TC514CPJ Microchip Technology, TC514CPJ Datasheet - Page 18

• Manufacturer Part Number: TC514CPJ
• Description: IC ANALOG FRONT END 17BIT 28DIP
• Manufacturer: Microchip Technology
• Type: Precision Analog Front Endsr

Specifications of TC514CPJ

• Number Of Channels: 4
• Package / Case: 28-DIP (0.300", 7.62mm)
• Number Of Bits: 17
• Power (watts): 18mW
• Voltage - Supply, Analog: 5V
• Voltage - Supply, Digital: 4.5 V ~ 5.5 V
• Interface Type: Serial (3-Wire)
• Supply Voltage (min): 4.5 V
• Supply Current: 1.8 mA
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: Through Hole
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TC500/A/510/514
8.6
The comparator delay and the controller’s response
latency may result in overshoot, causing charge
buildup on the integrator at the end of a conversion.
This charge must be removed or performance will
degrade. The integrator output zero phase should be
activated (AB = 00) until CMPTR goes high. It is
absolutely critical that this phase be terminated
immediately so that overshoot is not allowed to occur in
the opposite direction. At this point, it can be assured
that the integrator is near zero. Auto-zero should be
entered (AB = 01) and the TC5XX held in this state until
the next cycle is begun (see
FIGURE 8-2:
DS21428E-page 18
Comparator
Output Comp
Integrator
Output
Integrate
Integrator Output Zero Phase
Phase
Overshoot.
De-integrate Phase
Figure
Overshoot
8-2).
Crossing
Zero
Zero Phase
Integrator
8.7
8.7.1
A capacitive charge pump is employed to invert the
voltage on V
TC514. This voltage is also available on the V
to provide negative bias elsewhere in the system. Two
external capacitors are required to perform the
conversion.
Timing is generated by an internal state machine driven
from an on-board oscillator. During the first phase,
capacitor C
charged to V
C
normally runs at 100 kHz to ensure minimum output
ripple. This frequency can be reduced by placing a
capacitor from OSC to V
the capacitor value is shown in Section 2.0 “Typical
Performance Curves”.
8.7.2
The TC514 is equipped with a four-input differential
analog multiplexer. Input channels are selected using
select inputs (A1, A0). These are high-true control
signals (i.e., channel 0 is selected when (A1, A0 = 00).
OUT
– during the second phase. The oscillator
Using the TC510/TC514
F
NEGATIVE SUPPLY VOLTAGE
CONVERTER (TC510, TC514)
ANALOG INPUT MULTIPLEXER
(TC514)
S
is switched across the power supply and
DD
+. This charge is transferred to capacitor
for negative bias within the TC510/
© 2008 Microchip Technology Inc.
DD
. The relationship between
OUT
– pin