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参数资料
| 型号： | DS8023-RJX+T&R |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 3/17页 |
| 文件大小： | 0K |
| 描述： | IC INTERFACE SMART CARD 28-TSSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 应用： | 智能卡 |
| 接口： | 模拟 |
| 电源电压： | 2.7 V ~ 6 V |
| 封装/外壳： | 28-TSSOP（0.173"，4.40mm 宽） |
| 供应商设备封装： | 28-TSSOP |
| 包装： | 带卷 (TR) |
| 安装类型： | 表面贴装 |
| 配用： | DS8023-KIT-ND - EVALUATION KIT FOR DS8023 |
DS8023
Smart Card Interface
11
Maxim Integrated
Deactivation Sequence
When the host microcontroller is done communicating
with the smart card, it sets the CMDVCC line high to
execute an automatic deactivation sequence and
returns the card interface to the inactive mode.
The following sequence of events occurs during a
deactivation sequence (Figure 5):
1) RST goes low (t10).
2) CLK is held low (t12 = t10 + 0.5
× T), where T is 64
times the period of the internal oscillator (approxi-
mately 25s).
3) I/O, AUX1, and AUX2 are pulled low (t13 = t10 + T).
4) VCC starts to fall (t14 = t10 + 3T).
5) When VCC reaches its inactive state, the deactiva-
tion sequence is complete (at tDE).
6) All card contacts become low impedance to GND;
I/OIN, AUX1IN, and AUX2IN remain at VDD (pulled
up through an internal 11k
Ω resistor).
7) The internal oscillator returns to its lower frequency.
VCC Generator
The card voltage (VCC) generator can supply up to
80mA continuously at 5V, 65mA at 3V, or 30mA at 1.8V.
An internal overload detector triggers at approximately
120mA. Current samples to the detector are filtered.
This allows spurious current pulses (with a duration of a
few s) up to 200mA to be drawn without causing
deactivation. The average current must stay below the
specified maximum current value.
See the
Applications Information section for recommen-
dations to help maintain VCC voltage accuracy.
Fault Detection
The DS8023 integrates circuitry to monitor the following
fault conditions:
Short circuit or high current on VCC
Card removal while the interface is activated
VDD dropping below threshold
Card voltage generator operating out of the speci-
fied values (VDDA too low or current consumption
too high)
Overheating
There are two different cases for how the DS8023
reacts to fault detection (Figure 6):
Outside a Card Session (CMDVCC High). Output
OFF is low if a card is not in the card reader and
high if a card is in the reader. The VDD supply is
monitored—a decrease in input voltage generates
an internal power-on reset pulse but does not
affect the OFF signal. Short-circuit and tempera-
ture detection are disabled because the card is
not powered up.
Within a Card Session (CMDVCC Low). Output
OFF goes low when a fault condition is detected,
and an emergency deactivation is performed auto-
matically (Figure 7). When the system controller
resets CMDVCC to high, it may sense the OFF
level again after completing the deactivation
sequence. This distinguishes between a card
extraction and a hardware problem (OFF goes high
again if a card is present).
Depending on the connector’s card-present switch
(normally closed or normally open) and the mechanical
characteristics of the switch, bouncing can occur on
the PRES signals at card insertion or withdrawal. The
DS8023 has a debounce feature with an 8ms typical
duration (Figure 6). When a card is inserted, output
OFF goes high after the debounce time delay. When
the card is extracted, an automatic deactivation
sequence of the card is performed on the first true/false
transition on PRES and output OFF goes low.
Stop Mode (Low-Power Mode)
A low-power state, stop mode, can be entered by forc-
ing the CMDVCC, 5V/3V, and 1_8V input pins to a
logic-high state. Stop mode can only be entered when
the smart card interface is inactive. In stop mode all
internal analog circuits are disabled. The OFF pin fol-
lows the status of the PRES pin. To exit stop mode,
change the state of one or more of the three control
pins to a logic-low. An internal 220s (typ) power-up
delay and the 8ms PRES debounce delay are in effect
and OFF is asserted to allow the internal circuitry to sta-
bilize. This prevents smart card access from occurring
after leaving the stop mode. Figure 8 shows the control
sequence for entering and exiting stop mode. Note that
an in-progress deactivation sequence always finishes
before the DS8023 enters low-power stop mode.
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相关代理商/技术参数 |
参数描述 |
|---|---|
| DS8023-RRX+ | 功能描述:接口 - 专用 Smart Card Interface RoHS:否 制造商:Texas Instruments 产品类型:1080p60 Image Sensor Receiver 工作电源电压:1.8 V 电源电流:89 mA 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:BGA-59 |
| DS8023-RRX+T&R | 制造商:Maxim Integrated Products 功能描述:DS8023 SMART CARD INT 28 SOIC T&R - Tape and Reel 制造商:Maxim Integrated Products 功能描述:IC INTERFACE SMART CARD 28-SOIC |
| DS8023-RRX+T&R | 功能描述:接口 - 专用 Smart Card Interface RoHS:否 制造商:Texas Instruments 产品类型:1080p60 Image Sensor Receiver 工作电源电压:1.8 V 电源电流:89 mA 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:BGA-59 |
| DS8024 | 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:智能卡接口 |
| DS8024_V3 | 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:Smart Card Interface |
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