CD4521 24-Stage Frequency Divider

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The CD4521 belongs to the CD4000 IC series. CD4521 consists Of an oscillator section and 24 ripple-carry binary counter stages. The oscillator configuration (using IN’) allows the design of either NC or crystal oscillator circuits. INI should be tied either HIGH or LOW when not in use. A HIGH on the RESET causes the counter to go to the all-O’s state and disables the oscillator. The CD4521 IC has a wide range of working voltage, a wide range of working conditions, and directly interfaces with CMOS, NMOS, and TTL.

Frequency Divider

A Frequency Divider is a circuit that divides a given frequency by a factor of n, where n is an integer. Based on the application, Frequency Dividers can be designed for both Analog and Digital domains. Analog Frequency Dividers are used for very high frequency application but are very rarely used. They are further classified into Regenerative Dividers, Parametric Dividers and Harmonic Injection Dividers.

CD4521 Key Features

Reset disables the RC oscillator for low power standby condition
VDD’ and Vss’ pins are brought out from the crystal oscillator to allow use Of
- external resistors for low-power operation
Maximum input current Of 1 PA at 18 V
- Over full package-temperature range: 100 nA at 18 V and 250C
Common reset
100% tested for 20-V quiescent current
5, 10 and 15 V parametric ratings
Standardized symmetrical output characteristics

CD4521 Pinout

Pin No	Pin Name	Description
1	Q24	Output for 2^24 Count
2	RESET	Reset Pin
3	VSS’	Invert of Source Supply
4	OUT 2	Output Pin 2
5	VDD’	Invert of drain supply
6	IN 2	Input pin 2
7	OUT 1	Output Pin 1
8	VSS	Source Supply
9	IN 1	Input Pin 1
10	Q18	Output for 2^18 Count
11	Q19	Output for 2^19 Count
12	Q20	Output for 2^20 Count
13	Q21	Output for 2^21 Count
14	Q22	Output for 2^22 Count
15	Q23	Output for 2^23 Count
16	VDD	Drain Supply