuation vs. Load Current

≤ 4 A)

PACKAGE OPTION ADDENDUM

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19-Aug-2005

PACKAGING INFORMATION

Orderable Device Status

PTN78020AAH ACTIVE DIP MOD

(1)

Package

Type

Package Drawing

Pins Package

Qty

Eco Plan

EUK 7 20 TBD Call TI Level-1-235C-UNLIM

ULE

PTN78020AAS ACTIVE DIP MOD

EUL 7 20 TBD Call TI Level-1-235C-UNLIM

ULE

PTN78020AAST ACTIVE DIP MOD

EUL 7 200 TBD Call TI Level-1-235C-UNLIM

ULE

PTN78020AAZ ACTIVE DIP MOD

EUL 7 20 Pb-Free

ULE

PTN78020AAZT ACTIVE DIP MOD

EUL 7 200 Pb-Free

ULE

(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)

Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS) or Green (RoHS & no Sb/Br) - please check

http://www.ti.com/productcontent for the latest availability information and additional product content details.

TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements

for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)

(RoHS)

(2)

Lead/Ball Finish MSL Peak Temp

Call TI Level-3-260C-168 HR

(3)

MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder

temperature.

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Addendum-Page 1

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TEXAS INSTRUMENTS PTN78020A Technical data

Specifications and Main Features

Frequently Asked Questions

User Manual