- 您现在的位置：买卖IC网 > PDF目录378741 > UPD65804-QFP100P.7X.9 ASIC PDF资料下载
参数资料
| 型号： | UPD65804-QFP100P.7X.9 |
| 英文描述： | ASIC |
| 中文描述： | 专用集成电路 |
| 文件页数： | 28/64页 |
| 文件大小： | 399K |
| 代理商： | UPD65804-QFP100P.7X.9 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页当前第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页
28
μ
PD64A, 65
Data Sheet U14380EJ2V0DS00
7.1 Functions of POC Circuit
The POC circuit has the following functions:
Generates an internal reset signal when V
DD
≤
V
POC
.
Cancels an internal reset signal when V
DD
> V
POC
.
Here, V
DD
: power supply voltage, V
POC
: POC-detected voltage.
Notes 1.
In reality, there is the oscillation stabilization wait time until the circuit is switched to OPERATING
mode. The oscillation stabilization wait time is about 252/f
X
to 700/f
X
(when about 70 to 190
μ
s; f
X
= 3.64 MHz).
2.
For the POC circuit to generate an internal reset signal when the power supply voltage has fallen,
it is necessary for the power supply voltage to be kept less than the V
POC
for the period of 1 ms or
more. Therefore, in reality, there is the time lag of up to 1 ms until the reset takes effect.
3.
The POC-detected voltage (V
POC
) varies between approximately 1.7 to 2.0 V; thus, the resetting may
be canceled at a power supply voltage smaller than the assured range (V
DD
= 2.0 to 3.6 V). However,
as long as the conditions for operating the POC circuit are met, the actual lowest operating power
supply voltage becomes lower than the POC-detected voltage. Therefore, there is no malfunction
occurring due to the shortage of power supply voltage. However, malfunction for such reasons as
the clock not oscillating due to low power supply voltage may occur (refer to
Cautions 3
. in
7. POC
CIRCUIT
).
7.2 Oscillation Check at Low Supply Voltage
A reliable resetting operation can be expected of the POC circuit if it satisfies the condition that the clock can
oscillate even at low power supply voltage (the oscillation start voltage of the resonator being even lower than the
POC-detected voltage). Whether this condition is being met or not can be checked by measuring the oscillation
status on a product which actually contains a POC circuit, as follows.
<1> Connect a storage oscilloscope to the X
OUT
pin so that the oscillation status can be measured.
<2> Connect a power supply whose output voltage can be varied and then gradually raise the power supply
voltage V
DD
from 0 V (making sure to avoid V
DD
> 3.6V).
At first (during V
DD
< approx. 1.7 V), the X
OUT
pin is 0 V regardless of the V
DD
. However, at the point that V
DD
reaches the POC-detected voltage (V
POC
= 1.85 V (TYP.)), the voltage of the X
OUT
pin jumps to about 0.5 V
DD
.
Maintain this power supply voltage for a while to measure the waveform of the X
OUT
pin. If, by any chance, the
oscillation start voltage of the resonator is lower than the POC-detected voltage, the growing oscillation of the X
OUT
pin can be confirmed within several ms after the V
DD
has reached the V
POC
.
V
DD
3.6 V
2.0 V
V
POC
Approx. 1.7 V
0 V
Internal reset signal
Reset
Operating ambient temperature T
A
= – 40 to + 85
°
C
Clock frequency f
X
= 2.4 to 8 MHz
←
POC-detected voltage V
POC
= 1.85 V (TYP.)
Note 3
→
t
OPERATING mode
↑
Reset
Note 2
↑
Note 1
相关PDF资料 |
PDF描述 |
|---|---|
| UPD65804-QFP120P.63SQ | ASIC |
| UPD65804-QFP120P1.2SQ | ASIC |
| UPD65804-QFP160P1.2SQ | ASIC |
| UPD65806 | ASIC |
| UPD65806-QFP100P.63SQ | ASIC |
相关代理商/技术参数 |
参数描述 |
|---|---|
| UPD65804-QFP120P.63SQ | 制造商:未知厂家 制造商全称:未知厂家 功能描述:ASIC |
| UPD65804-QFP120P1.2SQ | 制造商:未知厂家 制造商全称:未知厂家 功能描述:ASIC |
| UPD65804-QFP160P1.2SQ | 制造商:未知厂家 制造商全称:未知厂家 功能描述:ASIC |
| UPD65806 | 制造商:未知厂家 制造商全称:未知厂家 功能描述:ASIC |
| UPD65806-QFP100P.63SQ | 制造商:未知厂家 制造商全称:未知厂家 功能描述:ASIC |
发布紧急采购，3分钟左右您将得到回复。