TDA8029 Datasheet, PDF (42/59 Pages) NXP Semiconductors – Low power single card reader

Philips Semiconductors
TDA8029
Low power single card reader
There are several possible situations:
• V_DCIN = 3 V and V_CC = 3 V: In this case the DC-to-DC converter is acting as a doubler
with a regulation of about 4.0 V
• V_DCIN = 3 V and V_CC = 5 V: In this case the DC-to-DC converter is acting as a tripler
with a regulation of about 5.5 V
• V_DCIN = 5 V and V_CC = 3 V: In this case, the DC-to-DC converter is acting as a
follower, V_DD is applied on VUP
• V_DCIN = 5 V and V_CC = 5 V. In this case, the DC-to-DC converter is acting as a doubler
with a regulation of about 5.5 V
• V_CC = 1.8 V. In this case, whatever value of V_DCIN, the DC-to-DC converter is acting
as a follower, V_DD is applied on VUP.
The switch between different modes of the DC-to-DC converter is done by the TDA8029 at
about V_DCIN = 3.5 V.
The output voltage is fed to the V_CC generator. V_CC and GNDC are used as a reference for
all other card contacts.
8.13 ISO 7816 security
The correct sequence during activation and deactivation of the card is ensured through a
specific sequencer, clocked by a division ratio of the internal oscillator.
Activation (bit START = 1 in register PCR) is only possible if the card is present (pin PRES
is HIGH) and if the supply voltage is correct (supervisor not active).
Pin PRES is internally biased with a current source of 45 µA typical to ground when the
pin is open (No card present). When pin PRES becomes HIGH, via the detection switch
connected to V_DD, this internal bias current is reduced to 2.5 µA to ground. This feature
allows direct connection of the detect switch to V_DD without a pull-down resistor.
The presence of the card is signalled to the controller by the HSR.
Bit PR1 in register MSR is set if the card is present. Bit PRL1 in register HSR is set if PR1
has toggled.
During a session, the sequencer performs an automatic emergency deactivation on the
card in the event of card take-off, short-circuit, supply dropout or overheating. The card is
also automatically deactivated in case of supply voltage drop or overheating. The HSR
register is updated and the INT0_N line falls down, so the system controller is aware of
what happened.
8.14 Protections and limitations
The TDA8029 features the following protections and limitations:
• I_CC limited to 100 mA, and deactivation when this limit is reached
• Current to or from pin RST limited to 20 mA, and deactivation when this limit is
reached
• Deactivation when the temperature of the die exceeds 150 °C
• Current to or from pin I/O limited to 10 mA
9397 750 14145
Product data sheet
Rev. 03 — 22 February 2005
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
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