功能作用:74LS247 TTL BCD—7段4线15V输出译码器/驱动器
图1 74247内部逻辑及引脚图
图2 7段数码应用电路
74LS247 GUARANTEED OPERATING RANGES保证工作范围 :
|
Symbol 符号 |
Parameter 参数 | 最小 | 典型 | 最大 | 单位 |
| VCC | Supply Voltage 电源电压 | 4.75 | 5.0 | 5.25 | V |
| TA | Operating Ambient Temperature Range 操作环境温度范围 | 0 | 25 | 70 | ℃ |
| IOH | Output Current–High BI/RBO 输出电流-BI/ RBO | –50 | μA | ||
| IOL | Output Current – Low BI/RBO 输出电流低BI/RBO | 3.2 | mA | ||
| VO(off) | Off–State Output Voltage 断态输出电压a – g | 15 | V | ||
| IO(on) | On–State Output Current a – g 通态输出电流 | 24 | mA |
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified)直流特性工作温度范围(除非另有说明):
|
Symbol 符号 |
Parameter 参数 |
数值 |
单位 | Test Conditions 测试条件 | ||||
| 最小 | 典型 | 最大 | ||||||
| VIH | Input HIGH Voltage 输入高电平电压 | 2.0 | V | Guaranteed Input HIGH Voltage for All Inputs | ||||
| VIL | Input LOW Voltage 输入低电平电压 | 0.8 | V | Guaranteed Input LOW Voltage for All Inputs | ||||
| VIK | Input Clamp Diode Voltage 输入电压钳位二极管 | –0.65 | –1.5 | V | VCC = 最小, IIN = – 18mA | |||
| VOH | Output HIGH Voltage 输出高电平电压BI/RBO | 2.4 | 4.2 | V | VCC = 最小, IOH = 最大, VIN = VIH or VIL per Truth Table | |||
| VOL | Output LOW Voltage 输出低电平电压 BI/RBO | 0.25 | 0.4 | V | IOL=1.6mA | VCC=VCC 最小, VIN=VIL or VIHVIN =VIL or VIH per Truth Table | ||
| 0.35 | 0.5 | V | IOL=3.2mA | |||||
| IO(off) | Off-State Output Current 断态输出电流a–g | 250 | μA | VCC = 最大, VIH = 2.0V, VO(off) = 15V, VIL =最大 | ||||
| VO(on) | On-State Output Voltage通态输出电流 a–g | 0.25 | 0.4 | V | IO(on)=12mA | VCC = 最小, VIH = 2.0V, VIL per Truth Table | ||
| 0.35 | 0.5 | V | IO(on)=24mA | |||||
| IIH | Input HIGH Current Input HIGH Current 输入高电平电流 | 20 | μA | VCC = 最大, VIN = 2.7V | ||||
| 0.1 | mA | VCC = 最大, VIN = 7.0V | ||||||
| IIL | Input LOW Current Any Input, except 输入低电平电流BI/RBO BI/RBO | –0.4 | mA | VCC = 最大, VIN = 0.4V Ωμ | ||||
| –1.2 | ||||||||
| IOS | Short Circuit Current BI/RBO (Note 1) 输出短路电流 | –0.3 | –2.0 | mA | VCC = 最大 | |||
| ICC | Power Supply Current 电源电流 | 7.0 | 13 | mA | VCC = 最大 | |||
AC CHARACTERISTICS (VCC=5.0V, TA=25℃)AC特性(Vcc=5.0V,TA=25℃ )
|
Symbol 符号 |
Parameter 参数 参数 |
数值 |
单位 | Test Conditions 测试条件 | |||
| 最小 | 典型 | 最大 | |||||
| tPLH | Turn-Off Time from A Input 关断时间由A输入 | 100 | ns | CL = 15pF
RL = 665Ω |
|||
| tPHL | Turn-On Time from A Input 开启时间从A输入 | 100 | |||||
| tPHL | Turn-Off Time from RBI Input 关断时间 | 100 | |||||
| tPLH | Turn-On Time from RBI Input 开启时间 | 100 | |||||
FUNCTION TABLE真值表:
|
十进制OROR功能 |
INPUTS 输入 | BI/RBO | OUTPUTS 输出 | NOTE | |||||||||||
| LT | RBI | D | C | B | A | a | b | c | d | e | f | g | 1 | ||
| 0 | H | H | L | L | L | L | H | ON | ON | ON | ON | ON | ON | OFF | |
| 1 | H | X | L | L | L | H | H | OFF | ON | ON | OFF | OFF | OFF | OFF | |
| 2 | H | X | L | L | H | L | H | ON | ON | OFF | ON | ON | OFF | ON | |
| 3 | H | X | L | L | H | H | H | ON | ON | ON | ON | OFF | OFF | ON | |
| 4 | H | X | L | H | L | L | H | OFF | ON | ON | OFF | OFF | ON | ON | |
| 5 | H | X | L | H | L | H | H | ON | OFF | ON | ON | OFF | ON | ON | |
| 6 | H | X | L | H | H | L | H | ON | OFF | ON | ON | ON | ON | ON | |
| 7 | H | X | L | H | H | H | H | ON | ON | ON | OFF | OFF | OFF | OFF | |
| 8 | H | X | H | L | L | L | H | ON | ON | ON | ON | ON | ON | ON | |
| 9 | H | X | H | L | L | H | H | ON | ON | ON | ON | OFF | ON | ON | |
| 10 | H | X | H | L | H | L | H | OFF | OFF | OFF | ON | ON | OFF | ON | |
| 11 | H | X | H | L | H | H | H | OFF | OFF | ON | ON | OFF | OFF | ON | |
| 12 | H | X | H | H | L | L | H | OFF | ON | OFF | OFF | OFF | ON | ON | |
| 13 | H | X | H | H | L | H | H | ON | OFF | OFF | ON | OFF | ON | ON | |
| 14 | H | X | H | H | H | L | H | OFF | OFF | OFF | ON | ON | ON | ON | |
| 15 | H | X | H | H | H | H | H | OFF | OFF | OFF | OFF | OFF | OFF | OFF | |
| BI | X | X | X | X | X | X | L | OFF | OFF | OFF | OFF | OFF | OFF | OFF | 2 |
| RBI | H | L | L | L | L | L | L | OFF | OFF | OFF | OFF | OFF | OFF | OFF | 3 |
| LT | L | X | X | X | X | X | H | ON | ON | ON | ON | ON | ON | ON | 4 |


