Texas Instruments PT78ST105H, PT78ST105S, PT78ST105V, PT78ST106H, PT78ST106S Datasheet

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PT78ST100 Series

1.5 AMP POSITIVE STEP-DOWN
INTEGRATED SWITCHING REGULATOR

Application Notes

Mechanical Outline

Product Selector Guide

Revised 7/15/98

• Very Small Footprint

• High Efficiency > 85%

• Self-Contained Inductor

• Internal Short-Circuit Protection

• Over-Temperature Protection

• Fast Transient Response

• Wide Input Range

3 terminal regulators. These ISRs have a
maximum output current of 1.5 Amps and an
output voltage that is laser trimmed to a variety
of industry standard voltages.

These 78 series regulators have excellent
line and load regulation with internal short­circuit and over-temperature protection, and
are offered in a variety of standard output

This is the new generation of

PT78ST100 Series wide input range

Pin-Out Information

Pin Function

1V

in

Standard Application

C2

Vout

+

COMCOM

Vin

C1

1

PT78ST100

C1 = Optional 1µF ceramic
C2 = Required 100µF electrolytic

3

2

Specifications

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

Ripple/Noise V

V

o

Transient Response t
(with 100µF output cap) Vo over/undershoot — 5 — %V

Efficiency η V

Switching Frequency ƒ
Absolute Maximum T

Operating Temperature Range
Recommended Operating T

Temperature Range At Vin= 24V, Io=1.0A
Thermal Resistance θ
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 — — — 6.5 — grams

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

Note:

The PT78ST100 Series requires a 100µF electrolytic or tantalum output capacitor for proper operation in all applications.

o

sc

in

o

line

load

n

tr

o

a

a

ja

s

2 GND
3V

out

Pkg Style 500

Over Vin range 0.1* — 1.5 A

Vin = V

min — 3.5 — Apk

in

0.1 ≤ Io ≤ 1.5A Vo= 3.3V 9 — 26 V

Over Vin range, Io=1.5A

Ta = 0°C to +60°C

Over Vin range — ±0.2 ±0.4 %V

0.1 ≤ Io ≤ 1.5A — ±0.1 ±0.2 %V
Vin= 9V, Io= 1.5A Vo= 5V — 65 — mV

Vin= 16V, Io= 1.5A Vo= 12V 90 mV
50% load change — 100 — µSec

= 10V, Io= 1A Vo= 3.3V — 80 — %

in

V

= 10V, Io= 1A Vo= 5V — 85 — %

in

Vin= 17V, Io= 1A Vo= 12V — 90 — %
Over Vin range, Io=1.5A 600 650 700 kHz
—

Free Air Convection, (40-60LFM)

Free Air Convection, (40-60LFM) — 45 — °C/W
— -40 — +125 °C

20-2000 Hz, soldered in a PC board

= 5V 9 — 38 V

V

o

Vo= 12V 16 — 38 V

voltages. These ISRs are very flexible and
may be used in a wide variety of applications.

Ordering Information

PT78ST1

Output Voltage

33 = 3.3 Volts
36 = 3.6 Volts
05 = 5.0 Volts
51 = 5.1 Volts
53 = 5.25 Volts
06 = 6.0 Volts
65 = 6.5 Volts
07 = 7.0 Volts
08 = 8.0 Volts
09 = 9.0 Volts
10 = 10.0 Volts
12 = 12.0 Volts
14 = 13.9 Volts
15 = 15.0 Volts

PT78ST100 SERIES

— ±1.0 ±2.0 %V

-40 — +85 °C

-40 — +80** °C

—5

XX Y

Package Suffix

V = Vertical Mount
S = Surface Mount
H = Horizontal

Mount

—

G’s

o

o
o

pp
pp

o

12

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

For assistance or to order, call [phone]

PT78ST100 Series

CHARACTERISTIC DATA

PT78ST133, 3.3 VDC (See Note 1) PT78ST105, 5.0 VDC (See Note 1) PT78ST112, 12.0 VDC (See Note 1)

Wide Input Range Products

DATA SHEETS

Efficiency vs Output Current Efficiency vs Output Current

100

90

80

70

60

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

50

40

0 0.25 0.5 0.75 1 1.25 1.5

Iout-(Amps)

Vin

9.0V

12.0V

15.0V

20.0V

26.0V

100

90

80

70

Efficiency - %

60

50

40

0 0.25 0.5 0.75 1 1.25 1.5

Iout-(Amps)

Ripple vs Output Current Ripple vs Output Current

100

80

60

40

20

0

00.250.50.7511.251.5

Iout-(Amps)

Vin

26.0V

20.0V

15.0V

12.0V

9.0V

150

120

90

60

Ripple-(mV)

30

0

0 0.25 0.5 0.75 1 1.25 1.5

Iout-(Amps)

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

9 13172125

85°C

60°C

70°C

Vin-(Volts) Vin-(Volts)Vin-(Volts)

1.6

1.4

1.2

1

0.8

0.6

Iout-(Amps)

0.4

0.2

0

9 12151821242730333639

60°C

70°C

85°C

Efficiency vs Output Current

100

Vin

9.0V

12.0V

18.0V

24.0V

30.0V

38.0V

90

80

70

Efficiency - %

60

50

40

0 0.25 0 .5 0.75 1 1.25 1.5

Vin

16.0V

18.0V

24.0V

30.0V

38.0V

Iout-(Amps)

Ripple vs Output Current

300

250

Vin

38.0V

30.0V

24.0V

18.0V

12.0V

9.0V

200

150

100

50

Ripple-(mV)Iout-(Amps)

0

0 0.25 0.5 0.75 1 1.25 1.5

Vin

38.0V

30.0V

24.0V

18.0V

16.0V

Iout-(Amps)

Thermal Derating (Ta) (See Note 2)

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0

16 19 22 25 28 31 34 37 40

85°C

70°C

60°C

Power Dissipation vs Output Current Power Dissipation vs Output Current

1.8

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0

00.250.50.7511.251.5

Vin

26.0V

20.0V

15.0V

12.0V

9.0V

2.5

2

1.5

1

PD-(Watts)

0.5

0

0 0.25 0.5 0.75 1 1.25 1.5

Vin

38.0V

30.0V

24.0V

18.0V

12.0V

9.0V

Power Dissipation vs Output Current

3

2.5

2

1.5

1

PD-(Watts)

0.5

0

0 0.25 0.5 0.75 1 1.25 1.5

Iout-(Amps) Iout-(Amps) 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. (See Thermal Application Notes.)

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

Vin

38.0V

30.0V

24.0V

18.0V

16.0V

13