- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄364678 > AN32502A For Information·Communication - PDA PDF資料下載
參數(shù)資料
| 型號： | AN32502A |
| 英文描述： | For Information·Communication - PDA |
| 中文描述： | 信息·通訊-掌上電腦 |
| 文件頁數(shù)： | 43/45頁 |
| 文件大?。?/td> | 574K |
| 代理商： | AN32502A |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁當(dāng)前第43頁第44頁第45頁
43
SDF00034AEB
AN32502A
Publication data: November 2002
Application Notes (continued)
8. Backup boost converter
52
51
CTL
50
OSC
(100 kHz)
-
On
Off
FBR2
SGND
to Ch.2
25
BACKUP
CTL
49
6
+
+
-
J
Q
Q
K
SET
CLR
Ch.2 feedback pin
V
REF
MOS
switch
Figure 8
1
A backup boost circuit is boost circuit of burst mode operation.
Figure 8
1 shows internal block configuration.
When the main battery voltage becomes equal to or less than 3.1 V, this circuit starts operating.
Simultaneously, the internal MOS switch between pin 50 and pin 51 becomes on and this boost circuit output is supplied to the
load circuit (memory circuit) on behalf of ch.2 regulator.
The internal oscillation circuit starts operating when pin 50 output voltage becomes below a low side detection threshold of
equal to or less than 3.1 V and it stops operation when pin 50 output voltage becomes above a high side detection threshold of
equal to or more than 3.3 V.
If a load current is constant, the output voltage goes down linearly. And when it reaches the above-stated low side detection
voltage, the oscillating circuit operates again and starts charging an output capacitor. It stops operation when output voltage is
equal to or less than 3.3 V. Then halting operation when output voltage reaches 3.3 V.
An output wave form of this circuit becomes a triangular wave variable between the thresholds of 3.1 V and 3.3 V.
For actual wave form, refer to figure 8
2 and figure 8
3.
Low and high side detection circuits are able to detect voltage by comparing pin 25 voltage with internal reference voltage.
Since pin 25 is a feedback pin for ch.2, its judging level varies according to ch.2 output voltage setting. The above-mentioned
thresholds of 3.1 V and 3.3 V are based on output setting to 3.2 V.
This circuit automatically becomes off when a backup battery voltage is equal to or less than 2.2 V, so as to prevent a backup
battery from being over-discharged.
1) On/off control
The circuit automatically operates when its main supply voltage (VB) is equal to or less than 3.1 V and its backup battery output
voltage is equal to or more than 2.2 V.
2) Power supply and GND
All circuit blocks are supplied from pin 49 (backup) and pin 6 is for GND.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| AN3294K | VCR， Other/Special/Miscellaneous |
| AN3327K | Record/Playback Amplifier for VCR |
| AN3726 | MA31750 - Use of console mode |
| AN3727 | MA31750 - Interrupt operations |
| AN3729 | MA31750 - Bus arbiter |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| AN325-8 | 制造商: 功能描述: 制造商:undefined 功能描述: |
| AN325A | 制造商:n/a 功能描述:Ships in 2 days |
| AN3-25A | 制造商:AN# - MILITARY 功能描述: |
| AN3-26 | 制造商:AN# - MILITARY 功能描述: |
| AN3266FAP | 制造商:PANASONIC 制造商全稱:Panasonic Semiconductor 功能描述:Video luminance signal recording/playback processing IC |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。