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

PT79SR100 Series

-1.5 Amp Negative Step-Down

Integrated Switching Regulator

• High Efficiency > 85%

• Self-Contained Inductor

• Short Circuit Protection

• Over-Temperature Protection

The PT79SR100 is a line of

Negative Input/Negative Output

3-terminal Integrated Switching

Regulators (ISRs). These ISRs have a

maximum output current of -1.5 Amps

and an output voltage that is laser

trimmed to most industry standard volt-

ages. They have excellent line and load

regulation, and are ideal for applications,

such as RS232 and Ethernet communica-

tions, ECL logic, and op-amp circuitry.

PT79SR1

COMCOM

-Vin

C2D1

-Vout

Pin-Out Information

Pin Function

1 GND

2-V

3-V

out

Ordering Information

PT79SR1

Output Voltage

05 = -5.0 Volts

52 = -5.2 Volts

06 = -6.0 Volts

08 = -8.0 Volts

09 = -9.0 Volts

12 = -12.0 Volts

15 = -15.0 Volts

Package Suffix

V = Vertical Mount

S = Surface Mount

H = Horizontal

Mount

Standard Application

C1 = Optional ceramic (1µF)

C2 = Optional ceramic (1-5µF)

D1 = Zener diode required to clamp

turn-on overshoot

(See Application Note)

Specifications

Characteristics

PT79SR100 SERIES

= 25°C unless noted) Symbols Conditions Min Typ Max Units

Output Current I

Over V

range -0.1* — -1.5 A

Short Circuit Current I

-4V — -3.5 — Apk

Input Voltage Range V

=-0.1 to -1.5 A V

=-5V -9 — -30 V

-0.1 ≥ I

≥ -1.5 A V

=-15V -19 — -30 V

Output Voltage Tolerance ∆V

Over Vin range, I

=-1.5 A

— ±1.0 ±3.0 %V

=-20°C to shutdown

Line Regulation Reg

line

Over V

range — ±1.0 ±2.0 %V

Load Regulation Reg

load

-0.1 ≤ I

≤ -1.5 A — ±0.5 ±1.0 %V

Ripple/Noise V

=-15V, I

=-1.0 A,V

=-5V — 35 — mV

Transient Response t

50% load change — 100 — µSec

=overshoot/undershoot — 30 — %V

Efficiency η V

=-10V, I

=-1.0A, V

=-5V — 85 — %

Switching Frequency ƒ

Over V

and I

ranges 0.95 1.0 1.05 MHz

Absolute Maximum T

-40 — +85 °C

Operating Temperature Range

Recommended Operating T

Free Air Convection, (40-60LFM)

-40 — +60** °C

Temperature Range Over V

and I

ranges

Thermal Resistance θ

Free Air Convection, (40-60LFM) — 45 — °C/W

Temperature Coefficient T

Over V

and I

ranges — ±0.5 ±1.5 mV/°C

Storage Temperature T

— -40 — +125 °C

Mechanical Shock — Per Mil-STD-883D, Method 2002.3 — 500 — G’s

Mechanical Vibration — Per Mil-STD-883D, Method 2007.2,

—5

—

G’s

20-2000 Hz, soldered in a PC board

Weight — — — 7.0 — Grams

* ISR will operate down to no load with reduced specifications. ** See Thermal Derating chart.

Pkg Style 500

SLTS061A

(Revised 6/30/2000)

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

Typical Characteristics

PT79SR105, -5.0 VDC (See Note 1)

PT79SR112, -12.0 VDC (See Note 1)

PT79SR115, -15.0 VDC (See Note 1)

Efficiency vs Output Current Efficiency vs Output Current Efficiency vs Output Current

Ripple vs Output Current Ripple vs Output Current Ripple vs Output Current

Power Dissipation vs Output Current Power Dissipation vs Output Current Power Dissipation vs Output Current

Note 1: All data listed in the above graphs, except for derating data, has been developed from actual products tested at 25°C. This data is considered typical data for the ISR.

Note 2: Thermal derating graphs are developed in free air convection cooling of 40-60 LFM soldered in a printed circuit board. (See Thermal Application Notes.)

Thermal Derating (T

) (See Note 2) Thermal Derating (T

) (See Note 2)

Efficiency - %Ripple-(mV)Iout-(Amps)PD-(Watts)

Iout-(Amps)

Vin-(Volts)

Iout-(Amps)

Vin-(Volts)

Iout-(Amps)

Vin-(Volts)

100

0 0.25 0.5 0.75 1 1.25 1.5

10.0V

15.0V

20.0V

25.0V

30.0V

Vin

0 0.25 0.5 0.75 1 1.25 1.5

30.0V

25.0V

20.0V

15.0V

10.0V

Vin

0.5

1.5

0 0.25 0.5 0.75 1 1.25 1.5

30.0V

25.0V

20.0V

15.0V

10.0V

Vin

100

0 0.25 0.5 0.75 1 1.25 1.5

16.0V

20.0V

25.0V

30.0V

Vin

0.5

1.5

2.5

0 0.25 0.5 0.75 1 1.25 1.5

30.0V

25.0V

20.0V

16.0V

Vin

100

0 0.25 0.5 0.75 1 1.25 1.5

19.0V

21.0V

24.0V

27.0V

30.0V

Vin

120

150

0 0.25 0.5 0.75 1 1.25 1.5

30.0V

27.0V

24.0V

21.0V

19.0V

Vin

0.2

0.4

0.6

0.8

1.2

1.4

1.6

7 9 11 13 15 17 19 21 23 25 27 29 31

60˚C

70˚C

85˚C

50˚C

0.2

0.4

0.6

0.8

1.2

1.4

1.6

15 17 19 21 23 25 27 29 31

60˚C

70˚C

85˚C

50˚C

0.2

0.4

0.6

0.8

1.2

1.4

1.6

18 20 22 24 26 28 30

60˚C

70˚C

85˚C

50˚C

100

0 0.25 0.5 0.75 1 1.25 1.5

30.0V

25.0V

20.0V

16.0V

Vin

0.5

1.5

2.5

0 0.25 0.5 0.75 1 1.25 1.5

30.0V

27.0V

24.0V

21.0V

19.0V

Vin

PT79SR100 Series

-1.5 Amp Negative Step-Down

Integrated Switching Regulator

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Post Office Box 655303

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Part #	PT79SR105H
Description	REGULATOR -5V/1.5A INT SW HORIZ
Category	VOLTAGE REGULAT
Availability	In Stock
Qty	1

PT79SR105H

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