SDA5273-2 SIEMENS [Siemens Semiconductor Group], SDA5273-2 Datasheet - Page 20

• Manufacturer Part Number: SDA5273-2
• Description: ICs for Consumer Electronics MEGATEXT and MEGATEXT PLUS ICs
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Characteristics (cont’d)
T
Parameter
Reset/Chip Initialization
A power-on reset or a reset pulse at pin RES lead to a hardware reset and a software initialization
of registers and internal DRAM. During initialization bus transfers are not allowed.
At / after power-on a reset pulse at pin RES is necessary. RES may return to 0 after the supply
voltage reached its lower limit for chip function (4.7 V). This may be achieved by a capacitor
between RES and
depend on the worst case rise time of
Initialization time after power-
on or falling edge of RES
If the supply voltage drops below
Pulse width RES
High level at pin RES causes chip reset.
In rare cases, the IC may remain in a permanent reset state after power up, depending on the
applicational context. After power up, the software should check proper operation. In case the
Megatext does not react properly, power supply should be switched off for at least 3 s. After that,
power supply can be switched on again.
Other Items
Horizontal frequency pull-in
range of CVBS-PLL:
Horizontal frequency pull-in
range of display-PLL:
Semiconductor Group
A
= 0 to 70 C
V
DD
and by a resistor
Symbol
t
INIT
V
DD min
V
, the IC has to be reset by pin RES.
DD
R
min.
100
15
15.2
15
.
between RES and
Limit Values
20
typ.
15.625 16.2
15.748 16.3
15.625 16.2
max.
25
V
SS
. The dimensions of
Unit
ms
ns
kHz
kHz
kHz
Test Condition
V
PAL
20.48 MHz crystal
NTSC
20.48 MHz crystal
20.48 MHz crystal
DD
SDA 5273-2 / 75-2
greater 4.7 V
SDA 5273 / 75
R
1997-09-01
and
C
C