lc78605e Sanyo Semiconductor Corporation, lc78605e Datasheet - Page 10

• Manufacturer Part Number: lc78605e
• Description: Compact Disc Player Dsp With Built-in Microcontroller
• Manufacturer: Sanyo Semiconductor Corporation

Notes on Application Design
While it goes without saying that this IC’s absolute maximum ratings and allowable operating ranges (and
recommended operating conditions) must be strictly observed to achieve reliability as a total system, adequate care is
also required with respect to the operating environment and mounting conditions such as ambient temperature and static
electricity. This section presents notes on items that require care during end product design and IC mounting.
• Handling Unused Pins
• Latchup Prevention
• Interface Notes
• Load Capacitance and Output Current
• Notes on Power Application and Power-on Reset
• Notes on thermal design
• Notes on PCB pattern design
If any unused input pins on this IC are left open the related internal circuits may become unstable. The instructions on
handling unused pins for specific pins given in the technical documentation must be followed. Also note that unused
output pins must not be shorted to power, ground, or other outputs.
— The stipulated supply voltage must be applied to each power supply pin. If there are multiple pins for which the
— Overvoltages and abnormal noise must not be applied to this IC.
— In general, latchup can be prevented by holding unused input pins fixed at either V
— The outputs must not be shorted.
When the inputs and outputs of different devices are connected, malfunctions may occur if the input V
do not match the corresponding output V
devices if devices with differing supply voltages, such as may occur in two power supply system applications, are
connected.
— When connected to high capacitance loads, lines may be melted since the effect of such loads is the same as the
— Excessive output sink or source currents can cause similar problems. Observe the maximum allowable power
— There are cases where special care is required at power on, during a reset, and after a reset is cleared. Refer to the
— This IC’s output pin states, I/O settings, and register values are undefined when power is first applied. The
The failure rate of semiconductor devices is accelerated greatly by increases in ambient temperature or power
consumption. To assure high reliability, design the application heat dissipation system to provide adequate margin for
variations in ambient conditions.
— Ideally, there should be separate power supply and ground lines for each system to reduce the influence of shared
— The power supply and ground lines should be as wide and as short as possible, and the impedance to high
*: In the servo systems, the same handling is required for the V
same supply voltage is stipulated, the same potential must be applied to all those pins.
handling of each pin must follow the specific instruction in the pin functions documentation.
load being shorted for an extended period. Also, charge/discharge currents may result in noise that may degrade
equipment performance and cause malfunctions. The recommended load capacitance ratings must be observed.
dissipation ratings and use this IC within the recommended current value range.
device specifications and design applications taking these concerns into account.
operation of items that are defined by a reset operation or mode settings is only guaranteed after the corresponding
reset or setting operation. A reset must be applied to this IC after power is first applied. The states immediately
after power on of pins and registers that are not explicitly defined cannot be relied on: they may differ from
versions of the same product purchased at different times.
impedances.
frequencies should be as small as possible. Ideally, decoupling capacitors (0.01 to 1µF) and 100 to 220µF
capacitors should be inserted between each power supply/ground pair. However, note that latchup may occur if
the values of these capacitors are too large.
V
heat dissipating effect.
CC
and ground lines. The driver ground lines must be especially wide and located under the device to provide a
OL
/V
OH
levels. Level shifters must be inserted to prevent destruction of the
LC78605E
REF
reference voltage line as well as for the driver
DD
or V
SS
. However, the
IL
No.7735-10/11
/V
IH
levels