ncn6001 ON Semiconductor, ncn6001 Datasheet - Page 13

• Manufacturer Part Number: ncn6001
• Description: Compact Smart Card Interface Ic
• Manufacturer: ON Semiconductor

STARTUP DEFAULT CONDITIONS
internal POR circuit sets the chip in the default conditions as
defined in Table 4.
CARD DETECTION
18. The internal circuit provides a positive bias of this pin
and the polarity of the insertion/extraction is programmable
by the MOSI protocol as depicted in Table 2.
observed to avoid leakage to ground from this pin to
maintain the logic function. In particular, using a low
impedance probe (< 1.0 MW) may lead to uncontrolled
operation during the debug.
be detected either by a Normally Open (default condition) or
a Normally Close switch (Table 2). On the other hand, the
meaning of the feedback message contained in the MISO
register bit b4, depends upon the SPI mode of operation as
defined here below:
SPI Normal Mode: the MISO bit b4 is High when a card is
inserted, whatever be the polarity of the card detect switch.
SPI Special Mode: the MISO bit b4 copies the logic state of
the Card detect switch as depicted here below, whatever be
the polarity of the switch used to handle the detection:
Table 4. Startup Default Conditions
At startup, when the V
The card is detected by the external switch connected pin
The bias current is 1.0 mA typical and care must be
Depending upon the programmed condition, the card can
CRD_DET = Low → MISO/b4 = Low
CRD_DET = High → MISO/b4 = High
CRD_VCC
CRD_DET
CRD_CLK
CRD_CLK
Protocol
Normally Open
Off
t
Low
Special Mode
r
and t
CC
f
= SLOW
power supply is turned on, the
Figure 3. Typical Startup CRD_VCC Sequence
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NCN6001
13
CRD_VCC OPERATION
voltage and can be programmed to run one of the three
possible values, 1.8 V, 3.0 V or 5.0 V, assuming the input
voltage V
CRD_VCC is voltage regulated, together with a current
overload detection. On the other hand, the power conversion
is automatically switched to handle either a boost or a buck
mode of operation, depending upon the difference between
the input voltage V
input value as depicted in Table 5.
built−in comparator makes sure the voltage is within the
ISO7816−3/ EMV specifications. If the voltage is no longer
within the minimum/maximum values, the DC/DC is
switched Off, the Power Down sequence takes place and an
interrupt is presented at the INT pin 2.
POWERUP SEQUENCE
signals are Low during the CRD_VCC positive going slope.
These lines are validated when CRD_VCC is above the
minimum
programmed CRD_VCC value).
Table 5. CRD_VCC Output Voltage Range
The built−in DC/DC converter provides the CRD_VCC
The CRD_VCC output current is a function of the V
Whatever the CRD_VCC output voltage may be, a
The Powerup Sequence makes sure all the card related
CRD_VCC
1.80 V
3.0 V
5.0 V
CC
specified voltage (depending upon the
is within the 2.7 V to 5.5 V range. In any case,
Maximum Output DC Current = 35 mA
Maximum Output DC Current = 60 mA
Maximum Output DC Current = 65 mA
CC
and the output supply CRD_VCC.
Comments
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