TS634

4/9

POWER DOWN MODE

V

POWER DOWN EQUIVALENT SCHEMATIC

OUPUT IMPEDANCE IN POWER DOWN MODE

In Power Down Mode the output of the driver is in

"high impedance" state. It is really the case for the

static mode. Regarding the dynamic mode, the im-

pedance decreases due to a capacitive effect of

the collector-substrat and base collector junction.

The impedance behaviour comes capacitive, typi-

cally: 1.4M

Ω // 33pF.

INTERMODULATION DISTORTION

The curves shown below are the measurements

results of a single operator wired as an adder with

a gain of 15dB. The operational amplifier is sup-

plied by a symmetric

±6V and is loaded with 25Ω.

Two synthesizers (Rhode & Schwartz SME) gen-

erate two frequencies (tones) (70 & 80kHz or 180

& 280kHz). An HP3585 spectrum analyzer mea-

sures the spurious level at different frequencies.

The curves are traced for different output levels

(the value in the X axis is the value of each tone).

The output levels of the two tones are the same.

The generators and spectrum analyzer are phase

locked to enhance measurement precision.

3rd ORDER INTERMODULATION

2 tones : 70kHz and 80kHz

2 tones : 180kHz and 280kHz

Symbol

Parameter

Min.

Typ.

Max

Unit

Thershold Voltage for Power Down Mode

V

Low Level

0

0.8

High Level

2

3.3

Total Power Down Mode Current Consumption

150

µA

Power Down Mode Ouput Impedance

1.4

ΜΩ

Power Down Mode Output Capacitance

33

pF

STANDBY CONTROL

OPERATOR STATUS

operator 1

operator 2

operator 1

operator 2

Standby

Active

Standby

Standby

Active

Active

Active

Standby

+

_

..

..

POWER

DOWN

Ouput

.

1

1,5

2

2,5

3

3,5

4

4,5

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

Vout peak (V)

230kHz

220kHz

90kHz

60kHz

1

1,5

2

2,5

3

3,5

4

4,5

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

Vout peak (V)

80kHz

640kHz

380kHz

740kHz