Gennum Corporation GB4570-CTA, GB4570-CKA, GB4570-CDA Datasheet

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GB4570 Monolithic

Video Buffer/Clamp

DATA SHEET

FEATURES

• accurate sync tip clamping (± 2 mV typical)

• less than 1 mV clamping distortion

• variable clamping voltage (V

+ 3 V to VCC -4.5 V)

EE

• ultra low differential gain and differential phase

• less than

•

± 0.1 dB flatness to 80 MHz

•

± 4.5 to ±13.2 V supply voltage range

± 0.15° phase delay variation at 3.58 MHz

PIN CONNECTIONS

GB4570

GND

V

IN

V

CLAMP

C

HOLD

1

2

3

4

8

V

CC

7

V

OUT

V

6

EE

NC

5

DESCRIPTION

The GB4570 is a high performance video buffer/clamp used
primarily for sync tip clamping of video signals. Key features
include operation from ± 4.5 to ±13.2 V supply voltages, ±0.1
dB flatness to 80 MHz and availability of industry standard DIP
and SOIC packages.

In a typical video application, the GB4570 clamps the sync tip
to a known voltage. The clamping level can be set for normal
sync tip clamping by connecting pin 3 to - 0.286 volts. For
applications requiring non-standard sync tip clamping, the
clamping voltage applied to pin 3 may be varied.

The GB4570 features a tight delay spread of only ± 0.15° at
color burst frequencies and less than ± 1 millivolts clamping
distortion.

APPLICATIONS

• Sync tip clamping of NTSC, PAL, SECAM and RGB
Video Signals

• Input buffering and clamping

• Inter-system video signal clamping

SIMPLIFIED CIRCUIT DIAGRAM

V

CC

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8

AVAILABLE PACKAGING

8 pin PDIP

8 pin SOIC

V

IN

COUPLING
CAP

2

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ORDERING INFORMATION

Part Number Package Temperature Range

GB4570-CDA 8 pin PDIP 0° to 70°C
GB4570-CKA 8 pin SOIC 0° to 70°C
GB4570-CTA 8 pin SOIC Tape 0° to 70°C

GENNUM CORPORATION P.O. Box 489, Stn A, Burlington, Ontario, Canada L7R 3Y3 tel. [phone] fax: [phone]

Japan Branch: A-302, Miyamae Village, 2-10-42, Miyamae, Suginami-ku, Tokyo 168, Japan tel. [phone] fax. [phone]

50k
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4

C

HOLD

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Document No. 521 - 18 - 01

6

3

V

OUT

V
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V

CLAMP

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EE

ABSOLUTE MAXIMUM RATINGS

PARAMETER VALUE/UNITS

Supply Voltage ±13.5 V
Operating Temperature Range 0°C ≤ T
Storage Temperature Range -65°C ≤ T

≤ 70°C

A

≤150°C

S

Lead Temperature (soldering, 10 seconds) 260°C
Differential Video Input Voltage ±5 V
Strobe Input Voltage -V

ELECTRICAL CHARACTERISTICS V

≤ V

S

= ±5 V, TA = 0° to 70°C, RL = 10kΩ, CL = 10 pF, unless otherwise shown.

S

STROBE

≤ +V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

POWER

SUPPLIES

Supply Voltage ± V

+ Supply Current I+-914mA

S

- Supply Current I--914mA
Small Signal B.W. B.W. ± 0.1 dB after insertion loss, 80 - - MHz

(flattened response) VIN=100 mV p-p

Phase Delay ød at 3.58 MHz and 4.43 MHz -1.85 -2.0 -2.15 deg
Differential Gain ∂g at 3.58 MHz and 4.43 MHz - 0.01 0.02 %
Differential Phase ∂p at 3.58 MHz and 4.43 MHz - 0.01 0.02 deg

CAUTION

ELECTROSTATIC

SENSITIVE DEVICES

DO NOT OPEN PACKAGES OR HANDLE

EXCEPT AT A STATIC-FREE WORKSTATION

S

± 4.5 ±5 ±13.2 V

SIGNAL

PATH

Input Voltage V

Input Resistance R

Input Capacitance C

Output Resistance R

IN

IN

IN

OUT

ƒ= 0 to 1 MHz - 8.6 10 Ω
ƒ= 100 MHz - 20 40 Ω

VEE+3V - VCC-3V V

25 - - kΩ

- 2.0 - pF

Insertion Loss I.L. ƒ= 100 kHz - 0.03 0.05 dB

Power Supply Rejection Ratio PSRR ƒ= 1 kHz 50 - - dB

ƒ= 10 MHz 30 - - dB

PP Signal / RMS Noise S/N V

Clamp Voltage Range V

CLAMP

=1 Vp-p 75 - - dB

SIG

V

= 1 Vp-p, VEE+3.0 - VCC-4.5 V

IN

Accuracy VIN = 0.5V to 2Vp-p - ±2 ±7mV
Clamping Distortion Amplitude during sync - - ±1mV

521 - 18 - 01

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