參數(shù)資料
型號(hào)： TDA8024
廠商： NXP Semiconductors N.V.
英文描述： ECONOLINE: RB & RA - Dual Output from a Single Input Rail- Power Sharing on Output- Industry Standard Pinout- 1kVDC & 2kVDC Isolation- Custom Solutions Available- UL94V-0 Package Material- Efficiency to 85%
中文描述： IC卡接口
文件頁(yè)數(shù)： 9/29頁(yè)
文件大?。?/td> 172K
代理商： TDA8024
2004 July 12
9
Philips Semiconductors
Product specification
IC card interface
TDA8024
8.2.2
W
ITH AN EXTERNAL DIVIDER ON PIN
PORADJ (
NOT
FOR THE
TDA8024AT)
If an external resistor bridge is connected to pin PORADJ
(R1 and R2 in Fig.1), then the following occurs:
The internal threshold voltage V
th2
is overridden by the
external voltage and by the hysteresis, therefore:
where V
bridge
= 1.25 V typ. and V
hys(ext)
= 60 mV typ.
The reset pulse width t
W
is doubled to approximately
16 ms.
Input PORADJ is biased internally with a pull-down current
source of 4
μ
A which is removed when the voltage on
pin PORADJ exceeds 1 V. This ensures that after
detection of the external bridge by the IC during power-on,
the input current on pin PORADJ does not cause
inaccuracy of the bridge voltage.
The minimum threshold voltage should be higher than 2 V.
The maximum threshold voltage may be up to V
DD
.
8.2.3
A
PPLICATION EXAMPLES
The voltage supervisor is used as Power-on reset and as
supply dropout detection during a card session.
Supply dropout detection is to ensure that a proper
deactivation sequence is followed before the voltage is too
low.
For the internal voltage supervisor to function, the system
microcontroller should operate down to 2.35 V to ensure a
proper deactivation sequence. If this is not possible,
external resistor values can be chosen to overcome the
problem.
8.2.3.1
Microcontroller requiring a 3.3 V
±
20% supply
For a microcontroller supplied by 3.3 V with a
±
5%
regulator and with resistors R1, R2 having a
±
1%
tolerance, the minimum supply voltage is 3.135 V.
V
PORADJ
= k
×
V
DD
, where
with S1 and S2
the actual values of nominal resistors R1 and R2.
This can be shown as
0.99
×
R1 < S1 < 1.01
×
R1 and
0.99
×
R2 < S2 < 1.01
×
R2
Transposed, this becomes
If V1 = V
th(ext)(rise)(max)
and V2 = V
th(ext)(fall)(min)
activation will always be possible if V
PORADJ
> V1
and deactivation will always be done for V
PORADJ
< V2.
Activation is always possible for
and deactivation is always possible for
.
That is V1 = 1.31 V and V2 = 1.19 V
and
Suppose R1 + R2 = 100 k
, then
2.365
= 42.3 k
and R1 = 57.7 k
.
Deactivation will be effective at
V2
×
(1 + 1.02
×
1.365) = 2.847 V in any case.
If the microcontroller continues to function down to 2.80 V,
the slew rate on V
DD
should be less than 2 V/ms to ensure
that clock CLK is correctly delivered to the card until
time t
12
(see Fig.9).
8.2.3.2
Microcontroller requiring a 3.3 V
±
10% supply
For a microcontroller supplied by a 3.3 V with a
±
1%
regulator and with resistors R1, R2 having a
±
0.1%
tolerance, the minimum supply voltage is 3.267 V.
The same calculations as in Section 8.2.3.1 conclude:
R2
Therefore
= 40.14 k
and R1 = 59.86 k
.
Deactivation will be effective at
V2
×
(1 + 1.002
×
1.491) = 2.967 V in any case.
If the microcontroller continues to function down to 2.97 V,
the slew rate on V
DD
should be less than 0.20 V/ms to
ensure that clock CLK is correctly delivered to the card
until time t
12
(see Fig.9).
V
th2(ext)(rise)
1
R2
+
V
bridge
V
-------2
+
×
=
V
th2(ext)(fall)
1
R2
R1
+
V
bridge
V
2
-------------------
–
×
=
k
+
S1
S2
-------S1
=
1
0.98
R2
×
+
1
1.01
R2
1
k
<
×
+
=
1
k
1
0.99
R2
×
+
<
1
1.02
R2
×
+
=
V
DD
k
>
V
DD
k
V2
<
R2
R1
1.31
1
–
0.98
×
1.365
=
<
R2
100 k
=
R1
3.267
1
–
0.998
×
1.491
=
<
R2
12.49
=
相關(guān)PDF資料
PDF描述
TDA8030 USB smart card reader (OTP or ROM)
TDA8030HL USB smart card reader (OTP or ROM)
TDA8031 USB smart card reader (OTP or ROM)
TDA8031HL USB smart card reader (OTP or ROM)
TDA8302 SMALL SIGNAL COMBINATION IC FOR COLOUR TV
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TDA8024AT 制造商:NXP Semiconductors 功能描述: 制造商:PHILIPS-SEMI 功能描述:
TDA8024AT/C1,112 功能描述:輸入/輸出控制器接口集成電路 IOCTRL 5V 1.5A 0.56W RoHS:否 制造商:Silicon Labs 產(chǎn)品: 輸入/輸出端數(shù)量: 工作電源電壓: 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-64 封裝:Tray
TDA8024AT/C1,118 功能描述:功率放大器 IC Card Interface 28-Pin RoHS:否 制造商:TriQuint Semiconductor 封裝 / 箱體: 工作電源電壓:28 V 電源電流:2.5 A 工作溫度范圍: 封裝:
TDA8024T 制造商:NXP Semiconductors 功能描述:
TDA8024T/C1 制造商:NXP Semiconductors 功能描述:
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*