ST8024LTR STMicroelectronics, ST8024LTR Datasheet - Page 25

• Manufacturer Part Number: ST8024LTR
• Description: Interface - Specialized Smart card interface 3V or 5V 26 MHz
• Manufacturer: STMicroelectronics

Specifications of ST8024LTR

• Product Category: Interface - Specialized
• Rohs: yes
• Product Type: Smart Card Interface
• Operating Supply Voltage: 2.7 V to 6.5 V
• Supply Current: 1.2 mA
• Maximum Power Dissipation: 0.56 W
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: TSSOP-20
• Minimum Operating Temperature: - 25 C

ST8024L
6.10
Fault detection
The following fault conditions are monitored:
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Depending on the type of card-present switch within the connector (normally closed or
normally open) and on the mechanical characteristics of the switch, bouncing may occur on
the PRES signals at card insertion or withdrawal.
There is a debounce feature in the device with an 8 ms typical duration (see
When a card is inserted, output OFF goes high only at the end of the debounce time.
When the card is extracted, an automatic deactivation sequence of the card is performed on
the first true/false transition on PRES or PRES and output OFF goes low.
Figure 8.
Short-circuit or high current on V
Removal of a card during a transaction
V
Step-up converter operating out of the specified values (V
V
Overheating
There are two different cases (see
–
–
DD
UP
too high)
dropping
CMDVCC high outside a card session. Output OFF is low if a card is not in the
card reader, and high if a card is in the reader. A voltage drop on the V
detected by the supply supervisor, this generates an internal power-on reset pulse
but does not act upon OFF. No short-circuit or overheating is detected because the
card is not powered-up.
CMDVCC low within a card session. Output OFF goes low when a fault condition
is detected. As soon as this occurs, an emergency deactivation is performed
automatically (see
it may sense the OFF level again after completing the deactivation sequence. This
distinguishes between a hardware problem or a card extraction (OFF goes high
again if a card is present).
Behavior of OFF, CMDVCC, PRES, and V
Figure
Doc ID 17709 Rev 5
9). When the system controller resets CMDVCC to high,
CC
Figure
8):
CC
DDP
too low or current from
Functional description
Figure
DD
supply is
8).
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