CD4045B是TI公司的一款计数器/算术/奇偶校验功能产品，CD4045B是CMOS 21 级计数器，本页介绍了CD4045B的产品说明、应用、特性等，并给出了与CD4045B相关的TI元器件型号供参考。
CD4045B - CMOS 21 级计数器 - 计数器/算术/奇偶校验功能 - 特殊逻辑 - TI公司（Texas Instruments，德州仪器）
CD4045B is a timing circuit consisting of 21 counter stages, two output-shaping flip-flops, two inverter output drivers, and input inverters for use in a crystal oscillator. The CD4045B configuration provides 21 flip-flop counting stages, and two flip-flops for shaping the output waveform for a 3.125% duty cycle. Push-pull operation is provided by the inverter output drivers.
The first inverter is intended for use as a crystal oscillator/amplifier. However, it may be used as a normal logic inverter if desired. A crystal oscillator circuit can be made less sensitive to voltage-supply variations by the user of source resistors. In this device, the sources of the p and n transistors have been brought out to package terminals. If external resistors are not required, the sources must be shorted to their respective substrates (Sp to VDD, Sn to VSS). See Fig. 1. The first inverter in conjunction with an outboard inverter, such as 1/6 CD4069, and RX, CX, and RS can also be used to construct an RC oscillator. The following data is supplied as a guide in the selection of values for RX, RS, and CX used in Fig. 11:
RX max = 10 M and CX = 50 pF CX max = 25 µF with RS = 560 kThe CD4045B types are supplied in 16-lead dual-in-line plastic packages (E suffix), 16-lead small-outline package (NSR suffix), and 16-lead thin shrink small-outline packages (PW and PWR suffixes).
- Very low operating dissipation . . . . . <1 mW (typ.) @ VDD = 5 V, f = 1 MHz
- Output drivers with sink or source capability . . . . . 7 mA (typ.) @ VDD = 5 V
- Medium speed (typ.) . . . f = 25 MHz @ VDD = 10 V
- 100% tested for quiescent current at 20 V
- 5-V, 10-V, and 15-V parametric ratings
- Meets all requirements of JEDEC Tentative Standard No. 13B, "Standard Specifications for Description of 'B' Series CMOS Devices"
- Applications
- Digital equipment in which ultra-low dissipation and/or operation using a battery source is required.
- Accurate timing from a crystal oscillator for timing applications such as wall clocks, table clocks, automobile clocks, and digital timing references in any circuit requiring accurately timed outputs at various intervals in the counting sequence.
- Driving miniature synchronous motors, stepping motors, or external bipolar transistors in push-pull fashion.
