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Part: CA3256M

Category:
 Multimedia
   -> Video
     -> Amplifiers

Description: 25mhz, Bimos Analog Video Switch And Amplifier

Company: Intersil Corporation

Datasheet: Download CA3256M datasheet     File size : 1382 kB

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Datasheet text preview:
Semiconductor

January 1999

CT T ODU MEN E PR PLACE -7747 T 2 OLE RE 0-44 OBS ENDED 1-80 .com MM ications arris l ECO h NO R ntral App entapp@ c Ce : Call or email

CA3256
25MHz, BiMOS Analog Video Switch and Amplifier

[ /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,

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

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 RON transmission gate insertion loss. The amplifier output impedance is typically 5 in a complementary symmetry output. The amplifier can directly drive a nominal 75 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.

Applications
· Video Multiplex Switch · 75 Video Amplifier/Line Driver · Video Signal-Level Control · Monitor Switching Control · TV/CATV Audio/Video Switch · Video Signal Adder/Fader Control

Part Number Information
PART NUMBER CA3256E CA3256M TEMP. RANGE (oC) -40 to 85 -40 to 85 PACKAGE 18 Ld PDIP 20 Ld SOIC PKG. NO. E18.3 M20.3

Pinouts
CA3256 (PDIP) TOP VIEW CA3256 (SOIC) TOP VIEW

IN 3 LED 4 IN 4 GND VENABLE CONTROL C FEEDBACK AMP OUT

1 2 3 4 5 6 7 8 9

18 CONTROL B 17 IN 2 16 CONTROL A 15 IN 1 14 V+ 13 IN/OUT 5 12 LED 1 11 LED 2 10 LED 3

IN3 LED4 IN4 GND VENABLE CONTROL C FEEDBACK AMP OUT

1 2 3 4 5 6 7 8 9

20 CONTROL B 19 IN2 18 CONTROL A 17 NC 16 IN1 15 V+ 14 IN/OUT5 13 NC 12 LED1 11 LED2

LED3 10

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

© Harris Corporation 1999

File Number

1769.5

8-1

CA3256 Block Diagram
IN/OUT 5 13 V+ 14 4 3 3 1 2 17 1 15 V+ BIAS REG VTG FEED BACK 8 1K 10K AMPLIFIER OUTPUT 9

+ 10K

4

LED DRIVER OUTPUTS 12 CHANNEL 1

TG

11 ENABLE 6 LOGIC LEVEL CONV. BINARY TO 1 OF 4 WITH ENABLE CHANNEL 2 TG

10 CHANNEL 3 A 16 B 18 TG V- 5 C 7 IN TG SW CONTROL OUT IN OUT IN OUT TG 2 CHANNEL 4

SW OPEN

SW CLOSED

(DIP PIN OUT)

Switch Control Logic
CHANNEL NUMBER 1 2 3 4 5 + (1-4) (Note) 5 None C 0 0 0 0 1 1 0 X A 0 0 1 1 Channel 1-4 Channel 5 Only X B 0 1 0 1 ENABLE 1 1 1 1 1 0 0

NOTE: For Maximum Video Bandwidth, Use Single Channel Selections

8-2

CA3256
Absolute Maximum Ratings
DC Supply Voltage Range (V+ to V-) . . . . . . . . . . . . . . . . . . . . . 18V Control Input Voltage Range, All Inputs . . . . . . . . . . . . . . . . V+ to VSignal Input Voltage Range, Channel 1-5 . . . . . . . . . . . . . . . .3VP-P Amplifier Output Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30mA DC LED Sink Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30mA

Thermal Information
Thermal Resistance (Typical, Note 1) JA (oC/W) PDIP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 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)

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

Electrical Specifications

TA = 25oC, V+ = 12V; V- = GND SYMBOL TYPICAL VALUES 10 to 17 ICC SWITCH 20 AMPLIFIER 35 -0.8 AOL 10 25 10 5 2.5 7 5 1 1 0.5 30 16 dB dB MHz MHz dB dB k VP-P VP-P V % Degree dB µs mA mA V UNITS V mA

PARAMETER Power Supply Voltage V+ to VPower Supply Current

Open Loop Gain Programmable Gain, FB Adjustment Range Full Power Bandwidth Unity Gain Bandwidth, 1k, 7pF Compensation Insertion Loss Signal Feedthrough, 5MHz Input Impedance Output Impedance Maximum Input Voltage Maximum Output Voltage, Clipped Reference Bias Output Voltage (V8 - V-) Differential Gain Differential Phase Off Isolation, Channel to Channel, ZIN = 75 LLC Switch Turn On/Off Time Delay Maximum LED Sink Current Typical Output Source Current Channel Control Switch A, B, C and EN Threshold (Notes 2, 3)

AOL

-0.8 -66

ZIN ZOUT VI(MAX) VO(MAX)

3 -66 -

VTH

Approximately (V+ - V-)/2

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
TA = 25oC, V+ = 12V, VLED = 12V, V- = GND, Pin 4 = GND, Feedback Switch Closed, VHIGH = 9V, VLOW = 3V (See Figure 1), Unless Otherwise Specified INPUTS CH 1 PARAMETERS Supply Current, VLED = 0V Dual Supply Current V+ = +7V, V- = -5V Amplifier Output Voltage, Open Loop VLED = 0V Amplifier Output Voltage, Closed Loop, VLED = 0V IOUT (MAX) (Source) Open Loop IOUT (MAX) (Sink) Open Loop Input Leakage Channel 1-5 Channel Control Input A, B, C, Enable Leakage LED Off Voltage, VOFF LED On Voltage, VON Switch Resistance, RDS RDS Match Amplifier Output Offset, VO , Feedback Switch Closed V+ = +7V, V- = -5V Closed Loop Gain NOTES: 4. VOUT = +7V. 5. VOUT = +3V. 6. DIP Pinout. 0V 0V CH 2 CH 3 CH 4 CH 5 A CHANNEL SWITCH CONTROL B C ENABLE NOTE 6 TEST PIN 6 PIN# 3V 14

PIN 15 PIN 17 PIN 1 0V 0V 0V

PIN 3 PIN 13 PIN 16 PIN 18 PIN 7 0V 0V 3V 3V 3V

MIN 10

TYP MAX UNITS 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 Note 4 9 Note 5 1, 3, 15, 17 6, 7, 16, 18

-

-70

-25

mA

0V

0V

0V

0V

0V

3V

3V

3V

3V

10

16

-

mA

3V

3V

3V

3V

3V

3V

3V

3V

3V

-15

5

15

nA

0V

0V

0V

0V

0V

Measure at 3V, 9V each; Enable and Channel Switching Control Inputs Select Channel 0-5

-20

10

20

nA

0V

0V

0V

0V

0V

2, 10, 11, 12 2, 10, 11, 12 9V

11.97 11.99

-

V

0V

0V

0V

0V

0V

Select Channel 0-5

-

0.1

0.3

V k % mV

±100µA Input Each Switch, Channel 1-4 + 5

Select Channel 1-4

9V

0.8

1.1

1.4

Calculation: (Max RDS - Min RDS)/Min RDS 0V 0V 0V 0V 0V 0V 7V

9

-100

3.6 45

5 100

3V

0V

0V

0V

0V

3V

3V

3V

9V

9

-0.5

-0.1

0.5

dB

8-4

CA3256 Test Circuits
V5 V+ 14 VBIAS (V- +5V) 10K IN 1 15 TG-1 10K OUTPUT AMP 1.1K IN 2 17 TG-2 1.1K IN 3 1 TG-3 1.1K IN 4 3 LLC ENABLE AND CHAN 1-4 SELECT TG-5 TG-4 1.1K 4 2 3 10 2 11 1 12 VLED +12 V +12 V FEEDBACK 8 FEEDBACK SWITCH

BIAS REG

1K

AMP OUT 9

+

IN/OUT 5 13

6 ENABLE

16 A

18 B

7C

4

GND

CONTROL INPUTS (CHANNEL SELECT)

FIGURE 1. CA3256 TEST CIRCUIT (DIP PINOUT)

Application Information
CMOS analog switches are available in a wide variety of forms, and have been known and used for some time. There are a number of advantages to using the CMOS transmission gate as a switch: · · · · · · · · · Ideal Suitability to Series Cascade Arrangements Simple Multiple Parallel Input Switching Arrangements No Bipolar Junctions and, Hence, No Offset Very Low Power Consumption Wide Signal-Swing Capability Fast Multiplexing and Video Switching Wide Bandwidth Low RON Channel Resistance Bidirectional Signal Handling speed as advantages, the price is high in voltage offset and current drain. The integrated device solution that is offered here is in the use of the BiMOS technology, where both the CMOS and bipolar processes complement each other to provide CMOS switching with bipolar amplifiers. The BiMOS process allows several CMOS switches to be coupled to a bipolar drive-amplifier in the same process to exploit the best of two technologies. Other advantages are gained when the BiMOS process is used for an IC video-switch amplifier design. The BiMOS process calls for a P-substrate and, therefore, isolated N-epitaxial wells can be built for both N and P channel parts. The boats provide for better isolation of the N and P channels. The N and P wells in a transmission-gate cell can be switched between source and rail; therefore, they have a smaller body effect on both N and P devices, which results in better gain linearity. Where desired, oxide capacitors are available for bipolar amplifier compensation. CA3256 Video-Switch Amplifier The Block Diagram shows the functional diagram of the CA3256, which consists of five MOS channels, each comprising a three-element T-switch. The output of the five switches is made common and fed into the input of a bipolar

An Integrated Video-Switch Amplifier
Commonly, integrated video-switch amplifiers have been fabricated in the bipolar technology using differential amplifiers in a current-switching mode. In this form, two differential pairs are needed for two input-signal sources. The handling of multiple sources is very much more complex. The advantages of the CMOS video-switch amplifier have already been noted. While the bipolar video switch has high output drive and switching

8-5




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