TC850 View Datasheet(PDF) - Microchip Technology
Part Name
Description
MFG CO.
'TC850' PDF : 26 Pages View PDF
TC850
2.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Table .
TABLE 2-1: PIN FUNCTION TABLE
Pin Number
(40-Pin
PDIP/CERDIP)
Pin Number
(44-Pin PLCC)
Symbol
Description
1
2
CS
Chip Select, active HIGH. Logically ANDed, with CE to enable read and write
inputs (Note 1).
2
3
CE
Chip enable, active LOW (Note 2).
3
4
WR
Write input, active LOW. When chip is selected (CS = HIGH and CE = LOW) and
in Demand mode (CONT/DEMAND = LOW), a logic LOW on WR starts a
conversion (Note 1).
4
5
RD
Read input, active LOW. When CS = HIGH and CE = LOW, a logic LOW on RD
enables the 3-state data outputs (Note 2).
5
6
CONT/ Conversion control input. When CONT/DEMAND = LOW, conversions are initi-
DEMAND ated by the WR input. When CONT/DEMAND = HIGH, conversions are
performed continuously (Note 1).
6
7
OVR/POL Overrange/polarity data-select input. When making conversions in the Demand
mode (CONT/DEMAND = LOW), OVR/POL controls the data output on DB7
when the high-order byte is active (Note 2).
7
8
L/H
Low/high byte-select input. When CONT/DEMAND = LOW, this input controls
whether low-byte or high-byte data is enabled on DB0 through DB7 (Note 2).
8
9
DB7
Most Significant data bit output. When reading the A/D conversion result, the
polarity, overrange and DB7 data are output on this pin.
9-15
10-17
DB6-DB0 Data outputs DB6-DB0. 3-state, bus compatible.
16
18
BUSY A/D conversion status output. BUSY goes to a logic HIGH at the beginning of the
de-integrate phase, then goes LOW when conversion is complete. The falling
edge of BUSY can be used to generate a μP interrupt.
17
19
OSC1 Crystal oscillator connection or external oscillator input.
18
20
OSC2 Crystal oscillator connection.
19
21
TEST For factory testing purposes only. Do not make external connection to this pin.
20
22
DGND Digital ground connection.
21
24
COMP Connection for comparator auto-zero capacitor. Bypass to VSS with 0.1 μF.
22
25
VSS
Negative power supply connection, typically -5V.
23
26
INTOUT Output of the integrator amplifier. Connect to CINT.
24
27
INTIN
Input to the integrator amplifier. Connect to summing node of RINT and CINT.
25
28
BUFFER Output of the input buffer. Connect to RINT.
26
29
CBUFB Connection for buffer auto-zero capacitor. Bypass to VSS with 0.1 μF.
27
30
CBUFA Connection to buffer auto-zero capacitor. Bypass to VSS with 0.1 μF.
28
31
CINTA
Connection for integrator auto-zero capacitor. Bypass to VSS with 0.1 μF.
29
32
CINTB
Connection for integrator auto-zero capacitor. Bypass to VSS with 0.1 μF.
30
33
ANALOG Analog common.
COMMON
31
35
IN–
Negative differential analog input.
32
36
IN+
Positive differential analog input.
Note 1: This pin incorporates a pull-down resistor to DGND.
2: This pin incorporates a pull-up resistor to VDD.
3: Pins 1, 23 and 34 (44-PLCC) package are NC “No Internal connection”.
DS21479C-page 6
© 2006 Microchip Technology Inc.
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