
9
The CLK2 trace from the Neuron Chip to the transceiver is
guarded by ground.
10
The LPT-11 device's logic ground is electrically floating from
all external ground connections.
11
The “leakage” capacitance the LPT-11 device's logic ground to
external ground is minimized, preferably less than 10pF.
12
The PCB has a 14-hole pattern for the SIP, according to the
mechanical dimensions in figure 3.1. If the LPT-11 SIP is
being loaded into a PCB that still has the LPT-10 SIP's 16-
hole pattern, appropriate assembly instructions are in place
to ensure that the 14-pin LPT-11 SIP is loaded with its pin-1
in the pin-1 hole of the LPT-10 pattern.
LPT-11 DC-DC Converter
Item Check
When
Completed
Description
13
The DC-DC switching inductor L1 meets the following
criteria over the device's operating temperature range:
L=1mH ± 10%, Isat
≥
200mA, and DCR
≤
4
Ω
.
14
The DC-DC input storage capacitor C1 meets the following
criteria over the device's operating temperature range:
C=100µF ±20%, DCWV
≥
63V, Iripple
≥
200mArms @
100kHz, ESR
≤
1.2
Ω
@100kHz.
15
The DC-DC output capacitor C2 meets the following criteria
over the device's operating temperature range: C=22µF
±20%, DCWV
≥
10V, Iripple
≥
200mArms@100kHz, ESR
≤
1.2
Ω
@100kHz.
16
For applications that require no more than 25mA of
sustained peak Icc application current, L1, C1, and C2 meet
at least the relaxed specifications presented in table 2.6.
17
In addition to the 22µF capacitor C2, no more than 1.0µF of
decoupling capacitance has been added to Vcc.
18
The lifetimes of C1 and C2 have been calculated, and an
appropriate capacitor vendor and series has been chosed to
meet the product’s expected operational lifetime.
19
If a periodic load is connected to Icc in this device with a load
frequency in the 10kHz to 1MHz range, that load’s Vcc
supply is post-filtered, as shown in figure 4.1.
20
If the device’s application circuitry or other nearby circuitry
can be disturbed by AC magnetic fields, then a toroidal or
shielded inductor is used for L1.
L
ON
W
ORKS
LPT-11 Transceiver User’s Guide
C-3