TDA8003TS Datasheet, PDF (8/24 Pages) NXP Semiconductors – I2C-bus SIM card interface

Philips Semiconductors
I²C-bus SIM card interface
Product specification
TDA8003TS
Power supply
The circuit operates within a supply voltage range of
2.5 to 6 V. The supply pins are V_DDS and SGND. Pins
V_DDP and PGND only supply the DC-to-DC converter for
the analog drivers to the card and must be decoupled
externally because of the large current spikes that the card
and the DC-to-DC converter can create. An integrated
spike killer ensures the card contacts to remain inactive
during power-up or power-down. An internal voltage
reference is generated for the DC-to-DC converter, the
voltage supervisor and the V_CC generator.
All interface signals with the microcontroller (PWROFF,
SIMCLK, SAD1, SAD0, SIMERR, SCL, SDA and SIMI/O)
are referenced to a separate supply pin V_DDI, which may
be different from V_DD (1.5 ≤ V_DDI ≤ 6 V).
The pull-up resistors on bus lines SDA and SCL may be
referenced to a voltage higher than V_DDI. This allows the
use of peripherals which do not operate at V_DDI.
The voltage supervisor (see Fig.3) senses V_DDS. It
generates an alarm pulse, whose length t_W is defined by
an external capacitor connected to pin DEL, when V_DD is
too low to ensure proper operation (1 ms per 1 nF typical).
During this alarm pulse, SIMERR is LOW and the I²C-bus
is unresponsive. SIMERR goes back to HIGH, and the
I²C-bus becomes operational at the end of this alarm
pulse. Bit SUPL is set as long as the status has not been
read.
It is also used to either block any spurious signals on card
contacts during microcontroller reset, or to force an
automatic deactivation of the contacts in the event of
supply drop-out.
Outside a card session, SIMERR is LOW as long as the
voltage supervisor is active. If a supply drop-out occurs
during a session, SIMERR falls to LOW, bit START is
cleared and an automatic deactivation is initiated.
handbook, full pagewidth
VDDS
DEL
tW
SIMERR
I²C-bus unresponsive
tW
status read
after event
I²C-bus OK
I²C-bus
unresponsive
I²C-bus OK
I²C-bus
unresponsive
MGR436
2000 Apr 20
Fig.3 Voltage supervisor.
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