JPH02106795A - Liquid crystal driving circuit - Google Patents

Liquid crystal driving circuit

Info

Publication number
JPH02106795A
JPH02106795A JP25972588A JP25972588A JPH02106795A JP H02106795 A JPH02106795 A JP H02106795A JP 25972588 A JP25972588 A JP 25972588A JP 25972588 A JP25972588 A JP 25972588A JP H02106795 A JPH02106795 A JP H02106795A
Authority
JP
Japan
Prior art keywords
circuit
common
test
output
liquid crystal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP25972588A
Other languages
Japanese (ja)
Inventor
Shigeaki Fujitaka
藤高 繁明
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP25972588A priority Critical patent/JPH02106795A/en
Publication of JPH02106795A publication Critical patent/JPH02106795A/en
Pending legal-status Critical Current

Links

Landscapes

  • Liquid Crystal (AREA)
  • Liquid Crystal Display Device Control (AREA)
  • Electronic Switches (AREA)

Abstract

PURPOSE:To simplify a test program for leak current and to shorten the time for testing by providing means for focibly turning off outputs Tr to a liquid crystal driving circuit. CONSTITUTION:The liquid crystal driving circuit has the circuit which can turn off the MOS transistor outputs Tr 3 to 6 of p channel outputs regardless of the operation of a control circuit 1. Namely, OR circuits 18, 19 output an H level and AND circuits 20, 21 output an L level regardless of the operation of the common signal control circuit 1 if the test signal is brought to an H by the instruction from a CPU. All of the outputs Tr 3 to 6 are, therefore, turned off and the state of allowing the leak current test is established. The circuit operations are the same as heretofore if the test signal 23 is brought to an L; therefore, there are no problems in the ordinary operation. The forma tion of the test program of the leak current is simplified in this way and the test time is shortened.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 この発明は液晶駆動回路を備えた半導体装置に関するも
のである。
DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device equipped with a liquid crystal drive circuit.

〔従来の技術〕[Conventional technology]

従来の液晶駆動回路としてここでぼ例えばマイクロコン
ピュータに内蔵された1/3バイアス1/3デユーテイ
のコモン信号発生回路を例として述べる。第2図ぼ従来
のコモン信号発生回路のブロック図であり、図において
、(1)にコモン信号制御回路であり、基準クロックを
入力とし、cpu (図示せず)からの命令によりコモ
ン信号ドライバ回路(2)に制御信号A +8+ 、 
B (91、C[IOi 、 D (II)を出力する
As an example of a conventional liquid crystal driving circuit, a 1/3 bias 1/3 duty common signal generating circuit built in a microcomputer will be described as an example. Figure 2 is a block diagram of a conventional common signal generation circuit. (2) control signal A +8+,
Output B (91, C[IOi, D (II)).

(+Z 、 03) 、 O舶はコモン信号の基準電圧
V3. V2. Vlである。コモン信号ドライバ回路
(2)の構成は以下のようになっており、f311dソ
ースが基準電圧v3篠ニ、ドレインがコモン0端子(7
)に、ゲートが曲部信号A(8)にそれぞれ接続された
Pチャンネル間O8出力トランジスタ(以下、出力Tr
と記す。)、+4itl!ソースが基準電電V2(13
)に、ドレインがコモン0端子(7)に、ゲートが制御
信号B(9)にそれぞれ接続されたPチャンネルMO8
出fi Tr 、 (51i’f:ンースが基準電圧V
I Q4)に、ドレインがコモン0端子(7)に、ゲー
トが制御信号C(101にそれぞれ接続されたNチャン
ネルMO8出力Tr、f6)idソースがグランドに、
ゲートが制御信号D (Illに、ドレインがコモン0
端子(7)にそれぞれ接続されfvNチャンネルMO8
出力Trである。また、θ5)、α6)ホコモン1信号
ドライバ回路及びコモン2信号ドライバ1嗜路であり、
構成にコモンO係号ドライバ回路と同様である。(内部
結線全省略) 次に、第3図の波形図を参照して動作及びIJ−り電流
テスト方法について説明する。ここでは簡単のためコモ
ン0信号の場合についてのみ述べる。
(+Z, 03), O ship uses the common signal reference voltage V3. V2. It is Vl. The configuration of the common signal driver circuit (2) is as follows, the f311d source is the reference voltage v3 Shinonichi, and the drain is the common 0 terminal (7
) and the P-channel O8 output transistor (hereinafter referred to as output Tr
It is written as ), +4itl! The source is the reference voltage V2 (13
), the drain is connected to the common 0 terminal (7), and the gate is connected to the control signal B (9), respectively.
Output fi Tr , (51i'f: the reference voltage V
I Q4), the drain is connected to the common 0 terminal (7), the gate is connected to the control signal C (101), and the N-channel MO8 output Tr, f6) id source is connected to the ground,
The gate is connected to the control signal D (Ill), the drain is connected to the common 0
fvN channel MO8 connected to terminal (7) respectively.
This is the output Tr. In addition, θ5), α6) a common 1 signal driver circuit and a common 2 signal driver 1 path,
The configuration is similar to the common O coefficient driver circuit. (All internal connections are omitted) Next, the operation and IJ current test method will be described with reference to the waveform diagram in FIG. Here, for simplicity, only the case of a common 0 signal will be described.

基準電圧V3. V2. Vl 1−X V2−2/3
V3. V1=1/3V3の電圧が印加されているもの
とする。コモンO信号制御回路(1)は基準クロックに
同期して、第3図中(b) (C) (d) (e)の
ような信号を出力する。それにより、出力Tr (3)
 、 14) 、 (51、16) fl ON、 O
FF シ、第3図中(f)の信号がコモン0端子(7)
に出力されることとなる0 次にリーク電流のテストヲ説明する。例えば出力Tr 
+31 、 [41’(rテストするには、命令により
コモン信号制御回路tll’に動作させ、第3図中状態
1と1(つた所で基鵡クロックを停止し、状態1を保持
したまま(つ−まり、出力Tr +31 、 +41が
OFF状態のまま)基準電圧V3 (121、V2 (
131にHレベル電圧全印加し、コモンO端子17)に
Lレベル電圧を印加し、″電流を測定する。
Reference voltage V3. V2. Vl 1-X V2-2/3
V3. It is assumed that a voltage of V1=1/3V3 is applied. The common O signal control circuit (1) outputs signals as shown in (b), (C), (d), and (e) in FIG. 3 in synchronization with the reference clock. As a result, the output Tr (3)
, 14) , (51, 16) fl ON, O
FF, signal (f) in Figure 3 is common 0 terminal (7)
Next, the leakage current test will be explained. For example, the output Tr
+31, [41'(r) To test, operate the common signal control circuit tll' by a command, and stop the base clock at the point where state 1 and 1 (in Figure 3) are reached, keeping state 1 ( In other words, the output Tr +31, +41 remains in the OFF state) reference voltage V3 (121, V2 (
131, apply an L level voltage to the common O terminal 17), and measure the current.

また、例えば出力’rr (51、+61をテストする
Kぼ同様にして、状態2となった所で基準クロックを停
止し、状態2を保持したま捷、つまり、出力Tr(51
、islがOFF状態のま1基準電圧Vl(14)にL
レベル電圧を印加し、コモンO端子(7)にHレベル“
醒比會印加し電流を測定する。
In addition, for example, when testing the output 'rr (51, +61), the reference clock is stopped when state 2 is reached, and state 2 is maintained, that is, the output Tr (51, +61) is tested.
, when isl is in the OFF state, the first reference voltage Vl (14) is set to L.
Apply a level voltage to the common O terminal (7) and
Apply the current and measure the current.

ここてに、コモン0端子(7)関係についてのみ述べた
が、コモン1端子(+51 、コモン2端子(16)に
ついても同様である。
Although only the relationship between the common 0 terminal (7) has been described here, the same applies to the common 1 terminal (+51) and the common 2 terminal (16).

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

従来の液晶駆動回路は以上のように構成されていたので
、リーク電流テスI−’に行う際命令により駆動回路全
動作させ、出力TrがOFFになった状態で、状態全保
持したまま測定することが必娶で、その念め、テストプ
ログラム作成が困難であり、またテスト時間も長くなる
という問題があった。
Conventional liquid crystal drive circuits are configured as described above, so when performing the leakage current test I-', the drive circuit is fully operated by a command, and the output Tr is turned OFF, and the measurement is performed while maintaining the entire state. Therefore, there were problems in that it was difficult to create a test program and the test took a long time.

この発明は上記のような開明を解消するためになされた
もので、リーク電流テストのプログラム作成が簡単で、
捷たテスト時間も短くなる液晶駆動装置を得ることを目
的とする。
This invention was made to solve the above-mentioned problems, and it is easy to create a leak current test program.
It is an object of the present invention to obtain a liquid crystal drive device in which the test time required for testing is shortened.

〔諌Iを解決するための手段〕[Means to solve the problem I]

この発明に係る液晶駆動装置は出力Trを制御回路の動
作と関係なく OFFできる回路を備えたものである。
The liquid crystal driving device according to the present invention includes a circuit that can turn off the output transistor regardless of the operation of the control circuit.

〔作用〕[Effect]

この発明における液晶駆動装置は制御回路の動作とW4
係なく出力Tr f OFFできる回路を備えたので、
リーク電流のテストプログラム作成が簡単になりテスト
時間も蝮くなる。
The liquid crystal driving device in this invention is characterized by the operation of the control circuit and W4.
Since it is equipped with a circuit that can turn off the output Tr f regardless of
It becomes easier to create a leakage current test program and the test time is reduced.

〔実施例〕〔Example〕

以下、この発明の一実施例を図について説明する。従来
の場合と同様に、ここでは例えばコモン信号発生回路V
C1)いて述べる。
An embodiment of the present invention will be described below with reference to the drawings. As in the conventional case, here, for example, the common signal generation circuit V
C1)

第1図において、illはコモン信号制御回路、(2)
はコモン0侶号ドライバ回路、+31 、 +41 、
 +51 、 +61はコモン0端子(7)の出力Tr
 、 i8) 、 191 、(101、(II)l’
ff制御個号A、B、C,Dであり、(12+ 、 (
131、(n)にコモン係号の基準゛電圧v3. v2
. Vlであり、(15) 、 Q6) iコモン1信
号ドライバ回路及びコモン2信号ドライバ回路であり、
これらはmJ記従来のものの構成と同じである。(l乃
にコモン信号制御回路+I+の動作に関係なく、全出力
TrをOFFにする回路であり、この発明のポイントで
ある。
In FIG. 1, ill is a common signal control circuit, (2)
is the common 0 driver circuit, +31, +41,
+51 and +61 are the output Tr of the common 0 terminal (7)
, i8) , 191 , (101, (II)l'
ff control numbers A, B, C, D, (12+, (
131, (n) is the reference voltage v3 of the common coefficient. v2
.. Vl, (15), Q6) i common 1 signal driver circuit and common 2 signal driver circuit,
These are the same as the structure of the conventional one in mJ. (It is a circuit that turns off all output transistors regardless of the operation of the common signal control circuit +I+, which is the key point of this invention.

次に構成について述べる。Q8)H出力が出力Tr(3
)K接続され、入力の1つがコモン制御信号A+8に接
続され、残りの入力がテスト信号(’6+に接続された
OR回路であり、(1匂は出力が出力Tr(4)に接続
され、入力の1つがコモン制御信号B(9)に接続され
、残りの入力がテス)48号い)に接続されたOR回路
であり、(20)は出力が出力Tr (5)に接続さね
、入力の1つがコモン制御信号C(+01に接続され、
残りの入力がインバータ(22) ’i介してテスト信
号(ム)に接続されたAND回路であり、Hは出力が出
力Tr6)に接続され、人力の1つがコモン制御信号D
(11に接続され、残りの入力がインバータ(2力を介
してテスト信号(23)に接続されたAND回路である
Next, we will discuss the configuration. Q8) H output is output Tr (3
) K is connected, one of the inputs is connected to the common control signal A+8, the remaining inputs are an OR circuit connected to the test signal ('6+), and the output of (1 is connected to the output Tr(4), It is an OR circuit in which one of the inputs is connected to the common control signal B (9), the remaining inputs are connected to the test (No. 48), and the output of (20) is connected to the output Tr (5). One of the inputs is connected to the common control signal C (+01,
The remaining input is an AND circuit connected to the test signal (MU) through the inverter (22)'i, the output of H is connected to the output Tr6), and one of the inputs is connected to the common control signal D.
(11) and the remaining input is an AND circuit connected to the test signal (23) via the inverter (2 outputs).

このように構成された液晶駆動回路について、以下にリ
ーク電流テスト方法全説明する。
A leakage current test method for the liquid crystal drive circuit configured as described above will be fully explained below.

例えばcpuからの命令によりテスト信号ff Hとす
ると、コモン信号制御回路tl+の動作にかかわらすO
R回路(18) 、 (+9)はJ(レベルを出力し、
AND回路(20+ 、 t2+) U Lレベルを出
力するので、出力Tr [3) 。
For example, if the test signal ffH is set by a command from the CPU, the O
R circuits (18) and (+9) output J (level,
AND circuit (20+, t2+) outputs UL level, so output Tr [3].

+41 、 +61 、 (61は全てOFFとなりリ
ーク電流テスト可能な状態となる。テスト信号(23)
 f Lとすると回路動作は従来と同じであるので、通
常の動作は問題ない。
+41, +61, (all 61 are OFF and the leak current test is possible. Test signal (23)
If f L, the circuit operation is the same as the conventional one, so there is no problem in normal operation.

テス+” (=号の出力手段は図示していないが、レジ
スタの一部に削りあてても、CPUからの命令で発生さ
せてもよい。ISお、上記実施例でにコモン信号関係に
ついて述べた。が、液晶駆動回路の他の端子についても
可能なことは本実施例から容易に想到できる。
Although the means for outputting the "test+" (= sign is not shown in the figure, it may be generated by cutting it into a part of the register or by a command from the CPU.) However, it is easy to imagine from this embodiment that other terminals of the liquid crystal drive circuit can also be used.

〔発明の効果〕〔Effect of the invention〕

以上のようにこの発明によれば、液晶駆動回路に出力T
rを強制的にOFFにする手段を備えたので、リーク4
f iMのテストブロクラムが簡単にでき、4た、テス
ト時間が短くなる効果がある。
As described above, according to the present invention, the output T is applied to the liquid crystal drive circuit.
Since we have a means to forcibly turn off r, leak 4
It is easy to create a f iM test block, and has the effect of shortening test time.

【図面の簡単な説明】[Brief explanation of drawings]

第1図にこの発明の一実施例におけるコモン信号発生回
路、第2図は従来のコモン信号発生回路、第3図は従来
のコモン信号発生回路の動作を説明する波形図である。 +I+・・・コモン信号制御回路、(21・・・コモン
0信号ドライバ回路、(31、+41 、 +51 、
 [61、、、コモンO出カTr。 (7)・・・コモンO端子、i8) 、 +91 、 
+lot 、 (Il+・・・制御信号A。 B 、 C、D 、 (+2’l 、 Q3) 、 Q
4)−・・基準電圧V3. V2. Vl、(15+・
・・コモン1信号ドライバ回路、Q6)・・・コモン2
@号ドライバ回路、(Iη・・・全出力Tr e OF
F Kfる回路、Q8)、Q9) ・= OR回路、I
2!o)、 (2+)−A N D回路、(22・・・
インバータ、(231・・・テスト信号。 なお、図中、同一符号は同一、捷たげ相当部分をボす。
FIG. 1 shows a common signal generating circuit according to an embodiment of the present invention, FIG. 2 shows a conventional common signal generating circuit, and FIG. 3 shows a waveform diagram illustrating the operation of the conventional common signal generating circuit. +I+...Common signal control circuit, (21...Common 0 signal driver circuit, (31, +41, +51,
[61, Common O output Tr. (7)...Common O terminal, i8), +91,
+lot, (Il+...control signal A. B, C, D, (+2'l, Q3), Q
4)--Reference voltage V3. V2. Vl, (15+・
...Common 1 signal driver circuit, Q6)...Common 2
@driver circuit, (Iη...Full output Tre OF
F Kfru circuit, Q8), Q9) ・= OR circuit, I
2! o), (2+)-A N D circuit, (22...
Inverter, (231... test signal. In the figure, the same reference numerals are the same and the parts corresponding to the distortion are omitted.

Claims (1)

【特許請求の範囲】[Claims] 液晶駆動用端子に接続されたアナログスイッチと、この
アナログスイッチを制御する制御手段とからなる液晶駆
動回路において、テスト用信号を発生させる発生手段と
、前記テスト用信号の状態により、前記アナログスイッ
チを前記制御手段の動作に関係なくOFF状態にする手
段を備えたことを特徴とする液晶駆動回路。
In a liquid crystal drive circuit consisting of an analog switch connected to a liquid crystal drive terminal and a control means for controlling the analog switch, a generating means for generating a test signal and a control means for controlling the analog switch according to the state of the test signal are provided. A liquid crystal drive circuit characterized by comprising means for turning off the control means regardless of the operation of the control means.
JP25972588A 1988-10-14 1988-10-14 Liquid crystal driving circuit Pending JPH02106795A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP25972588A JPH02106795A (en) 1988-10-14 1988-10-14 Liquid crystal driving circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP25972588A JPH02106795A (en) 1988-10-14 1988-10-14 Liquid crystal driving circuit

Publications (1)

Publication Number Publication Date
JPH02106795A true JPH02106795A (en) 1990-04-18

Family

ID=17338082

Family Applications (1)

Application Number Title Priority Date Filing Date
JP25972588A Pending JPH02106795A (en) 1988-10-14 1988-10-14 Liquid crystal driving circuit

Country Status (1)

Country Link
JP (1) JPH02106795A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5644331A (en) * 1993-06-21 1997-07-01 Sony Corporation Flat panel display device and method of inspection of same
JP2006098639A (en) * 2004-09-29 2006-04-13 Seiko Epson Corp Electro-optic device and test method thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5644331A (en) * 1993-06-21 1997-07-01 Sony Corporation Flat panel display device and method of inspection of same
JP2006098639A (en) * 2004-09-29 2006-04-13 Seiko Epson Corp Electro-optic device and test method thereof

Similar Documents

Publication Publication Date Title
US7271793B2 (en) Liquid crystal display device, driving method for liquid crystal display devices, and inspection method for liquid crystal display devices
AU1726000A (en) Dynamic register with iddq testing capability
US5612697A (en) D/A converter with differential switching circuit providing symmetrical switching
JPH02106795A (en) Liquid crystal driving circuit
JP2820131B2 (en) Liquid crystal driving method and liquid crystal driving circuit
JPH08327705A (en) Comparator circuit
JPH10177368A (en) Sampling and holding circuit
JP2707595B2 (en) ROM code number reading circuit
US6522168B2 (en) Interface latch for data level transfer
KR100597061B1 (en) Tft lcd gate driver circuit with two-transistion output level shifter
JP2912361B1 (en) Output buffer circuit
JP3739690B2 (en) Stress test circuit for semiconductor integrated circuit and stress test method using this circuit
JPH02186826A (en) Level shifter
JPS5941196B2 (en) LCD drive method
JPH05303889A (en) Semiconductor device
JP3093685B2 (en) Integrated circuit and its function test method
JP3031090B2 (en) Output port circuit
JPS60245141A (en) Semiconductor integrated circuit device
JP3531577B2 (en) Semiconductor inspection equipment
JPH04149517A (en) Liquid crystal driving circuit
JPS5918742B2 (en) Large scale integrated circuit
SU1524168A1 (en) Device for switching voltages
JPH0322860A (en) High voltage generating circuit
JPH10327061A (en) Output circuit device
JPH09127185A (en) Test input cell and test method