應(ying)用比較廣泛快(kuai)速(su)(su)充(chong)(chong)電管理芯片(pian)基本上有兩種類型。一種是單片(pian)機，另一種是快(kuai)速(su)(su)充(chong)(chong)電管理專(zhuan)用集成(cheng)電路。成(cheng)都國(guo)騰微電子有限(xian)公司成(cheng)功開發(fa)出一款(kuan)鎳氫/鎳鎘電池快(kuai)速(su)(su)充(chong)(chong)電智能(neng)管理芯片(pian)――GM6801。該芯片(pian)外(wai)部管腳控(kong)制功能(neng)可編程，無需外(wai)部控(kong)制器支持，使充(chong)(chong)電過(guo)程檢測控(kong)制完全自(zi)動化，所需外(wai)圍器件少，應(ying)用設計簡(jian)單。

GM6801應用(yong)方案優勢

   GM6801是快速充電管(guan)理專用集成電路。與(yu)單片機相比(bi)，由專用集成電路實現快速充電管(guan)理優勢主要體現在幾個(ge)方面：

1. 專用(yong)集(ji)(ji)成(cheng)電路在硬件(jian)(jian)中(zhong)集(ji)(ji)成(cheng)了對(dui)快速充電管理全部算法，無需開發(fa)控制(zhi)軟件(jian)(jian)，從(cong)而有效縮短產品設計周(zhou)期，簡化設計流程，所需外圍器件(jian)(jian)少，使應用(yong)設計變得(de)簡單；

2. 采用單片機實現中高端快速充電器時(shi)，對(dui)單片(pian)機(ji)有較(jiao)(jiao)高要求，比如需(xu)要較(jiao)(jiao)多I/O口，需(xu)要自帶AD等(deng)，還(huan)要開發(fa)相關軟件(jian)，這樣采(cai)用單片(pian)機(ji)所需(xu)成本往往較(jiao)(jiao)高；

3. 專用集成電(dian)路可(ke)以(yi)實現對快速充(chong)(chong)電(dian)過(guo)程(cheng)精確控制，比如GM6801就采用了帶瞬間放電(dian)過(guo)程(cheng)脈沖充(chong)(chong)電(dian)形式(shi)。這(zhe)樣(yang)可(ke)以(yi)在快速充(chong)(chong)電(dian)過(guo)程(cheng)中及時消除(chu)大電(dian)流造(zao)成電(dian)極(ji)化(hua)效(xiao)應，使電(dian)池充(chong)(chong)電(dian)效(xiao)果(guo)更佳；

4. 由于快速充電器涉及安全問題，專用集成電路良好一致性和穩(wen)定性相(xiang)對(dui)普通(tong)單片機來說更具優勢。

   此外，GM6801本(ben)身采(cai)用一些個性化設計：GM6801內置(zhi)10位AD轉換器，可以實時采(cai)集每(mei)(mei)節(jie)電(dian)(dian)池(chi)電(dian)(dian)壓和溫(wen)度信息，自帶“Condition fit”功能能夠避免環境變(bian)化帶來干擾，保證對(dui)快速充(chong)電(dian)(dian)/放(fang)電(dian)(dian)過(guo)程檢(jian)(jian)測(ce)判(pan)斷(duan)準確可靠。GM6801對(dui)每(mei)(mei)節(jie)電(dian)(dian)池(chi)充(chong)電(dian)(dian)/放(fang)電(dian)(dian)過(guo)程檢(jian)(jian)測(ce)判(pan)斷(duan)方法有電(dian)(dian)壓負增(zeng)長(-ΔV)、最(zui)大(da)電(dian)(dian)壓、最(zui)大(da)充(chong)電(dian)(dian)時間、最(zui)高溫(wen)度四種方式，通過(guo)多(duo)參數評估來進行綜(zong)合判(pan)斷(duan)，以確保電(dian)(dian)池(chi)被(bei)最(zui)大(da)化充(chong)滿(man)，同時避免過(guo)充(chong)，從而延長電(dian)(dian)池(chi)使用壽(shou)命。

   GM6801自動(dong)(dong)判斷電(dian)(dian)(dian)(dian)(dian)池有效性、自動(dong)(dong)識(shi)別電(dian)(dian)(dian)(dian)(dian)池種類，具(ju)備超(chao)溫保(bao)(bao)護和最大充電(dian)(dian)(dian)(dian)(dian)時間保(bao)(bao)護，保(bao)(bao)證了充電(dian)(dian)(dian)(dian)(dian)過程安全性。更(geng)完善功能(neng)包括：可(ke)(ke)直(zhi)接(jie)驅動(dong)(dong)4個(ge)雙色LED顯示各個(ge)電(dian)(dian)(dian)(dian)(dian)池狀態；可(ke)(ke)對充電(dian)(dian)(dian)(dian)(dian)/放電(dian)(dian)(dian)(dian)(dian)狀態進行聲(sheng)音(yin)提(ti)示；在高溫情況下可(ke)(ke)以自動(dong)(dong)啟(qi)動(dong)(dong)風扇(shan)；具(ju)備充電(dian)(dian)(dian)(dian)(dian)/放電(dian)(dian)(dian)(dian)(dian)狀態數據輸出功能(neng)，可(ke)(ke)直(zhi)觀顯示各個(ge)電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)量。

GM6801解決方(fang)案設計

   GM6801應用方案(an)如圖(tu)1所示(shi)，設計第(di)一(yi)步需要(yao)確定智能快速充(chong)電(dian)器電(dian)源電(dian)流。根(gen)據充(chong)電(dian)電(dian)池容量以(yi)及(ji)想要(yao)達到充(chong)電(dian)速度，可(ke)以(yi)計算(suan)出快速充(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，再根(gen)據GM6801數(shu)據手冊(ce)中計(ji)算公式可以推算出充(chong)電(dian)器電(dian)源實際電(dian)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(dian)(dian)器時，充(chong)電(dian)(dian)器電(dian)(dian)源(yuan)電(dian)(dian)流值應該設計成(cheng)等于(yu)或(huo)略大于(yu)4,200mA。另外需(xu)要強調是(shi)，選擇熱敏電(dian)(dian)阻(zu)非(fei)常(chang)重要。

   熱(re)敏(min)電(dian)(dian)(dian)(dian)阻(zu)是GM6801應(ying)(ying)(ying)用(yong)系統中(zhong)采集(ji)溫度關鍵元件。在GM6801應(ying)(ying)(ying)用(yong)電(dian)(dian)(dian)(dian)路(lu)中(zhong)，熱(re)敏(min)電(dian)(dian)(dian)(dian)阻(zu)必須直接(jie)或通過導熱(re)材料與(yu)(yu)被測電(dian)(dian)(dian)(dian)池緊密接(jie)觸。熱(re)敏(min)電(dian)(dian)(dian)(dian)阻(zu)B值=3,300K，熱(re)敏(min)電(dian)(dian)(dian)(dian)阻(zu)電(dian)(dian)(dian)(dian)阻(zu)值根據(ju)(ju)應(ying)(ying)(ying)用(yong)電(dian)(dian)(dian)(dian)路(lu)確定，按照(zhao)GM6801數據(ju)(ju)手冊(ce)中(zhong)提(ti)供(gong)應(ying)(ying)(ying)用(yong)電(dian)(dian)(dian)(dian)路(lu)(如圖2所示)，熱(re)敏(min)電(dian)(dian)(dian)(dian)阻(zu)(RT)與(yu)(yu)一(yi)(yi)個電(dian)(dian)(dian)(dian)阻(zu)(R)串聯，電(dian)(dian)(dian)(dian)阻(zu)另一(yi)(yi)端連接(jie) 5V電(dian)(dian)(dian)(dian)源(Vi)，熱(re)敏(min)電(dian)(dian)(dian)(dian)阻(zu)另一(yi)(yi)端接(jie)地，熱(re)敏(min)電(dian)(dian)(dian)(dian)阻(zu)與(yu)(yu)電(dian)(dian)(dian)(dian)阻(zu)連接(jie)點引出反應(ying)(ying)(ying)溫度變化電(dian)(dian)(dian)(dian)壓采樣信(xin)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(zai)不同(tong)溫度(du)點采(cai)(cai)集到(dao)電(dian)壓Vt值(zhi)與GM6801數據(ju)(ju)手冊中提供(gong)數據(ju)(ju)基本(ben)一致(zhi)，這樣才能(neng)保證(zheng)由該熱敏電(dian)阻網絡采(cai)(cai)集到(dao)電(dian)池溫度(du)信息與設計中溫度(du)刻(ke)度(du)一致(zhi)。推薦RT和R標(biao)稱值(zhi)都采(cai)(cai)用27kΩ(25℃時)。

   接下來，需要完成一(yi)些控制引(yin)腳和輸(shu)入(ru)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(feng)裝芯片采用(yong)四(si)路充(chong)電(dian)(dian)(dian)/放電(dian)(dian)(dian)回路獨立控制(zhi)，可對最(zui)多4節不(bu)同型號(hao)、容(rong)量接近鎳(nie)氫(qing)/鎳(nie)鎘電(dian)(dian)(dian)池任意組(zu)合進(jin)行并聯充(chong)電(dian)(dian)(dian)/放電(dian)(dian)(dian)管(guan)理。如圖(tu)4所(suo)示，在應(ying)用(yong)于(yu)四(si)路并聯充(chong)電(dian)(dian)(dian)/放電(dian)(dian)(dian)控制(zhi)方式(shi)時(shi)(shi)，GM6801VCC和Vref通常接 5V，其中Vref要(yao)求加10uF旁路電(dian)(dian)(dian)容(rong)增加穩定性。工作時(shi)(shi)鐘(zhong)選用(yong)32.768kHz無源晶振。

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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)別(bie)提供充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)控(kong)(kong)(kong)制輸(shu)(shu)(shu)出(chu)、放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)控(kong)(kong)(kong)制輸(shu)(shu)(shu)出(chu)、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)采集(ji)輸(shu)(shu)(shu)入(ru)、風(feng)扇驅(qu)(qu)動輸(shu)(shu)(shu)出(chu)、蜂(feng)鳴器輸(shu)(shu)(shu)出(chu)、雙(shuang)(shuang)色LED控(kong)(kong)(kong)制輸(shu)(shu)(shu)出(chu)以(yi)及(ji)串行(xing)數據輸(shu)(shu)(shu)出(chu)，這些功能管腳(jiao)(jiao)定義和功能分(fen)別(bie)為(wei)：充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)控(kong)(kong)(kong)制輸(shu)(shu)(shu)出(chu)(CHGCTRL1~4)高(gao)(gao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)平(ping)有(you)效(xiao)，控(kong)(kong)(kong)制對(dui)應(ying)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)回(hui)路(lu)開(kai)關打開(kai)或(huo)(huo)關閉；放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)控(kong)(kong)(kong)制輸(shu)(shu)(shu)出(chu)(DISCHG1~4)低(di)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)平(ping)有(you)效(xiao)，控(kong)(kong)(kong)制對(dui)應(ying)放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)回(hui)路(lu)開(kai)關打開(kai)或(huo)(huo)關閉；電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)采集(ji)輸(shu)(shu)(shu)入(ru)口(CELVOLT1~4)分(fen)別(bie)與(yu)四(si)路(lu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)回(hui)路(lu)中(zhong)一(yi)個電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)正極相(xiang)(xiang)連，用于采集(ji)每節電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值；電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)溫度(du)采集(ji)輸(shu)(shu)(shu)入(ru)口(CELTMP1~4)分(fen)別(bie)與(yu)四(si)個溫度(du)傳感器中(zhong)一(yi)個相(xiang)(xiang)連，采集(ji)相(xiang)(xiang)應(ying)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)溫度(du)信息(xi)；風(feng)扇驅(qu)(qu)動輸(shu)(shu)(shu)出(chu)(FANDRV)高(gao)(gao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)平(ping)有(you)效(xiao)，與(yu)風(feng)扇正輸(shu)(shu)(shu)入(ru)腳(jiao)(jiao)相(xiang)(xiang)連，在一(yi)定條(tiao)件(jian)下可(ke)直(zhi)(zhi)接驅(qu)(qu)動風(feng)扇；蜂(feng)鳴器輸(shu)(shu)(shu)出(chu)(BUZZER)高(gao)(gao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)平(ping)有(you)效(xiao)，與(yu)蜂(feng)鳴器正輸(shu)(shu)(shu)入(ru)腳(jiao)(jiao)相(xiang)(xiang)連，在一(yi)定條(tiao)件(jian)下可(ke)直(zhi)(zhi)接驅(qu)(qu)動蜂(feng)鳴器；顯示電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)/放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態雙(shuang)(shuang)色LED控(kong)(kong)(kong)制輸(shu)(shu)(shu)出(chu)(LED1A/LED1B~LED4A/LED4B)低(di)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)平(ping)有(you)效(xiao)，其(qi)中(zhong)LED1A~4A分(fen)別(bie)與(yu)四(si)個雙(shuang)(shuang)色LED紅色極陰極相(xiang)(xiang)連，LED1B~4B分(fen)別(bie)與(yu)四(si)個雙(shuang)(shuang)色LED綠(lv)色極陰極相(xiang)(xiang)連，這四(si)個雙(shuang)(shuang)色LED采用共陽極方式(shi)；串行(xing)數據輸(shu)(shu)(shu)出(chu)引腳(jiao)(jiao)(SERIES_OUT)以(yi)串行(xing)數據方式(shi)實時送出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量信息(xi)，用于直(zhi)(zhi)觀顯示電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量。

   GM6801系列QFP44封裝(zhuang)芯片也可以(yi)對串(chuan)聯(lian)電池組進行(xing)充電/放電管(guan)理。在針對串(chuan)聯(lian)電池組進行(xing)充電/放電控(kong)制時(shi)，只需(xu)要GM6801其中一路充電/放電控(kong)制回路即可實現。

   例(li)如：設定(ding)對一個(ge)四節電(dian)池串聯電(dian)池組進行充電(dian)/放電(dian)，采(cai)用GM6801第一個(ge)控制回路(lu)進行充電(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)方案如圖(tu)5所示，在(zai)針對串(chuan)(chuan)(chuan)聯(lian)電(dian)(dian)(dian)池(chi)組(zu)充(chong)(chong)電(dian)(dian)(dian)/放(fang)(fang)電(dian)(dian)(dian)管(guan)理(li)(li)(li)方案中，GM6801控(kong)制引(yin)腳和輸(shu)(shu)入(ru)輸(shu)(shu)出引(yin)腳設定與并聯(lian)充(chong)(chong)電(dian)(dian)(dian)/放(fang)(fang)電(dian)(dian)(dian)管(guan)理(li)(li)(li)不同之(zhi)處為：電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓采(cai)集輸(shu)(shu)入(ru)口(kou)(這里(li)取CELVOLT1)通過(guo)一(yi)個(ge)分壓電(dian)(dian)(dian)路(lu)(lu)與串(chuan)(chuan)(chuan)聯(lian)電(dian)(dian)(dian)池(chi)組(zu)正極相(xiang)連，串(chuan)(chuan)(chuan)聯(lian)電(dian)(dian)(dian)池(chi)組(zu)電(dian)(dian)(dian)壓值經過(guo)分壓電(dian)(dian)(dian)路(lu)(lu)把相(xiang)當于(yu)一(yi)節電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓值送到電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓采(cai)集輸(shu)(shu)入(ru)口(kou)(CELVOLT1)；原來為了實現自動(dong)判(pan)斷充(chong)(chong)電(dian)(dian)(dian)/放(fang)(fang)電(dian)(dian)(dian)回路(lu)(lu)是否有電(dian)(dian)(dian)池(chi)而(er)在(zai)電(dian)(dian)(dian)壓采(cai)集輸(shu)(shu)入(ru)口(kou)(CELVOLT1)之(zhi)前加 5V上(shang)(shang)拉電(dian)(dian)(dian)路(lu)(lu)不再(zai)適用(yong)，去掉該(gai)上(shang)(shang)拉電(dian)(dian)(dian)路(lu)(lu)后，充(chong)(chong)電(dian)(dian)(dian)/放(fang)(fang)電(dian)(dian)(dian)開(kai)始(shi)由芯(xin)片使(shi)能(neng)(neng)開(kai)關控(kong)制，當芯(xin)片使(shi)能(neng)(neng)開(kai)關接通地(di)電(dian)(dian)(dian)位(GND)時，開(kai)始(shi)充(chong)(chong)電(dian)(dian)(dian)/放(fang)(fang)電(dian)(dian)(dian)，充(chong)(chong)電(dian)(dian)(dian)/放(fang)(fang)電(dian)(dian)(dian)過(guo)程(cheng)管(guan)理(li)(li)(li)及控(kong)制由GM6801自動(dong)完成。當芯(xin)片使(shi)能(neng)(neng)開(kai)關接通 5V時，芯(xin)片停止(zhi)工(gong)作。