TDA8029 Philips Semiconductors, TDA8029 Datasheet - Page 43

• Manufacturer Part Number: TDA8029
• Description: Low power single card reader
• Manufacturer: Philips Semiconductors

Philips Semiconductors
8.11
The circuit operates within a supply voltage range of
2.7 to 6 V. The supply pins are V
PGND. Pins DCIN and PGND supply the analog drivers to
the cards and have to be externally decoupled because of
the large current spikes the card and the step-up converter
can create. V
An integrated spike killer ensures the contacts to the card
to remain inactive during power-up or -down. An internal
voltage reference is generated which is used within the
step-up converter, the voltage supervisor, and the V
generators.
V
2003 Oct 30
handbook, full pagewidth
DCIN
Low power single card reader
may be higher than V
Supply
RSTOUT
DD
CDEL
SUPL
V th1
V DD
V th2
and GND supply the rest of the chip.
INT
Power-on
DD
.
DD
, DCIN, GND and
t w
Fig.11 Voltage supervisor.
CC
Supply dropout
Status read
43
The voltage supervisor generates an alarm pulse, whose
length is defined by an external capacitor connected to the
CDEL pin, when V
(1 ms per 2 nF typical). This pulse is used as a Power-on
reset pulse, and also to block either any spurious signals
on card contacts during controllers reset or to force an
automatic deactivation of the contacts in the event of
supply drop-out (see Sections 8.16 and 8.17).
After power-on or after a voltage drop, the bit SUPL is set
within the Hardware Status Register (HSR) and remains
set until HSR is read when the alarm pulse is inactive.
As long as the Power-on reset is active, INT0_N is LOW.
The same occurs when leaving shut-down mode or when
the RESET pin has been set active.
Reset by CDEL
DD
is too low to ensure proper operation
Power-off
MDB815
Product specification
TDA8029