PN746X Datasheet, PDF (22/86 Pages) NXP Semiconductors – NFC Cortex-M0 microcontroller

NXP Semiconductors
PN746X_736X
NFC Cortex-M0 microcontroller
When the V_DDP(VBUSP) is going below the threshold value, in the one of the conditions
indicated below, a card deactivation is performed:
• Class A card activated, and V_DDP(VBUSP) going below 3 V
• Class B card activated, and V_DDP(VBUSP) going below 3.9 V (DC-to-DC converter in
follower mode)
• Class B card activated, and V_DDP(VBUSP) going below 2.7 V (DC-to-DC converter in
doubler mode)
• Class C card activated, and V_DDP(VBUSP) going below 2.7 V
The VBUSP voltage monitor can be configured so that an automatic “card deactivation”
sequence is performed automatically when V_DDP(VBUSP) is going below the threshold
value.
8.9.3 Clock circuitry
The card clock is generated from the crystal oscillator, connected on the pin XTAL1 and
XTAL2.
The card frequency is configured through the contact interface registers. The following
value can be chosen: f_XTAL / 2, f_XTAL / 3, f_XTAL / 4, f_XTAL / 5, f_XTAL / 6, f_XTAL / 8, and
f_XTAL / 16.
It is possible to put the card clock to a logical level 0 or 1 (clock stop feature).
The duty cycle on the pin CLK is between 45 % and 55 %, for all the available clock
dividers.
8.9.4 I/O circuitry
The three data lines I/O, AUX1 and AUX2 are identical.
I/O is referenced to V_CC. To enter in the idle state, the I/O line is pulled HIGH via a 10 k
resistor (I/O to V_CC).
The active pull-up feature ensures fast LOW to HIGH transitions. At the end of the active
pull-up pulse, the output voltage depends on the internal pull-up resistor and the load
current.
The maximum frequency on these lines is 1.5 MHz.
8.9.5 VCC regulator
VCC regulator delivers up to 60 mA for class A cards (0 V to 5 V). It also delivers up to 55
mA for class B cards (0 V to 3 V) and up to 35 mA for class C cards (from 0 V to 1.8 V).
The VCC has an internal overload detection at approximately 110 mA for class A and B,
and 90 mA for class C.
This detection is internally filtered, allowing the card to draw spurious current pulses as
defined in EMVCo specification, without causing a deactivation. The average current
value must remain below the maximum.
PN746X_736X
Product data sheet
COMPANY PUBLIC
All information provided in this document is subject to legal disclaimers.
Rev. 3.1 — 5 April 2016
369231
© NXP Semiconductors N.V. 2016. All rights reserved.
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