Datasheet CBT6820 Datasheet (Philips)

INTEGRATED CIRCUITS

CBT6820

20-bit bus switch with precharged outputs
and Schottky undershoot protection for
live insertion

Product specification

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1999 Apr 05

Philips Semiconductors Product specification

20-bit bus switch with precharged outputs and
Schottky undershoot protection for live insertion

FEA TURES

•TTL compatible inputs and outputs

•5Ω switch connection between two port A and port B

•Thin shrink small outline (TSSOP)

•Undershoot protection included to prevent shoot through level

changes

•Bias voltage pre-charges the outputs to minimize signal distortion

during live insertion

DESCRIPTION

The CBT6820 provides twenty bits of high-speed TTL-compatible
bus switching. The low on-state resistance of the switch allows
bi-directional connections to be made while adding near-zero
propagation delay. The device also precharges the B port to a
user-selectable bias voltage (BIASV) to minimize live-insertion
noise.

The device is organized as two 10-bit switch with individual enable
(OE) input. When OE is low, the switch is on and port A is
connected to port B. When OE is high, the switch between port A
and port B is open and the B port is precharged to BIASV through
the equivalent of a 10-kΩ resistor.

Special clamp circuitry and Schottky diode clamps to ground are
used to prevent an under voltage on the A side (Vin < GND) from
causing the B side precharge voltage to drop below the ‘‘1” state.

PIN CONFIGURATION

BIASV

1A1
1A2

1A3

1A4
1A5
1A6

GND

1A7
1A8

1A9

1A10

2A1
2A2

V

2A3

GND

2A4
2A5

2A6

2A7

2A8

2A9

2A10

CBT6820

1
2
3

4
5

6
7
8

9
10
11
12
13
14
15

CC

16
17
18
19
20
21

22

23
24

1OE

48

2OE

47

1B1

46

1B2

45
44

1B3

43

1B4

42

1B5
GND

41
40

1B6

39

1B7
1B8

38

1B9

37

1B10

36

2B1

35

2B2

34

2B3

33

GND

32

2B4

31

2B5

30

2B6

29

2B7

28

2B8

27

2B9

26

2B10

25

SA00520

QUICK REFERENCE DA TA

SYMBOL PARAMETER

t

PLH/tPHL

C

IN

C

I/O

Propagation delay
An to Bn or Bn to An

Input capacitance 4.5 pF
Input/output capacitance Outputs disabled; VO = 0 V or V

CL = 50 pF, VCC = 5 V 0.25 ns

CONDITIONS

T

= 25°C; GND = 0V

amb

CC

TYPICAL UNIT

9.5 pF

ORDERING INFORMATION

PACKAGES TEMPERATURE RANGE OUTSIDE NORTH AMERICA NORTH AMERICA DWG NUMBER

48-Pin Plastic TSSOP Type II –40°C to +85°C CBT6820 DGG CBT6820 DGG SOT362–1

1999 Apr 05 853–2152 21177

2

Philips Semiconductors Product specification

SYMBOL

PARAMETER

UNIT

20-bit bus switch with precharged outputs and
Schottky undershoot protection for live insertion

PIN DESCRIPTION

PIN NUMBER SYMBOL NAME AND FUNCTION

1 BIASV Bias voltage

2, 3, 4, 5, 6,

7, 9, 10, 11,12

1A1–1A10 Port 1A1 to Port 1A10

8, 17, 32, 41 GND Ground (V)

13, 14, 16, 18, 19,

20, 21, 22, 23, 24

15 V

35, 34, 33, 31, 30,

29, 28, 27, 26, 25

46, 45, 44, 43, 42,

40, 39, 38, 37, 36

2A1–2A10 Port 2A1 to Port 2A10

CC

Positive supply voltage

2B1–2B10 Port 2B1 to Port 2B10

1B1–1B10 Port 1B1 to Port 1B10

48, 47 1OE, 2OE Switch enables

FUNCTION TABLE

OE STATE

L A Port = B Port
H A Port = Z
H B Port = BIASV

H = High voltage level
L = Low voltage level
Z = High impedance “off” state

LOGIC SYMBOL

xA10

2, 13

xA1

12, 24

48, 47

xOE

where x = 1 – 2

CBT6820

1

BIASV

46, 35

xB1

36, 25

xB10

SA00506

ABSOLUTE MAXIMUM RATINGS

SYMBOL PARAMETER CONDITIONS RATING UNIT

V

I

V

BIASV

T

øJA

I

V

SW

CC

IK

stg

DC supply voltage –0.5 to +7.0 V
DC clamp diode current VI < 0 –50 mA
DC input voltage

I

DC continuous channel current VO = 0 to V

1

CC

–0.5 to +7.0 V

±128 mA
DC bias voltage –0.5 to +7.0 V
Storage temperature range –65 to 150 °C
Plastic thin shrink small outline package

(TSSOP)

104 °C/W

NOTE:

1. The input and output voltage ratings may be exceeded if the input and output current ratings are observed.

RECOMMENDED OPERATING CONDITIONS

LIMITS

Min Max

V

CC

BIASV DC supply voltage 1.3 V

V
V

T

amb

DC supply voltage 4.0 5.5 V

High-level input voltage (control pin) 2.0 V

IH

Low-level Input voltage (control pin) 0.8 V

IL

Operating free-air temperature range –40 +85 °C

CC

V

1999 Apr 05

3

Philips Semiconductors Product specification

3

20-bit bus switch with precharged outputs and

CBT6820

Schottky undershoot protection for live insertion

DC ELECTRICAL CHARACTERISTICS

LIMITS

SYMBOL PARAMETER TEST CONDITIONS T

∆I

C

O(OFF)

V

I

I

CC

C

Input clamp voltage VCC = 4.5V; II = –18mA –1.2 V

IK

I

Input leakage current (control pin) VCC = 5.5V; VI = GND or 5.5V ±5 µA

I

Output bias current (B pins) VCC = 4.5V; BiasV = 2.4V; VO = 0, OE = V

O

CC

Quiescent supply current VCC = 5.5V; IO = 0, VI = VCC or GND 2.5 mA
Control pins

CC

Input capacitance per OE pin VI= 3V or 0 4.5 pF

I

2

VCC = 5.5V , one input at 3.4V,
other inputs at VCC or GND

Capacitance per port (OFF-state) VO = 3V or 0; switch off 9.5 pF

VCC = 4.5V; VI = 0V; II = 64mA 5 7

r

on

On-resistance VCC = 4.5V; VI = 0V; II = 30mA 5 7 Ω

VCC = 4.5V; VI = 2.4V; II = –15mA 10 15

I

USP

V

Pass voltage VIN = VCC = 4.5V; I

P

Undershoot static current
protection

4

VCC = 5.0V, V
IB = –5µA, VB ≥ 3.0V

= –100µA 3.4 3.6 3.9 V

out

= V

Bias

CC

NOTES:

1. All typical values are at VCC = 5V, TA = 25 C

2. This is the increase in supply current for each input that is at the specified TTL voltage level rather than V

3. Measured by the voltage drop between the A and the B terminals at the indicated current through the switch. On–state resistance is
determined by the lowest voltage of the two (A or B) terminals.

4. Force I

, measure VB ≥ 3V

USP

= –40°C to +85°C UNIT

amb

Min Typ

1

–10 mA

or GND

CC

Max

–0.25 mA

2.5 mA

1999 Apr 05

4

Philips Semiconductors Product specification

20-bit bus switch with precharged outputs and

CBT6820

Schottky undershoot protection for live insertion

AC CHARACTERISTICS FOR VCC = 5.0V ±0.5V RANGE

GND = 0V; tr = tf ≤ 2.5ns; CL = 50pF.

LIMITS

SYMBOL PARAMETER WAVEFORM T

MIN TYP

2

1 0.25 ns
2 1.3 3.1 5.3 ns

2 1.4 2.9 4.6 ns

2 1.7 2.8 4.5 ns

2 2.8 4.4 6.6 ns

t

PZH

t

PZL

t

PHZ

t

PLZ

t

pd

Propagation delay; An to Bn; Bn to An
3-State output enable time

OE to An; OE to Bn; BIASV = GND
3-State output enable time

OE to An; OE to Bn; BIASV = 3.0V
3-State output enable time

OE to An; OE to Bn; BIASV = GND
3-State output enable time

OE to An; OE to Bn; BIASV = 3.0V

NOTE:

1. All typical values are measured at T

2. Warranted but not production tested. The propagation delay is based on the RC time constant of the typical ON-state resistance of the

= 25°C and VCC = 5.0V

amb

switch and a load capacitance of 50pF, when driven by an ideal voltage source (zero output impedance)

AC WAVEFORMS

TEST CIRCUIT AND WAVEFORMS

VM = 1.5V, VIN = GND to 3.0V

INPUT

1.5V

t

PLH

1.5V

t

PHL

3 V

0 V

V

OH

From Output

Under Test

C

L

= 50 pF

= –40 to +85°C UNIT

amb

1

500 Ω

500 Ω

Load Circuit

MAX

S1

7 V

Open

GND

1.5V 1.5V

OUTPUT

V

SA00028

OL

Waveform 1. W aveforms Showing the Input (An) to Output (Bn)

Propagation Delays

+ 0.3V

– 0.3V

SA00029

3V

0V

3.5V

V
V

0V

OL

OH

Output Control

(Low-level

enabling

Output

Waveform 1

S1 at 7 V

(see Note)

Output

Waveform 2

S1 at Open

(see Note)

1.5 V 1.5 V

t

PZL

1.5 V

t

PZH

1.5 V

Note:

Waveform 1 is for an output with internal conditions such that
the output is low except when disabled by the output control.

Waveform 2 is for an output with internal conditions such that
the output is high except when disabled by the output control.

t

t

PHZ

PLZ

V

OL

V

OH

Waveform 2. Waveforms Showing the 3-State Output Enable

and Disable Times

TEST S1

t

pd

t

PLZ/tPZL

t

PHZ/tPZH

DEFINITIONS

= Load capacitance includes jig and probe capacitance;

C

L

see AC CHARACTERISTICS for value.

open

7 V

open

SA00012

NOTES:

1. All input pulses are supplied by generators having the following
characteristics: PRR ≤ 10MHz, Z

2. The outputs are measured one at a time with one transition per

= 50 Ω, tr ≤ 2.5 ns, tf ≤ 2.5 ns.

O

measurement.

1999 Apr 05

5

Philips Semiconductors Product specification

20–bit bus switch with precharged outputs and

CBT6820

Schottky undershoot protection for live insertion

TSSOP48: plastic thin shrink small outline package; 48 leads; body width 6.1mm SOT362-1

1999 Apr 05

6

Philips Semiconductors Product specification

20–bit bus switch with precharged outputs and
Schottky undershoot protection for live insertion

NOTES

CBT6820

1999 Apr 05

7

Philips Semiconductors Product specification

20–bit bus switch with precharged outputs and
Schottky undershoot protection for live insertion

CBT6820

DEFINITIONS

Data Sheet Identification Product Status Definition

Objective Specification

Preliminary Specification

Product Specification

Formative or in Design

Preproduction Product

Full Production

Philips Semiconductors and Philips Electronics North America Corporation reserve the right to make changes, without notice, in the products,
including circuits, standard cells, and/or software, described or contained herein in order to improve design and/or performance. Philips
Semiconductors assumes no responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright,
or mask work right to these products, and makes no representations or warranties that these products are free from patent, copyright, or mask
work right infringement, unless otherwise specified. Applications that are described herein for any of these products are for illustrative purposes
only. Philips Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing
or modification.

LIFE SUPPORT APPLICA TIONS
Philips Semiconductors and Philips Electronics North America Corporation Products are not designed for use in life support appliances, devices,
or systems where malfunction of a Philips Semiconductors and Philips Electronics North America Corporation Product can reasonably be expected

to result in a personal injury. Philips Semiconductors and Philips Electronics North America Corporation customers using or selling Philips
Semiconductors and Philips Electronics North America Corporation Products for use in such applications do so at their own risk and agree to fully
indemnify Philips Semiconductors and Philips Electronics North America Corporation for any damages resulting from such improper use or sale.

Philips Semiconductors
811 East Arques Avenue
P.O. Box 3409
Sunnyvale, California 94088–3409
Telephone [phone]

This data sheet contains the design target or goal specifications for product development. Specifications
may change in any manner without notice.

This data sheet contains preliminary data, and supplementary data will be published at a later date. Philips
Semiconductors reserves the right to make changes at any time without notice in order to improve design
and supply the best possible product.

This data sheet contains Final Specifications. Philips Semiconductors reserves the right to make changes
at any time without notice, in order to improve design and supply the best possible product.

Philips Semiconductors and Philips Electronics North America Corporation

register eligible circuits under the Semiconductor Chip Protection Act.

 Copyright Philips Electronics North America Corporation 1998

All rights reserved. Printed in U.S.A.