TC815CBU View Datasheet(PDF) - Microchip Technology
Part Name
Description
Manufacturer
TC815CBU
Microchip Technology
TC815CBU Datasheet PDF : 26 Pages
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TC815
11.0 “BUZZER” DRIVE SIGNAL
The TC815 BUZ output (Pin 4) will drive a piezo electric
audio transducer. The signal is activated to indicate an
input overrange condition for current and voltage
measurements, or continuity during resistance
measurements.
During a resistance measurement, a reading less than
19 on any full scale range, causes a continuous 4kHz
signal to be output. This is used as a continuity
indication.
A voltage or current input measurement overrange is
indicated by a noncontinuous 4kHz signal at the BUZ
output. The LCD display MSD also flashes and the
three least significant digits are set to display zero.
The buzzer drive signal for over range is shown in
Figure 11-1 The buzzer output is active for any reading
over 2000 counts in both manual and auto-range oper-
ation. The buzzer is activated during an extended res-
olution measurement. The BUZ signal swings from VCC
(Pin 28) to Digital Ground (Pin 58). The signal is at VCC
when not active.
The BUZ output is also activated for 15msec whenever
a range change is made in auto-range or manual oper-
ation. Changing the type of measurement (voltage, cur-
rent, or resistance) or measurement option (AC/DC,
Ω/LOΩ) will also activate the buzzer output for 15msec.
A range change during a current measurement will not
activate the buzzer output.
FIGURE 11-1:
TC815 WAVEFORM FOR BUZZER OUTPUT
122ms 122ms 122ms 122ms 610ms 122ms
1 Conversion
Digital Ground
4kHz Signal
Power-up
VIN = 250mV
Noncontinuous Buzzer Signal Indicates Input Overrange
4000
8000 12000
Change Range
Change Range
Change Range
Change Input
VIN = 3.2V
Integrate
Internal
TC815 De-integrate
Signals
Auto-Zero
1000 Clock Pulses
100ms
1638.5CP
122ms
2000CP
250CP
250CP
2500CP
250CP
3000CP
BUZ
(Pin 4)
Auto-Ranging
200mV Range
Over Range
2,000V Range
In Range
2,000V Range
In Range
Manual Range
200mV Range
Extended Range
2,000V Range
In Range
2,000V Range
Out of Range
4kHz
4kHz
One Cycle of Over Range
Buzzer
Buzzer activated due
to Power-up
15ms
15ms
Due to Manual
Due to
Range Change Range
Change
15ms
4kHz 4kHz
Due to
Range
Change
122ms 122ms122ms
Buzzer activated due to
Previous Conversion Over Range
610ms
Buzzer
activated due
to Previous
Over Range
DS21474B-page 20
© 2002 Microchip Technology Inc.
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