USB-DAQ-SS HEXWAX, USB-DAQ-SS Datasheet - Page 4

• Manufacturer Part Number: USB-DAQ-SS
• Description: IC, USB DATA LOGGER/PROCESS CTRL SSOP-20
• Manufacturer: HEXWAX

Specifications of USB-DAQ-SS

• Usb Type: Data Logger
• Usb Version: 2.0
• Supply Voltage Range: 1.8V To 5.5V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: SSOP
• No. Of Pins: 20
• Termination Type: SMD
• Filter Terminals: SMD
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

INTx, KBIx
Interrupt-on-edge (INT) and interrupt-on-change (KBI)
input pins.
CCPx, P1x
Capture / compare / pulse width modulation pins.
TX, RX
Asynchronous UART
SCK, MISO, MOSI, SSn
Synchronous serial (SPI) port
SCL, SDA
Synchronous serial (I2C) port
CxIN-, CxIN+, CxOUT
Comparator pins
TxCKI
Counter inputs
Memory
Internal Memory
In order to maximize available storage space, the
internal memory is pre-formatted as a 16-sector FAT12
file system with 512 bytes per sector.
sectors are required for the file system and root
directories.) Reformatting by the PC is not permitted.
The root directory can contain up to 16 entries, including
the volume name.
containing no files. If ordered in 5K+ quantities, files
can be pre-loaded.
To indicate to USB-DAQ that the internal memory
should be used, the SCK-M input should be biased low
on startup.
Pages of internal memory may be erased and rewritten
approximately 100K times. In order to minimize wear,
USB-DAQ does not update directory entries; it only
changes the contents of files.
External Memory – 25AA1024
For
25AA1024
connected to the MISO-M, MOSI-M, SCK-M and SSn-M
lines.
SCK-M. The media detect input should be permanently
biased low.
When first used, the memory will automatically be
formatted as a 16-sector FAT12 file system with 512
bytes per sector. The PC may re-format the drive if
required.
External Memory – SD card / integrated circuit
For large storage applications, an SD-compatible
memory of up to 1GB may be connected to the MISO-M,
MOSI-M, SCK-M and SSn-M lines. 4k7 pull-up resistors
p4 of 8
moderate
A 4k7 pull-up resistor should be provided for
memory
storage
26-Aug-10
The volume is normally supplied
(128kByte
applications,
storage)
a
(4 of these
USB-DAQ
Microchip
may
be
should be provided for these lines, and also for unused
SD card I/O pins.
The memory can be a removable SD card or a SD-
compatible chip. If the memory is removable, the media
detect input should be connected to a switch to indicate
when the card is present. Devices with SD card readers
will be able to read the data on the SD card directly.
Memories larger than 1GB will be ignored, as will non-
standard memories which do not have block sizes of
512 bytes. San-Disk products are used for testing.
Accessing SD card memory is slow.
mostly for long-term logging applications only.
option is only available for the 28-pin and 40/44-pin
devices.
Memory Integrity
In the event of power loss during a USB-DAQ write
operation, it is possible that the contents of data may be
corrupted.
affected.
Real Time Clock
The real time clock is self-managing and incorporates
day-of-week calculator, leap-year calculator and optional
daylight savings time calculator. On power-up, the time
is set to 00:00:00, Jan 1
Whenever a file in the root directory is modified by the
PC, the time and date are automatically set to the ‘last
modified’ time and date of the file most recently written
to in the root directory. To set the time, the user simply
needs to open a file in the root directory, modify it, and
save it.
Application Circuits
The following circuits show typical implementations of
the USB-DAQ.
shown in table 5.
In figure 3, the internal memory is used and only
contains components that are strictly necessary. The
device has its own power source Vdd and does not draw
power from the USB port.
Oscillator X1/C2/C3 may be replaced by a low-cost
resonator, provided its frequency tolerance is greater
than 0.25%. C1 and C6 should be placed close to the
R1-R3, R40-R43
C6-C7, C9
C2, C3
C4, C5
D1-D2
Label
LED1
R21
R6
T1
C1
C8
X1
X2
Table 5. Suggested component values
HW147-5
Functionality should not otherwise be
Suggested component values are
P-channel Mosfet, e.g. NDS352P
st
2000.
32758Hz parallel cut crystal
12MHz parallel cut crystal
Low Vf switching diode
Light emitting diode
100nF capacitor
470nF capacitor
22pF capacitor
27pF capacitor
470Ω resistor
1μF capacitor
Component
22k resistor
1k resistor
www.hexwax.com
It is intended
This