Intersil Corporation CA3256 Datasheet

Semiconductor

CA3256

OBSOLETE PRODUCT

[ /Title
(CA32

56)
/Sub­ject
(25MH
z,
BiMO
S Ana­log
Video
Switch
and
Ampli­fier)
/Autho
r ()
/Key­words
(Har­ris
Semi­con­ductor,
4x1,
video
cross­point
switch,
multi­plexer
multi­plexor,
cable
driver,
5x1,
moni
tor out­put,
adjust­able
gain,

NO RECOMMENDED REPLACEMENT

January 1999

Call Central Applications 1-800-442-7747

or email: [e-mail]

Features

• 5 Multiplex Video Channels

- 1 Independent Channel

- 4 Channels with Enable

• 4 LED Channel Indicator Outputs

• Wideband Video Amplifier . . . . . . . .25MHz Unity Gain

• Adjustable Video Amplifier Gain

• High Signal-Drive Capability

Applications

• Video Multiplex Switch

•75Ω Video Amplifier/Line Driver

• Video Signal-Level Control

• Monitor Switching Control

• TV/CATV Audio/Video Switch

• Video Signal Adder/Fader Control

Part Number Information

TEMP.

PART NUMBER

CA3256E -40 to 85 18 Ld PDIP E18.3
CA3256M -40 to 85 20 Ld SOIC M20.3

RANGE (oC) PACKAGE

Pinouts

CA3256

(PDIP)

TOP VIEW

IN 3

LED 4

IN 4

GND

ENABLE

CONTROL C

FEEDBACK

AMP OUT

1
2
3
4

V- V+

5
6
7
8
9

18

CONTROL B

17

IN 2

16

CONTROL A
IN 1

15
14
13

IN/OUT 5
LED 1

12

LED 2

11

LED 3

10

PKG.

NO.

25MHz, BiMOS Analog

Video Switch and Amplifier

Description

The CA3256 BiMOS analog video switch has five channels
of CMOS multiplex switching for general-purpose video­signal control. One of four CMOS channels may be selected
in parallel with channel 5. The CMOS switches are inputs to
the video amplifier but may be used in bilateral switching
between channels 1 to 4 and channel 5. The analog
switches of channels 1 to 4 are digitally controlled with logic
level conversion and binary decoding to select 1 of 4
channels. The enable function controls channels 1 to 4 but
does not affect channel 5. LED output drivers are selected
with the channel 1-to-4 switch selection to indicate the ON­channel. Channel 5 may be used as a monitor output for
data or signal information on channels 1 to 4. The
transmission gate switches shown in the block diagram of
the CA3256 are configured in a “T” design to minimize
feedthrough. When the switch is off, the shunt or center of
the “T” is grounded.

The amplifier has high input impedance to minimize the R
transmission gate insertion loss. The amplifier output imped­ance is typically 5Ω in a complementary symmetry output.
The amplifier can directly drive a nominal 75Ω coaxial cable
to provide line-to-line video switching. The gain of the ampli­fier is programmable by different feedback resistor values
between pins 8 and 9. Compensation may also be used
between these pins for an optimally flat frequency response.
An internal regulated 5V bias reference with temperature
compensation permits stable direct-coupled output drive and
minimizes DC offset during signal switching.

CA3256

(SOIC)

TOP VIEW

IN3

LED4

IN4

GND

ENABLE

CONTROL C

FEEDBACK

AMP OUT

LED3

1
2
3
4

V-

5
6
7
8
9

10

CONTROL B

20

IN2

19

CONTROL A

18

NC

17

IN1

16

V+

15

IN/OUT5

14

NC

13
12

LED1
LED2

11

ON

CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright

© Harris Corporation 1999

8-1

File Number 1769.5

Block Diagram

V+

14

CA3256

IN/OUT

5 4 3 2 1

13 3 1

FEED BACK

V+

BIAS

1517

4

REG

V-

TG

TG

8

1K

10K

10K

AMPLIFIER

OUTPUT

-

+

LED DRIVER

OUTPUTS

12

CHANNEL 1

9

ENABLE

6

A

16
18

B

V-

5

C

7

LOGIC
LEVEL
CONV.

IN OUT

SW

CONTROL

Switch Control Logic

CHANNEL

NUMBER C A B ENABLE

10001

BINARY

TO

1 OF 4

WITH

ENABLE

TG

IN OUT

SW

OPEN

(DIP PIN OUT)

TG

TG

TG

IN OUT

SW

CLOSED

11

CHANNEL 2

10

CHANNEL 3

2

CHANNEL 4

20011

30101

40111

5 + (1-4) (Note) 1 Channel 1-4 1

5 1 Channel 5 Only 0

None 0 X X 0

NOTE: For Maximum Video Bandwidth, Use Single Channel Selections

8-2

CA3256

Absolute Maximum Ratings Thermal Information

DC Supply Voltage Range (V+ to V-) . . . . . . . . . . . . . . . . . . . . . 18V

Control Input Voltage Range, All Inputs . . . . . . . . . . . . . . . . V+ to V-

Signal Input Voltage Range, Channel 1-5 . . . . . . . . . . . . . . . .3V

Amplifier Output Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30mA

DC LED Sink Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30mA

Operating Conditions

Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . -40oC to 85oC

CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation
of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.

NOTE:

1. θJA is measured with the component mounted on an evaluation PC board in free air.

Thermal Resistance (Typical, Note 1) θJA (oC/W)

PDIP Package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

P-P

SOIC Package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Maximum Junction Temperature (Die). . . . . . . . . . . . . . . . . . . .175oC

Maximum Junction Temperature (Plastic Package) . . . . . . . . 150oC

Maximum Storage Temperature Range . . . . . . . . . -65oC to 150oC

Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . . 300oC

(SOIC - Lead Tips Only)

Electrical Specifications T

= 25oC, V+ = 12V; V- = GND

A

PARAMETER SYMBOL TYPICAL VALUES UNITS

Power Supply Voltage V+ to V- 10 to 17 V
Power Supply Current I

CC

20 mA

SWITCH AMPLIFIER

Open Loop Gain A

OL

Programmable Gain, FB Adjustment Range - -0.8 A

-35dB

OL

Full Power Bandwidth - 10 MHz
Unity Gain Bandwidth, 1kΩ, 7pF Compensation - 25 MHz
Insertion Loss -0.8 - dB
Signal Feedthrough, 5MHz -66 - dB
Input Impedance Z
Output Impedance Z
Maximum Input Voltage V
Maximum Output Voltage, Clipped V

O(MAX)

IN

OUT

I(MAX)

-10kΩ

-5Ω
3 2.5 V

-7V

Reference Bias Output Voltage (V8 - V-) - 5 V

dB

P-P

P-P

Differential Gain - 1 %
Differential Phase - 1 Degree
Off Isolation, Channel to Channel, ZIN = 75Ω -66 - dB
LLC Switch Turn On/Off Time Delay - 0.5 µs
Maximum LED Sink Current - 30 mA
Typical Output Source Current - 16 mA
Channel Control Switch A, B, C and EN Threshold

V

TH

Approximately (V+ - V-)/2 V

(Notes 2, 3)

CAUTION: Connect the V- power supply voltage before or during the V+ turn-on.
NOTES:

2. Threshold value is referenced to GND.

3. VTH is restricted by the equation, VTH < V+ -1.

8-3

CA3256

Electrical Specifications T

CH 1 CH 2 CH 3 CH 4 CH 5 A B C ENABLE NOTE 6

PARAMETERS

Supply Current,
V

= 0V

LED

Dual Supply Current
V+ = +7V, V- = -5V

Amplifier Output
Voltage, Open Loop
V

= 0V

LED

Amplifier Output
Voltage , Closed Loop,
V

= 0V

LED

I

OUT (MAX)

(Source)

Open Loop
I

OUT (MAX)

(Sink)

Open Loop
Input Leakage

Channel 1-5

0V 0V 0V 0V 0V 3V 3V 3V 3V 14 10 16 22 mA

0V 0V 0V 0V 0V 0V 0V 0V 7V 14/5 10 20 26 mA

0V 0V 0V 0V 0V 3V 3V 3V 3V 9 6 8.5 10 V

0V 0V 0V 0V 0V 3V 3V 3V 3V 9 4.8 5.1 5.4 V

0V 0V 0V 0V 0V 3V 3V 3V 3V 9

0V 0V 0V 0V 0V 3V 3V 3V 3V 9

3V 3V 3V 3V 3V 3V 3V 3V 3V 1, 3, 15,17-15 5 15 nA

= 25oC, V+ = 12V, V

A

= 12V , V- = GND, Pin 4 = GND , F eedback Switch Closed, V

LED

(See Figure 1), Unless Otherwise Specified

INPUTS CHANNEL SWITCH CONTROL

TEST

PIN#PIN 15 PIN 17 PIN 1 PIN 3 PIN 13 PIN 16 PIN 18 PIN 7 PIN 6

Note 4

Note 5

HIGH

= 9V , V

LOW

= 3V

MIN TYP MAX UNITS

- -70 -25 mA

10 16 - mA

Channel Control
Input A, B, C,
Enable Leakage

LED Off Voltage, V

0V 0V 0V 0V 0V Measure at 3V, 9V each;

Enable and Channel

Switching Control Inputs

0V 0V 0V 0V 0V Select Channel 0-5 2, 10,

OFF

6, 7, 16,18-20 10 20 nA

11.97 11.99 - V

11, 12

LED On Voltage, V

0V 0V 0V 0V 0V Select Channel 0-5 2, 10,

ON

- 0.1 0.3 V

11, 12

Switch Resistance,
R

DS

RDS Match Calculation: (Max RDS - Min RDS)/Min R
Amplifier Output

±100µA Input Each Switch,

Channel 1-4 + 5

Select Channel

1-4

9V 9V 0.8 1.1 1.4 kΩ

DS

- - 3.6 5 %

0V 0V 0V 0V 0V 0V 0V 0V 7V 9 -100 45 100 mV
Offset, VO, Feedback
Switch Closed
V+ = +7V, V- = -5V

Closed Loop Gain 3V 0V 0V 0V 0V 3V 3V 3V 9V 9 -0.5 -0.1 0.5 dB

NOTES:

4. V

5. V

OUT
OUT

= +7V.
= +3V.

6. DIP Pinout.

8-4