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参数资料
| 型号： | FCD4A14CC |
| 元件分类： | 模拟信号调理 |
| 英文描述： | IMAGE SENSOR, CDIP20 |
| 封装： | CERAMIC, DIP-20 |
| 文件页数： | 4/18页 |
| 文件大小： | 426K |
| 代理商： | FCD4A14CC |
FCD4A14
PRELIMINARY SPECIFICATION
12/18
TEMPERATURE MANAGEMENT
Each pixel of the FingerChip is a temperature sensor that
detects temperature changes. This change is generated by
the temperature difference between the finger and the chip.
The best case happens when there is a large temperature
difference, for instance when the chip temperature is very low
or very high: this is a rather unusual case. The worst case
happens when the finger temperature is exactly the same as
the chip temperature.
In order to get a contrasted image, we need at least one
degree difference between the sensor and the finger. Critical
temperature is in the range of 33
°C (±5 as finger temperature
may
vary).
Chip
temperature
stabilization
circuitry
is
implemented on the FCD4A14 to stabilize the sensor image
quality when needed.
Several strategies may be used depending on external
constraints:
First, read the sensor temperature. Most of the time, it
will be out of the critical area (near 33
°C), so no
stabilization is required.
If power is not a critical resource, and if the sensor
temperature is typically close to the critical area, the user
may always stabilize the temperature above the usual
finger temperature (>37
°C). Note that this stabilization
may take one minute or more, depending on the
surroundings, thermal resistance and the chip’s initial
temperature.
If power is a critical resource, the best solution is to have
a first trial with the finger without stabilization as most of
the time the temperature difference will be high enough.
If authentication fails and we detect a chip temperature
that is in the critical area, simply enable the stabilization
feature and try again. It may take a few seconds, as we
just need to stabilize a few degrees above the measured
temperature.
Two separate features are available in the FCD4A14:
1.
An absolute temperature sensor. Information is digitally
provided in the dummy bytes DB3 and DB4.
2.
Temperature stabilization circuitry, with two pins, TPP
and TPE.
The stabilization feedback is externally managed: an external
processor or algorithm will decide whether or not this feature
is enabled. In this way, the user has full control over power
consumption.
TPP is the pin that delivers power, and must be externally
connected to the power supply through a resistor to limit the
maximum current and avoid reaching extreme temperatures.
Value of the resistor depends on external conditions such as
voltage, environmental use, thermal isolation…
TPE controls the injected power: when the temperature is
below the desired temperature, TPE must be set to high, and
when the temperature is reached, TPE must be set to low.
This is a digital input: no power is required to drive this pin, so
any processor output or bus may drive it.
Please contact TCS for more information and assistance in
your specific application.
Temperature information is digitally provided on DB3 & DB4.
Data format, values and a program to manage to manage the
temperature stabilization circuitry will be available once
characterization of the chip is complete.
POWER MANAGEMENT
Nap mode
Several strategies are possible to reduce power consumption
when not in use.
The simplest and most efficient is to cut the power supply,
using external means.
A nap mode is also implemented in the FCD4A14. To activate
this nap mode, user must:
1.
Set the reset RST pin to high. Doing this, all analog
sections of the device are internally powered down.
2.
Set the clock PCLK pin to high (or low), thus stopping the
entire digital section.
3.
Set the TPE pin to low or disconnect TPP to stop the
temperature stabilization feature.
4.
Set Output Enable OE pin to high, so current can be
drained through the outputs.
Nap
Nap mode
Clock PCLK
Reset RST
相关PDF资料 |
PDF描述 |
|---|---|
| FCD4A14CC | IMAGE SENSOR, CDIP20 |
| FCD4A14CCB | IMAGE SENSOR |
| FCP-101 | 2-OUTPUT 9.6 W AC-DC REG PWR SUPPLY MODULE |
| FCP-031 | 2-OUTPUT 2.9 W AC-DC REG PWR SUPPLY MODULE |
| FCP-032 | 2-OUTPUT 3 W AC-DC REG PWR SUPPLY MODULE |
相关代理商/技术参数 |
参数描述 |
|---|---|
| FCD4B14 | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:Thermal Fingerprint Sensor with 0.4 mm x 14 mm Sensing Area and Digital Output |
| FCD4B14CC | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:Thermal Fingerprint Sensor with 0.4 mm x 14 mm Sensing Area and Digital Output |
| FCD4B14CCB | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:Thermal Fingerprint Sensor with 0.4 mm x 14 mm Sensing Area and Digital Output |
| FCD4C1690 | 制造商:n/a 功能描述:Power Semiconductor |
| FCD4N60 | 制造商:FAIRCHILD 制造商全称:Fairchild Semiconductor 功能描述:600V N-Channel MOSFET |
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