Overview
The CD74HC390E is a high-speed CMOS logic dual decade ripple counter produced by Texas Instruments. This device is part of the 74HC series, known for its high-speed and low power consumption. It features two independent 4-bit decade counters, each consisting of a divide-by-2 and a divide-by-5 counter, allowing for flexible configuration. The counters are falling-edge clocked with asynchronous clear inputs, making them versatile for various counting applications.
Key Specifications
| Parameter | Value | Unit | Conditions |
|---|---|---|---|
| Supply Voltage Range (VCC) | 2 to 6 | V | HC Types |
| Supply Voltage Range (VCC) | 4.5 to 5.5 | V | HCT Types |
| Operating Temperature Range | -55 to 125 | °C | |
| Maximum Clock Frequency | Up to 35 MHz | MHz | VCC = 6V, HC Types |
| Maximum Clock Frequency | Up to 27 MHz | MHz | VCC = 5V, HCT Types |
| Input High Level Voltage (VIH) | 1.5 to 4.2 V | V | Depending on VCC |
| Input Low Level Voltage (VIL) | 0.5 to 1.8 V | V | Depending on VCC |
| Output High Level Voltage (VOH) | 1.9 to 5.9 V | V | Depending on VCC and IOH |
| Output Low Level Voltage (VOL) | 0.1 V | V | IOL = 20 μA |
| Propagation Delay (tpd) | Up to 265 ns | ns | VCC = 2V, HC Types |
| Propagation Delay (tpd) | Up to 53 ns | ns | VCC = 6V, HC Types |
| Package Type | PDIP (16 pins) | ||
| Package Dimensions | 19.31 mm x 6.35 mm | mm |
Key Features
- Two independent 4-bit decade ripple counters, each consisting of a divide-by-2 and a divide-by-5 counter.
- Flexible configuration: can be configured to divide-by-2, 4, 5, 10, 20, 25, 50, 100.
- Asynchronous clear inputs (1CLR and 2CLR) to clear each decade counter individually.
- Wide operating temperature range: -55°C to 125°C.
- High noise immunity: NIL = 30%, NIH = 30% of VCC at VCC = 5V for HC types.
- Direct LSTTL input logic compatibility for HCT types.
- Significant power reduction compared to LSTTL logic ICs.
- Balanced propagation delay and transition times.
- Fanout capability: up to 10 LSTTL loads for standard outputs and up to 15 LSTTL loads for bus driver outputs.
Applications
- Counting circuits in digital systems.
- Frequency division and timing applications.
- BCD (Binary Coded Decimal) and bi-quinary counters.
- Automotive and industrial control systems requiring high reliability and wide temperature range operation.
- Consumer electronics where low power consumption and high speed are critical).
Q & A
- What is the CD74HC390E?
The CD74HC390E is a high-speed CMOS logic dual decade ripple counter produced by Texas Instruments.
- What are the key components of the CD74HC390E?
The device includes two independent 4-bit decade counters, each consisting of a divide-by-2 and a divide-by-5 counter.
- What is the operating temperature range of the CD74HC390E?
The operating temperature range is -55°C to 125°C.
- What are the supply voltage ranges for the CD74HC390E?
The supply voltage range is 2V to 6V for HC types and 4.5V to 5.5V for HCT types.
- What is the maximum clock frequency for the CD74HC390E?
The maximum clock frequency is up to 35 MHz for HC types and up to 27 MHz for HCT types.
- How many LSTTL loads can the CD74HC390E drive?
The device can drive up to 10 LSTTL loads for standard outputs and up to 15 LSTTL loads for bus driver outputs.
- What are the asynchronous clear inputs used for?
The asynchronous clear inputs (1CLR and 2CLR) are used to clear each decade counter individually.
- What type of package is the CD74HC390E available in?
The CD74HC390E is available in a 16-pin PDIP package.
- What are the dimensions of the PDIP package?
The dimensions of the PDIP package are 19.31 mm x 6.35 mm.
- What are some common applications of the CD74HC390E?
Common applications include counting circuits, frequency division, timing applications, and use in automotive and industrial control systems.
