74LS139: 马来西亚的首选 Utsource Holding Company Limited

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Below is the parameter table and instructions for the 74LS139 dual 1-of-4 line decoders/demultiplexers.

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
Supply Voltage	V_CC	4.75	5.0	5.25	V	-
Input Low Voltage	V_IL	0.8	-	-	V	-
Input High Voltage	V_IH	-	-	2.0	V	-
Output Low Voltage	V_OL	0.4	0.5	0.6	V	I_OL = 16 mA
Output High Voltage	V_OH	2.4	2.7	3.4	V	I_OH = -0.4 mA
Input Leakage Current	I_IL	-1.0	-	-	μA	V_CC = 5V, T_A = 25°C
Output Sink Current	I_OL	-16	-	-	mA	V_OL = 0.4V, T_A = 25°C
Output Source Current	I_OH	-	-	-0.4	mA	V_OH = 2.4V, T_A = 25°C
Propagation Delay Time	t_pd	15	22	34	ns	V_CC = 5V, T_A = 25°C, V_OH = 2.4V, V_OL = 0.4V
Power Dissipation	P_D	-	-	100	mW	Per Package

A1, A2: Address inputs for the first decoder.
B1, B2: Address inputs for the second decoder.
G1, G2: Enable inputs (active low) for the first and second decoders, respectively.
Y1 to Y4: Outputs for the first decoder.
Y5 to Y8: Outputs for the second decoder.
V_CC: Positive supply voltage.
GND: Ground.

Enable Inputs (G1, G2):
- When G1 is low, the first decoder is enabled.
- When G2 is low, the second decoder is enabled.
- When either G1 or G2 is high, the corresponding decoder is disabled, and all outputs are high.
Address Inputs (A1, A2, B1, B2):
- The address inputs determine which output is active low.
- For example, if A1 and A2 are both low and G1 is low, Y1 will be low, and all other outputs will be high.
Outputs (Y1 to Y8):
- The outputs are active low.
- Only one output per decoder is active at any given time, based on the address inputs and enable status.

Decoder 1:
- If A1 = 0, A2 = 0, and G1 = 0, then Y1 = 0 (low), and Y2, Y3, Y4 = 1 (high).
Decoder 2:
- If B1 = 1, B2 = 0, and G2 = 0, then Y5 = 1, Y6 = 0 (low), Y7, Y8 = 1 (high).

Multiplexing/Demultiplexing: Used to route data from a single source to multiple destinations.
Memory Address Decoding: Used to select specific memory locations.
Control Logic: Used in various control circuits to manage different states or conditions.

This table and instructions should provide a comprehensive overview of the 74LS139 dual 1-of-4 line decoders/demultiplexers.

(For reference only)