ALD4211/ALD4212

Advanced Linear Devices

4

ALD4213

AC ELECTRICAL CHARACTERISTICS

The ALD4211/ALD4212/ALD4213

feature very high

precision due to these factors:

1. The analog switch has ultra low capacitive charge coupling

so that the charge stored on a 200pF sampling capacitor

is minimally affected.

2. With special charge balancing and charge cancellation

circuitry designed on chip, the ALD4211/ALD4212/

ALD4213 achieves ultra low charge injection of typically

only 0.2pC resulting in extremely low signal distortion to

the external circuit.

3. The analog switch switching transistors have pA leakage

currents minimizing the droop rate of the sampling circuit.

4. The internal switch timing allows for the analog switch to

turn off internally without producing any residual transistor

channel charge injection, which may affect external

circuits. With a low loss polystyrene or polypropylene

sampling capacitor, long data retention times are possible

without significant signal loss.

The ALD4211/ALD4212/ALD4213 CMOS analog switches,

when used with industry standard pinout connection, have

the input and output pins reversed with the signal source

input connected to OUT pins and COM pins used as output

pins. In this connection and when used with 1,000pF or

greater value capacitors, or when connected to a DC current

or resistive load, the switch would not be operating in an ultra

low charge injection mode. Typical charge injection, in this

case, would be 5pC as the pin to pin capacitive coupling

effect would dominate. In this connection, all the other

characteristics of the ALD4211/ALD4212/ALD4213 CMOS

analog switches remain the same.

Parameter

Symbol

Min

Typ

Max

Min

Typ

Max

Min

Typ

Max

Unit

Test Conditions

Turn On

Delay time

85

170

85

170

85

170

ns

(Note 7)

Turn Off

Delay time

46

90

46

90

46

90

ns

(Note 7)

Break-Before-Make

Delay Time

15

40

15

40

15

40

ns

Charge Injection

0.2

1.0

0.2

1.0

0.2

1.0

pC

(Note 3) (Note 4)

Off Isolation

75

75

75

dB

At f = 100KHz, (Note 5)

Crosstalk

90

90

90

dB

At f = 100KHz, (Note 6)

Total Harmonic

0.05

0.05

0.05

%

Distortion

0.01

0.01

0.01

Com/Out

COM(OFF)

Off Capacitance

OUT(OFF)

3.0

3.0

3.0

pF

Channel On

5.7

5.7

5.7

pF

Capacitance

Pin to Pin

0.5

0.6

0.25

pF

Capacitance