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參數資料
| 型號： | MC33342 |
| 廠商： | ON SEMICONDUCTOR |
| 英文描述： | BATTERY FAST CHARGE CONTROLLERS |
| 中文描述： | 電池快速充電控制器 |
| 文件頁數： | 5/12頁 |
| 文件大?。?/td> | 304K |
| 代理商： | MC33342 |
MC33340 MC33342
5
MOTOROLA ANALOG IC DEVICE DATA
dV
–
V
Figure 8. Typical Charge Characteristics for NiCd and NiMh Batteries
1.6
CHARGE INPUT PERCENT OF CAPACITY
1.5
1.4
1.3
1.2
1.0
0
40
80
120
160
Relative Pressure
1.1
70
60
50
40
30
20
10
C
°
C
Temperature
Voltage
Tmax
Vmax
dt
OPERATING DESCRIPTION
The MC33340/342 starts up in the fast charge mode when
power is applied to VCC. A change to the trickle mode can
occur as a result of three possible conditions. The first is if the
Vsen input voltage is above 2.0 V or below 1.0 V. Above 2.0 V
indicates that the battery pack is open or disconnected, while
below 1.0 V indicates the possibility of a shorted or defective
cell. The second condition is when the MC33340/342 detects
a fully charged battery by measuring a negative slope in
battery voltage. The MC33340/342 recognize a negative
voltage slope after the preset holdoff time (thold) has elapsed
during a fast charge cycle. This indicates that the battery
pack is fully charged. The third condition is either due to the
battery pack being out of a programmed temperature range,
or that the preset timer period has been exceeded.
There are three conditions that will cause the controller to
return from trickle to fast charge mode. The first is if the Vsen
input voltage moved to within the 1.0 to 2.0 V range from
initially being either too high or too low. The second is if the
battery pack temperature moved to within the programmed
temperature range, but only from initially being too cold. Third
is by cycling VCC off and then back on causing the internal
logic to reset. A concise description of the major circuit blocks
is given below.
Negative Slope Voltage Detection
A representative block diagram of the negative slope
voltage detector is shown in Figure 9. It includes a
Synchronous Voltage to Frequency Converter, a Sample
Timer, and a Ratchet Counter. The Vsen pin is the input for the
Voltage to Frequency Converter (VFC), and it connects to the
rechargeable battery pack terminals through a resistive
voltage divider. The input has an impedance of
approximately 6.0 M
and a maximum voltage range of
–1.0 V to VCC + 0.6 V or 0 V to 10 V, whichever is lower. The
10 V upper limit is set by an internal zener clamp that
provides protection in the event of an electrostatic discharge.
The VFC is a charge–balanced synchronous type which
generates output pulses at a rate of FV = Vsen (24 kHz).
The Sample Timer circuit provides a 95 kHz system clock
signal (SCK) to the VFC. This signal synchronizes the FV
output to the other Sample Timer outputs used within the
detector. At 1.38 second intervals the Vsen Gate output goes
low for a 33 ms period. This output is used to momentarily
interrupt the external charging power source so that a precise
voltage measurement can be taken. As the Vsen Gate goes
low, the internal Preset control line is driven high for 11 ms.
During this time, the battery voltage at the Vsen input is
allowed to stabilize and the previous FV count is preloaded.
At the Preset high–to–low transition, the Convert line goes
high for 22 ms. This gates the FV pulses into the ratchet
counter for a comparison to the preloaded count. Since the
Convert time is derived from the same clock that controls the
VFC, the number of FV pulses is independent of the clock
frequency. If the new sample has more counts than were
preloaded, it becomes the new peak count and the cycle is
repeated 1.38 seconds later. If the new sample has two fewer
counts, a less than peak voltage event has occurred, and a
register is initialized. If two successive less than peak voltage
events occur, the –
V ‘AND’ gate output goes high and the
Fast/Trickle output is latched in a low state, signifying that the
battery pack has reached full charge status.
Negative slope voltage detection starts after 60 ms have
elapsed in the fast charge mode. This does not affect the
Fast/Trickle output until the holdoff time (thold) has elapsed
during the fast charge mode. Two scenarios then exist.
Trickle mode holdoff is implemented to ignore any initial drop
in voltage that may occur when charging batteries that have
been stored for an extended time period. If the negative slope
voltage detector senses that initial drop during the holdoff
time, and the input voltage rises as the battery charges, the
Fast/Trickle output will remain open. However, if the negative
slope voltage detector senses a negative drop in voltage
during the holdoff time and the input voltage never rises
above that last detected level, the Fast/Trickle output will
latch into a low state. The negative slope voltage detector
has a maximum resolution of 2.0 V divided by 1023, or 1.955
mV per count with an uncertainty of
±
1.0 count. This yields a
detection range of 1.955 mV to 5.865 mV. In order to obtain
maximum sensing accuracy, the R2/R1 voltage divider must
be adjusted so that the Vsen input voltage is slightly less than
2.0 V when the battery pack is fully charged. Voltage
variations due to temperature and cell manufacturing must
be considered.
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| MC33364DR2 | Critical Conduction GreenLine SMPS Controller |
| MC33364D1R2 | Critical Conduction GreenLine SMPS Controller |
| MC33364D1 | 50mA Switched-Cap DC/DC Converter 8-MSOP |
| MC33364D2 | 50mA Switched-Cap DC/DC Converter 8-MSOP |
| MC33364D | 50mA Switched-Cap DC/DC Converter 8-MSOP |
相關代理商/技術參數 |
參數描述 |
|---|---|
| MC33342D | 功能描述:電池管理 18V Max NiCD/NiMH RoHS:否 制造商:Texas Instruments 電池類型:Li-Ion 輸出電壓:5 V 輸出電流:4.5 A 工作電源電壓:3.9 V to 17 V 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:VQFN-24 封裝:Reel |
| MC33342DG | 功能描述:電池管理 18V Max NiCD/NiMH Fast Charge RoHS:否 制造商:Texas Instruments 電池類型:Li-Ion 輸出電壓:5 V 輸出電流:4.5 A 工作電源電壓:3.9 V to 17 V 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:VQFN-24 封裝:Reel |
| MC33342DR2 | 功能描述:電池管理 18V Max NiCD/NiMH RoHS:否 制造商:Texas Instruments 電池類型:Li-Ion 輸出電壓:5 V 輸出電流:4.5 A 工作電源電壓:3.9 V to 17 V 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:VQFN-24 封裝:Reel |
| MC33342DR2G | 功能描述:電池管理 18V Max NiCD/NiMH Fast Charge RoHS:否 制造商:Texas Instruments 電池類型:Li-Ion 輸出電壓:5 V 輸出電流:4.5 A 工作電源電壓:3.9 V to 17 V 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:VQFN-24 封裝:Reel |
| MC33342P | 功能描述:電池管理 18V Max NiCD/NiMH RoHS:否 制造商:Texas Instruments 電池類型:Li-Ion 輸出電壓:5 V 輸出電流:4.5 A 工作電源電壓:3.9 V to 17 V 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:VQFN-24 封裝:Reel |
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