MB40178 Fujitsu Microelectronics, Inc., MB40178 Datasheet - Page 18

• Manufacturer Part Number: MB40178
• Description: Single Chip 8-bit A/d And 9-bit D/a Converter
• Manufacturer: Fujitsu Microelectronics, Inc.

18
MB40168/MB40178
Power Supply Lines
Coupling Capacitors
Digital Output Load
OTHER NOTES ON OPERATION
NOTES ON PCB LAYOUT
The device’s power supply lines (V
be separated in so far as possible from other digital lines in order to reduce noise. Also the track widths of these
lines should be as wide as possible to reduce parasitic impedance.
The device’s power supply lines V
be decoupled to analog ground by means of approx. 1 F capacitors which should be placed as close as possible
to these pins.
The load at the digital outputs should be kept as low as possible to prevent noise in the power supply lines
caused by digital output switching. If, due to long wiring, the load becomes large then a buffer with small input
capacitance should be inserted to reduce load capacitance.
When using the D/A converter with its V
be connected to the V
When using the D/A converter with 8 bit resolution the DD9 (LSB) pin should be grounded.
REF
because otherwise the internal reference voltage generation circuitry cannot output 3 V.
CCA
CCA
and V
, V
RIN
CCD
pin connected to the V
CCD
, AGND and DGND) should be laid out as analog lines and should
and the reference voltage pins V
REF
pin, the A/D converter’s V
RIN
, V
REF
, V
RB
, and V
RB
pin must also
RT
should