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TC7109/A
DS21456C-page 6
2006 Microchip Technology Inc.
2.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in
Table 2-1.
TABLE 2-1:
PIN FUNCTION TABLE
Pin Number
(40-Pin PDIP)
Symbol
Description
1
GND
Digital ground, 0V, ground return for all digital logic.
2
STATUS
Output HIGH during integrate and de-integrate until data is latched. Output LOW when
analog section is in auto-zero or zero integrator configuration.
3
POL
Polarity – High for positive input.
4
OR
Over Range – High if over ranged (Three-State Data bit).
5B12
Bit 12 (Most Significant bit) (Three-State Data bit).
6B11
Bit 11 (Three-State Data bit).
7B10
Bit 10 (Three-State Data bit).
8B9
Bit 9 (Three-State Data bit).
9B8
Bit 8 (Three-State Data bit).
10
B7
Bit 7 (Three-State Data bit).
11
B6
Bit 6 (Three-State Data bit).
12
B5
Bit 5 (Three-State Data bit).
13
B4
Bit 4 (Three-State Data bit).
14
B3
Bit 3 (Three-State Data bit).
15
B2
Bit 2 (Three-State Data bit).
16
B1
Bit 1 (Least Significant bit) (Three-State Data bit).
17
TEST
Input High – Normal operation. Input LOW – Forces all bit outputs HIGH.
Note: This input is used for test purposes only.
18
LBEN
Low Byte Enable – with MODE (Pin 21) LOW, and CE/LOAD (Pin 20) LOW, taking this pin
LOW activates low order byte outputs, B1–B8. With MODE (Pin 21) HIGH, this pin serves as
19
HBEN
High Byte Enable – with MODE (Pin 21) LOW, and CE/LOAD (Pin 20) LOW, taking this pin
LOW activates high order byte outputs, B9–B12, POL, OR. With MODE (Pin 21) HIGH, this
pin serves as high byte flag output used in Handshake mode. See Figures 3-7, 3-8, and 3-9.
20
CE/LOAD
Chip Enable/Load – with MODE (Pin 21) LOW, CE/LOAD serves as a master output enable.
When HIGH, B1–B12, POL, OR outputs are disabled. When MODE (Pin 21) is HIGH, a load
21
MODE
Input LOW – Direct Output mode where CE/LOAD (Pin 20), HBEN (Pin 19), and LBEN (Pin
18) act as inputs directly controlling byte outputs. Input Pulsed HIGH - Causes immediate
entry into Handshake mode and output of data as in
Figure 3-9.Input HIGH – enables CE/LOAD (Pin 20), HBEN (Pin 19), and LBEN (Pin 18) as outputs,
at conversions completion.
22
OSC IN
Oscillator Input.
23
OSC OUT
Oscillator Output.
24
OSC SEL
Oscillator Select – Input HIGH configures OSC IN, OSC OUT, BUFF OSC OUT as RC
oscillator – clock will be same phase and duty cycle as BUFF OSC OUT. Input LOW
configures OSC IN, OSC OUT for crystal oscillator - clock frequency will be 1/58 of frequency
at BUFF OSC OUT.
25
BUFF OSC OUT
Buffered Oscillator Output.
26
RUN/HOLD
Input HIGH – Conversions continuously performed every 8192 clock pulses.
Input LOW – Conversion in progress completed; converter will stop in auto-zero seven
counts before integrate.
27
SEND
Input - Used in Handshake mode to indicate ability of an external device to accept data.
Connect to V+ if not used.
28
V-
Analog Negative Supply – Nominally -5V with respect to GND (Pin 1).
29
REF OUT
Reference Voltage Output – Nominally 2.8V down from V+ (Pin 40).