LTC1164

7

1164fa

Power Supplies (Pins 7,19)

They should be bypassed with 0.1µF ceramic disc. Low

noise, non-switching, power supplies are recommended.

The device operates with a single 5V supply and with dual

supplies. The absolute maximum operating power supply

voltage is ±8.25V. Supply reversal is not allowed and can

cause latch up. When using dual supplies, loads between

the positive and negative supply (even light loads) can

cause momentary supply reversal during power-up. A

clamp diode from each supply to ground will prevent

reversal and latch problems.

Clock (Pin 18)

For ±5V supplies the logic threshold level is 1.8V. For ±8V

and 0 to 5V supplies the logic threshold level is 2.8V. The

logic threshold levels vary ±100mV over the full military

temperature range. The recommended duty cycle of the

input clock is 50%, although for clock frequencies below

500kHz the clock “on” time can be as low as 200ns. The

maximum clock frequency for single 5V supply and Q

values <5 is 500kHz and for ±5V supplies and above is

1MHz. The clock input can be applied before power is

turned on as long as there is no chance the clock signal will

AGND (PIN 6)

When the LTC1164 operates with dual supplies, Pin 6

should be tied to system ground. When the LTC1164

operates with a single positive supply, the analog ground

pin should be tied to 1/2 supply and it should be bypassed

with a 4.7µF solid tantalum in parallel with a 0.1µF ceramic

disc, Figure 2. The positive input of all the internal op

amps, as well as the common reference of all the internal

switches, are internally tied to the analog ground pin.

Because of this, a very “clean” ground is recommended.

50/100 (Pin 17)

to-center frequency ratio internally set at 50:1. When Pin

Pin 17 is shorted to the negative supply pin, all filter

Figure 2. Single Supply Operation

LTC1164 • PD01

TO DIGITAL

GROUND

ANALOG

GROUND

PLANE

NOTE: PIN 5, 8, 20, IF NOT USED, SHOULD BE CONNECTED TO PIN 6.

7.5k

LT1004*

124

223

322

421

520

619

4.7µF

0.1µF

0.1µF

718

817

916

10

15

11

14

12

13

CLOCK INPUT

LTC1164

AGND

CLK

50/100

+

PI FU CTIO S