Datasheet

AD7623
Rev. 0 | Page 10 of 28
Pin No. Mnemonic Type
1
Description
35
CNVST
DI
Conversion Start. A falling edge on
CNVST puts the internal sample-and-hold into the hold state and
initiates a conversion.
36 AGND P Analog Power Ground Pin.
37 REF AI/O
Reference Output/Input.
When PDREF/PDBUF = low, the internal reference and buffer are enabled, producing 2.048 V on this pin.
When PDREF/PDBUF = high, the internal reference and buffer are disabled, allowing an externally
supplied voltage reference up to AVDD volts. Decoupling is required with or without the internal
reference and buffer. Refer to the
Voltage Reference Input section.
38 REFGND AI Reference Input Analog Ground.
39 IN− AI Differential Negative Analog Input.
43 IN+ AI Differential Positive Analog Input.
45 TEMP AO Temperature Sensor Analog Output.
46 REFBUFIN AI/O
Internal Reference Output/Reference Buffer Input.
When PDREF/PDBUF = low, the internal reference and buffer are enabled, producing the 1.2 V (typical)
band gap output on this pin, which needs external decoupling. The internal fixed gain reference buffer
uses this to produce 2.048V on the REF pin.
When using an external reference with the internal reference buffer (PDBUF = low, PDREF = high),
applying 1.2 V on this pin produces 2.048 V on the REF pin. Refer to the
Voltage Reference Input section.
47 PDREF DI
Internal Reference Power-Down Input.
When low, the internal reference is enabled.
When high, the internal reference is powered down, and an external reference must be used.
48 PDBUF DI
Internal Reference Buffer Power-Down Input.
When low, the buffer is enabled (must be low when using internal reference).
When high, the buffer is powered-down.
1
AI = analog input; AI/O = bidirectional analog; AO = analog output; DI = digital input; DI/O = bidirectional digital; DO = digital output; P = power.