Datasheet

Data Sheet AD7952
Rev. A | Page 11 of 32
Pin No. Mnemonic Type
1
Description
37 REF AI/O
Reference Input/Output. When PDREF/PDBUF = low, the internal reference and buffer are enabled,
producing 5 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 with at least a 22 F
capacitor is required with or without the internal reference and buffer. See the Reference Decoupling
section.
38 REFGND AI Reference Input Analog Ground. Connected to analog ground plane.
39 IN− AI
Analog Input. Referenced to IN+.
In the 0 V to 5 V input range, IN− is between 0 V and V
REF
V centered about V
REF
/2. In the 0 V to
10 V range, IN− is between 0 V and 2 V
REF
V centered about V
REF
.
In the ±5 V and ±10 V ranges, IN− is true bipolar up to ±2 V
REF
V (±5 V range) or ±4 V
REF
V (±10 V range)
and centered about 0 V.
In all ranges, IN− must be driven 180° out of phase with IN+.
40 VCC P High Voltage Positive Supply. Normally 7 V to 15 V.
41 VEE P High Voltage Negative Supply. Normally 0 V to −15 V (0 V in unipolar ranges).
43 IN+ AI
Analog Input. Referenced to IN−.
In the 0 V to 5 V input range, IN+ is between 0 V and V
REF
V centered about V
REF
/2. In the 0 V to
10 V range, IN+ is between 0 V and 2 V
REF
V centered about V
REF
.
In the ±5 V and ±10 V ranges, IN+ is true bipolar up to ±2 V
REF
V (±5 V range) or ±4 V
REF
V (±10 V range)
and centered about 0 V.
In all ranges, IN+ must be driven 180° out of phase with IN−.
45 TEMP AO
Temperature Sensor Analog Output. When the internal reference is enabled (PDREF = PDBUF = low),
this pin outputs a voltage proportional to the temperature of the AD7952. See the Temperature Sensor
section.
46 REFBUFIN AI
Reference Buffer Input. When using an external reference with the internal reference buffer
(PDBUF = low, PDREF = high), applying 2.5 V on this pin produces 5 V on the REF pin.
See the Single-to-Differential Driver 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.
49 EPAD
3
NC
Exposed Pad. The exposed pad is not connected internally. It is recommended that the pad be
soldered to VEE.
1
AI = analog input; AI/O = bidirectional analog; AO = analog output; DI = digital input; DI/O = bidirectional digital; DO = digital output; P = power.
2
In serial configuration mode (SER/
PAR
= high, HW/
SW
= low), this input is programmed with the serial configuration register, and this pin is a don’t care. See the
Hardware Configuration section and Software Configuration section.
3
LFCSP_VQ package only.