EL4390C [ELANTEC]

Triple 80 MHz Video Amplifier with DC Restore; 三重80 MHz的视频放大器，直流恢复


型号：	EL4390C
厂家：	ELANTEC SEMICONDUCTOR
描述：	Triple 80 MHz Video Amplifier with DC Restore 三重80 MHz的视频放大器，直流恢复视频放大器
文件：	总16页 (文件大小：310K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

Features

General Description

The EL4390C is three wideband current-mode feedback amplifi-

ers optimized for video performance, each with a DC restore

amplifier. The DC restore function is activated by a common

TTL/CMOS compatible control signal while each channel has a

separate restore reference.

# 80 MHz 3 dB bandwidth for

gains of 1 to 10

# 800 V/ms slew rate

# 15 MHz bandwidth flat to 0.1 dB

# Excellent differential gain and

phase

Each amplifier can drive a load of 150X at video signal levels.

# TTL/CMOS compatible DC

restore function

The EL4390C operates on supplies as low as 4V up to 15V.

Being a current-mode feedback design, the bandwidth stays rel-

# Available in 16 lead P-DIP, 16

lead SOL

atively constant at approximately 80MHz over the 1 to 10

gain range. The EL4390C has been optimized for use with

1300X feedback resistors.

Applications

# RGB drivers requiring DC

restoration

Connection Diagram

# RGB multiplexers requiring DC

restoration

# RGB building blocks

# Video gain blocks requiring DC

restoration

# Sync and color burst processing

Ordering Information

Package Outline

Part No. Temp. Range

40 C to 85 C 16-Pin P-DIP MDP0031

EL4390CN

EL4390CM

40 C to 85 C 16-Lead SOL MDP0027

4390–1

Note: All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a ‘‘controlled document’’. Current revisions, if any, to these

specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation.

1994 Elantec, Inc.

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

Absolute Maximum Ratings (T

Voltage at V

25 C)

Voltage between V

and V

33V

18V

Internal Power Dissipation

See Curves

40 C to 85 C

150 C

Operating Ambient Temp. Range

Operating Junction Temperature

Storage Temperature Range

Voltage at V

65 C to 150 C

5mA

Voltage between V

and V

Current into V

and V

Important Note:

All parameters having Min/Max specifications are guaranteed. The Test Level column indicates the specific device testing actually

performed during production and Quality inspection. Elantec performs most electrical tests using modern high-speed automatic test

equipment, specifically the LTX77 Series system. Unless otherwise noted, all tests are pulsed tests, therefore T

Test Level

Test Procedure

100% production tested and QA sample tested per QA test plan QCX0002.

25 C ,

100% production tested at T

25 C and QA sample tested at T

and T

per QA test plan QCX0002.

MIN

MAX

QA sample tested per QA test plan QCX0002.

Parameter is guaranteed (but not tested) by Design and Characterization Data.

III

Parameter is typical value at T

25 C for information purposes only.

Open Loop DC Electrical Characteristics Supplies at 15V, Load 1KX

Test

Parameter

Description

Temp

Min

Typ

Max

Units

Level

Amplifier Section (not restored)

Input Offset Voltage

25 C

Input Bias Current

25 C

0.2

25 C

Transimpedance (Note 1)

25 C

100

220

Resistance

25 C

CMRR

PSRR

Common-Mode Rejection Ratio (Note 2)

25 C

Power Supply Rejection Ratio (Note 4)

25 C

Output Voltage Swing; R

Short-Circuit Current

1kX

25 C

100

Supply Current (Quiescent)

25 C

Restoring Section

, COMP

Composite Input Offset Voltage (Note 3)

25 C

0.2

Input Bias Current

Restore I

25 C

Restoring Current Available

Power Supply Rejection Ratio (Note 4)

Conductance

25 C

OUT

PSRR

25 C

mA/V

OUT

, RES

Supply Current, Restoring

RES Logic Low Threshold

RES Logic High Threshold

25 C

1.0

1.8

, RES

25 C

1.4

25 C

1.4

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

Open Loop DC Electrical Characteristics Supplies at 15V, Load 1KX Ð Contd.

Test

Parameter

Description

Temp

Min

Typ

Max

Units

Level

Restoring Section

, RES

RES Input Current, Logic Low

25 C

RES Input Current, Logic High

25 C

0.5

Note 1: For current feedback amplifiers, A

OL IN

VOL

Note 2: V

10V for V

15V.

to amplifier output, while restoring.

Note 3: Measured from V

Note 4: V is measured at V

4.5V and V

16V, both supplies are changed simultaneously.

Closed Loop AC Electrical Characteristics

Supplies at 15V, Load

150X and 15 pF, T

25 C (See note 7 re: test fixture)

Test

Parameter

Description

Min

Typ

Max

Units

Level

Amplifier Section

Slew Rate (Note 5)

800

550

V/ms

Slew Rate w/ 5V Supplies (Note 5)

Bandwidth, 3dB, A

5V Supplies, 3dB

MHz

Bandwidth, 0.1 dB

MHz

5V Supplies, 0.1dB

Differential Gain at 3.58 MHz

0.02

at 5V Supplies (Note 6)

Differential Phase at 3.58 MHz

0.03

0.06

( )

at 5V Supplies (Note 6)

Restoring Section

Time to Enable Restore

Time to Disable Restore

Note 6: DC offset from 0.714V to 0.714V, AC amplitude is 286m Vp-p, equivalent to 40 ire.

200X.

Note 5: SR is measured at 20% to 80% of 4V pk-pk square wave, with A

5, R

820X, R

Note 7: Test fixture was designed to minimize capacitance at the I

capacitance to ground at this very sensitive pin. See application notes for further details.

input. A ‘‘good’’ fixture should have less than 2 pF of stray

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

Table 1. Charge Storage Capacitor Value vs. Droop and Charging Rates

Cap Value

(nF)

Droop in

Charge in

60mS (mV)

2mS (mV)

4mS (mV)

13.6

6.4

400

182

800

364

170

100

220

3.0

1.36

These numbers represent the worst case bias current, and the worst case charging current. Note that to

get the full (2mA ) charging current, the clamp input must have 250mV of error voltage.

Note that the magnitude of the bias current will decrease as temperature increases.

The basic droop formula is :

(Line time Charge time) / capacitor value

V (droop)

and the basic charging formula is:

Charge time / capacitor value

V (charge)

OUT

Where I

is:

OUT

(Clamp voltage

b a

IN voltage) / 120

OUT

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

Typical Performance Curves

Gain Flatness

for Various R

Gain Flatness

for Various R

Gain Flatness

for Various R and R Values

0 dB

5V, A

15V, A

0 dB

6 dB

15V, A

4390–3

4390–2

4390–4

Gain Flatness

for Various R and R Values

Phase Shift

Phase Shift for A

1000X

for A

at V

6 dB

15V

5V, A

1300X

5V and V

4390–5

4390–7

4390–6

Gain Flatness

Phase Shift

for A

/R as Shown

5V, A

15V, A

14 dB,

5 dB, R

820X,

200X, V

4390–10

4390–8

4390–9

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

Typical Performance Curves Ð Contd.

Gain Flatness

/R as Shown

5V, A

680X, R

5V, A

20 dB,

26 dB,

36X

Differential Gain

at V

15V

4390–11

4390–12

4390–17

Differential Phase

Differential Gain

Differential Phase

at V

15V

at V

4390–19

4390–18

4390–20

Frequency Response

for Various C

Frequency Response

for Various C

Crosstalk,

Channel R and B to Channel G,

, V

15V,

, V

5V,

LOAD

1300X

LOAD

1300X

5V, R

4390–13

4390–14

4390–15

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

Typical Performance Curves Ð Contd.

Crosstalk,

Channel R and G to Channel B,

during HOLD, V

Input Impedance

during SAMPLE, V

5V, R

1300X

4390–21

4390–22

4390–16

Phase Shift at I

during Restore,

Restoring vs Clamp,

Pulse Response with A

OUT

Voltage at V

R 1300X at V

75X and 150X, V

4390–24

4390–25

4390–23

200X

Output during DC-Restoration,

Showing DC Droop

Pulse Response with A

820X and R

Output during DC-Restoration,

at V

1300X, V

15V

4390–27

4390–28

4390–26

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

Typical Performance Curves Ð Contd.

Maximum Power Dissipation

vs Ambient TemperatureÐ

16-Pin PDIP

Maximum Power Dissipation

vs Ambient TemperatureÐ

16-Pin SOL

4390–29

4390–30

4390–31

Simplified Schematic of One Channel of EL4390

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

In normal circuit operation, the picture content

Applications Information

will also cause a slow change in voltage across the

capacitor, so at every back porch time period,

these error terms can be corrected.

Circuit Operation

Each channel of the EL4390 contains a current

feedback amplifier and a TTL/CMOS compatible

clamp circuit. The current that the clamp can

source or sink into the non-inverting input is ap-

proximately:

When a signal source is being switched, eg. from

two different surveillance cameras, it is recom-

mended to synchronize the switching with the

vertical blanking period, and to drive the HOLD

pin (pin 6) low, during these lines. This will en-

sure that the system has been completely re-

stored, regardless of the average intensity of the

two pictures.

CLAMP

) / 120

So, when the non-inverting input is at the same

voltage as the clamp reference, no current will

flow, and hence no charge is added to the capaci-

tor. When there is a difference in voltage, current

will flow, in an attempt to cancel the error AT

THE NON-INVERTING input. The amplifier’s

Application Hints

Figures 1 & 2 shows a three channel DC-restoring

system, suitable for R-G-B or Y-U-V component

video, or three synchronous composite signals.

offset voltage and (I

R ) DC errors are not

cancelled with this loop. It is purely a method of

adding a controlled DC offset to the signal.

Figure 1 shows the amplifiers configured for non-

inverting gain, and Figure 2 shows the amplifiers

configured for inverting gains. Note that since

the DC-restoring function is accomplished by

clamping the amplifier’s non-inverting input,

during the back porch period, any signal on the

non-inverting input will be distorted. For this

reason, it is recommended to use the inverting

configuration for composite video, since this

avoids the color burst being altered during the

clamp time period.

As well as the offset voltage error, which goes up

with gain, there is also the I

the amplifier is capacitively coupled, this small

current is slowly integrated and shows up as a

very slow ramp voltage. Table below shows the

output voltage drift in 60mS for various values of

coupling capacitor, all assuming the very worst

with gain, and the I

R error which drops

error term. Since

current.

Table 1. Charge Storage Capacitor Value vs.

Droop and Charging Rates

Since all three amplifiers are monolithic, they

run at the same temperature, and will have very

similar input bias currents. This can be used to

advantage, in situations where the droop voltage

needs to be compensated, since a single trim cir-

cuit can be used for all three channels. A 560KX

or similar value resistor helps to isolate each sig-

nal. See Figure 2. The advantage of compensat-

ing for the droop voltage, is that a smaller capaci-

tor can be used, which allows a larger level resto-

ration within one line. See Table 1 for values of

capacitor and charge/droop rates.

Cap Value

Droop in

Charge in

(nF)

60mS (mV)

2mS (mV)

4mS (mV)

13.6

6.4

400

182

800

364

170

100

220

3.0

1.36

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

Applications Information Ð Contd.

4390–32

Figure 1

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

Applications Information Ð Contd.

4390–33

Figure 2

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

Applications Information Ð Contd.

4390–34

Figure 3

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

Since there are three amplifiers all in one pack-

Applications Information Ð Contd.

age, and each amplifier can sink or source typi-

cally more than 70mA, some care is needed to

avoid excessive die temperatures. Sustained, DC

currents, of over 30mA, are not recommended,

due to the limited current handling capability of

the metal traces inside the IC. Also, the short cir-

cuit protection can be tripped with currents as

low as 45mA, which is seen as excessive distor-

tion in the output waveform. As a quick rule of

thumb, both the SOL and DIP 16 pin packages

In Figure 3, one of the three channels is used,

together with a low-offset op-amp, to automati-

cally trim the bias current of the other two chan-

nels. The two remaining channels are shown in

the non-inverting configuration, but could equal-

ly well be set to provide inverting gains. Two

DC-restored channels are typically needed in fad-

er applications. See the EL4094 and EL4095 for

suitable, monolithic video faders.

can dissipate about 1.4 watts at 25 C, and with

Layout and Dissipation Considerations

of 32mA, yields 0.96 watts, before any load is

15V supplies and a worst case quiescent current

As with all high frequency circuits, the supplies

should be bypassed with a 0.1mF ceramic capaci-

tor very close to the supply pins, and a 4.7mF

tantalum capacitor fairly close, to handle the

high current surges. While a ground plane is rec-

ommended, the amplifier will work well with a

‘‘star’’ grounding scheme. The pin 3 ground is

only used for the internal bias generator and the

reference for the TTL compatible ‘‘HOLD’’ in-

put.

driven.

Dissipation of the EL4390 can be reduced by low-

ering the supply voltage. Although some per-

formance is degraded at lower supplies, as seen in

the characteristic curves, it is often found to be a

useful compromise. The bandwidth can be recov-

ered, by reducing the value of R , and R as ap-

propriate.

As with all current feedback capacitors, all stray

capacitance to the inverting inputs should be

kept as low as possible, to avoid unwanted peak-

ing at the output. This is especially true if the

value of Rf has already been reduced to raise the

bandwidth of the part, while tolerating some

peaking. In this situation, additional capacitance

on the inverting input can lead to an unstable

amplifier.

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

EL4390C

Triple 80 MHz Video Amplifier with DC Restore

General Disclaimer

Specifications contained in this data sheet are in effect as of the publication date shown. Elantec, Inc. reserves the right to make changes

in the circuitry or specifications contained herein at any time without notice. Elantec, Inc. assumes no responsibility for the use of any

circuits described herein and makes no representations that they are free from patent infringement.

WARNING Ð Life Support Policy

Elantec, Inc. products are not authorized for and should not be

used within Life Support Systems without the specific written

consent of Elantec, Inc. Life Support systems are equipment in-

tended to support or sustain life and whose failure to perform

Elantec, Inc.

1996 Tarob Court

when properly used in accordance with instructions provided can

be reasonably expected to result in significant personal injury or

death. Users contemplating application of Elantec, Inc. products

Milpitas, CA 95035

in Life Support Systems are requested to contact Elantec, Inc.

Telephone: (408) 945-1323

(800) 333-6314

factory headquarters to establish suitable terms & conditions for

these applications. Elantec, Inc.’s warranty is limited to replace-

ment of defective components and does not cover injury to per-

Fax: (408) 945-9305

European Office: 44-71-482-4596

sons or property or other consequential damages.

Printed in U.S.A.

EL4390C [ELANTEC]

相关型号：

SI9130DB

SI9135LG-T1

SI9135LG-T1-E3

SI9135_11

SI9136_11

SI9130CG-T1-E3

SI9130LG-T1-E3

SI9130_11

SI9137

SI9137DB

SI9137LG

SI9122E