DG540/541/542

Vishay Siliconix

www.vishay.com

S FaxBack 408-970-5600

4-8

Document Number: 70055

S-00399—Rev. G, 13-Sep-99

TEST CIRCUITS

X

V

OUT

V

IN

10

W

75

W

V+

V–

+15 V

–15 V

C

C

GND

2.4 V

FIGURE 6. All Hostile Crosstalk

APPLICATIONS

Device Description

The DG540/541/542 family of wideband switches offers true

bidirectional switching of high frequency analog or digital

signals with minimum signal crosstalk, low insertion loss, and

negligible non-linearity distortion and group delay.

Built on the Siliconix D/CMOS process, these “T” switches

provide excellent off-isolation with a bandwidth of around

500 MHz (350 MHz for DG541). Silicon-gate D/CMOS

processing also yields fast switching speeds.

An on-chip regulator circuit maintains TTL input compatibility

over the whole operating supply voltage range, easing control

logic interfacing.

Circuit layout is facilitated by the interchangeability of source

and drain terminals.

Frequency Response

attenuation effect on the analog signal – which is frequency

dependent (like an RC low-pass filter). The –3-dB bandwidth

of the DG540 is typically 500 MHz (into 50

figure of 500 MHz illustrates that the switch channel can not

be represented by a two stage RC combination. The on

capacitance

of

the

channel

is

distributed

along the

on-resistance, and hence becomes a more complex multi

Off-Isolation and Crosstalk

Off-isolation and crosstalk are affected by the load resistance

and

parasitic

inter-electrode

capacitances.

Higher

down the line. Stray capacitances, even a fraction of 1 pF, can

cause a large crosstalk increase. Good layout and ground

shielding techniques can considerably improve your ac circuit

performance.