欢迎访问ic37.com |
会员登录 免费注册
发布采购

QT60325-AS 参数 Datasheet PDF下载

QT60325-AS图片预览
型号: QT60325-AS
PDF下载: 下载PDF文件 查看货源
内容描述: 32 , 48 , 64 KEY QMatrix KEYPANEL传感器IC [32, 48, 64 KEY QMatrix KEYPANEL SENSOR ICS]
分类和应用: 传感器
文件页数/大小: 42 页 / 810 K
品牌: QUANTUM [ QUANTUM RESEARCH GROUP ]
 浏览型号QT60325-AS的Datasheet PDF文件第4页浏览型号QT60325-AS的Datasheet PDF文件第5页浏览型号QT60325-AS的Datasheet PDF文件第6页浏览型号QT60325-AS的Datasheet PDF文件第7页浏览型号QT60325-AS的Datasheet PDF文件第9页浏览型号QT60325-AS的Datasheet PDF文件第10页浏览型号QT60325-AS的Datasheet PDF文件第11页浏览型号QT60325-AS的Datasheet PDF文件第12页  
© Quantum Research Group Ltd.  
being checked be first fully recalibrated in order to allow the  
Cz and DAC offset values to alter.  
Individual keys or groups of keys can be recalibrated with a  
single command depending on the current command scope.  
The time required to recalibrate many keys is not  
multiplicative; the cal process for multiple keys runs in  
parallel.  
If a key is outside of a limit, either of bits 2 and 3 of command  
'e' will be set for that key. The error will also appear as an  
error in a bitfield reported with command 'E'.  
There is no mechanism by which keys will automatically  
recalibrate if the reference drifts past a guardband boundary.  
2.11 Boundary Error Reporting  
See also commands e, page 23; ^N, page 27  
Unlike guardband error reporting, boundary error reporting  
only works within the active ADC signal window segment in  
which the key's signal resides. Complex factoring of Cz and  
Offset are not required for these tests, and the tests do not  
require that the key be recalibrated to see the error condition.  
2.9 Adjacent Key Suppression (AKS)  
See also command ^P, page 27  
QT60xx5 devices incorporate adjacent key suppression  
(AKS- patent pending) that can be selected on a per-key  
basis. AKS permits the suppression of multiple key presses  
based on relative signal strength. This feature assists in  
solving the problem of surface moisture which can bridge a  
key touch to an adjacent key, causing multiple key presses.  
This feature is also useful for panels with tightly spaced keys,  
where a fingertip might inadvertently activate an adjacent key.  
Drift compensation can cause a key's reference level to move  
near to the border of the ADC's 8-bit signal window; this may  
make a key inoperable if the reference pegs near zero,  
depriving the signal of the ability to move further negative  
when a key is touched. Normally the reference level should  
be reasonably centered within the ADC's current range, i.e. at  
a level of about 128 decimal / 0x80 hex.  
AKS works for keys that are AKS-enabled anywhere in the  
matrix and is not restricted to physically adjacent keys; the  
device has no knowledge of which keys are actually  
physically adjacent. When enabled for a key, adjacent key  
suppression causes detections on that key to be suppressed  
if any other AKS-enabled key in the panel has a more  
negative signal deviation from its reference.  
The truth logic for reference level drift error reporting is:  
e/b2 = Reference > 191  
e/b3 = Reference < 64  
where e/b2 is command 'e' bit 2, and e/b3 is command 'e' bit  
3. If either bit is set, the key should be recalibrated using  
command 'b'. Note that guardbanding errors (Section 2.8)  
also use these same bits for error reporting, but  
guardbanding does not usually affect these bits until after a  
recalibration.  
This feature does not account for varying key gains (burst  
length) but ignores the actual negative detection threshold  
setting for the key. If AKS-enabled keys in a panel have  
different sizes, it may be necessary to reduce the gains of  
larger keys relative to smaller ones to equalize the effects of  
AKS. The signal threshold of the larger keys can be altered to  
compensate for this without causing problems with key  
suppression.  
Each Reference Boundary error will also appear as an error  
in a bitfield reported from command 'E'.  
There is no mechanism by which keys can be made to  
automatically recalibrate if the reference drifts past a window  
boundary.  
Adjacent key suppression works to augment the natural  
moisture suppression of narrow gated transfer switches  
(Section 3.13), creating a more robust sensing method.  
2.12 Device Status & Reporting  
See also commands 7, page 22; e, page 23; E, page 23;  
k, page 23, K, page 24  
2.10 Full Recalibration  
See also command b, page 28  
The device can report on the general device status or specific  
key states including touches and error conditions, depending  
on the command used.  
The devices fully recalibrate on powerup, after a hard reset, a  
soft reset or after a recalibrate bcommand using an  
algorithm that seeks out the optimal level of R2R offset and  
Cz cancellation on a per-key basis. After powerup or a reset  
the matrix is scanned key by key and appropriate calibrations device status using command 7first, as the response to this  
Usually it is most efficient to periodically request the general  
are set for each in accordance with user-defined setup  
information. Since the circuit can tolerate a very wide signal  
command is a single byte which reports back on behalf of all  
keys. 7indicates if there are any keys detecting, calibrating,  
range, it is capable of adapting to a wide mix of key sizes and or in error.  
shapes having widely varying Cx coupling capacitances.  
If command 7reports a condition requiring further  
If a false calibration occurs due to a key touch or foreign  
object on the keys during powerup, the affected key will  
recalibrate again when the object is removed depending on  
the settings of Positive Threshold and Positive Recal Delay  
(Sections 2.2 and 2.7).  
investigation, the host device can then use commands e, E,  
kor Kto provide further details of the event(s) in progress.  
This hierarchical approach provides for a concise information  
flow using minimal data transfers and low host software  
overhead.  
Full recalibration is distinct from fast-recalibration, wherein Bit 4 of command 7 reports if there is a discrepancy between  
only the Reference level is quickly adjusted. Full recalibration the eeprom and the Flash ROM backup of the eeprom in  
requires 26 burst cycles to complete whereas fast  
recalibration requires only one cycle (Section 2.5). The time  
required for recalibration is dependent on the burst spacing  
setting ^G (Section 3.8).  
case of data corruption; it is also set whenever a Setup  
parameter has changed but was not yet been copied into  
Flash. See Section 4.6. Resetting the device will force the  
eeprom changes to be copied to Flash if legitimate, or it will  
lQ  
8
www.qprox.com QT60xx5 / R1.05