آي سي درايفر شاشة كريستال سائل موديل: HCF4056

The HCF4056B is a monolithic integrated circuit designed as a BCD-to-7-segment decoder/driver specifically optimized for driving liquid-crystal displays (LCDs). It belongs to a family of display drivers that includes the 4054B and 4055B, all of which feature on-chip logic-level conversion to bridge different input and output signal swings.

Key Functional Features

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  Strobed Latch Function: Unlike the 4055B, the HCF4056B includes a strobed-latch function at the BCD inputs. Data is transferred from the input to the output when a high voltage level is applied to the strobe input; a low level latches the data.

  
  


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  Logic-Level Conversion: The device permits BCD input-signal swings (VDD to VSS) to be independent of the 7-segment output-signal swings (VDD to VEE). For example, inputs can swing from 0 to +3V while outputs swing from 0 to -5V.

  
  


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  LCD Driving Capability: It provides equivalent AC output drive for LCDs without requiring external capacitors. By using a square wave at the Display-Frequency (DF) input, the device can effectively double the voltage across selected segments, resulting in a 36V (p-p) drive from an 18V supply.

  
  


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  Full Decoding: The chip provides full decoding for all input combinations, allowing for the display of numeric characters 0–9 and specialized characters L, H, P, A, -, as well as a blank position.

  
  

Electrical Specifications

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  Supply Voltage (VDD): Recommended operating range is 3V to 15V for HCF types.

  
  


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  Quiescent Current: 100% tested and specified up to 20V for certain package types.

  
  


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  Operating Temperature: The HCF version is designed for an intermediate temperature range of -40°C to +85°C.

  
  


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  Low Power Consumption: Designed for ultra-low-power displays when used with COS/MOS circuits.

  
  

Pin Configuration and Packages

The HCF4056B is typically available in a 16-lead configuration. Common package types include:

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  EY: Plastic Dual In-Line Package (DIP).

  
  


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  F: Ceramic Frit Seal Package.

  
  


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  M1: Micro Package (SO16).

  
  


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  C1: Plastic Chip Carrier (PLCC20).

  
  

Typical Applications

The HCF4056B is primarily used in digital clock displays and 3½-digit crystal displays. When used for LCDs, it must be paired with an HCF4054B to provide the common Display-Frequency (DF) output. It can also be adapted to drive LED displays if external exclusive-OR gates are used for sufficient current drive

Datasheet