Datasheet

Data Sheet AD7091R
Rev. 0 | Page 7 of 20
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Figure 3. Pin Configuration, 10-Lead LFCSP
Figure 4. Pin Configuration, 10-Lead MSOP
Table 5. Pin Function Descriptions
Pin No.
LFCSP MSOP Mnemonic Description
1 1 V
DD
Power Supply Input. The V
DD
range is from 2.7 V to 5.25 V. This supply pin should be decoupled to
GND. The typical recommended values are 10 µF and 0.1 µF.
2 2 REF
IN
/REF
OUT
Voltage Reference Input Output. Decouple this pin to GND. The typical recommended decoupling
capacitor value is 2.2 µF. The user can either access the internal 2.5 V reference or overdrive the
internal reference with an externally applied voltage. The reference voltage range for an externally
applied reference is 2.7 V to V
DD
.
3 3 V
IN
Analog Input. The single-ended analog input range is from 0 V to V
REF
.
4 4 REGCAP Decoupling Capacitor Pin for Voltage Output from Internal Regulator. This output pin should be
decoupled separately to GND using a 1 μF capacitor. The voltage at this pin is 1.8 V typical.
5 5 GND Analog Ground. This pin is the ground reference point for all circuitry on the AD7091R. The analog
input signal should be referred to this GND voltage.
6 6
CONVST
Convert Start. Active low edge triggered logic input. The falling edge of
CONVST
places the track-
and-hold into hold mode and initiates a conversion.
7 7
CS
Chip Select. Active low logic input. The serial bus is enabled when
CS
is held low, and in this mode
CS
is used to frame the output data on the SPI bus.
8 8 SCLK Serial Clock. This pin acts as the serial clock input.
9
9
SDO
Serial Data Output. The conversion output data is supplied to this pin as a serial data stream. The bits
are clocked out on the falling edge of the SCLK input. The data is provided MSB first.
10 10 V
DRIVE
Logic Power Supply Input. The voltage supplied at this pin determines the operating voltage of the
interface. Decoupling capacitors should be connected between V
DRIVE
and GND. The typical
recommended values are 10 µF and 0.1 µF. The voltage range of this pin is 1.65 V to 5.25 V.
11 N/A EPAD Exposed Pad. The exposed pad is not connected internally. For increased reliability of the solder
joints and for maximum thermal capability, solder the exposed pad to the substrate, GND.
NOTES
1. THE EXPOSED PAD IS NOT CONNECTED INTERNALLY.
FOR INCREASED RELIABILITY OF THE SOLDER JOINTSAND
FOR MAXIMUM THERMAL CAPABILITY, SOLDER THE EXPOSED
PAD TO THE SUBSTRATE, GND.
AD7091R
1V
DD
2REF
IN
/REF
OUT
3V
IN
4REGCAP
5GND
10 V
DRIVE
9 SDO
8 SCLK
7 CS
6 CONVST
TOP VIEW
(Not to Scale)
10494-003
V
DD
REF
IN
/REF
OUT
V
IN
REGCAP
GND
V
DRIVE
SDO
SCLK
CS
CONVST
1
2
3
4
5
10
9
8
7
6
AD7091R
TOP VIEW
(Not to Scale)
10494-004