tc3400 Microchip Technology Inc., tc3400 Datasheet - Page 5

• Manufacturer Part Number: tc3400
• Description: +1.8v, Low Power, 16-bit Sigma-delta A/d Converter
• Manufacturer: Microchip Technology Inc.

2.0
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1:
©
(8-Pin SOIC)
(8-Pin PDIP)
2002 Microchip Technology Inc.
Pin No.
1
2
3
4
5
6
7
8
PIN DESCRIPTIONS
Symbol
REF
REF
SDAT
SCLK
GND
PIN FUNCTION TABLE
V
IN+
IN-
DD
OUT
IN
Analog Input. This is the positive terminal of a true differential input consisting of IN+ and IN-.
V
Analog Input. This is the negative terminal of a true differential input consisting of IN+ and IN-.
V
Analog Input. The converter’s reference voltage is the differential between this pin and ground times
two. It may be tied directly to REF
voltage less than 1.25V may be used in place of REF
Ground Terminal.
Analog Output. The internal reference connects to this pin. It may be scaled externally, if desired, and
tied to the REF
external circuitry to this pin.
Digital Output (push-pull). This is the microPort™ serial data output. SDAT is driven low while the
TC3400 is converting data, effectively providing a “busy” signal. After the conversion is complete,
every high to low transition on the SCLK pin puts a bit from the resulting data word on the SDAT pin
(from MSB to LSB).
Digital Input. This is the microPort™ serial clock input. The TC3400 comes out of sleep mode and a
conversion cycle begins when this pin is driven low. After the conversion starts, each additional falling
edge (up to six) detected on SCLK for t
conversion is complete, the data word can be shifted out on the SDAT pin by clocking the SCLK pin.
Power Supply Input.
IN1
IN
= (IN+ – IN-) IN- can swing to, but not below, ground.
= (IN+ – IN-). See Section 1.0 Electrical Characteristics.
IN
input to provide the converter’s reference voltage. Care must be taken in connecting
OUT
or scaled using a resistor divider. Any user supplied reference
4
seconds reduces the A/D resolution by one bit. When the
Description
OUT
.
TC3400
DS21409B-page 5