Overview
The CD74HC4511, produced by Texas Instruments, is a BCD-to-7 segment latch/decoder/driver integrated circuit. This device is designed to convert Binary Coded Decimal (BCD) inputs into the corresponding 7-segment display outputs. It features four address inputs (D0-D3), an active-low blanking (BL) input, a lamp-test (LT) input, and a latch-enable (LE) input. The LE input, when high, enables the latches to store the BCD inputs, while a low LE makes the outputs transparent to the BCD inputs.
The CD74HC4511 operates over a wide voltage range of 2 V to 6 V, making it versatile for various applications. It is known for its high-output sourcing capability, balanced propagation delays, and significant power reduction compared to LSTTL logic ICs.
Key Specifications
| Parameter | Unit | Min | Typ | Max |
|---|---|---|---|---|
| VCC (Supply Voltage) | V | 2 | - | 6 |
| VIH (High-level input voltage) | V | - | - | 2 |
| VIL (Low-level input voltage) | V | 0.8 | - | - |
| IOH (High level output voltage) at VCC = 6 V, IOH = -20 μA | V | 4.4 | - | - |
| VOL (Low level output voltage) at VCC = 6 V, IOL = 20 μA | V | 0.1 | - | - |
| ICC (Supply current) at VCC = 6 V, IO = 0 | μA | - | - | 160 |
| Input Capacitance | pF | - | - | 10 |
| tW (Pulse duration, LE low) at VCC = 6 V | ns | 14 | - | 20 |
| tsu (Setup time, BCD inputs before LE↑) at VCC = 6 V | ns | 10 | - | 15 |
| th (Hold time, BCD inputs before LE↑) at VCC = 6 V | ns | 3 | - | 3 |
Key Features
- Operates over a wide voltage range of 2 V to 6 V.
- High-output sourcing capability: up to 10 mA at 6 V.
- Input latches for BCD code storage.
- Lamp test and blanking capability.
- Balanced propagation delays and transition times.
- Significant power reduction compared to LSTTL logic ICs.
- High noise immunity: NIL or NIH = 30% of VCC at VCC = 5 V for 'HC4511).
- Direct LSTTL input logic compatibility and CMOS input compatibility for CD74HCT4511).
Applications
- Display drivers for 7-segment displays in various digital instruments and appliances.
- BCD-to-7 segment decoding in digital clocks, calculators, and other electronic devices).
- Industrial control panels and instrumentation).
- Automotive and consumer electronics where display control is necessary).
Q & A
- What is the voltage range for the CD74HC4511? The CD74HC4511 operates over a voltage range of 2 V to 6 V).
- What is the maximum output current sourcing capability of the CD74HC4511? The device can source up to 10 mA at 6 V).
- What inputs does the CD74HC4511 have? The device has four address inputs (D0-D3), an active-low blanking (BL) input, a lamp-test (LT) input, and a latch-enable (LE) input).
- How do the latches work in the CD74HC4511? When the LE input is high, the latches store the BCD inputs. When LE is low, the latches are disabled, making the outputs transparent to the BCD inputs).
- What is the significance of the lamp test and blanking capability? These features allow for testing the display and blanking it when necessary, enhancing the functionality of the display system).
- What are the thermal considerations for the CD74HC4511? The device has specified thermal metrics, and proper bypass capacitors are recommended to prevent power disturbances).
- How should unused inputs be handled in the CD74HC4511? Unused inputs must be held at VCC or GND to ensure proper device operation).
- What are the typical applications of the CD74HC4511? It is used in display drivers for 7-segment displays, BCD-to-7 segment decoding, industrial control panels, and various electronic devices).
- What is the input capacitance of the CD74HC4511? The input capacitance is typically 10 pF).
- What are the timing requirements for the LE input? The pulse duration for LE low is between 14 ns and 20 ns at VCC = 6 V, with setup and hold times specified accordingly).
