LTC1064 Linear Technology, LTC1064 Datasheet - Page 6

• Manufacturer Part Number: LTC1064
• Description: Low Noise/ Fast/ Quad Universal Filter Building Block
• Manufacturer: Linear Technology

LTC1064
PIN
V
bypassed with a 0.1 F ceramic capacitor. Low noise,
nonswitching power supplies are recommended. The de-
vice operates with a single 5V supply and with dual
supplies. The absolute maximum operating power supply
voltage is 8V.
CLK (Pin 18): Clock. For 5V supplies the logic threshold
level is 1.4V. For 8V and 0V to 5V supplies the logic
threshold levels are 2.2V and 3V respectively. The logic
threshold levels vary 100mV over the full military tem-
perature 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 5V supplies is 4MHz. For
supplies and above, the maximum clock frequency is
7MHz.
6
+
, V
U
–
FUNCTIONS
(Pins 7, 19): Power Supplies. They should be
U
NOTE: PINS 5, 8, 20, IF NOT USED, SHOULD BE CONNECTED TO PIN 6
1 F
U
+
GROUND
ANALOG
PLANE
V
+
5k
5k
V+/2
0.1 F
10
11
12
1
2
3
4
5
6
7
8
9
Figure 1. Single Supply Operation
AGND
V
+
LTC1064
7V
50/100
CLK
V
–
24
23
22
21
20
19
18
17
16
15
14
13
AGND (Pin 6): Analog Ground. When the LTC1064 oper-
ates with dual supplies, Pin 6 should be tied to system
ground. When the LTC1064 operates with a single positive
supply, the analog ground pin should be tied to 1/2 supply
and it should be bypassed with a 1 F solid tantalum in
parallel with a 0.1 F ceramic capacitor, Figure 1. The
positive input of all the internal op amps, as well as the
common reference of all the internal switches, are inter-
nally tied to the analog ground pin. Because of this, a very
“clean” ground is recommended.
50/100 (Pin 17): By tying Pin 17 to V
operate with a clock-to-center frequency ratio internally
set at 50:1. When Pin 17 is at mid-supplies, sections B and
C operate with (f
operate at 100:1. When Pin 17 is shorted to the negative
supply pin, all filter sections operate with (f
100:1.
1064 F01
CLK
/f
TO DIGITAL
GROUND
CLOCK INPUT
V
V
V
O
+
+
+
) = 50:1 and sections A and D
= 15V, TRIP VOLTAGE = 7V
= 10V, TRIP VOLTAGE = 6.4V
= 5V, TRIP VOLTAGE = 3V
+
, all filter sections
CLK
/f
O
) =