Power Trends 78ST100 User Manual

For assistance or to order, call [phone]

78ST100 Series

1.5 AMP POSITIVE STEP-DOWN
INTEGRATED SWITCHING REGULATOR

Revised 6/30/98

Standard Application

Vin

C1

1

78ST100

2

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

• Very Small Footprint

• High Efficiency > 85%

• Self-Contained Inductor

• Internal Short-Circuit Protection

• Over-Temperature Protection

• Fast Transient Response

• Wide Input Range

The 78ST100 is a series of wide input
voltage, 3-terminal Integrated Switching
Regulators (ISRs). These ISRs have a maxi­mum output current of 1.5A 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, are
very flexible, and may be used in a wide
variety of applications.

Pin-Out Information

Pin Function

1V

in

2 GND
3V

out

C2

Vout

+

GNDGND

3

Ordering Information

78ST1

Output Voltage

33 = 3.3 Volts
36 = 3.6 Volts
05 = 5.0 Volts
51 = 5.1 Volts
65 = 6.5 Volts
07 = 7.0 Volts
08 = 8.0 Volts
09 = 9.0 Volts
12 = 12.0 Volts

C

XX Y

Package Suffix

V = Vertical Mount
S = Surface Mount
H = Horizontal

Mount

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 78ST100 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

Pkg Style 500

78ST100 SERIES

Over Vin range 0.1* — 1.5 A

Vin = V

min — 3.5 — Apk

in

0.1 ≤ Io ≤ 1.5A Vo= 3.3V 7 — 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 7 — 30 V

V

o

Vo= 12V 14.5 — 30 V

— ±1.0 ±2.0 %V

-40 — +85 °C

-40 — +80** °C

—5

—

G’s

o

o
o

pp
pp

o

2

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

CHARACTERISTIC DATA

For assistance or to order, call [phone]

78ST100 Series

78ST133_ 3.3 VDC (See Note 1)

78ST105_ 5.0 VDC (See Note 1)

Efficiency vs Output Current Efficiency vs Output Current

100

90

80

70

60

Efficiency (%)Ripple (mV)Iout (A)Pd (Watts)

50

40

0.0 0.5 1.0 1.5

Iout (A)

Vin

7.0V

10.0V

15.0V

20.0V

25.0V

30.0V

100

90

80

70

60

Efficiency (%)

50

40

0.0 0.5 1.0 1.5

Iout (A)

Ripple vs Output Current Ripple vs Output Current

60

50

40

30

20

10

0

0.0 0.5 1.0 1.5

Iout (A)

Vin

7.0V

10.0V

15.0V

20.0V

25.0V

30.0V

80

70

60

50

40

30

Ripple (mV)

20

10

0

0.0 0.5 1.0 1.5

Iout (A)

78ST112_ 12.0 VDC (See Note 1)

DATA SHEETS

Efficiency vs Output Current

100

90

Vin

7.0V

10.0V

15.0V

20.0V

25.0V

30.0V

80

70

60

Efficiency (%)

50

40

0.0 0.5 1.0 1.5

Vin

14.0V

20.0V

25.0V

30.0V

35.0V

Iout (A)

Ripple vs Output Current

140

Vin

7.0V

10.0V

15.0V

20.0V

25.0V

30.0V

120

100

80

60

Ripple (mV)Iout (A)

40

20

0

0.0 0.5 1.0 1.5

Iout (A)

Vin

14.0V

20.0V

25.0V

30.0V

35.0V

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

1.6

1.4

1.2

1

0.8

Iout (A)

0.6

0.4

0.2

0

9 12151821242730333639

60°C

70°C

85°C

Thermal Derating (Ta) (See Note 2)

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0

85°C

16 19 22 25 28 31 34 37 40

Vin (Volts)

Power Dissipation vs Output Current Power Dissipation vs Output Current

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

0.0 0.5 1.0 1.5

Vin

7.0V

10.0V

15.0V

20.0V

25.0V

30.0V

1.8

1.6

1.4

1.2

1.0

0.8

Pd (Watts)

0.6

0.4

0.2

0.0

0.0 0.5 1.0 1.5

Vin

7.0V

10.0V

15.0V

20.0V

25.0V

30.0V

Power Dissipation vs Output Current

2.5

2.0

1.5

1.0

Pd (Watts)

0.5

0.0

0.0 0.5 1.0 1.5

Iout (A) Iout (A) Iout (A)

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.)

60°C

70°C

Vin (Volts)Vin (Volts)

Vin

14.0V

20.0V

25.0V

30.0V

35.0V

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

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