200417044 Π) 玖、發明說明 【發明所屬之技術領域】 本發明是關於發光二極體之驅動電路，特別是適用使 用於與訊號接受用的類比電路部一起積體化於一晶片內的 LED顯示驅動器的技術。 【先前技術】 近年來針對各種領域的電子機器，朝裝置的小型化、 輕量化、薄型化的開發係急速地進行。在其中，以半導體 的積體化技術的急速進展爲背景，將複數個功能處理電路 積體化於一晶片的1C被開發。特別是關於無線電接收機 、行動電話裝置、PDA(Personal Digital Assistants:個人 數位處理器）等的攜帶型（portable)機器，幾乎全部的電路 都Ϊ C化成一晶片較佳。 第1圖係顯示一般的無線電接收機的構成圖。第1圖 所示的無線電接收機係包含天線1、高頻放大電路2、混 合電路（mixer)3、局部振盪電路（0SC)4、中頻放大電路5 、檢波器6、功率放大器7、揚聲器8以及控制電路9而 構成。 高頻放大電路2輸入以天線1接收的電波，選擇性地 放大特定的頻帶（frequency band)的RF訊號（高頻訊號）。 混合電路3以及局部振盪電路4構成變頻器，藉由混合由 局頻放大電路2輸出的高頻訊號與由局部振盪電路4輸出 的局部振盪訊號進行變頻，生成IF訊號（中頻訊號）而輸 -4- (2) (2)200417044 出。 中頻放大電路5放大被混合電路3生成的中頻訊號。 檢波器6檢波被放大的中頻訊號，解調（demodulate)包含 於來自放送局的RF訊號中的調變訊號（modulation signal) 的聲音訊號。功率放大器7係放大通過檢波器6的聲音訊 號，藉由得到的訊號驅動揚聲器8。 上述局部振盪電路4具有使局部振盪頻率變化，選台 來自複數個放送局的RF訊號的功能。在最近的收信機 (receiver)中，此局部振盪電路4 一般係藉由PLL頻率合 成器（frequency synthesizer)構成。PLL頻率合成器包含 VCO(電壓控制振盪器）、可程式計數器（或可變分頻器）、 基準振盪器、相位比較器以及低通濾波器而構成。此PLL 頻率合成器藉由以控制電路9設定可程式計數器的計數値 或可變分頻器的分頻比，以得到任意頻率的局部振盪訊號 而構成。 如以上，一般的無線電接收機包含：包括高頻放大電 路2、混合電路3、中頻放大電路5以及檢波器6的訊號 接收用類比電路部5 0，與包括P L L頻率合成器等的局部 振盪電路4以及控制電路9的控制用數位電路部6 0。在 如此構成的無線電接收機中，用以將迄今使用雙載子 (bipolar)技術爲一般的類比電路部5 0與數位電路部60聚 積於同一 CMOS晶片的開發也被進行。 近年中的積體化技術的進步很醒目，今後顯示電子機 益的動作狀悲寺（右以無線電接收機的例子來說的話，收 -5 - (3) (3)200417044 信頻率、音量階（volume level)等）驅動通知使用者用的顯 示裝置之顯示驅動器等也被預料會集中於積體化於與包含 高頻電路的類比電路部相同的晶片內。 習知在無線電接收機、行動電話裝置、PDA等的攜帶 型電子機器的大部分中，顯示裝置係使用在顯示畫面可顯 示文字、記號、圖形等的許多資訊的液晶顯示裝置（LCD) 。因此，在具有這種LCD的電子機器中當想使顯示驅動 器一晶片化時，積集於晶片內的顯示驅動器成爲所謂的液 晶驅動器。但是，在攜帶型的電子機器中，積體化液晶驅 動器於一晶片內的情形與AC電源比較，爲了即使使用低 電壓的電池而使用裝置時也能充分地使LCD發光，需使 用 DC-DC轉換器提昇電池的直流電壓。但是，若使用 DC-DC轉換器則會產生大的輸出雜訊。而且，液晶驅動 器因需經常進行掃描，故在框頻（frame frequency)會產生 大的雜訊。 因此，若將液晶驅動器積體化於與類比電路部相同的 晶片內，則來自液晶驅動器的輸出雜訊會給予類比電路部 不良影響，引起接收訊號的品質下降或誤動作等之虞會發 生。因此，考慮取代L C D使用發光效率高的發光二極體 (LED) ’積體化LCD顯示驅動器於與類比電路部相同的晶 片。 顯示裝置對於使用即使在電池等的低電壓也能充分發 光的發光二極體的情形，即使是內裝顯示驅動器於I C晶 片的情形也無須在1C晶片內具備像DC-DC轉換器的昇壓 -6- (4) (4)200417044 電路。因此，可抑制輸出雜訊，減輕對位於相同I c晶片 內的類比電路部的不良影響。 但是，LED以單體無法顯示許多資訊。因此，例如在 無線電接收機中，爲了顯示收信頻率、音量階等的資訊， 需組合複數個LED控制每一個的發光狀態。 第2圖係針對使用複數個發光二極體，顯示收信頻帶 的例子而顯示的圖。例如對使用者提示F Μ放送的收信頻 率時係以η個發光二極體LED1〜LEDn之中位於依照收信 頻率的位置的兩個發光二極體爲組而發光。 即將FM放送的頻帶如 76.0M〜77.4MHz、77.5M〜 7 8.8MHz、...88.6M〜90·0ΜΗζ，每一 1.4MHz 的頻帶寬度分 割成1 〇個頻帶。而且，當使用者選台最初的分割頻帶 (76.0M〜77·4ΜΗζ)時，如第2圖（a)所示，使由最左起的兩 個發光二極體LED1、LED2發光。 而且，當使用者選台第二個分割頻帶（77.5M〜 78.8MHz z)時，如第2圖（b)所示，使由第2圖（a)的狀態 向右移動一個的兩個發光二極體LED 2、LED3發光。以下 同樣地，每次所選擇的收信頻帶變大而使其發光的兩個 LED向右各移動一'個。而且，虽使用者選台最後的分割頻 帶（88.6M〜90.0MHz)時，使最後的兩個發光二極體LEDn-l 、：LEDn 發光。 如此，依照使用者藉由鍵操作選擇的收信頻率，使位 於預先決定的位置的兩個LED發光，使用者藉由看η個 發光二極體LED1〜LEDn的任兩個是否發光，可視覺地確 (5) (5)200417044 認所選擇的收信頻帶。 對使用者提示AM放送的收信頻率時也一樣，1 0分 割153K〜279KHz、5 3 0 K〜1 7 1 0 Κ Η z的頻帶，決定對各個分 割頻帶發光的兩個LED。而且，依照使用者所選擇的收信 頻率，使位於預先決定的位置的兩個LED發光。此時， 藉由以FM放送與AM放送使顯示樣態不同（例如FM放送 的情形爲燈亮，AM放送的情形爲燈熄），也能明確地區別 F Μ放送的收信頻帶或AM放送的收信頻帶。 第 3圖係如第 2圖顯示使用 η個發光二極體 LED1〜LEDn的情形的一般的顯示驅動器的構成圖。如第 3圖（a)所示，顯示驅動器70具備η組驅動部K1〜Kn、 J1〜Jn，η個發光二極體LED 1〜LEDn的陽極係分別連接於 驅動部K1〜Kn。而且，η個發光二極體LED1〜LEDn的陰 極係分別經由驅動部J 1〜Jn連接於地線。 對於使用這種構成的顯示驅動器7 0使特定的L E D發 光的情形如第3圖（b)所示，動態（dynamic)地驅動各驅動 部 K1〜Kn、J1〜Jn。此外，第 3圖（b)係顯示使第二個 LED2發光的情形的驅動狀態。動態驅動係指以一定的間 隔重複η個發光二極體LED1〜LEDn，一邊掃描一邊驅動 的工作週期（duty cycle)驅動。在此動態驅動中，一般需 要增大LED發光時的電流。 積體化如上述第3圖（a)所示的顯示驅動器7 0於I C 的情形需在1C配設與LED同數的插腳（pin)以及連接於該 插腳的配線。因此，會發生成爲阻礙1C的小型化的要因 -8- (6) (6)200417044 的問題。而且，若如上述動態地驅動特定的L E D，則在顯 示驅動器7 0發生的大的數位雜訊經由地線進入高感度的 類比電路部，也會發生大大地使類比訊號的特性劣化的問 題。特別是類比電路部對於像包含AM無線電收音機 (radio)的棒狀天線（bar antenna)的情形，雜訊容易闖進此 棒狀天線。 本發明乃鑒於這種實情所進行的創作，其目的爲在積 體化LED顯τκ驅動器於與訊號接受用的類比電路部相同 的晶片內的情形，盡可能減少1C的插腳數或配線數可謀 求晶片的小型化，並且可抑制由顯示驅動器對類比電路部 的輸出雜訊的影響。 【發明內容】 依照本發明的發光二極體之驅動電路，係積集於與訊 號接收用類比電路部以及控制用數位電路部相同的半導體 晶片內，驅動η個發光二極體的驅動電路，其特徵爲：具 備i+j(但是ixj=：Q)個驅動部，藉由上述i+j個驅動部靜態 地驅動在i個驅動部與j個驅動部之間連接成矩陣狀的上 述η個發光二極體。 在本發明的其他樣態中，其特徵爲：在上述i個驅動 部連接上述η個發光二極體的陰極，並且在上述j個驅動 部連接上述η個發光二極體的陽極，令上述i個驅動部的 至少一個爲低位準（low level)，並且令上述j個驅動部的 至少一個爲高位準（high level)，使上述η個發光二極體的 (7) (7)200417044 至少一個發光。 在本發明的再其他樣態中，係積集於與訊號接收用類 比電路部以及控制用數位電路部相同的半導體晶片內，驅 動η個發光二極體的驅動電路，其特徵爲：具備連接於上 述η個發光二極體的陰極以及陽極的複數個驅動部，藉由 令陰極側的驅動部爲低位準，並且令陽極側的驅動部爲高 位準，以靜態地驅動上述η個發光二極體的至少一個。 本發明如上述因在i個驅動部與j個驅動部之間連接 η個發光二極體成矩陣狀，故具備比η個還少的僅（i+j)個 的驅動部的話佳。據此，可減少積集有驅動電路的半導體 晶片的插腳數以及配線數，僅僅於此可小型化晶片。 而且，如果依照本發明，因在η個發光二極體的陰極 以及陽極的雙方連接驅動部，令陰極側的驅動部爲低位準 ，並且令陽極側的驅動部爲高位準，以靜態地驅動任一個 發光二極體，故可抑制在驅動電路產生的數位雜訊經由地 線進入相同晶片內的類比電路部的情況不佳。 【實施方式】 以下根據圖面說明本發明的一實施形態。 第4圖係顯示依照本實施形態的發光二極體的驅動電 路的構成圖。而且，第5圖係顯示搭載該當驅動電路的無 線電接收機的全體構成的方塊圖。第5圖所示的無線電接 收機係包含天線1、高頻放大電路2、混合電路（mixer)3 、藉由PLL頻率合成器構成的局部振盪電路（〇sc)4、中 -10- (8) (8)200417044 頻放大電路5、檢波器6、功率放大器7、揚聲器8、控制 電路9以及顯示驅動器1 0而構成。 高頻放大電路2輸入以天線1接收的電波，選擇性地 放大特定的頻帶的高頻訊號。混合電路3係藉由混合由高 頻放大電路2輸出的高頻訊號與由局部振盪電路4輸出的 局部振盪訊號進行變頻，生成中頻訊號而輸出。 中頻放大電路5係放大被混合電路3生成的中頻訊號 。檢波器6檢波被放大的中頻訊號，解調包含於來自放送 局的RF訊號中的調變訊號的聲音訊號。功率放大器7係 放大通過檢波器6的聲音訊號，藉由得到的訊號驅動揚聲 器8。 控制電路9藉由設定局部振盪電路4所具備的可程式 計數器的計數値或可變分頻器的分頻比，使局部振盪電路 4產生任意頻率的局部振盪訊號而控制。此控制電路9也 藉由令顯示驅動器1 0所具備的複數個驅動部爲高位準或 低位準，控制複數個發光二極體的驅動。在如上述構成的 無線電接收機中，包含高頻放大電路2、混合電路3、中 頻放大電路5以及檢波器6的訊號接收用類比電路部，與 包含局部振盪電路4以及控制電路9的控制用數位電路部 ，與顯示驅動器1 0係被積體化於一個半導體晶片丨〇〇內 〇 顯示驅動器1 0係如第4圖而構成。即顯示驅動器1 0 在驅動η個發光二極體LED1〜LEDn的情形中，具備i+j( 但是ixj=n)個驅動部。例如驅動i 2個發光二極體的情形 -11 - (9) (9)200417044 具備3個+4個=7個或2個+6個=8個驅動部。此外，在 第 4圖中顯示i = 4，j = 3的例子。12個發光二極體 LED 1〜LED 12係在四個驅動部 D1〜D4與三個驅動部 D5〜D7之間連接成矩陣狀。即令連接有四個驅動部 D1〜D4的端子爲a〜d，令連接有三個驅動部D5〜D7的端 子爲 A〜C的情形，第 1個到第 4個發光二極體 LED 1〜LED4係各個陰極分別連接於端子a〜d，並且各個陽 極均連接於端子A。 而且，第5個到第8個發光二極體LED 5〜LED8係各 個陰極分別連接於端子a〜d，並且各個陽極均連接於端子 B。再者，第9個到第12個發光二極體LED 9〜LED12係 各個陰極分別連接於端子a〜d，並且各個陽極均連接於端 子C。 使12個發光二極體LED1〜LED12之中至少一個發光 的情形係令四個驅動部D 1〜D 4的至少一個爲低位準，驅 動三個驅動部D 5〜D 7的至少一個爲高位準。例如欲使第3 個發光二極體LED3發光的情形係驅動驅動部D3成低位 準，驅動驅動部D 5成高位準。如此，驅動連接有四個發 光二極體LED 1〜LED4的陽極的驅動部D5成高位準的情 形，若不想使第3個發光二極體LED3以外發光的話，連 接有四個之中剩餘的三個發光二極體 LED1、LED2、 LED4的陰極的驅動部Dl、D2、D4也被驅動成高位準。 據此，陽極側與陰極側被設成大致同一位準。此外，陰極 側比陽極側更成爲高位準而驅動也可以。 -12 - (10) (10)200417044 在本實施形態中使用上述7個驅動部D 1〜D7靜態地 驅動1 2個發光二極體LED 1〜LED 1 2。靜態驅動係指與進 行掃描的動態驅動不同，爲個別且斷續地發光控制僅想使 其發光的 LED的驅動方式。若以此靜態驅動方式驅動 LED的話，可以較少的電流得到高的亮度。 如以上詳細說明的，如果依照本實施形態因在i個驅 動部與j個驅動部之間連接η個發光二極體LED 1〜LEDn 成矩陣狀，故驅動部具備比η個還少的僅（i+j)個的話佳。 據此，可減少積集有顯示驅動器1 0的1C晶片1 00的插腳 數以及配線數，可對1C晶片1 00的小型化貢獻。 而且如果依照本實施形態，因令i個驅動部的至少一 個爲低位準，並且令j個驅動部的至少一個爲高位準，以 靜態地驅動任一個發光二極體，故無在顯示驅動器1 0產 生的數位雜訊經由1C晶片1 00的地線進入類比電路部， 可高品質地維持類比訊號的特性。此外，在上述實施形態 中雖然電子機器的例子舉無線電接收機來說明，惟也能適 用於無線電接收機以外的電子機器。例如行動電話裝置或 P D A、無線電話機、電視接收機（t e 1 e v i s i ο n r e c e i v e r)、汽 車導航系統、遊戲機、藍芽（bluetooth)或無線LAN製品 等具備無線通訊功能的電子機器的話都可適用本發明。 而且，在上述實施形態中雖然針對在i個驅動部與j 個驅動部之間連接所有的發光二極體LED 1〜LEDn成矩陣 狀的例子來說明，惟將所有的發光二極體分成複數個群， 在各個群內於陽極側的驅動部與陰極側的驅動部之間連接 -13- (11) (11)200417044 複數個發光二極體成矩陣狀也可以。 其他，以上所說明的實施形態只不過是顯示當實施本 發明時的具體化的一例，不可據此限定地解釋本發明的技 術範圍◦即本發明在不脫離其精神或其主要特徵下可以種 種的形來實施。 〔產業上的可利用性〕 本發明對於在積體化LED顯示驅動器於與訊號接受 用的類比電路部相同的晶片內的情形，盡可能減少1C的 插腳數或配線數可謀求晶片的小型化，並且可抑制由顯示 驅動器對類比電路部的輸出雜訊的影響有用。 【圖式簡單說明】 第1圖係顯示一般的無線電接收機的構成圖。 第2圖係針對使用複數個發光二極體，顯示收信頻帶 的例子而顯示的圖。 第3圖係顯示使用複數個發光二極體的情形的一般的 顯示驅動器的構成以及驅動的樣子圖。 第4圖係顯示依照本實施形態的發光二極體的驅動電 路的構成例圖。 第5圖係顯示搭載依照本實施形態的發光二極體的驅 動電路的無線電接收機的全體構成的方塊圖。 〔符號說明〕 -14- (12) (12)200417044 1 :天線 2 :高頻放大電路 3 :混合電路 4 :局部振盪電路 5 :中頻放大電路 6 :檢波器 7 :功率放大器 8 :揚聲器 9 :控制電路 1 〇、7 0 :顯示驅動器 5 〇 :訊號接收用類比電路部 60 :控制用數位電路部 1〇〇 :半導體晶片 a〜d、A〜C:端子 D1〜D7、K1〜Kn、J1〜Jn:驅動部 LED1〜LEDn ··發光二極體200417044 Π) 发明 Description of the invention [Technical field to which the invention belongs] The present invention relates to a driving circuit for a light emitting diode, and is particularly suitable for an LED display integrated in a chip together with an analog circuit unit for signal reception Drive technology. [Prior Art] In recent years, electronic devices in various fields have been rapidly developed toward miniaturization, weight reduction, and thinness of devices. Among them, 1C, in which a plurality of functional processing circuits are integrated on one wafer, has been developed against the background of the rapid advancement of semiconductor integration technology. In particular, for portable devices such as radio receivers, mobile phone devices, and PDAs (Personal Digital Assistants), almost all of the circuits are preferably formed into a single chip. Fig. 1 is a block diagram showing a general radio receiver. The radio receiver shown in FIG. 1 includes an antenna 1, a high-frequency amplifier circuit 2, a mixer 3, a local oscillation circuit (0SC) 4, an intermediate frequency amplifier circuit 5, a detector 6, a power amplifier 7, and a speaker. 8 and a control circuit 9. The high-frequency amplifier circuit 2 inputs radio waves received by the antenna 1 and selectively amplifies an RF signal (high-frequency signal) in a specific frequency band. The hybrid circuit 3 and the local oscillation circuit 4 constitute an inverter. The high frequency signal output from the local frequency amplifying circuit 2 and the local oscillation signal output from the local oscillation circuit 4 are mixed to perform frequency conversion to generate an IF signal (intermediate frequency signal) and then output. -4- (2) (2) 200417044. The intermediate frequency amplifier circuit 5 amplifies the intermediate frequency signal generated by the hybrid circuit 3. The detector 6 detects the amplified IF signal, and demodulates a sound signal including a modulation signal in the RF signal from the broadcasting station. The power amplifier 7 amplifies the sound signal passing through the detector 6, and drives the speaker 8 by the obtained signal. The local oscillation circuit 4 has a function of changing the local oscillation frequency and selecting the RF signals from a plurality of broadcasting stations. In recent receivers, this local oscillation circuit 4 is generally constituted by a PLL frequency synthesizer. The PLL frequency synthesizer is composed of a VCO (Voltage Controlled Oscillator), a programmable counter (or variable frequency divider), a reference oscillator, a phase comparator, and a low-pass filter. This PLL frequency synthesizer is constituted by setting the count of a programmable counter or the frequency division ratio of a variable frequency divider by the control circuit 9 to obtain a local oscillation signal of an arbitrary frequency. As described above, a general radio receiver includes a signal receiving analog circuit section 50 including a high-frequency amplifier circuit 2, a hybrid circuit 3, an intermediate-frequency amplifier circuit 5, and a detector 6, and a local oscillation including a PLL frequency synthesizer and the like. The control digital circuit portion 60 of the circuit 4 and the control circuit 9 is 60. In the radio receiver thus constituted, development of integrating the analog circuit unit 50 and the digital circuit unit 60, which have hitherto used bipolar technology as a general one, has also been carried out on the same CMOS chip. The progress of integration technology in recent years is very eye-catching. In the future, it will show the action of the electronic machine. (From the example of the radio receiver on the right, it is -5-(3) (3) 200417044. (Volume level, etc.) It is expected that display drivers, etc., which drive the display device for the user, will be integrated in the same chip as the analog circuit section including the high-frequency circuit. It is known that in most portable electronic devices such as radio receivers, mobile phone devices, and PDAs, the display device is a liquid crystal display device (LCD) that displays a lot of information such as characters, symbols, and graphics on a display screen. Therefore, in an electronic device having such an LCD, when the display driver is to be formed into a single wafer, the display driver accumulated in the wafer becomes a so-called liquid crystal driver. However, in the case of a portable electronic device, the integrated liquid crystal driver is contained in a chip compared with an AC power supply. In order to fully illuminate the LCD even when the device is used with a low-voltage battery, DC-DC is required. The converter boosts the DC voltage of the battery. However, if a DC-DC converter is used, large output noise will be generated. In addition, since the liquid crystal driver needs to scan frequently, a large noise may be generated at a frame frequency. Therefore, if the liquid crystal driver is integrated in the same chip as the analog circuit portion, the output noise from the liquid crystal driver will adversely affect the analog circuit portion, which may cause the quality of the received signal to deteriorate or malfunction. Therefore, it is considered to use a light-emitting diode (LED) 'integrated LCD display driver with high luminous efficiency instead of LCD on the same chip as the analog circuit portion. The display device does not need to be boosted like a DC-DC converter in a 1C chip even if it uses a light-emitting diode that can sufficiently emit light even at a low voltage such as a battery, even when a display driver is built into the IC chip. -6- (4) (4) 200417044 circuit. Therefore, the output noise can be suppressed, and the adverse effect on the analog circuit portion located in the same IC chip can be reduced. However, LED alone cannot display a lot of information. Therefore, for example, in a radio receiver, in order to display information such as a reception frequency and a volume level, it is necessary to combine a plurality of LEDs to control each of the light-emitting states. Fig. 2 is a diagram showing an example where a plurality of light emitting diodes are used to display a reception frequency band. For example, when the user is prompted for the receiving frequency of F M transmission, two groups of light emitting diodes located at positions corresponding to the receiving frequency among the n light emitting diodes LED1 to LEDn are set to emit light. That is, the frequency bands of FM broadcasting are 76.0M ~ 77.4MHz, 77.5M ~ 7 8.8MHz, ... 88.6M ~ 90 · 0MΗζ, and each 1.4MHz band width is divided into 10 frequency bands. In addition, when the user selects the first divided frequency band (76.0M ~ 77 · 4M 台 ζ) of the channel, as shown in Fig. 2 (a), the two light-emitting diodes LED1 and LED2 from the leftmost are illuminated. In addition, when the user selects the second divided frequency band (77.5M ~ 78.8MHz z), as shown in Fig. 2 (b), the two lights that are shifted to the right by one in the state of Fig. 2 (a) are emitted. Diode LED 2 and LED 3 emit light. In the same way, the two LEDs that are selected each time the receiving frequency band is increased so that they emit light are shifted to the right by one each. Moreover, when the user selects the last divided frequency band (88.6M ~ 90.0MHz), the last two light-emitting diodes LEDn-1 and: LEDn are illuminated. In this way, the two LEDs at predetermined positions are caused to emit light in accordance with the receiving frequency selected by the user through key operation. The user can visually see whether any two of the n light-emitting diodes LED1 to LEDn emit light. (5) (5) 200417044 Confirm the selected receiving frequency band. It is also the same when the user is prompted for the reception frequency of AM transmission. The frequency bands of 153K ~ 279KHz and 530K ~ 1710 0 K Η z are divided by 10 points, and two LEDs which emit light to each divided band are determined. In addition, the two LEDs located at predetermined positions are caused to emit light in accordance with the receiving frequency selected by the user. At this time, by using FM broadcasting and AM broadcasting to make the display state different (for example, the light is on in the case of FM transmission and the light is off in the case of AM transmission), it is also possible to clearly distinguish the receiving frequency band of the FM transmission or the AM transmission. Receiving frequency band. Fig. 3 is a configuration diagram of a general display driver in the case where n light emitting diodes LED1 to LEDn are used as shown in Fig. 2. As shown in FIG. 3 (a), the display driver 70 includes n sets of driving sections K1 to Kn, J1 to Jn, and anodes of the n light emitting diodes LEDs 1 to LEDn are connected to the driving sections K1 to Kn, respectively. The cathodes of the n light-emitting diodes LED1 to LEDn are connected to the ground through the driving sections J1 to Jn, respectively. As shown in Fig. 3 (b), when the display driver 70 having such a structure is used to illuminate a specific LED, the driving sections K1 to Kn and J1 to Jn are dynamically driven. In addition, Fig. 3 (b) shows a driving state when the second LED 2 is turned on. The dynamic driving means a duty cycle driving in which n light-emitting diodes LED1 to LEDn are repeated at a certain interval and driven while scanning. In this dynamic driving, it is generally necessary to increase the current when the LED emits light. In the case where the display driver 70 is integrated with I C as shown in FIG. 3 (a) above, the same number of pins as LEDs and the wiring connected to the pins must be provided at 1 C. Therefore, there is a problem that becomes a factor hindering the miniaturization of 1C -8- (6) (6) 200417044. Furthermore, if a specific LED is driven dynamically as described above, a large digital noise generated in the display driver 70 enters a high-sensitivity analog circuit section via a ground line, and a problem that the characteristics of the analog signal are greatly deteriorated also occurs. In particular, in a case where the analog circuit section includes a bar antenna including an AM radio, noise easily breaks into the bar antenna. The present invention is made in view of this fact, and its purpose is to reduce the number of pins or wiring of 1C as much as possible in the case where the integrated LED display τκ driver is in the same chip as the analog circuit portion for signal reception. The miniaturization of the chip is achieved, and the influence of the display driver on the output noise of the analog circuit section can be suppressed. [Summary of the Invention] The driving circuit of the light-emitting diode according to the present invention is integrated in a semiconductor chip which is the same as the analog circuit portion for signal reception and the digital circuit portion for control, and drives a driving circuit for n light-emitting diodes. It is characterized by having i + j (but ixj =: Q) driving units, and statically driving the above-mentioned η connected in a matrix between i driving units and j driving units by the i + j driving units. Light-emitting diodes. In another aspect of the present invention, the cathodes of the n light-emitting diodes are connected to the i driving portions, and the anodes of the n light-emitting diodes are connected to the j driving portions. At least one of the i driving parts is at a low level, and at least one of the j driving parts is at a high level, so that (7) (7) 200417044 of the n light emitting diodes is at least One glows. In still another aspect of the present invention, the driving circuit integrated in the same semiconductor chip as the signal receiving analog circuit portion and the control digital circuit portion to drive n light-emitting diodes is characterized by having a connection The driving portions of the cathodes and anodes of the n light-emitting diodes are driven at a low level and the anode-side driving portions are high to drive the n light-emitting diodes statically. At least one of the polar bodies. As described above, in the present invention, since n light emitting diodes are connected in a matrix form between i driving portions and j driving portions, it is preferable to include only (i + j) driving portions that are smaller than n driving portions. As a result, the number of pins and the number of wirings of the semiconductor chip on which the driving circuit is accumulated can be reduced, and only the chip can be miniaturized. Furthermore, according to the present invention, since the driving portions are connected to both the cathode and the anode of the n light-emitting diodes, the driving portion on the cathode side is set to a low level, and the driving portion on the anode side is set to a high level to be driven statically. Any one of the light-emitting diodes can prevent the digital noise generated in the driving circuit from entering the analog circuit section in the same chip via the ground wire. [Embodiment] An embodiment of the present invention will be described below with reference to the drawings. Fig. 4 is a configuration diagram showing a driving circuit of a light emitting diode according to this embodiment. Fig. 5 is a block diagram showing the overall configuration of a radio receiver equipped with the driver circuit. The radio receiver shown in FIG. 5 includes an antenna 1, a high-frequency amplifier circuit 2, a mixer 3, a local oscillation circuit (〇sc) constituted by a PLL frequency synthesizer 4, and a medium -10- (8 (8) 200417044 is composed of a frequency amplifier circuit 5, a detector 6, a power amplifier 7, a speaker 8, a control circuit 9, and a display driver 10. The high-frequency amplifier circuit 2 inputs radio waves received by the antenna 1 to selectively amplify high-frequency signals in a specific frequency band. The mixing circuit 3 converts the high-frequency signal output from the high-frequency amplifier circuit 2 and the local oscillation signal output from the local oscillation circuit 4 to a frequency, generates an intermediate frequency signal, and outputs it. The intermediate frequency amplifier circuit 5 amplifies the intermediate frequency signal generated by the hybrid circuit 3. The detector 6 detects the amplified IF signal, and demodulates the sound signal of the modulation signal included in the RF signal from the broadcasting station. The power amplifier 7 amplifies the sound signal passing through the detector 6, and drives the speaker 8 by the obtained signal. The control circuit 9 sets the count of the programmable counter provided in the local oscillation circuit 4 or the frequency division ratio of the variable frequency divider, so that the local oscillation circuit 4 generates a local oscillation signal of an arbitrary frequency and controls. This control circuit 9 also controls the driving of the plurality of light emitting diodes by setting the plurality of driving sections provided in the display driver 10 to a high level or a low level. The radio receiver configured as described above includes a signal receiving analog circuit section including the high-frequency amplifier circuit 2, the hybrid circuit 3, the intermediate-frequency amplifier circuit 5, and the detector 6, and the control including the local oscillation circuit 4 and the control circuit 9. The digital circuit unit and the display driver 10 are integrated into a single semiconductor wafer. The display driver 10 is configured as shown in FIG. 4. That is, in a case where the display driver 10 drives n light emitting diodes LED1 to LEDn, the display driver 10 includes i + j (but ixj = n) driving sections. For example, in the case of driving i 2 light-emitting diodes -11-(9) (9) 200417044 is provided with 3 +4 = 7 or 2 +6 = 8 driving sections. In addition, an example of i = 4 and j = 3 is shown in Fig. 4. The twelve light emitting diodes LED 1 to LED 12 are connected in a matrix form between four driving sections D1 to D4 and three driving sections D5 to D7. That is, when the terminals connected to the four driving sections D1 to D4 are a to d, and the terminals connected to the three driving sections D5 to D7 are A to C, the first to fourth light emitting diode LEDs 1 to LED4 Each cathode is connected to terminals a to d, and each anode is connected to terminal A. Further, the cathodes of the fifth to eighth light-emitting diode LEDs 5 to LED8 are respectively connected to terminals a to d, and each anode is connected to terminal B. Furthermore, the ninth to twelfth light-emitting diodes LEDs 9 to 12 are each connected to the terminals a to d, and each anode is connected to the terminal C. When at least one of the twelve light-emitting diodes LED1 to LED12 is caused to emit light, at least one of the four driving sections D1 to D4 is at a low level, and at least one of the three driving sections D5 to D7 is at a high level. quasi. For example, when the third light-emitting diode LED3 is to be lighted, the driving unit D3 is driven to a low level, and the driving unit D5 is driven to a high level. In this way, when the driving portion D5 that drives the anodes of the four light-emitting diode LEDs 1 to 4 is connected to a high level, if the third light-emitting diode LED3 is not intended to emit light, the remaining four of them are connected. The driving portions D1, D2, and D4 of the cathodes of the three light-emitting diodes LED1, LED2, and LED4 are also driven to a high level. Accordingly, the anode side and the cathode side are set at substantially the same level. The cathode side may be driven at a higher level than the anode side. -12-(10) (10) 200417044 In this embodiment, the aforementioned seven driving sections D 1 to D 7 are used to statically drive 12 light emitting diode LEDs 1 to LED 12. The static driving means a driving method of an LED that is controlled to emit light only intermittently and intermittently, unlike a dynamic driving that performs scanning. If the LED is driven by this static driving method, high brightness can be obtained with less current. As explained in detail above, if n light-emitting diode LEDs 1 to LEDn are connected in a matrix form between i driving portions and j driving portions according to this embodiment, the driving portion has only fewer than n driving portions. (I + j) words are good. This can reduce the number of pins and wiring of the 1C chip 100 in which the display driver 10 is accumulated, and can contribute to the miniaturization of the 1C chip 100. Moreover, according to this embodiment, since at least one of the i driving sections is set at a low level and at least one of the j driving sections is set at a high level, any one light emitting diode is driven statically, so there is no display driver 1 The digital noise generated by 0 enters the analog circuit section through the 100C ground of the 1C chip, which can maintain the characteristics of the analog signal with high quality. In addition, in the above-mentioned embodiment, although an example of an electronic device has been described using a radio receiver, it can also be applied to an electronic device other than a radio receiver. For example, mobile phones or PDAs, wireless phones, television receivers (te 1 evisi ο nreceiver), car navigation systems, game consoles, bluetooth or wireless LAN products and other electronic devices with wireless communication functions can be applied to this invention. Furthermore, in the above-mentioned embodiment, although the example in which all the light-emitting diodes LEDs 1 to LEDn are connected in a matrix is described between i driving portions and j driving portions, all the light-emitting diodes are divided into a plurality of numbers. Each cluster may be connected between the anode-side driving unit and the cathode-side driving unit in each cluster. (13) (11) (11) 200417044 A plurality of light-emitting diodes may be arranged in a matrix. In addition, the embodiment described above is merely an example showing the actualization when the present invention is implemented, and the technical scope of the present invention cannot be interpreted in a limited manner. That is, the present invention can be various without departing from the spirit or main characteristics thereof. Shape to implement. [Industrial Applicability] In the case where the integrated LED display driver is in the same chip as the analog circuit portion for signal reception, the present invention reduces the number of pins or wiring of 1C as much as possible to achieve miniaturization of the chip. It is useful to suppress the influence of the display driver on the output noise of the analog circuit section. [Brief Description of the Drawings] Fig. 1 is a block diagram showing a general radio receiver. Fig. 2 is a diagram showing an example where a plurality of light emitting diodes are used to display a reception frequency band. Fig. 3 is a diagram showing the structure of a general display driver and the state of driving when a plurality of light emitting diodes are used. Fig. 4 is a diagram showing a configuration example of a driving circuit of a light emitting diode according to this embodiment. Fig. 5 is a block diagram showing the overall configuration of a radio receiver equipped with a driver circuit of a light emitting diode according to this embodiment. [Notation] -14- (12) (12) 200417044 1: Antenna 2: High-frequency amplifier circuit 3: Hybrid circuit 4: Local oscillation circuit 5: Intermediate frequency amplifier circuit 6: Detector 7: Power amplifier 8: Speaker 9 : Control circuit 1 0, 7 0: Display driver 5 0: Signal receiving analog circuit section 60: Control digital circuit section 100: Semiconductor wafers a to d, A to C: Terminals D1 to D7, K1 to Kn, J1 ~ Jn: Drive unit LED1 ~ LEDn ·· Light emitting diode