Datasheet
9
LTC1060
1060fb
Table 2. Wideband RMS Noise
f
CLK
NOTCH/HP BP LP
V
S
f
0
(µV
RMS
)(µV
RMS
)(µV
RMS
) CONDITIONS
±5V 50:1 49 (42) 52 (43) 75 (65) Mode1, R1 = R2 = R3
±5V 100:1 70 (55) 80 (58) 90 (88) Q = 1
±2.5V 50:1 33 (31) 36 (32) 48 (43)
±2.5V 100:1 48 (40) 52 (40) 66 (55)
±5V 50:1 20 (18) 150 (125) 186 (155) Mode 1, Q = 10
±5V 100:1 25 (21) 220 (160) 240 (180) R1 = R3 for BP out
±2.5V 50:1 16 (15) 100 (80) 106 (87) R1 = R2 for LP out
±2.5V 100.1 20 (17) 150 (105) 150 (119)
±5V 50:1 57 57 62 Mode 3, R1 = R2 = R3 = R4
±5V 100:1 72 72 80 Q = 1
±2.5V 50:1 40 40 42
±2.5V 100.1 50 50 53
±5V 50:1 135 120 140 Mode 3, R2 = R4, Q = 10
±5V 100:1 170 160 185 R3 = R1 for BP out
±2.5V 50:1 100 88 100 R4 = R1 for LP and HP out
±2.5V 100:1 125 115 130
Short-Circuit Currents
Short circuits to ground, positive or negative power supply
are allowed as long as the power supplies do not exceed
±5V and the ambient temperature stays below 85˚C.
Above ±5V and at elevated temperatures, continuous
short circuits to the negative power supply will cause
excessive currents to flow. Under these conditions, the
device will get damaged if the short-circuit current is
allowed to exceed 80mA.
Each building block of the LTC1060, together with an
external clock and a few resistors, closely approximates
2nd order filter functions. These are tabulated below in the
frequency domain.
1. Bandpass function: available at the bandpass output
Pins 2 (19). (Figure 1.)
G(s) = H
OBP
sω
o
/Q
s
2
+ (sω
o
/Q) + ω
o
2
H
OBP
= Gain at ω = ω
o
f
0
= ω/2π; f
0
is the center frequency of the complex
pole pair. At this frequency, the phase shift
between input and output is –180˚.
Q = Quality factor of the complex pole pair. It is the
ratio of f
0
to the –3dB bandwidth of the 2nd or-
der bandpass function. The Q is always mea-
sured at the filter BP output.
2. Lowpass function: available at the LP output Pins
1 (20). (Figure 2.)
G(s) = H
OLP
ω
o
s
2
+ s(ω
o
/Q) + ω
o
2
2
H
OLP
DC gain of the LP output.
APPLICATIO S I FOR ATIO
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DEFINITION OF FILTER FUNCTIONS
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