REV. A

–8–

AD5533

PIN FUNCTION DESCRIPTIONS

Pin

Function

AGND(1–2)

Analog GND Pins

Analog Supply Pins. Voltage range from 4.75 V to 5.25 V.

DGND

Digital GND Pins

Digital Supply Pins. Voltage range from 2.7 V to 5.25 V.

DAC_GND(1–2)

Reference GND Supply for All the DACs

REF_IN

Reference Voltage for Channels 0–31

REF_OUT

Reference Output Voltage

Analog Output Voltages from the 32 Channels

Analog Input Voltage

A4–A1

1, A02

Parallel Interface: 5-Address Pins for 32 Channels. A4 = MSB of Channel Address. A0 = LSB.

CAL

1

CS/SYNC

This pin is both the Active Low Chip Select Pin for the parallel interface and the Frame Synchronization Pin

for the serial interface.

WR1

Parallel Interface: Write Pin. Active low. This is used in conjunction with the

CS Pin to address the device

using the parallel interface.

OFFSET_SEL

1

Parallel Interface: Offset Select Pin. Active high. This is used to select the offset channel.

SCLK

2

Serial Clock Input for Serial Interface. This operates at clock speeds up to 20 MHz.

DIN

2

Data Input for Serial Interface. Data must be valid on the falling edge of SCLK.

Output from the DAC Registers for read back. Data is clocked out on the rising edge of SCLK and is valid

on the falling edge of SCLK.

SER/

PAR1

This pin allows the user to select whether the serial or parallel interface will be used. If the pin is tied low,

the parallel interface will be used. If it is tied high, the serial interface will be used.

OFFS_IN

Offset Input. The user can supply a voltage here to offset the output span. OFFS_OUT can also be tied to

this pin if the user wants to drive this pin with the offset channel.

OFFS_OUT

Offset Output. This is the acquired offset voltage that can be tied to the OFFS_IN Pin to offset the span.

BUSY

This output tells the user when the input voltage is being acquired. It goes low during acquisition and

returns high when the acquisition operation is complete.

TRACK/RESET2

of

TRACK. See TRACK Function section for further information. This input can also be used as a means

of resetting the complete device to its power-on-reset conditions. This is achieved by applying a low-going

pulse of between 90 ns and 200 ns to this pin. See section on

RESET Function for further details.

NOTES