Programmable Select Options - Broadcom HEDS-9930PRGEVB User Manual

HEDS-9930PRGEVB User Guide
Table 1: Selection Table for AEDR-9930 397 LPI (Continued)
No. SEL1
27
a
Open
a. Open selection must be connected to the middle of a voltage divider circuit.
Figure 5: Example of Voltage Divider Circuit
Vcc
4.7k
SEL
4.7k 4
Use 2 × 4.7 kΩ resistors (V
NOTE:
The preceding digital interpolation factor may be used with the following equations to cater to various rotational speeds
(RPM) and counts per revolution (CPR).
RPM = (Count Frequency × 60) / CPR
The CPR (at 1X interpolation) is based on the following equation that is dependent on radius of operation (R
CPR = LPI × 2π × R
LPmm (lines per mm) = LPI / 25.4.
NOTE:

2.2 Programmable Select Options

The SPI is programmable with an interpolator factor from 1x to 1024x.
1. Configure the external selection to SPI Mode: Program Selection.
2. For signal output after configuration, set the external selection to SPI Mode: Output Enabled.
Broadcom
SEL2 SEL3
a a
Open Open
– GND).
CC
(inch) or CPR = LP mm × 2π × R
OP
Interpolation
Factor IND SEL
SPI Mode Low
High
(mm)
OP
Evaluation Board and Programming Kit
Index
SPI Mode: Program Selection
SPI Mode: Output Enabled
).
OP
HEDS-9930PRGEVB-UG100
8