應用(yong)(yong)比較(jiao)廣泛(fan)快速(su)充電管(guan)理芯片(pian)基本上有(you)兩種類型。一種是單片(pian)機，另一種是快速(su)充電管(guan)理專用(yong)(yong)集(ji)成(cheng)電路。成(cheng)都國騰微電子有(you)限公司成(cheng)功開發出一款鎳(nie)氫/鎳(nie)鎘電池快速(su)充電智能(neng)管(guan)理芯片(pian)――GM6801。該芯片(pian)外部(bu)管(guan)腳控制功能(neng)可(ke)編程，無需外部(bu)控制器支持，使充電過程檢測控制完全自動化，所(suo)需外圍器件少，應用(yong)(yong)設計簡單。

GM6801應用方案優勢

   GM6801是快(kuai)(kuai)速(su)充電(dian)管理(li)專用(yong)集(ji)成電(dian)路。與單片機相比，由專用(yong)集(ji)成電(dian)路實(shi)現快(kuai)(kuai)速(su)充電(dian)管理(li)優勢主(zhu)要體現在幾個方(fang)面：

1. 專用集(ji)成電(dian)路在(zai)硬件(jian)中(zhong)集(ji)成了對(dui)快速(su)充(chong)電(dian)管理全部(bu)算法(fa)，無需開(kai)發控制軟件(jian)，從(cong)而有效縮短(duan)產(chan)品設(she)計周期，簡化設(she)計流程，所需外(wai)圍器(qi)件(jian)少，使應(ying)用設(she)計變得(de)簡單(dan)；

2. 采用單片機實現中高端快速充電器時，對單片機有(you)較(jiao)高要(yao)求(qiu)，比如(ru)需要(yao)較(jiao)多I/O口，需要(yao)自(zi)帶(dai)AD等，還要(yao)開發相關軟(ruan)件，這(zhe)樣(yang)采用單片機所需成本往往較(jiao)高；

3. 專用集成電(dian)路可以實現(xian)對快速(su)充電(dian)過(guo)程(cheng)精確控制，比(bi)如(ru)GM6801就采用了(le)帶瞬間(jian)放電(dian)過(guo)程(cheng)脈沖充電(dian)形式。這樣可以在快速(su)充電(dian)過(guo)程(cheng)中及時(shi)消除大電(dian)流造成電(dian)極(ji)化(hua)效應，使電(dian)池充電(dian)效果更佳(jia)；

4. 由于快速充電器涉及安全(quan)問題，專用集(ji)成電路(lu)良好一(yi)致(zhi)性和(he)穩定性相對普(pu)通單片機來說(shuo)更具優勢(shi)。

   此外，GM6801本身采(cai)用一(yi)些個(ge)性化(hua)設計：GM6801內置10位AD轉換器(qi)，可以(yi)實時(shi)(shi)采(cai)集每節(jie)電(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)和溫(wen)度(du)信息，自帶“Condition fit”功能(neng)能(neng)夠避(bi)免環境變化(hua)帶來(lai)干擾，保證對快速充電(dian)(dian)(dian)(dian)(dian)(dian)/放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)過(guo)(guo)程檢(jian)(jian)測判斷準確(que)(que)可靠(kao)。GM6801對每節(jie)電(dian)(dian)(dian)(dian)(dian)(dian)池充電(dian)(dian)(dian)(dian)(dian)(dian)/放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)過(guo)(guo)程檢(jian)(jian)測判斷方法有(you)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)負增長(-ΔV)、最大(da)(da)(da)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)、最大(da)(da)(da)充電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)間、最高溫(wen)度(du)四種方式，通過(guo)(guo)多參數(shu)評(ping)估來(lai)進行綜合判斷，以(yi)確(que)(que)保電(dian)(dian)(dian)(dian)(dian)(dian)池被最大(da)(da)(da)化(hua)充滿，同時(shi)(shi)避(bi)免過(guo)(guo)充，從而(er)延長電(dian)(dian)(dian)(dian)(dian)(dian)池使(shi)用壽(shou)命。

   GM6801自(zi)動(dong)判(pan)斷電(dian)(dian)池有效性、自(zi)動(dong)識別電(dian)(dian)池種(zhong)類，具備超溫保(bao)護(hu)和(he)最大充電(dian)(dian)時間保(bao)護(hu)，保(bao)證了充電(dian)(dian)過(guo)程安(an)全性。更完善功能(neng)包括：可直(zhi)接驅動(dong)4個雙色LED顯(xian)示(shi)各個電(dian)(dian)池狀態；可對充電(dian)(dian)/放電(dian)(dian)狀態進(jin)行(xing)聲音(yin)提示(shi)；在高溫情況下可以自(zi)動(dong)啟動(dong)風扇；具備充電(dian)(dian)/放電(dian)(dian)狀態數據輸出功能(neng)，可直(zhi)觀顯(xian)示(shi)各個電(dian)(dian)池電(dian)(dian)量。

GM6801解決方案(an)設(she)計

   GM6801應(ying)用(yong)方案如圖(tu)1所示，設計(ji)第(di)一步需要(yao)確定(ding)智能快速(su)充(chong)(chong)電(dian)器電(dian)源電(dian)流。根(gen)據充(chong)(chong)電(dian)電(dian)池容量(liang)以(yi)及想要(yao)達到(dao)充(chong)(chong)電(dian)速(su)度，可以(yi)計(ji)算(suan)出(chu)快速(su)充(chong)(chong)電(dian)器電(dian)源電(dian)流值。

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圖1：GM6801應用方案示意圖

   例如，設計一個針對2,000mAh充電電池充電器，若需要把充滿兩節電池最大時間控制在90分鐘以內，那么根據GM6801數據手冊中相關參數可以確定充電時間為1C，由此確定平均充電電流I_C=2,000mA。放電電流I_dischg由放電回路電阻值確定，假定放電電流I_DISCHG≈1,000mA，再(zai)根據GM6801數據手冊(ce)中計算公式(shi)可以推(tui)算出充電器(qi)電源實際(ji)電流值為：

I_CHG＝(I_C I_DISCHG/32)×(64/31)＝(2,000mA 1,000mA/32)×(64/31)≈4,200mA。

   即設計充(chong)電器時，充(chong)電器電源(yuan)電流值應該設計成等于(yu)或略大(da)于(yu)4,200mA。另外需要(yao)強(qiang)調是，選擇熱敏電阻非(fei)常重要(yao)。

   熱(re)(re)敏(min)電(dian)(dian)(dian)(dian)(dian)阻(zu)是GM6801應用(yong)系統(tong)中采集溫度關鍵元(yuan)件。在GM6801應用(yong)電(dian)(dian)(dian)(dian)(dian)路(lu)中，熱(re)(re)敏(min)電(dian)(dian)(dian)(dian)(dian)阻(zu)必須直接(jie)(jie)或通過導熱(re)(re)材料與(yu)被測電(dian)(dian)(dian)(dian)(dian)池緊密接(jie)(jie)觸。熱(re)(re)敏(min)電(dian)(dian)(dian)(dian)(dian)阻(zu)B值=3,300K，熱(re)(re)敏(min)電(dian)(dian)(dian)(dian)(dian)阻(zu)電(dian)(dian)(dian)(dian)(dian)阻(zu)值根據(ju)應用(yong)電(dian)(dian)(dian)(dian)(dian)路(lu)確定，按照GM6801數據(ju)手(shou)冊中提供應用(yong)電(dian)(dian)(dian)(dian)(dian)路(lu)(如(ru)圖2所(suo)示)，熱(re)(re)敏(min)電(dian)(dian)(dian)(dian)(dian)阻(zu)(RT)與(yu)一個電(dian)(dian)(dian)(dian)(dian)阻(zu)(R)串聯，電(dian)(dian)(dian)(dian)(dian)阻(zu)另一端連接(jie)(jie) 5V電(dian)(dian)(dian)(dian)(dian)源(yuan)(Vi)，熱(re)(re)敏(min)電(dian)(dian)(dian)(dian)(dian)阻(zu)另一端接(jie)(jie)地，熱(re)(re)敏(min)電(dian)(dian)(dian)(dian)(dian)阻(zu)與(yu)電(dian)(dian)(dian)(dian)(dian)阻(zu)連接(jie)(jie)點引(yin)出反(fan)應溫度變(bian)化(hua)電(dian)(dian)(dian)(dian)(dian)壓(ya)采樣信息(Vt)。

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圖2：GM6801應用方案中熱敏電阻應用電路示意圖

   要求在不同溫(wen)度(du)點采集(ji)到(dao)電(dian)壓Vt值與GM6801數(shu)據手冊中(zhong)(zhong)提供(gong)數(shu)據基本一(yi)致，這(zhe)樣(yang)才能保證由該熱敏電(dian)阻網絡采集(ji)到(dao)電(dian)池溫(wen)度(du)信息與設(she)計中(zhong)(zhong)溫(wen)度(du)刻度(du)一(yi)致。推薦RT和R標稱值都采用(yong)27kΩ(25℃時)。

   接下(xia)來(lai)，需要完成一些控制引(yin)腳和輸(shu)入輸(shu)出引(yin)腳設定。

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圖3：GM6801控制部分應用電路圖

   如圖3所示，在GM6801應用電路中，鎳氫/鎳鎘電池選擇引腳(NH/ND)與一個外部開關連接，通過開關選擇該引腳接高電平或低電平來決定充電電池類型，低電平為鎳氫，高電平為鎳鎘，當該引腳狀態改變時，同時具有復位功能；充電/放電選擇引腳(CHG/DISCHG)與一個外部開關連接，通過開關選擇該引腳接高電平或低電平來決定充電或放電，低電平為充電，高電平為放電；充電時間選擇引腳(CHGTIME0/CHGTIME1)分別與外部電路連接，通過設定該引腳接高電平或低電平，由CHGTIME0/CHGTIME1兩個引腳狀態決定充電時間(即C值)。 
  

   GM6801系列QFP44封裝芯片采用(yong)四路(lu)充電(dian)(dian)/放(fang)(fang)電(dian)(dian)回路(lu)獨立(li)控制(zhi)，可對最多4節不同型號、容(rong)量接近(jin)鎳氫/鎳鎘電(dian)(dian)池任意組合進行并聯(lian)充電(dian)(dian)/放(fang)(fang)電(dian)(dian)管理。如(ru)圖4所(suo)示，在應(ying)用(yong)于四路(lu)并聯(lian)充電(dian)(dian)/放(fang)(fang)電(dian)(dian)控制(zhi)方式時，GM6801VCC和Vref通常接 5V，其(qi)中(zhong)Vref要(yao)求(qiu)加10uF旁(pang)路(lu)電(dian)(dian)容(rong)增加穩定性。工作時鐘(zhong)選用(yong)32.768kHz無(wu)源晶振。

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圖4：GM6801應用于四路并聯充電/放電管理方案輸入輸出部分電路圖

   GM6801分(fen)(fen)別(bie)提(ti)供充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)控(kong)(kong)制(zhi)(zhi)輸(shu)(shu)出(chu)、放(fang)電(dian)(dian)(dian)(dian)(dian)控(kong)(kong)制(zhi)(zhi)輸(shu)(shu)出(chu)、電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓采(cai)集(ji)(ji)輸(shu)(shu)入(ru)(ru)、風扇(shan)驅動輸(shu)(shu)出(chu)、蜂鳴(ming)器輸(shu)(shu)出(chu)、雙色(se)LED控(kong)(kong)制(zhi)(zhi)輸(shu)(shu)出(chu)以及串行(xing)數(shu)據(ju)輸(shu)(shu)出(chu)，這些功(gong)能(neng)管腳定(ding)(ding)(ding)義(yi)和功(gong)能(neng)分(fen)(fen)別(bie)為(wei)：充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)控(kong)(kong)制(zhi)(zhi)輸(shu)(shu)出(chu)(CHGCTRL1~4)高(gao)(gao)(gao)電(dian)(dian)(dian)(dian)(dian)平(ping)有(you)(you)效(xiao)，控(kong)(kong)制(zhi)(zhi)對應(ying)(ying)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)回路(lu)開(kai)(kai)關打開(kai)(kai)或關閉(bi)；放(fang)電(dian)(dian)(dian)(dian)(dian)控(kong)(kong)制(zhi)(zhi)輸(shu)(shu)出(chu)(DISCHG1~4)低電(dian)(dian)(dian)(dian)(dian)平(ping)有(you)(you)效(xiao)，控(kong)(kong)制(zhi)(zhi)對應(ying)(ying)放(fang)電(dian)(dian)(dian)(dian)(dian)回路(lu)開(kai)(kai)關打開(kai)(kai)或關閉(bi)；電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓采(cai)集(ji)(ji)輸(shu)(shu)入(ru)(ru)口(CELVOLT1~4)分(fen)(fen)別(bie)與(yu)四(si)路(lu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)回路(lu)中一(yi)(yi)個(ge)(ge)(ge)電(dian)(dian)(dian)(dian)(dian)池(chi)正極(ji)(ji)(ji)相(xiang)連(lian)，用于(yu)采(cai)集(ji)(ji)每節電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓值；電(dian)(dian)(dian)(dian)(dian)池(chi)溫度采(cai)集(ji)(ji)輸(shu)(shu)入(ru)(ru)口(CELTMP1~4)分(fen)(fen)別(bie)與(yu)四(si)個(ge)(ge)(ge)溫度傳感(gan)器中一(yi)(yi)個(ge)(ge)(ge)相(xiang)連(lian)，采(cai)集(ji)(ji)相(xiang)應(ying)(ying)電(dian)(dian)(dian)(dian)(dian)池(chi)溫度信(xin)息；風扇(shan)驅動輸(shu)(shu)出(chu)(FANDRV)高(gao)(gao)(gao)電(dian)(dian)(dian)(dian)(dian)平(ping)有(you)(you)效(xiao)，與(yu)風扇(shan)正輸(shu)(shu)入(ru)(ru)腳相(xiang)連(lian)，在(zai)一(yi)(yi)定(ding)(ding)(ding)條件下可直(zhi)接驅動風扇(shan)；蜂鳴(ming)器輸(shu)(shu)出(chu)(BUZZER)高(gao)(gao)(gao)電(dian)(dian)(dian)(dian)(dian)平(ping)有(you)(you)效(xiao)，與(yu)蜂鳴(ming)器正輸(shu)(shu)入(ru)(ru)腳相(xiang)連(lian)，在(zai)一(yi)(yi)定(ding)(ding)(ding)條件下可直(zhi)接驅動蜂鳴(ming)器；顯示(shi)電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)/放(fang)電(dian)(dian)(dian)(dian)(dian)狀態雙色(se)LED控(kong)(kong)制(zhi)(zhi)輸(shu)(shu)出(chu)(LED1A/LED1B~LED4A/LED4B)低電(dian)(dian)(dian)(dian)(dian)平(ping)有(you)(you)效(xiao)，其中LED1A~4A分(fen)(fen)別(bie)與(yu)四(si)個(ge)(ge)(ge)雙色(se)LED紅(hong)色(se)極(ji)(ji)(ji)陰(yin)極(ji)(ji)(ji)相(xiang)連(lian)，LED1B~4B分(fen)(fen)別(bie)與(yu)四(si)個(ge)(ge)(ge)雙色(se)LED綠色(se)極(ji)(ji)(ji)陰(yin)極(ji)(ji)(ji)相(xiang)連(lian)，這四(si)個(ge)(ge)(ge)雙色(se)LED采(cai)用共陽極(ji)(ji)(ji)方式；串行(xing)數(shu)據(ju)輸(shu)(shu)出(chu)引腳(SERIES_OUT)以串行(xing)數(shu)據(ju)方式實時送(song)出(chu)電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)量信(xin)息，用于(yu)直(zhi)觀顯示(shi)電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)量。

   GM6801系列(lie)QFP44封裝(zhuang)芯片也可以(yi)對(dui)串聯(lian)電池(chi)組進(jin)行(xing)充(chong)電/放電管(guan)理(li)。在針對(dui)串聯(lian)電池(chi)組進(jin)行(xing)充(chong)電/放電控(kong)制時(shi)，只需要(yao)GM6801其中一路充(chong)電/放電控(kong)制回(hui)路即可實現。

   例如：設定對一個四(si)節電(dian)池串(chuan)聯電(dian)池組進(jin)行(xing)充電(dian)/放電(dian)，采用GM6801第一個控制回路進(jin)行(xing)充電(dian)/放電(dian)管理。

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圖5：GM6801應用于串聯電池組充電/放電管理方案輸入輸出部分電路圖

   應用(yong)(yong)方案(an)(an)如圖5所(suo)示(shi)，在針對串(chuan)聯電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)組充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)/放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)管理(li)方案(an)(an)中(zhong)，GM6801控制引腳和(he)輸(shu)入(ru)(ru)輸(shu)出引腳設(she)定與并聯充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)/放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)管理(li)不(bu)同之(zhi)處為(wei)：電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓采(cai)集輸(shu)入(ru)(ru)口(kou)(這里取CELVOLT1)通(tong)過一個(ge)分壓電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)與串(chuan)聯電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)組正極相連，串(chuan)聯電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)組電(dian)(dian)(dian)(dian)(dian)(dian)壓值經過分壓電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)把(ba)相當于一節(jie)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓值送到電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓采(cai)集輸(shu)入(ru)(ru)口(kou)(CELVOLT1)；原來為(wei)了實現(xian)自動(dong)判斷充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)/放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)回路(lu)是否有電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)而在電(dian)(dian)(dian)(dian)(dian)(dian)壓采(cai)集輸(shu)入(ru)(ru)口(kou)(CELVOLT1)之(zhi)前加 5V上拉電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)不(bu)再適用(yong)(yong)，去掉該上拉電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)后(hou)，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)/放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)開(kai)始由芯(xin)片使(shi)能開(kai)關控制，當芯(xin)片使(shi)能開(kai)關接通(tong)地電(dian)(dian)(dian)(dian)(dian)(dian)位(GND)時(shi)(shi)，開(kai)始充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)/放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)/放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)過程管理(li)及(ji)控制由GM6801自動(dong)完(wan)成。當芯(xin)片使(shi)能開(kai)關接通(tong) 5V時(shi)(shi)，芯(xin)片停止工(gong)作。