NCN6010
http://onsemi.com
7
Card Supply Charge Pump Converter
The NCN6010 device provides three pins to control the
operation of the interface as depicted in Table 1. The built-in
charge pump converter circuit provides either a 3.0 V or a
5.0 V output voltage as defined by the programming mode.
The external capacitor connected across pins 12 and 13 is
used to generate the step up voltage. Since the device
operates at 800 kHz typically, one must use high quality,
Low ESR type, ceramic capacitor (220 nF recommended).
The second external capacitor, connected across pin 14 and
GND, smooths the output voltage coming from the Charge
Pump. A high quality, Low ESR capacitor is necessary to
achieve the SIM_VCC ripple voltage (1.0 mF Ceramic type
is recommended).
The setting of the SIM_VCC voltage, using MOD_VCC
= 0 or 1, can only be made when PWR_ON is Low.
Consequently, a new supply voltage adjustment is
performed by first deactivating the SIM card, followed by
reactivating it with the new supply voltage. The SIM_VCC
voltage can be reprogrammed straightforward when the
output voltage increases from 3.0 V to 5.0 V. On the other
hand, although it is possible to change the SIM_VCC
voltage from 5.0 V to 3.0 V, it is recommended to switch off
the Charge Pump prior to reprogram the SIM_VCC voltage
from the high 5.0 V to a low 3.0 V.
The DC-DC converter operates under two modes as
defined by the logic level present at MOD_VCC/pin 3:
MOD_VCC = 0 SIM_CC = 5.0 V, "10%. This is the
default condition at start up.
MOD_VCC = 1 The Charge Pump is not activated and the
SIM_VCC voltage is equal to the V
DD
supply minus the internal maximum
50 mV drop.
The NCN6010 provides a POWER DOWN sequence,
according to the ISO7816-3 specification.
Since a built-in active pull down MOS pull the SIM_VCC
pin to ground when the smart card is deactivated, a 350 ms
minimum delay must be observed prior to reactivate the
power supply. This timing assumes a 1.0 mF external
reservoir capacitor connected across SIM_VCC and
Ground.
Table 1. Programming Functions
STOP MOD_VCC PWR_ON Operation Mode
0 X X The SIM card supply is disabled, the SIM_VCC pin is Open, SIM_RST = L,
SIM_I/O = L, SIM_CLK = L
1 0 0 The NCN6010 is in the power down mode. The SIM card supply is disabled,
SIM_VCC = Open, SIM_RST = L, SIM_CLK = L, SIM_IO = L.
The SIM_VCC voltage is programmed to 5.0 V.
1 1 0 The NCN6010 is in the power down mode. The SIM card supply is disabled,
SIM_VCC = Open, SIM_RST = L, SIM_CLK = L, SIM_IO = L.
The SIM_VCC voltage is programmed to 3.0 V.
1 X 1 The NCN6010 is in normal operating mode. The SIM card supply is enabled, SIM_VCC
voltage is the one previously programmed, all the SIM interface pins are active.
Table 1: Programming Mode
When the card is removed, the STOP pin shall be asserted
Low to disable the NCN6010. A mechanical switch, or
equivalent, can be either sensed by the MPU, or directly
connected to pin 2, to handle the procedure.
Power Up Sequence
When the charge pump is activated, MOD_VCC = Low,
the SIM card related level shifter pins are biased to the 5.0 V
voltage. When the output voltage starts from zero, as
depicted in Figure 3, a 50 ms stabilization delay (typical) is
necessary to make sure all the output signals are biased at the
nominal 5.0 V voltage. To avoid a card transaction error, the
user must take this delay into account and program the chip
accordingly.
