TL783C

TL783HIGH-VOLTAGE ADJUSTABLE REGULATOR

SLVS036E – SEPTEMBER 1981 – REVISED FEBRUARY 2000

1POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

Output Adjustable From 1.25 V to 125 VWhen Used With an External ResistorDivider

700-mA Output Current

Full Short-Circuit, Safe-Operating-Area, andThermal-Shutdown Protection

0.001%/V Typical Input Voltage Regulation

0.15% Typical Output Voltage Regulation

76-dB Typical Ripple Rejection

Standard TO-220AB Package

description

The TL783 is an adjustable three-terminalhigh-voltage regulator with an output range of1.25 V to 125 V and a DMOS output transistorcapable of sourcing more than 700 mA. It isdesigned for use in high-voltage applications where standard bipolar regulators cannot be used. Excellentperformance specifications, superior to those of most bipolar regulators, are achieved through circuit designand advanced layout techniques.

As a state-of-the-art regulator, the TL783 combines standard bipolar circuitry with high-voltage double-diffusedMOS transistors on one chip to yield a device capable of withstanding voltages far higher than standard bipolarintegrated circuits. Because of its lack of secondary-breakdown and thermal-runaway characteristics usuallyassociated with bipolar outputs, the TL783 maintains full overload protection while operating at up to 125 V frominput to output. Other features of the device include current limiting, safe-operating-area (SOA) protection, andthermal shutdown. Even if ADJ is inadvertently disconnected, the protection circuitry remains functional.

Only two external resistors are required to program the output voltage. An input bypass capacitor is necessaryonly when the regulator is situated far from the input filter. An output capacitor, although not required, improvestransient response and protection from instantaneous output short circuits. Excellent ripple rejection can beachieved without a bypass capacitor at the adjustment terminal.

The TL783C is characterized for operation over the virtual junction temperature range of 0°C to 125°C.

AVAILABLE OPTIONS

PACKAGED DEVICECHIP

TJHEAT-SINKMOUNTED

(KC)

CHIPFORM

(Y)

0°C to 125°C TL783CKC TL783Y

Chip forms are tested at 25°C.

TO-220AB

The OUT terminal is in electricalcontact with the mounting base.

KC PACKAGE(TOP VIEW)

INOUTADJ

I O A

PRODUCTION DATA information is current as of publication date.Products conform to specifications per the terms of Texas Instrumentsstandard warranty. Production processing does not necessarily includetesting of all parameters.

Copyright 2000, Texas Instruments Incorporated

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications ofTexas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.



2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

functional block diagram

+

–

ProtectionCircuit

OUT

IN

VrefR1

R2

VO

VI

ErrorAmplifier

ADJ

VO Vref1 R2R1

absolute maximum ratings over operating temperature range (unless otherwise noted) †

Input-to-output differential voltage, Vl – VO 125 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Operating free-air, TA; case, TC; or virtual junction, TJ, temperature 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . Package thermal impedance, θJA (see Notes 1 and 2) 22°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds 260°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Storage temperature range, Tstg –65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, andfunctional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is notimplied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

NOTES: 1. Maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any allowableambient temperature is PD = (TJ(max) – TA)/θJA. Operating at the absolute maximum TJ of 150°C can impact reliability. Due tovariations in individual device electrical characteristics and thermal resistance, the built-in thermal overload protection may beactivated at power levels slightly above or below the rated dissipation.

2. The package thermal impedance is calculated in accordance with JESD 51.

recommended operating conditions

MIN MAX UNIT

Input-to-output voltage differential, VI – VO 125 V

Output current, IO 15 700 mA

Operating virtual junction temperature, TJ TL783C 0 125 °C




electrical characteristics at V l – VO = 25 V, IO = 0.5 A, TJ = 0°C to 125°C (unless otherwise noted)

PARAMETER TEST CONDITIONS†TL783C

UNITPARAMETER TEST CONDITIONS†MIN TYP MAX

UNIT

Input voltage VI VO = 20 V to 125 V P ≤ rated dissipationTJ = 25°C 0.001 0.01

%/Vgregulation‡ VI – VO = 20 V to 125 V, P ≤ rated dissipation

TJ = 0°C to 125°C 0.004 0.02%/V

Ripple rejection ∆VI(PP) = 10 V, VO = 10 V, f = 120 Hz 66 76 dB

IO = 15 mA to 700 mA TJ = 25°CVO ≤ 5 V 7.5 25 mV

Output voltageIO = 15 mA to 700 mA, TJ = 25°C

VO ≥ 5 V 0.15% 0.5%gregulation

IO = 15 mA to 700 mA P ≤ rated dissipationVO ≤ 5 V 20 70 mV

IO = 15 mA to 700 mA, P ≤ rated dissipationVO ≥ 5 V 0.3% 1.5%

Output voltage changewith temperature

0.4%

Output voltagelong-term drift

1000 hours at TJ = 125°C, VI – VO = 125 V 0.2%

Output noise voltage f = 10 Hz to 10 kHz, TJ = 25°C 0.003%

Minimumoutput current tomaintain regulation

VI – VO = 125 V 15 mA

VI – VO = 25 V, t = 1 ms 1100

Peak output currentVI – VO = 15 V, t = 30 ms 715

mAPeak output currentVI – VO = 25 V, t = 30 ms 700 900

mA

VI – VO = 125 V, t = 30 ms 100 250

ADJ input current 83 110 µA

Change inADJ input current

VI – VO = 15 V to 125 V, IO = 15 mA to 700 mA, P ≤ rated dissipation 0.5 5 µA

Reference voltage(OUT to ADJ)

VI – VO = 10 V to 125 V,See Note 3

IO = 15 mA to 700 mA, P ≤ rated dissipation,1.2 1.27 1.3 V

† Pulse-testing techniques maintain the junction temperature as close to the ambient temperature as possible. Thermal effects must be taken intoaccount separately.

‡ Input voltage regulation is expressed here as the percentage change in output voltage per 1-V change at the input.NOTE 3: Due to the dropout voltage and output current-limiting characteristics of this device, output current is limited to less than 700 mA at

input-to-output voltage differentials of less than 25 V.




electrical characteristics at V l – VO = 25 V, IO = 0.5 A, TJ = 25°C (unless otherwise noted)

PARAMETER TEST CONDITIONS†TL783Y

UNITPARAMETER TEST CONDITIONS†MIN TYP MAX

UNIT

Input voltageregulation‡ VI – VO = 20 V to 125 V, P ≤ rated dissipation 0.001 %/V

Ripple rejection ∆VI(PP) = 10 V, VO = 10 V, f = 120 Hz 76 dB

IO = 15 mA to 700 mAVO ≤ 5 V 7.5 mV

Output voltageIO = 15 mA to 700 mA

VO ≥ 5 V 0.15%gregulation

IO = 15 mA to 700 mA P ≤ rated dissipationVO ≤ 5 V 20 mV

IO = 15 mA to 700 mA, P ≤ rated dissipationVO ≥ 5 V 0.3%

Output voltage changewith temperature

0.4%

Output noise voltage f = 10 Hz to 10 kHz 0.003%

VI – VO = 25 V, t = 1 ms 1100

Peak output currentVI – VO = 15 V, t = 30 ms 715

mAPeak output currentVI – VO = 25 V, t = 30 ms 900

mA

VI – VO = 125 V, t = 30 ms 250

ADJ input current 83 µA

Change inADJ input current

VI – VO = 15 V to 125 V, IO = 15 mA to 700 mA, P ≤ rated dissipation 0.5 µA

Reference voltage(OUT to ADJ)

VI – VO = 10 V to 125 V,See Note 3

IO = 15 mA to 700 mA, P ≤ rated dissipation,1.27 V

† Pulse-testing techniques maintain the junction temperature as close to the ambient temperature as possible. Thermal effects must be taken intoaccount separately.

‡ Input voltage regulation is expressed here as the percentage change in output voltage per 1-V change at the input.NOTE 3: Due to the dropout voltage and output current-limiting characteristics of this device, output current is limited to less than 700 mA at

input-to-output voltage differentials of less than 25 V.




TYPICAL CHARACTERISTICS

Figure 1

2

1.8

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0250 50 75 100 125

Out

put C

urre

nt L

imit

– A

VI – VO – Input-to-Output Voltage Differential – V

OUTPUT CURRENT LIMITvs

INPUT-TO-OUTPUT VOLTAGE DIFFERENTIAL

ÎÎÎÎtw = 1 ms

ÎÎÎÎÎÎÎÎ

TC = 0°C

ÎÎÎÎÎÎÎÎ

TC = 25°C

ÎÎÎÎÎÎÎÎÎÎ

TC = 125°C

Figure 2

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

00 25 50 75 100

Out

put C

urre

nt L

imit

– A


INPUT-TO-OUTPUT VOLTAGE DIFFERENTIAL

VI – VO – Input-to-Output Voltage Differential – V

ÎÎÎÎÎtw = 30 ms

ÎÎÎÎTC = 0°C

ÎÎÎÎÎÎÎÎ

TC = 25°C


TC = 125°C

125

Figure 3

0 10 20 30 40

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0

Out

put C

urre

nt L

imit

– A

Time – ms


TIME


VI – VO = 25 VTC = 25°C

Figure 4

0 10 20 30 40 50 60 70 80 90

100

80

60

40

20

0

120

Rip

ple

Rej

ectio

n –

dB

VO – Output Voltage – V

RIPPLE REJECTIONvs

OUTPUT VOLTAGE

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ

VI(AV) – VO = 25 V∆VI(PP) = 10 VIO = 100 mAf = 120 HzCo = 0TJ = 25°C

100




TYPICAL CHARACTERISTICS †

Figure 5

0 100 200 300 400 500 600 700 800

Rip

ple

Rej

ectio

n –

dB

IO – Output Current – mA

RIPPLE REJECTIONvs

OUTPUT CURRENT

100

80

60

40

20

0

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ

VI(AV) = 25 V∆VI(PP) = 10 VVO = 10 Vf = 120 HzCo = 0TJ = 25°C

Figure 6

100

0.01

90

80

70

60

50

40

30

20

10

00.1 1 10 100 1000

ÎÎÎÎCo = 10 µF

Rip

ple

Rej

ectio

n –

dB

f – Frequency – kHz

RIPPLE REJECTIONvs

FREQUENCY

ÎÎÎÎCo = 0ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ

VI(AV) = 25 V∆VI(PP) = 10 VVO = 10 VIO = 500 mATJ = 25°C

Figure 7

1

f – Frequency – kHz

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ

VI = 35 VVO = 10 VIO = 500 mATJ = 25°C

101 102 103 104 105 106 107

10–1

10–2

10–3

10–4

101

102

OUTPUT IMPEDANCEvs

FREQUENCY

– O

utpu

t Im

peda

nce

–Ω

Zo

Figure 8

1.30

1.29

1.28

1.27

1.26

1.25

1.24

1.23

1.22–75 –50 –25 0 25 50 75 100 125 150

– R

efer

ence

Vol

tage

– V

TJ – Virtual Junction Temperature – °C

REFERENCE VOLTAGEvs

VIRTUAL JUNCTION TEMPERATURE

ÎÎÎÎÎÎÎÎ

VI = 20 VIO = 15 mA

Vre

f

175

† Data at high and low temperatures are applicable only within the recommended operating free-air temperature ranges of the various devices.





Figure 9

86

84

82

800 25 50 75

88

INPUT CURRENT AT ADJvs

VIRTUAL JUNCTION TEMPERATURE90

100 125


VI = 25 VVO = VrefIO = 500 mA

AD

J In

put C

urre

nt –

µA

Figure 10

20

10

5

0–75 –50 –25 0 25 50

Dro

pout

Vol

tage

– V

DROPOUT VOLTAGEvs


75 100 125

25

15


∆VO = 100 mV

IO = 700 mAIO = 600 mAIO = 500 mA

IO = 250 mA

IO = 100 mAIO = 15 mA

Figure 11

–0.2

–0.3

–0.4

–0.50 25 50 75 100 125 150

– O

utpu

t Vol

tage

Dev

iatio

n –

% –0.1

0

OUTPUT VOLTAGE DEVIATIONvs


∆VO


VI = 25 VVO = 5 VIO = 15 mA to 700 mA

Figure 12

6

4

2

00 25 50 75

– O

utpu

t Cur

rent

– m

A 8

10

12

100 125

OUTPUT CURRENT†

vsINPUT VOLTAGE

I O

VI – Input Voltage – V

TC = 25°C

TC = 125°C

TC = 0°C

† This is the minimum current required to maintain voltage regulation.





Figure 13

ÎÎÎÎTJ = 25°C

ÎÎÎÎÎÎ

Co = 0


Co = 10 µF

0 1 2 3 4

Time – µs

– O

utpu

t Vol

tage

Dev

iatio

n –

VV

OC

hang

e in

Inpu

t Vol

tage

– V

0.4

0.2

0

–0.2

1

0.5

0

LINE TRANSIENT RESPONSE

∆

Figure 14

VI = 35 VVO = 10 VCo = 1 µFTJ = 25°C

– O

utpu

t Cur

rent

– A

I O

6

4

2

0

–2

–4

–6

0.8

0.6

0.4

0.2

00 40 80 120 160 200 240

Time – µs

LOAD TRANSIENT RESPONSE

– O

utpu

t Vol

tage

Dev

iatio

n –

VV

O∆

DESIGN CONSIDERATIONS

The internal reference (see functional block diagram) generates 1.25 V nominal (Vref) between OUT and ADJ. Thisvoltage is developed across R1 and causes a constant current to flow through R1 and the programming resistor R2,giving an output voltage of:

VO = Vref (1 + R2/R1) + lI(ADJ) (R2)

or

VO ≈ Vref (1 + R2/R1)

The TL783 was designed to minimize the input current at ADJ and maintain consistency over line and load variations,thereby minimizing the associated (R2) error term.

To maintain II(ADJ) at a low level, all quiescent operating current is returned to the output terminal. This quiescentcurrent must be sunk by the external load and is the minimum load current necessary to prevent the output from rising.The recommended R1 value of 82 Ω provides a minimum load current of 15 mA. Larger values can be used whenthe input-to-output differential voltage is less than 125 V (see the output-current curve in Figure 14) or when the loadsinks some portion of the minimum current.





bypass capacitors

The TL783 regulator is stable without bypass capacitors; however, any regulator becomes unstable with certainvalues of output capacitance if an input capacitor is not used. Therefore, the use of input bypassing isrecommended whenever the regulator is located more than four inches from the power-supply filter capacitor.A 1-µF tantalum or aluminum electrolytic capacitor usually is sufficient.

Adjustment-terminal capacitors are not recommended for use on the TL783 because they can seriouslydegrade load transient response as well as create a need for extra protection circuitry. Excellent ripple rejectionpresently is achieved without this added capacitor.

Due to the relatively low gain of the MOS output stage, output voltage dropout may occur under large loadtransient conditions. The addition of an output bypass capacitor greatly enhances load transient response andprevents dropout. For most applications, it is recommended that an output bypass capacitor be used, with aminimum value of:

Co (µF) = 15/VO

Larger values provide proportionally better transient-response characteristics.

protection circuitry

The TL783 regulator includes built-in protection circuits capable of guarding the device against most overloadconditions encountered in normal operation. These protective features are current limiting, safe-operating-areaprotection, and thermal shutdown. These circuits protect the device under occasional fault conditions only.Continuous operation in the current limit or thermal shutdown mode is not recommended.

The internal protection circuits of the TL783 protect the device up to maximum-rated VI as long as certainprecautions are taken. If Vl is instantaneously switched on, transients exceeding maximum input ratings mayoccur, which can destroy the regulator. These are usually caused by lead inductance and bypass capacitorscausing a ringing voltage on the input. In addition, when rise times in excess of 10 V/ns are applied to the input,a parasitic npn transistor in parallel with the DMOS output can be turned on, causing the device to fail. If thedevice is operated over 50 V and the input is switched on rather than ramped on, a low-Q capacitor, such astantalum or aluminum electrolytic should be used rather than ceramic, paper, or plastic bypass capacitors. AQ factor of 0.015 or greater usually provides adequate damping to suppress ringing. Normally, no problemsoccur if the input voltage is allowed to ramp upward through the action of an ac line rectifier and filter network.

Similarly, when an instantaneous short circuit is applied to the output, both ringing and excessive fall times canresult. A tantalum or aluminum electrolytic bypass capacitor is recommended to eliminate this problem.However, if a large output capacitor is used and the input is shorted, addition of a protection diode may benecessary to prevent capacitor discharge through the regulator. The amount of discharge current delivered isdependent on output voltage, size of capacitor, and fall time of Vl. A protective diode (see Figure 17) is requiredonly for capacitance values greater than:

Co (µF) = 3 x 104/(VO)2

Care always should be taken to prevent insertion of regulators into a socket with power on. Power should beturned off before removing or inserting regulators.





IN

TL783

OUT VO

R1

R2

ADJ

VI

Co

Figure 15. Regulator With Protective Diode

load regulation

The current-set resistor (R1) should be located close to the regulator output terminal rather than near the load.This eliminates long line drops from being amplified, through the action of R1 and R2, to degrade load regulation.To provide remote ground sensing, R2 should be near the load ground.

VI

TL783

R1

Rline

RL

R2

VOIN OUT

ADJ

Figure 16. Regulator With Current-Set Resistor




APPLICATION INFORMATION

VI = 125 V

TL783

IN OUT

ADJ

1 µF†

0 to 8 k Ω

10 µF

† Needed if device is more than 4 inches from filter capacitor

R2

R182 Ω

++

VO Vref 1 R2R1

Figure 17. 1.25-V to 115-V Adjustable RegulatorFigure 18. 125-V Short-Circuit-Protected

Off-Line Regulator

10 µF

0.1 µF

IN

OUT

ADJ

R28.2 kΩ, 2W

125 V

120 V, 1.5 W

7.5 kΩ, 1 W

VI = 145 to 200 V

TIP150

TL783R1

82 Ω

+

50 µF

82 Ω+

VI = 70 to 125 V

10 Ω

1 kΩ

TIP30C

TIPL762

VO = 50 Vat 0.5 A

TL783

3.3 kΩ, 1W

10 kΩ

Figure 19. 50-V Regulator With Current Boost

INOUT

ADJ

Figure 20. Adjustable RegulatorWith Current Boost and Current Limit

50 µF+

125 V

10 Ω

1 kΩ TIPL762

1 Ω

R2

TL783

R182 Ω

10 kΩIN

OUT

ADJ VO Vref 1 R2R1




APPLICATION INFORMATION

Figure 21. Current-Sinking Regulator

VI

Load

R

I Vref

R

IN

OUT

ADJ

TL783

Figure 22. Current-Sourcing Regulator

VI

1 µF

R

TL783

Load

IN

OUT

ADJ

I Vref

R

Figure 23. High-Voltage Unity-Gain Offset Amplifier

V +

INPUT

V –

TL081

R2

OUTPUT

VCC

1 µF

–

+

TL783

82 Ω

VOFFSET Vref I R282

IN

OUT

ADJ

Figure 24. 48-V, 200-mA Float Charger

6.25 Ω

48 V

82 Ω

3.9 kΩ

VI = 90 V

TL783

TL783

INOUT

ADJ

IN

OUT

ADJ

IMPORTANT NOTICE

Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinueany product or service without notice, and advise customers to obtain the latest version of relevant informationto verify, before placing orders, that information being relied on is current and complete. All products are soldsubject to the terms and conditions of sale supplied at the time of order acknowledgement, including thosepertaining to warranty, patent infringement, and limitation of liability.

TI warrants performance of its semiconductor products to the specifications applicable at the time of sale inaccordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extentTI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarilyperformed, except those mandated by government requirements.

CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OFDEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICALAPPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, ORWARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHERCRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TOBE FULLY AT THE CUSTOMER’S RISK.

In order to minimize risks associated with the customer’s applications, adequate design and operatingsafeguards must be provided by the customer to minimize inherent or procedural hazards.

TI assumes no liability for applications assistance or customer product design. TI does not warrant or representthat any license, either express or implied, is granted under any patent right, copyright, mask work right, or otherintellectual property right of TI covering or relating to any combination, machine, or process in which suchsemiconductor products or services might be or are used. TI’s publication of information regarding any thirdparty’s products or services does not constitute TI’s approval, warranty or endorsement thereof.

Copyright 2000, Texas Instruments Incorporated

TL783C

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