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Texas Instruments SN75494 Digit Driver Chip aka SN27423, SN27914

• Features

The SN75494 provides the same basic function as the SN75492 but with some key differences:

• Operates from lower VCC voltages, as low as 3.2 V
• The SN75494 provides access to the pre-driver collectors via the VCC pin to allow good saturation of the output transistors
• An enable input is provided to allow display blanking


The SN75494 is preferred on designs running on 3 batteries and is typically found in early designs with additional segment drivers (TMS0120).

QUICK-LINK to Display Drivers.

• Family Members and Applications

SR-10 and other early LED calculators

• Technical Specifications

Item Min Typ Max Unit Comments
VCC 3.2 7.2 8.8 V  
VSS 6.5 7.2 8.8 V  
IL  250     mA VI=6.5 V, VO=3.5 V
IL     0.2 mA Output Leakage Current
VI-VD     10 V  

• Technology

The SN75494 was manufactured in a 10 um metal gate Bipolar process (metal width = 0.4 mil / 10 um, metal spacing = 0.4 mil / 10 um).

The die size of the SN75494 is approximately tbd mils * tbd mils / tbd mm * tbd mm.

• Packaging

The SN75494 uses a standard 0.3” wide 16-pin DIP (Dual In-line Package with a 0.1” / 2.54 mm lead pitch).

• Pin Configuration

Pin IO Function Pin IO Function
1 V VSS 16 V VCC
2 I Digit input 1 15 I Digit input 6
3 O Digit output 1 14 O Digit output 6
4 O Digit output 2 13 O Digit output 5
5 I Digit input 2 12 I Digit input 5
6 O Digit output 3 11 O Digit output 4
7 I Digit input 3 10 I Digit input 4
8 V VDD 9 I Enable drivers


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If you have additions to the above datasheet please email: joerg@datamath.org.

© Joerg Woerner, February 02, 2001. No reprints without written permission.