TC1030 Datasheet, PDF (5/14 Pages) TelCom Semiconductor, Inc – LINEAR BUILDING BLOCK - QUAD LOW POWER OP AMP

TC1030
3.0 DETAILED DESCRIPTION
The TC1030 is one of a series of very low power, linear
building block products targeted at low voltage, single
supply applications. The TC1030 minimum operating
voltage is 1.8V, and maximum supply current is only
32µA (fully enabled). It combines four op amps in a
single package.
Microchip’s op amps are internally compensated to be
unity-gain stable and have a typical gain bandwidth
product of 90kHz with typical slew rates of 35V/msec.
The amplifier's input range extends beyond both
supplies by 200mV and the outputs will swing to within
several millivolts of the supplies depending on the load
current being driven.
Two shutdown mode pins are incorporated for easy
adaptation to system power management schemes. In
this state, the shutdown pins allow the user to power on
one, two, three, or all four op amps (see Table 4-1). Pin
SHDNB can be used to disable op amp B and pin
SHDNC/D to disable op amps C and D. Op amp A is
always powered on regardless of the states of the
shutdown pins. When both shutdown pins are low, the
total quiescent current of the TC1030 is only 6µA,
typical.
Input offset voltage is 500µV max at 25°C with an input
bias current of less than 100pA. This makes the
TC1030 extremely suitable for precision, low power
applications.
4.0 TYPICAL APPLICATIONS
The TC1030 lends itself to a wide variety of
applications, particularly in battery-powered systems. It
typically finds application in power management,
process supervisory and interface circuitry.
4.1 Voice Band Receive Filter
The majority of spectral energy for human voices is
found to be in a 2.7kHz frequency band from 300Hz to
3kHz. To properly recover a voice signal in applications
such as radios, cellular phones and voice pagers a low-
power bandpass filter that is matched to the human
voice spectrum can be implemented using Microchip’s
CMOS op amps. Figure 4-1 shows a unity gain multi-
pole Butterworth filter with ripple less than 0.15dB in
the human voice band. The lower 3dB cut-off frequency
is 70Hz (single order response) while the upper cut-off
frequency is 3.5kHz (fourth order response).
4.2 Supervisory Audio Tone (SAT)
Filter for Cellular
Supervisory Audio Tones (SAT) provide a reliable
transmission path between cellular subscriber units
and base stations. The SAT tone functions much like
the current/voltage used in land line telephone systems
to indicate that a phone is off the hook. The SAT tone
may be one of three frequencies: 5970, 6000 or
6030Hz. A loss of SAT implies that channel conditions
are impaired and if SAT is interrupted for more than 5
seconds a cellular call is terminated.
Figure 4-2 shows a high Q (30) second order SAT
detection bandpass filter using Microchip’s CMOS op
amp architecture. This circuit nulls all frequencies
except the three SAT tones of interest.
TABLE 4-1: TC1030 SHUTDOWN POWER CONTROL LOGIC
SHDNC/D
V_IL
V_IL
V_IH
V_IH
SHDNB
V_IL
V_IH
V_IL
V_IH
OP AMPS ENABLED
A
A,B
A,C,D
A,B,C,D
OP AMPS DISABLED
B,C,D
C,D
B
None
MAX. DEVICE
SUPPLY CURRENT
10µA
16µA
24µA
32µA
© 2002 Microchip Technology Inc.
DS21341B-page 5