LSI Computer Systems LS7220
The LS7220 is a MOS digital lock circuit. When wired to a ten-digit keypad, the circuit will recognize one four-digit combination out of a possible 5040 combinations. These features include Sense input which enables the IC, Save Memory for Valet Parking, Convenience Delay to maintain Unlock condition for short term interruptions of the Sense input and Save Status and Lock Status outputs which can be used for direct drive of LED indicators.| Part No. | LS7220 |
|---|---|
| Datasheet | LS7220 Download |
| Manufacturer |  LSI Computer Systems |
| Description | DIGITAL LOCK FOR AUTOMOTIVE IGNITIONS |
| Buy | Stock & Price |
FEATURES
:● 5040 Four-Digit Combinations (for a 10 digit Keypad)
● Combinations are Hard-Wire Programmed
● Sense Input Enables Operation
● Save Memory Feature for Valet Parking
● Convenience Delay Controlled by External Capacitor
● Static or Momentary Lock Control Output
● Save Memory and Lock Status Outputs
● +5V to +18V Operation (Vss - VDD)
● LS7220 (DIP), LS7220-S (SOIC) - See Figure 1
DESCRIPTION
: The LS7220 is a MOS digital lock circuit. The LS7220 is configured with the features required for an Automotive Ignition Anti-Theft Digital Lock (See Figure 5). LS 7220 LSI PIN ASSIGNMENT - TOP VIEW SENSE IN 1 14 V SS (+V) UNSELECTED KEYS 2 (RESET) I1 3 13 LOCK OUT 12 CONVENIENCE DELAY SELECTED KEYS (IN SEQUENCE) I2 4 I3 5 I4 6 11 SAVE IN 10 SAVE STATUS OUT 9 VDD (-V) LOCK IN 7 FIGURE 1. 8 LOCK STATUS OUT UNSELECTED KEYS (RESET) INPUT (Pin 2) A high at this input resets the Sequential Detector for the SELECTED KEYS inputs. This input must be wired to all digit keys which are not part of the Four-Digit Combination.
