Texas Instruments PT79SR105H, PT79SR105S, PT79SR105V, PT79SR108H, PT79SR108S Datasheet

For assistance or to order, call [phone]

PT79SR100 Series

-1.5 AMP NEGATIVE STEP-DOWN
INTEGRATED SWITCHING REGULATOR

Application Notes

Mechanical Outline

Product Selector Guide

Revised 5/15/98

Standard Application

C1

-Vin

C1 = Optional ceramic (1µF)
C2 = Optional ceramic (1-5µF)
D1 = Zener diode required to clamp

1

23

PT79SR1

turn-on overshoot
(See Application Note)

• High Efficiency > 85%

• Self-Contained Inductor

• Short Circuit Protection

• Over-Temperature Protection

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 volt­ages. They have excellent line and load

The PT79SR100 Series is a new
line of Negative Input/Negative Out­put 3-terminal Integrated Switching

Pin-Out Information

Pin Function

1 GND

2-V

in

3-V

COMCOM

C2D1

-Vout

out

regulation, and are ideal for applications,
such as RS232 and Ethernet communica­tions, ECL logic, and op-amp circuitry.

Ordering Information

PT79SR1

Output Voltage

05 = -5.0 Volts
52 = -5.2 Volts
08 = -8.0 Volts
09 = -9.0 Volts
12 = -12.0 Volts
15 = -15.0 Volts

Y

XX

Package Suffix

V = Vertical Mount
S = Surface Mount
H = Horizontal

Mount

Specifications

Pkg Style 500

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

Output Current I
Short Circuit Current I
Input Voltage Range V

Output Voltage Tolerance ∆V

Line Regulation Reg
Load Regulation Reg
V

Ripple/Noise V

o

Transient Response t

Efficiency η Vin=-10V, Io=-1.0A, Vo=-5V — 85 — %
Switching Frequency ƒ
Absolute Maximum T

Operating Temperature Range
Recommended Operating T

Temperature Range Over Vin and Io ranges
Thermal Resistance θ
Temperature Coefficient T
Storage Temperature T
Mechanical Shock — Per Mil-STD-883D, Method 2002.3 — 500 — G’s
Mechanical Vibration — Per Mil-STD-883D, Method 2007.2,

Weight — — — 7.0 — Grams

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

o

sc

in

o

line

load

n

tr

o

a

a

ja

c

s

Over Vin range -0.1* — -1.5 A
Vin=Vo-4V — -3.5 — Apk
Io=-0.1 to -1.5 A Vo=-5V -9 — -30 V

-0.1 ≥ Io ≥ -1.5 A Vo=-15V -19 — -30 V
Over Vin range, Io=-1.5 A

Ta=-20°C to shutdown
Over Vin range — ±1.0 ±2.0 %V

-0.1 ≤ Io ≤ -1.5 A — ±0.5 ±1.0 %V
Vin=-15V, Io=-1.0 A,Vo=-5V — 35 — mV
50% load change — 100 — µSec

Vo=overshoot/undershoot — 30 — %V

Over Vin and Io ranges 0.95 1.0 1.05 MHz

Free Air Convection, (40-60LFM)

Free Air Convection, (40-60LFM) — 45 — °C/W
Over Vin and Io ranges — ±0.5 ±1.5 mV/°C
— -40 — +125 °C

20-2000 Hz, soldered in a PC board

PT79SR100 SERIES

— ±1.0 ±3.0 %V

-40 — +85 °C

-40 — +60** °C

—5

—

o

o

o

pp

o

G’s

22

Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 [phone] Fax: [phone] http://www.powertrends.com

For assistance or to order, call [phone]

PT79SR100 Series

CHARACTERISTIC DATA

PT79SR105, -5.0 VDC (See Note 1)

PT79SR112, -12.0 VDC (See Note 1)

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

100

90

80

70

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

60

50

40

0 0.25 0.5 0.75 1 1.25 1.5

Iout-(Amps)

Vin

9V

10.0V

15.0V

20.0V

25.0V

30.0V

100

90

80

70

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

60

50

40

0 0.25 0.5 0.75 1 1.25 1.5

Iout-(Amps)

Vin

16.0V

20.0V

25.0V

30.0V

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

60

50

40

30

20

10

0

0 0.25 0.5 0.75 1 1.25 1.5

Iout-(Amps)

Vin

30.0V

25.0V

20.0V

15.0V

10.0V
9V

100

80

60

40

20

0

0 0.25 0.5 0.75 1 1.25 1.5

Iout-(Amps)

Vin

30.0V

25.0V

20.0V

16.0V

PT79SR115, -15.0 VDC (See Note 1)

100

90

80

70

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

60

50

40

0 0.25 0.5 0.75 1 1.25 1.5

Iout-(Amps)

150

120

90

60

30

0

0 0.25 0.5 0.75 1 1.25 1.5

Iout-(Amps)

Vin

Vin

30.0V

27.0V

24.0V

21.0V

19.0V

19.0V

21.0V

24.0V

27.0V

30.0V

Wide Input Range Products

DATA SHEETS

Thermal Derating (Ta) (See Note 2) Thermal Derating (Ta) (See Note 2) Thermal Derating (Ta) (See Note 2)

1.6

1.4

1.2
1

0.8

0.6

0.4

0.2
0

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

70˚C

85˚C

Vin-(Volts)

60˚C

50˚C

1.6

1.4

1.2
1

0.8

0.6

0.4

0.2
0

15 17 19 21 23 25 27 29 31

85˚C

Vin-(Volts)

60˚C

70˚C

50˚C

1.6

1.4

1.2
1

0.8

0.6

0.4

0.2
0

18 20 22 24 26 28 30

70˚C

85˚C

Vin-(Volts)

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

2

1.5

1

0.5

0

0 0.25 0.5 0.75 1 1.25 1.5

Vin

30.0V

25.0V

20.0V

15.0V

10.0V
9V

Iout-(Amps)

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.)

2.5

2

1.5

1

0.5

0

0 0.25 0.5 0.75 1 1.25 1.5

Iout-(Amps)

Vin

30.0V

25.0V

20.0V

16.0V

2.5

2

1.5

1

0.5

0

0 0.25 0.5 0.75 1 1.25 1.5

Iout-(Amps)

60˚C

50˚C

Vin

30.0V

27.0V

24.0V

21.0V

19.0V

Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 [phone] Fax: [phone] http://www.powertrends.com

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