PT4123A_技术文档

PT4120 Series

20-W 48-V Input Isolated

DC/DC Converter

SLTS092B

(Revised 2/26/2002)

Features

• Input Voltage Range:

36V to 75V

• Short Circuit Protection

• Over Temperature Shutdown

• Under-Voltage Lockout

• UL1950 Recognized

• 20W Rated

• 82% Efficiency

• 1500 VDC Isolation

• Low Profile (8.5 mm)

• Small Footprint: 1.52in x 1.73in

• Remote On/Off

• CSA 22.2 950 Certified

• EN60950 Approved

6

• 4×10 Hrs MTBF

Pin-Out Information

Description

Ordering Information

Pin Function

PT 4121r = 3.3V/5A (16.5W)

PT 4122r = 5.0V/4A

The PT4120 power modules are a series

of isolated DC/DC converters housed a low-

profile package. Rated for 20 watts or 5A, the

series includes standard output voltages rang-

ing from as low as 1.5VDC to 15VDC. The

output may be adjusted 10% of nominal.

These converters are ideal for Telecom,

Industrial, Computer, and other distributed

power applications that require input-to-

output isolation.

†

1

2

3

4

5

6

Remote On/Off

PT 4123r = 12.0V/1 6A

PT 4124r = 15.0V/1 3A

PT 4125r = 5.2V/3·8A

PT 4126r = 1.5V/5A (7.5W)

PT 4127r = 1.8V/5A (9W)

PT 4128r = 2.5V/5A (12.5W)

PT 4129r = 1.65V/5A (8·25W)

–V

+V

in

–Vout

+Vout

V

Adjust ^†

out

† For further information, see

application notes.

Using multiple PT4120 modules, system

designers can implement a complete custom

power supply solution. The flexibility of full

isolation also allows the input or output to be

configured for negative voltage operation.

The PT4120 series requires no additional

components for proper operation.

PT Series Suffix

Case/Pin

Configuration

(PT1234x)

O rder

Suffix

Package

Code *

Horizontal

SMD

A

C

(EGD)

(EGE)

* Previously known as package style 710.

(Reference the applicable package code draw-

ing for the dimensions and PC board layout)

Standard Application

+V_IN

+V_OUT

3

5

LOAD

PT4120

–V_IN

–V_OUT

2

4

1

6

Remote

On/Off

V_OAdj

Q₁

BSS138

For technical support and more information, see inside back cover or visit www.ti.com

PT4120 Series

20-W 48-V Input Isolated

DC/DC Converter

Specifications (Unless otherwise stated, T_a=25°C, V_in=48V, C_out=0µF, and I_o=I_omax)

PT4120 SERIES

Typ

Characteristic

Symbol

Conditions

Min

Max

Units

(1)

Output Current

I_o

Over V_inrange

V_o= 15V

V_o= 12V

V_o=5.0V

V_o≤3.3V

0.1

—

1.3

1.6

4.0

5.0

0.1 ⁽¹⁾

A

(1)

0.1

(1)

0.1

Input Voltage Range

Set Point Voltage Tolerance

V_in

V_otol

Over I_oRange

36.0

—

48.0

1

—

0.5

0.2

7

0.4

13

2

75.0

1.5

50

—

1.0

33

1.0

33

—

VDC

%V_o

mV

%V_o

mV

%V_o

mV

%V_o

mV

V_o≥5.0V

V_o≤3.3V

Temperature Variation

Line Regulation

Reg_temp

Reg_line

–40° ≤T_a≤ +85°C

Over V_inrange

V_o≥5.0V

V_o≤3.3V

Vo ≥5.0V

V_o≤3.3V

V_o≥5.0V

V_o≤3.3V

V_o= 15V

V_o= 12V

V_o=5.0V

V_o=3.3V

V_o=1.8V

Load Regulation

Reg_load

∆V_otot

η

Over I_orange

Total Output Voltage Variation

Efficiency

Includes set-point, line load,

–40° ≤T_a≤ +85°C

67

—

86

83

82

78

67

—

%

V_oRipple (pk-pk)

V_r

20MHz bandwidth

V_o≥5.0V

V_o≤3.3V

—

600

800

—

0.5

15

100

3.0

150

2xI_omax

650

850

31

—

700

900

—

%V_o

mV_pp

µs

%V_o

mV

A

Transient Response

t_tr

0.1A/µs, load step 50% to 100% I_omax

V_oover/undershoot

V_o≥5.0V

V_o≤3.3V

∆V_tr

Short Circuit Current

Switching Frequency

I_sc

ƒ_s

Over V_inrange

V_o≥12.0V

V_o≤ 5.2V

kHz

V

Under-Voltage Lockout

UVLO

Remote On/Off (Pin 1)

Referenced to –Vin (pin 2)

(2)

+0.8

Input High Voltage

V_IH

V_IL

I_IL

2.5

—

–10

7

0.5

—

1100

—

7.0

V

–0.2

Input Low Voltage

Input Low Current

—

0

–

µA

mA

µF

V

pF

MΩ

Standby Input Current

Internal Input Capacitance

External Output Capacitance

Isolation Voltage

Capacitance

Resistance

I_instandby

C_in

C_out

pins 1 & 2 connected

50

—

200

Between +V_oand –V_o

Input to output

1500

—

10

(3)

Operating Temperature Range

Storage Temperature

Reliability

T

Over V_inrange

—

-40

—

+85

°C

a

T

+125

s

MTBF

Per Bellcore TR-332

6

4.0

—

10 Hrs

50% stress, T_a=40°C, ground benign

Mechanical Shock

—

Per Mil-Std-883D, method 2002.3,

1mS, half-sine, mounted to a fixture

Per Mil-Std-883D, method 2007.2,

20-2000Hz, soldered in a PC board

500

—

G’s

Mechanical Vibration

—

15

23

G’s

Weight

Flammability

—

grams

Materials meet UL 94V-0

Notes: (1) The DC/DC converter will operate at no load with reduced specifications.

(2) The Remote On/Off (pin 1) has an internal pull-up, and if it is left open circuit the PT4120 will operate when input power is applied. Refer to the

application notes for interface considerations.

(3) See Safe Operating Area curves or contact the factory for the appropriate derating.

For technical support and more information, see inside back cover or visit www.ti.com

Typical Characteristics

PT4120 Series

20-W 48-V Input Isolated

DC/DC Converter

PT4121, 3.3 VDC (See Note A)

PT4122, 5.0 VDC (See Note A)

PT4123, 12.0 VDC (See Note A)

Efficiency vs Output Current

90

85

80

75

70

65

60

55

50

80

70

60

50

80

V_in

75

36.0V

48.0V

75.0V

36.0V

48.0V

75.0V

70

65

60

55

50

48.0V

75.0V

0

1

2

3

4

5

0

0.5

1

1.5

2

2.5

3

3.5

4

0

0.2 0.4 0.6 0.8

Iout (A)

1

1.2 1.4 1.6

Iout (A)

Ripple vs Output Current

12

10

8

16

14

12

10

8

70

60

50

40

30

20

10

0

V_in

75.0V

48.0V

36.0V

75.0V

48.0V

36.0V

75.0V

48.0V

36.0V

6

4

2

0

1

2

3

4

5

0

0.5

1

1.5

2

2.5

3

3.5

4

0

0.2 0.4 0.6 0.8

Iout (A)

1

1.2 1.4 1.6

Iout (A)

Power Dissipation vs Output Current

6

5

4

3

2

1

0

6

5

4

3

2

1

0

6

5

4

3

2

1

0

V_in

75.0V

48.0V

36.0V

75.0V

48.0V

36.0V

75.0V

48.0V

36.0V

0

1

2

3

4

5

0

0.5

1

1.5

2

2.5

3

3.5

4

0

0.2 0.4 0.6 0.8

Iout (A)

1

1.2 1.4 1.6

Iout (A)

Safe Operating Area, V_in=48V (See Note B)

90

80

70

60

50

40

30

20

90

80

70

60

50

40

30

20

90

80

70

60

50

40

30

20

Airflow

200LFM

120LFM

60LFM

200LFM

120LFM

60LFM

200LFM

120LFM

60LFM

Nat conv

0

1

2

3

4

5

0

1

2

3

4

0

0.25 0.5 0.75

1

1.25 1.5 1.75

Iout (A)

Note A: Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the Converter.

Note B: SOA curves represent the conditions at which internal components are at or below the manufacturer’s maximum operating temperatures

For technical support and more information, see inside back cover or visit www.ti.com

Application Notes

PT4120/4140 Series

Using the Remote On/Off Function on the PT4120/

PT4140 Series of Isolated DC/DC Converters

For applications requiring output voltage on/off control,

the PT4120/4140 series of DC/DC converters incorporate

a remote on/off function. This function may be used in

applications that require battery conservation, power-up/

shutdown sequencing, and/or to co-ordinate the power-

up of the regulator for active in-rush current control. (See

the related application note, AN21).

6. Keep the on/off transition to less than 1ms. This prevents

erratic operation of the ISR, whereby the output voltage

may drift un-regulated between 0V and the rated output

during power-up.

Figure 1

+V _o

This function is provided by the Remote On/Off control,

pin1. If pin 1 is left open-circuit, the converter provides a

regulated output whenever a valid source voltage³is ap-

plied between +V_in(pin 3), and –V_in(pin 2). Applying a

low-level ground signal ¹to pin 1 will disable the regula-

tor output ⁵.

3

2

5

4

+Vin

+Vout

+V _in

PT4121

–Vin

–Vout

Remote

On/Off

V_o(adj)

6

–V _o

1

Q1

BSS138

Table 1 provides details of the threshold requirements for

the Remote On/Off pin. Figure 1 shows how a discrete

MOSFET (Q₁) ⁴, may be referenced to the negative input

voltage rail and used with this control input.

Inh

Note

2

–V _in

Table 1 Inhibit Control Thresholds

Parameter

min

max

Turn-On Time: The converter typically produces a fully

regulated output voltage within 50ms after the applica-

tion of power, or the removal of the low voltage signal ⁶

from the Remote On/Off pin. The actual turn-on time

will vary with the input voltage, output load, and the

total amount of capacitance connected to the output.

Using the circuit of Figure 1, Figure 2 shows the output

voltage and input current waveforms of a PT4121 after

Q₁is turned off. The turn off of Q₁corresponds to the

drop in Q₁V_gsvoltage. The waveforms were measured

with a 48Vdc input voltage, and 2.75-A resistive load.

2, 4

Enable (V_IH

Disable (V_IL

)

2.5V

–0.3V

(Open Circuit)

0.8V

Notes:

1. The on/off control uses -V_in(pin 2), the primary side of

the converter as its ground reference. All voltages specified

are with respect to -V_in.

2. The on/off control internal circuitry is a high impedance

10µA current source. The open-circuit voltage may be as

high as 8.3Vdc.

3. The PT4120/40 series incorporates an “Under Voltage

Lockout” (UVLO) function. This function automatically

inhibits the converter output until there is sufficient input

voltage for the converter to produce a regulated output.

Table 2 gives the applicable UVLO thresholds.

Figure 2

Vout (2V/Div)

Iin (0.2A/Div)

Table 2 UVLO Thresholds

Series

UVLO Threshold

V_inRange

PT4120

PT4140

31V Typical

15V Typical

36 – 75V

18 – 40V

4. The Remote On/Off input of the PT4120/40 series regulators

must be controlled with an open-collector (or open-drain)

discrete transistor or MOSFET. Do not use a pull-up resistor.

Q1 Vgs (10V/Div)

5. When the converter output is disabled, the current drawn

from the input supply is typically reduced to 8mA (16mA

maximum).

HORIZ. SCALE: 5ms/Div

For technical support and more information, see inside back cover or visit www.ti.com

Application Notes

PT4120/4140 Series

Adjusting the Output Voltage of the PT4120/

PT4140 Series of Isolated DC/DC Converters

The factory pre-set output voltage of Power Trends’

PT4120 and PT4140 series of isolated DC/DC converters

may be adjusted within 10% of nominal. Adjustment is

4. Never connect capacitors to V_oadjust. Any capacitance

added to the V_oadjust control pin will affect the stability of

the ISR.

1

made from the secondary side of the regulator with a

The values of (R₁) [adjust down], and R₂[adjust up], can also

be calculated using the following formulas.

single external resistor. For the input voltage range

specified in the data sheet Table 1 gives the allowable

adjustment range for each model, as V_o(min) and V_o(max).

K_o(V_a– V_r)

V_r(V_o– V_a)

(R₁)

R₂

=

– R_s

kΩ

Adjust Up: An increase in the output voltage is obtained

by adding a resistor, R₂between pin 6 (V_oadjust), and pin

4 (-V_out).

K_o

(V_a– V_o)

– R_s

Adjust Down: Add a resistor (R₁), between pin 6 (V_oad-

just) and pin 5 (+V_out).

Where V_o= Original output voltage

V_a= Adjusted output voltage

V_r= Reference voltage (Table 1)

K_o= Multiplier constant (Table 1)

R_s= Internal series resistance (Table 1)

Refer to Figure 1 and Table 2 for both the placement

and value of the required resistor, (R₁) or R₂.

Notes:

1. The PT4120 and PT4140 series of DC/DC converters

incorporate isolation between the V_inand V_oterminals.

Adjustment of the output voltage is made to the

regulation circuit on the secondary or output side of

the converter.

Figure 1

+V_o

2. The maximum rated output power for this series is

20W. An increase in the output voltage may therefore

require a corresponding reduction in the maximum

output current (see Table 1). The revised maximum

output current must be determined as follows:-

+V_in

(R1)

Adj Down

3

2

5

4

+Vin

+Vout

PT4120/40

–Vin

–Vout

Remote

R2

Adj

Up

On/Off

V_o(adj)

6

20

1

I_o(max)

=

A,

or 5A, whichever is less.

–V_in

V_a

–V_o

Where V_ais the adjusted ouput voltage.

3. Use only a single 1% resistor in either the (R₁) or R₂

location. Place the resistor as close to the ISR as possible.

Table 1

DC/DC CONVERTER ADJUSTMENT RANGE AND FORMULA PARAMETERS

Series Pt #

48V Bus

24V Bus

Max Current ²

V_o(nom)

Va(min)

Va(max)

V_r

PT4126

PT4146

5A

PT4129

PT4127

PT4147

5A

PT4128

PT4148

5A

PT4121

PT4141

5A

PT4122

PT4142

4A

PT4125

PT4123

PT4143

1.6A

12.0

10.8

13.2

2.5

139.8

110.0

PT4124

PT4144

1.3A

15.0

13.5

16.5

2.5

137.6

90.9

5A

3.8A

5.2V

4.75

5.75

2.5

1.5

1.35

1.65

1.225

67.07

43.2

1.65

1.49

1.81

1.225

63.9

66.5

1.8

1.62

1.98

1.225

69.7

2.5

2.25

2.75

1.225

64.2

3.3

5.0

4.5

5.5

2.5

125.2

187.0

2.95

3.65

1.225

69.3

187.0

K_o(V·kΩ)

R_s(kΩ)

134.7

243.0

110.0

187.0

For technical support and more information, see inside back cover or visit www.ti.com

Application Notes continued

PT4120/4140 Series

Table 2

DC/DC CONVERTER SERIES ADJUSTMENT RESISTOR VALUES

Series Pt #

48V Bus

24V Bus

V_o(nom)

V_a(req’d)

PT4126

PT4146

1.5Vdc

PT4127

PT4147

1.8Vdc

PT4128

PT4148

2.5Vdc

PT4121

PT4141

3.3Vdc

PT4122

PT4142

5.0Vdc

PT4123

PT4143

12.0Vdc

PT4124

PT4144

15.0Vdc

V_a(req’d)

1.35

1.4

1.45

1.5

1.55

1.6

1.65

1.7

1.75

1.8

1.85

1.9

1.95

2.25

2.3

2.35

2.4

2.45

2.5

2.55

2.6

2.65

2.7

2.75

2.95

3.0

3.05

3.1

3.15

3.2

3.25

3.3

(2.8)kΩ

(53.2)kΩ

(204.0)kΩ

4.5

4.55

4.6

4.65

4.7

4.75

4.8

4.85

4.9

4.95

5.0

5.05

5.1

5.15

5.2

(12.6)kΩ

(40.3)kΩ

(75.0)kΩ

(120.0)kΩ

(179.0)kΩ

(262.0)kΩ

(387.0)kΩ

(595.0)kΩ

(1.01)MΩ

10.8

11.0

11.2

11.4

11.6

11.8

12.0

12.2

12.4

12.6

12.8

13.0

13.2

13.5

13.6

13.8

14.0

14.2

14.4

14.6

14.8

15.0

15.2

15.4

15.6

15.8

16.0

16.5

(276.0)kΩ

(365.0)kΩ

(497.0)kΩ

(719.0)kΩ

(1.16)MΩ

1.3MΩ

627.0kΩ

404.0kΩ

(51.7)kΩ

(161.0)kΩ

(489.0)kΩ

588.0kΩ

239.0kΩ

123.0kΩ

64.6kΩ

29.7kΩ

6.4kΩ

1.28MΩ

587.0kΩ

355.0kΩ

1.06MΩ

645.0kΩ

437.0kΩ

312.0kΩ

229.0kΩ

169.0kΩ

125.0kΩ

90.2kΩ

(26.5)kΩ

(92.9)kΩ

(203.0)kΩ

(425.0)kΩ

(1.09)MΩ

(312.0)kΩ

(345.0)kΩ

(427.0)kΩ

(542.0)kΩ

(713.0)kΩ

(1.0)MΩ

5.25

5.3

5.35

5.4

5.45

5.5

1.09MΩ

450.0kΩ

237.0kΩ

131.0kΩ

67.7kΩ

(1.57)MΩ

62.4kΩ

597.0kΩ

253.0kΩ

138.0kΩ

81.0kΩ

46.6kΩ

0.8kΩ

(90.7)kΩ

(146.0)kΩ

(224.0)kΩ

(341.0)kΩ

(536.0)kΩ

(926.0)kΩ

(2.09)MΩ

3.35

3.4

3.45

3.5

3.55

3.6

1.19MΩ

502.0kΩ

272.0kΩ

158.0kΩ

88.7kΩ

42.7kΩ

3.65

9.9kΩ

R₁= (Blue)

R₂= Black

For technical support and more information, see inside back cover or visit www.ti.com

PACKAGE OPTION ADDENDUM

www.ti.com

24-Jun-2005

PACKAGING INFORMATION

Orderable Device

PT4121A

PT4121C

PT4122A

PT4122C

PT4122CT

PT4123A

PT4123C

PT4124A

PT4124C

PT4125A

PT4125C

PT4126A

PT4126C

PT4127A

PT4127C

PT4128A

PT4128C

Status ⁽¹⁾

ACTIVE

Package Package

Pins Package Eco Plan ⁽²⁾Lead/Ball Finish MSL Peak Temp ⁽³⁾

Qty

Type

Drawing

DIP MOD

ULE

EGD

6

16

100

16

TBD

Call TI

Level-1-215C-UNLIM

DIP MOD

ULE

EGE

EGD

EGE

EGD

EGE

EGD

EGE

EGD

EGE

EGD

EGE

EGD

EGE

EGD

EGE

DIP MOD

ULE

DIP MOD

ULE

DIP MOD

ULE

DIP MOD

ULE

DIP MOD

ULE

DIP MOD

ULE

DIP MOD

ULE

DIP MOD

ULE

DIP MOD

ULE

DIP MOD

ULE

DIP MOD

ULE

DIP MOD

ULE

DIP MOD

ULE

DIP MOD

ULE

DIP MOD

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)

Addendum-Page 1

PACKAGE OPTION ADDENDUM

www.ti.com

24-Jun-2005

(3)

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

temperature.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is

provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the

accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take

reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on

incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited

information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI

to Customer on an annual basis.

Addendum-Page 2

IMPORTANT NOTICE

Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,

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型号：	PT4123A
厂家：	TEXAS INSTRUMENTS
描述：	20-W 48-V Input Isolated DC/DC Converter 20 -W 48 V输入隔离DC / DC转换器转换器
文件：	总9页 (文件大小：178K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

PT4123A [TI]

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