TDA8034T(2010) 查看數據表（PDF） - NXP Semiconductors.

零件编号

产品描述 (功能)

生产厂家

TDA8034T
(Rev.:2010)

Smart card interface

NXP Semiconductors. 

NXP Semiconductors

TDA8034T; TDA8034AT

Smart card interface

• In card sessions, pin CMDVCCN is LOW: when pin OFFN goes LOW, the fault

detection circuit triggers the automatic emergency deactivation sequence (see

Figure 8). When the microcontroller resets pin CMDVCCN to HIGH, after the

deactivation sequence, pin OFFN is rechecked. If the card is still present, pin OFFN

returns to HIGH. This check identifies the fault as either a hardware problem or a card

removal incident.

On card insertion or removal, bouncing can occur in the PRESN signal. This depends on

the type of card presence switch in the connector (normally open or normally closed) and

the mechanical characteristics of the switch. To correct for this, a debouncing feature is

integrated in to the TDA8034T/TDA8034AT. This feature operates at a typical duration of

4.5 ms (tdeb = 640 × (1∨fosc(int)low). Figure 9 on page 12 shows the operation of the

debouncing feature.

On card insertion, pin OFFN goes HIGH after the debounce time has elapsed. When the

card is extracted, the automatic card deactivation sequence is performed on the first

HIGH/LOW transition on pin PRESN. After this, pin OFFN goes LOW.

OFFN

PRESN

RST

CLK

I/O

VCC

XTAL

OSCINT

high frequency

t10

t12

t13

t14

tdeact

low frequency

Fig 8. Emergency deactivation sequence after card removal

001aai971

TDA8034T_TDA8034AT

Product data sheet

All information provided in this document is subject to legal disclaimers.

Rev. 2.0. — 12 November 2010

© NXP B.V. 2010. All rights reserved.

11 of 29

Share Link: