Data Sheet
ADN2850
Rev. E | Page 9 of 28
PIN 1
INDICATOR
1
SDO
2
GND
3
VSS
4
V1
11 WP
12 PR
10 VDD
9V2
5
W
1
6
B
1
7
B
2
8
W
2
1
5
C
L
K
1
6
S
D
I
1
4
R
D
Y
1
3
C
S
ADN2850
NOTES
1. THE EXPOSED PAD IS LEFT FLOATING
OR IS TIED TO VSS.
TOP VIEW
(Not to Scale)
(EXPOSED
PAD)
026
60-
105
Figure 5. Pin Configuration
Table 5. Pin Function Descriptions
Pin No.
Mnemonic
Description
1
SDO
Serial Data Output. Serves readback and daisy-chain functions. Command 9 and Command 10 activate the SDO
output for the readback function, delayed by 24 or 25 clock pulses, depending on the clock polarity before and
previously shifted out SDI can be used for daisy-chaining multiple devices. Whenever SDO is used, a pull-up
resistor in the range of 1 kΩ to 10 kΩ is needed.
2
GND
Ground Pin, Logic Ground Reference.
3
VSS
Negative Supply. Connect to 0 V for single-supply applications. If VSS is used in dual supply, it must be able to sink
2 mA for 15 ms when storing data to EEMEM.
4
V1
Log Output Voltage 1. Generates voltage from an internal diode configured transistor.
5
W1
Wiper terminal of RDAC1. ADDR (RDAC1) = 0x0.
6
B1
Terminal B of RDAC1.
7
B2
Terminal B of RDAC2.
8
W2
Wiper terminal of RDAC2. ADDR (RDAC2) = 0x1.
9
V2
Log Output Voltage 2. Generates voltage from an internal diode configured transistor.
10
VDD
Positive Power Supply.
11
A
WPE
Optional Write Protect. When active low,
A
WPE
A
prevents any changes to the present contents, except
A
PRE
A
strobe.
CMD_1 and COMD_8 refresh the RDAC register from EEMEM. Tie
A
WPE
A
to VDD, if not used.
12
A
PRE
Optional Hardware Override Preset. Refreshes the scratchpad register with current contents of the EEMEM
register. Factory default loads midscale until EEMEM is loaded with a new value by the user.
A
PRE
A
is activated
at the logic high transition. Tie
A
PRE
A
to VDD, if not used.
13
A
CSE
Serial Register Chip Select Active Low. Serial register operation takes place when
A
CSE
A
returns to logic high.
14
RDY
Ready. Active high open-drain output. Identifies completion of Instruction 2, Instruction 3, Instruction 8,
Instruction 9, Instruction 10, and
A
PRE
A
.
15
CLK
Serial Input Register Clock. Shifts in one bit at a time on positive clock edges.
16
SDI
Serial Data Input. Shifts in one bit at a time on positive clock CLK edges. MSB loads first.
EP
Exposed Pad. The exposed pad is left floating or is tied to VSS.