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HI-REL DESIGN

• REPLACES APEX DB2800S SERIES

• SURFACE MOUNT MAGNETICS

• WELDED HERMETIC PACKAGE

• LOW INTERNAL TEMPERATURE GRADIENTS

• ALL CERAMIC CAPACITORS

• WITHSTANDS 5000G

OTHER FEATURES—SINGLE OUTPUT

• NO DERATING — –55°C to +125°C

• OUTPUT VOLTAGE ADJUSTMENT STANDARD

• REMOTE SHUTDOWN

DESCRIPTION

The BBF2800S series of DC-DC converters provides the

ruggedness, reliability and features required to meet the

advanced design challenges of today’s hi-rel market. This has

been accomplished using a package having very low thermal

gradients, excellent hermeticity and high voltage isolation.

The use of advanced substrate and reflow soldering tech-

niques during construction results in a rugged, cost-effective

pin solderable package.

The BBF2800S hybrid converter series utilizes all ceramic

capacitors and surface mount magnetics to provide reliable

operation at all operating temperatures while surviving very

high G forces.

BBF2800S series standard features include kelvin sense,

indefinite short circuit protection, remote shutdown, output

fault monitoring, turn on voltage point adjustment, switching

frequency synchronization of up to 3 units using no external

components and pi-network input filtering. An output voltage

adjustment/load compensation pin is also standard.

Fault tolerant design protects these converters from most

external circuit faults. The output and output adjust pins will

withstand +35V while the shutdown and all synchronization

pins will withstand +50V protecting the converters from a

variety of system or board faults, i.e. solder bridges, etc.

Unique load fault protection circuitry allows this converter to

pull up loads having difficult static load line characteristics and

allows short term load excursions significantly beyond ratings

in most applications.

The BBF2800 series is a current mode push-pull topology

converter which operates at a switching frequency of 500KHz.

Internal filtering of both input and output eliminates the need for

external capacitors in many applications.

The 12-pin power dip package allows connection to a

heatsink and is hermetically sealed and isolated from the

internal circuits.

P W M 

CURRENT MODE 

CONTROLLER

ERROR AMPLIFIER

REFERENCE AND

ISOLATION

8

7

5

6

1

2

3

10

11

12

4

BLOCK DIAGRAM

4707 Dey Road  Liverpool, N.Y. 13088

    M.S.KENNEDY CORP.

(315) 701-6751

BBF2800S

    

SERIES

ISO-9001 CERTIFIED BY DSCC

20W

DC-DC

CONVERTERS

Rev. -  3/01

1

EXTERNAL CONNECTIONS

1

2

3

4

5

6

+INPUT

SHUTDOWN PLUS

CLOCK

ADJUST/COMP

-OUTPUT

+OUTPUT

12

11

10

9

8

7

-INPUT

TIMING 2

TIMING 1

CASE

-SENSE

+SENSE

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BBF2803S

ABSOLUTE MAXIMUM RATINGS

SPECIFICATIONS

ABSOLUTE MAXIMUM

RATINGS

INPUT VOLTAGE RANGE (Pin 12 to 1, 2, 3, 10 or 11)

0 - 50 Vdc

INPUT TRANSIENT (Pin 12 to 1)

80 V @ 50 ms

OUTPUT WITHSTAND (Pin 5 and 8 to 7, 6 or 4)

35 Vdc

OUTPUT CURRENT (Continuous)

5.5 Adc

BBF2803S

4.0 Adc

BBF2805S

1.9 Adc

BBF2812S

1.5 Adc

BBF2815S

TEMPERATURE, Storage

–65

o

C, 150

o

C

TEMPERATURE, Pin Soldering 10s

                      300

o

C

NOTES:

1.

Unless otherwise stated:

T

C

 = 25°, V

IN

 = 28V, I

OUT

 = I

MAX AMPS

2.

Derate power linearly to zero from 125°C to 135°C.

3.

Regulation measured between pin 8 and pin 7.

4.

Recovery spec assumes that converter has been OFF for at least 500ms.

CAUTION:

The internal substrate contains beryllia (BeO). Do not break the seal. If accidentally broken, do not crush, machine, or

subject to temperatures in excess of 850°C to avoid generating toxic fumes.

CAUTION

SPECIFICATIONS

BBF2803S

PARAMETER

TEST CONDITIONS

1

MIN

TYP

MAX

UNITS

STEADY STATE CHARACTERISTICS

INPUT VOLTAGE RANGE

16

28

40

Vdc

OUTPUT VOLTAGE

V

IN

; min to max Vdc @ I

MIN

3.2

3.3

3.4

Vdc

OUTPUT CURRENT

V

IN

; min to max Vdc

500

5500

mAdc

EFFICIENCY

66

%

OUTPUT RIPPLE VOLTAGE

Bandwidth 10 kHz to 1MHz

20

50

mVrms

INPUT RIPPLE CURRENT

Bandwidth 10 kHz to 1MHz

20

50

mArms

OUTPUT POWER

2

1.6

18.0

W

LINE REGULATION

3

V

IN

; min to max

3

2

20

mVdc

LOAD REGULATION

3

I

OUT

; min to max

3

1

15

mVdc

TEMPERATURE COEFFICIENT

.01

%/°C

TEMPERATURE RANGE, case

2

–55

125

°C

QUIESCENT CURRENT

I

OUT

 = 0 A

35

40

mAdc

INHIBITED

V

PIN5

 ; < 8 Vdc

.09

1.25

2.5

mAdc

ISOLATION CHARACTERISTICS

 (INPUT/OUTPUT/CASE)

LEAKAGE RESISTANCE

(V

TEST

 = 500Vdc)

100

M

LEAKAGE CAPACITANCE

(f = 10kHz)

50

pF

DYNAMIC CHARACTERISTICS

LINE STEP RESPONSE

V

IN;

 T

R

, T

F

 = 10µs

VOLTAGE CHANGE

V

IN

; 16 to 40 Vdc

300

mV

RECOVERY TIME (95%)

30

µs

WITH 100µF OUTPUT CAP

VOLTAGE CHANGE

V

IN

; 16 to 40 Vdc

100

mV

RECOVERY TIME (95%)

100

µs

LOAD STEP RESPONSE

I

OUT;

 T

R

, T

F

 = 10µs

VOLTAGE CHANGE

I

OUT

; 50% to max Adc

1400

mV

RECOVERY TIME (95%)

40

µs

WITH 100µF OUTPUT CAP

VOLTAGE CHANGE

I

OUT

; 50% to max Adc

300

mV

RECOVERY TIME (95%)

60

µs

START-UP OVERSHOOT

V

IN

 ;  0 to 40 Vdc

0

mV

SHUTDOWN DELAY

V

PIN5

 ; > 10 Vdc to < 8 Vdc

220

500

µs

SHUTDOWN RECOVERY

4

V

PIN5

 ; < 8 Vdc to > 10 Vdc

30

60

mS

Rev. -  3/01

2

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SPECIFICATIONS

BBF2805S • BBF2812S • BBF2815S

BBF2805S

BBF2812S

BBF2815S

MIN

TYP

MAX

MIN

TYP

MAX

MIN

TYP

MAX

UNITS

16

28

40

16

28

40

16

28

40

Vdc

5.00

5.05

5.1

12.00

12.05

12.1

15.0

15.1

15.2

Vdc

400

4000

190

1900

150

1500

mAdc

70

72

73

%

20

50

25

50

25

50

mVrms

20

30

20

30

20

30

mArms

2

20

2.3

23

2.2

22

W

5

50

5

50

10

50

mVdc

2

25

5

50

20

50

mVdc

.01

.01

.01

%/°C

–55

125

–55

125

–55

125

°C

35

40

35

40

35

40

mAdc

.09

1.25

2.5

.09

1.25

2.5

.9

1.25

2.5

mAdc

100

100

100

M

50

80

85

pF

400

300

300

mV

30

40

40

µs

200

150

150

mV

250

250

250

µs

1400

800

800

mV

40

60

60

µs

500

280

280

mV

150

400

400

µs

0

0

0

mV

220

500

220

500

220

500

µs

30

60

30

60

30

60

ms

PACKAGE THERMAL SPECIFICATIONS

MIN

TYP

MAX

UNITS

RESISTANCE, case to air

12

°C/W

TEMPERATURE RISE, junction to case

10

15

°C

Rev. -  3/01

3

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BBF2803S

TYPICAL PERFORMANCE

GRAPHS

0.0

6.0

OUTPUT CURRENT, I

OUT

 (A)

10

12

14

16

18

20

LOW LINE DROP OUT

INPUT VOLTAGE, V

IN

 (V)

2.0

4.0

10K

90K

60K

20K

30K 40K

INPUT VOLTAGE, V

IN

 (V)

TIME, t (500

µ

sec/DIV)

LOAD TRANSIENT RESPONSE 1000

µ

F

LINE TRANSIENT RESPONSE

EFFICIENCY CONTOURS

16

30

40

35

20

25

OUTPUT RESPONSE, X (UNITS/DIV)

OUTPUT CURRENT, I

OUT

 (A)

4.4

.55 1.1

2.2

3.3

5.5

SET POINT RESISTOR, R

SP

  (

)

TIME, t (5msec/DIV)

12

16

20

24

28

TURN ON THRESHOLD

TURN ON VOLTAGE, E

TO

 (V)

TURN ON RESPONSE

100 200 400

FREQUENCY, f (Hz)

–100

AUDIO REJECTION

AUDIO REJECTION, A

V

 (dB)

0

–20

–40

1K 2K

10K 20K

100K

–60

–80

RESPONSE, X (UNITS/DIV)

3.3V

0V

0V

28V

V

OUT

 

V

IN

TEMP = 25

°

C

40%

50%

56%

60%

64%

66%

67%

68%

69%

66%

70%

INPUT VOLTAGE, V

IN

 (V)

EFFICIENCY CONTOURS

16

30

40

35

20

25

OUTPUT CURRENT, I

OUT

 (A)

TEMP = 125

°

C

40%

50%

60%

64%

66%

67%

68%

69%

70%

64%

INPUT VOLTAGE, V

IN

 (V)

EFFICIENCY CONTOURS

16

30

40

35

20

25

OUTPUT CURRENT, I

OUT

 (A)

4.4

1.1

.55

2.2

3.3

5.5

4.4

1.1

.55

2.2

3.3

5.5

TEMP = 

–55

°

C

30%

40%

50%

54%

58%

60%

62%

64%

65%

66%

67%

INCLUDES 1000

µ

F ON OUTPUT BUS

TIME, t (200

µ

sec/DIV)

TIME, t (200

µ

sec/DIV)

LOAD TRANSIENT RESPONSE 100

µ

F

OUTPUT RESPONSE, X (UNITS/DIV)

OUTPUT RESPONSE, X (UNITS/DIV)

LOAD = 5.5A

LOAD = 5.5A

INCLUDES 100

µ

F ON OUTPUT BUS

INCLUDES 100

µ

F ON OUTPUT BUS

INCLUDES 100

µ

F ON

OUTPUT BUS

TIME, t (100

µ

sec/DIV)

LOAD TRANSIENT RESPONSE

OUTPUT RESPONSE, X (UNITS/DIV)

5.5A

5.5A

5.5A

2.75A

2.75A

2.75A

V

OUT

V

OUT

V

OUT

V

IN

16V

40V

V

OUT

I

OUT

I

OUT

I

OUT

1 V

2 A

1 V

2 A

100mV

10V

1 V

10 V

2

 V

2 A

NO OUTPUT BUS CAPCITANCE

V

IN

 = 28VDC

I

OUT

 = 5.5 Amps

OUTPUT DC

CURRENT RATING

TEMP = 25

°

C

Rev. -  3/01

4

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BBF2805S

TYPICAL PERFORMANCE

GRAPHS

0.0

5.0

OUTPUT CURRENT, I

OUT

 (A)

10

12

14

16

18

20

LOW LINE DROP OUT

INPUT VOLTAGE, V

IN

 (V)

1.0

2.0

3.0

4.0

10K

90K

70K

20K

30K 40K50K

INPUT VOLTAGE, V

IN

 (V)

TIME, t (500

µ

sec/DIV)

LOAD TRANSIENT RESPONSE 1000

µ

F

LINE TRANSIENT RESPONSE

EFFICIENCY CONTOURS

16

30

40

35

20

25

OUTPUT RESPONSE, X (UNITS/DIV)

OUTPUT CURRENT, I

OUT

 (A)

3.2

.4

.8

1.6

2.4

4

SET POINT RESISTOR, R

SP

  (

)

TIME, t (5msec/DIV)

12

16

20

24

28

TURN ON THRESHOLD

TURN ON VOLTAGE, E

TO

 (V)

TURN ON RESPONSE

100 200 400

FREQUENCY, f (Hz)

–100

AUDIO REJECTION

AUDIO REJECTION, A

V

 (dB)

0

–20

–40

1K 2K

10K 20K

100K

–60

–80

RESPONSE, X (UNITS/DIV)

5.1V

0V

0V

28V

V

OUT

 

V

IN

TEMP = 25

°

C

30%

40%

50%

60%

68%

70%

63%

66%

71%

72%

73%

INPUT VOLTAGE, V

IN

 (V)

EFFICIENCY CONTOURS

16

30

40

35

20

25

OUTPUT CURRENT, I

OUT

 (A)

3.2

.4

.8

1.6

2.4

4

TEMP = 

125

°

C

30%

50%

60%

64%

67%

67%

69%

70%

71%

72%

73%

INPUT VOLTAGE, V

IN

 (V)

EFFICIENCY CONTOURS

15

30

40

35

20

25

OUTPUT CURRENT, I

OUT

 (A)

3.2

.8

1.6

2.4

4

TEMP = 

–55

°

C

40%

50%

55%

60%

64%

71%

66%

68%

70%

69%

INCLUDES 1000

µ

F ON OUTPUT BUS

TIME, t (200

µ

sec/DIV)

TIME, t (200

µ

sec/DIV)

LOAD TRANSIENT RESPONSE 100

µ

F

OUTPUT RESPONSE, X (UNITS/DIV)

OUTPUT RESPONSE, X (UNITS/DIV)

INCLUDES 100

µ

F ON OUTPUT BUS

INCLUDES 100

µ

F ON OUTPUT BUS

INCLUDES 100

µ

F ON OUTPUT BUS

TIME, t (100

µ

sec/DIV)

LOAD TRANSIENT RESPONSE

OUTPUT RESPONSE, X (UNITS/DIV)

4A

4A

4A

2A

2A

2A

V

OUT

V

OUT

V

OUT

V

IN

16V

40V

LOAD 4A

LOAD 4A

V

OUT

I

OUT

I

OUT

I

OUT

1 V

1 A

1 V

1 A

100mV

10V

1 V

10 V

2

 V

1 A

NO OUTPUT BUS CAPCITANCE

V

IN

 = 28VDC

I

OUT

 = 4 Amps

OUTPUT DC

CURRENT RATING

TEMP = 25

°

C

Rev. -  3/01

5

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BBF2800S SERIES

APPLICATION

INFORMATION

OUTPUT ADJUST / COMP

 The output voltage of the BBF2800S may be adjusted from

90% to 110% of nominal value by the use of a 50K

 potenti-

ometer as shown. Adjustment beyond this range is possible

however certain characteristics of the converter such as but

not limited to input voltage range, efficiency, ripple and tem-

perature performance will change. Characterization by the

user is recommended in such applications.

 Adjust/comp (pin 4) may be driven by external circuitry

referenced to pin 8 (-output sense) if desired. Grounding pin

4 causes output voltage to increase (25% typically) while

driving pin 4 above 1.3 V causes output voltage to decrease.

Pin 4 may be driven through 10K

 or more if connection of the

comp function is also required.

The comp function of pin 4 allows transient response and

phase margin to be tailored to suit a specific application. This

feature may be utilized by connecting a small (1-500 nf)

capacitor between pins 4 and 6 or 7. This is generally recom-

mended when very large low ESR load capacitances are

used.

SHUTDOWN PLUS

Pin 2 is used for remote shutdown, output fault detection,

and/or setting the input voltage point at which the converter

will turn on as shown in the typical application diagram. No

connection to pin 2 is necessary for normal operation of the

converter. Pin 2 is referenced to pin 12 (-input).

Shutdown may be implemented by simply connecting pin 2

to an open collector logic output or switch rated at 2.5 mA, 25

Vdc or higher.

Input voltage turn on point is programmed with a single

resistor from pin 2 to 12. An input turn on/off hysteresis

(typically 3.5% of Vin) will be observed. This should be

considered when making or verifying set point adjustment.

The value of the setpoint resistor may be determined by the

following:

210 • 10

3

R =

(±10% accuracy at 25°C)

E

TO

 – 9.5

 Set point temperature coefficient is typically +400ppm/°C.

Output fault monitoring is accomplished by observing pin 2

with a high impedance monitoring circuit. Pin 2 voltage drops

from over 10 V to below 1 V when a load fault causes the

converters fault protection circuitry to activate. It will remain

low for at least 100 mS and return high. If the load fault is still

present pin 2 will return low and the cycle will repeat. If there

is no input setpoint programming resistor already in place a

resistor > 400 K

 from pin 2 to 12 will provide pin 2 pull down.

MULTIPLE CONVERTER SYNCHRONIZATION

Synchronized operation of up to three BBF2800S series

converters may be accomplished without external compo-

nents. One unit selected to be the master is connected

normally with pin 10 grounded. The clock output pin 3 will

provide the sync signal for up to two slave units. The slave

units have pin 10 not connected and receive the clock signal

into pin 11. The clock signal lines may be shielded to prevent

radiation. A separate 50 ohm coax to each slave unit is

recommended in order to preserve signal integrity. Shield

ends should be connected to pin 12 of the nearest converter.

BBF2800S converters may also be synchronized to an

external 500 KHz (+/- 5%) frequency source driving pin 11 of

the converters. Pin 10 is not connected. The converters

synchronize to the positive edge of the frequency source

allowing a variety of wave forms (pulse, square, spike) to be

used. Pin 11 is internally capacitively coupled allowing unipo-

lar or bipolar frequency sources to be used. The source should

have a waveform rise time of 20 ns or less and be capable of

driving at least 4 volts peak into each 50 ohm pin 11 input (50

volts peak max).

An externally synchronized unit may be used to synchronize

other (slave) units. The slave units may be used in turn to

synchronize other slave units from their pin 3 outputs. Each

“generation” of slave units has a delay (100-200ns typical)

from the unit that it is synchronizing to.

4

7

8

50K

TYPICAL APPLICATION

 The above diagram shows the remote sense feature which

reduces Vo errors due to the resistance of the conductors

feeding the load. This diagram also shows the connections for

non-synchronized operation (TIMING 1 and 2) as well as

output voltage trim, remote shutdown, fault monitoring, and

input voltage turn on point adjustment.

Rev. -  3/01

6

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The information contained herein is believed to be accurate at the time of printing. MSK reserves the right to make

changes to its products or specifications without notice, however, and assumes no liability for the use of its products.

Please visit our website for the most recent revision of this datasheet.

M.S. Kennedy Corp.

4707 Dey Road, Liverpool, New York 13088

Phone (315) 701-6751

FAX (315) 701-6752

www.mskennedy.com

NOTE:  ALL DIMENSIONS ARE ±0.010 INCHES UNLESS OTHERWISE LABELED.

           ESD Triangle indicates Pin 1.

   BBF2812S

The above example is an industrial grade 12V single output converter

ORDERING INFORMATION

SCREENING

   BLANK= INDUSTRIAL;  E= EXTENDED RELIABILITY;

   H= CLASS H;  K= CLASS K

SINGLE OUTPUT

OUTPUT VOLTAGE

 

 

  03=3.3V; 05=5V; 12=12V; 15=15V

NOMINAL INPUT VOLTAGE

GENERAL PART NUMBER

Rev. -  3/01

7

MECHANICAL SPECIFICATIONS