The SN74ALS568A decade counter and ´ALS569A binary counters are programmable, count up or down, and offer both synchronous and asynchronous clearing. All synchronous functions are executed on the positive-going edge of the clock (CLK) input.

The clear function is initiated by applying a low level to either asynchronous clear (ACLR\) or synchronous clear (SCLR\). Asynchronous (direct) clearing overrides all other functions of the device, while synchronous clearing overrides only the other synchronous functions. Data is loaded from the A, B, C, and D inputs by holding load () low during a positive-going clock transition. The counting function is enabled only when enable P (ENP\) and enable T (ENT\) are low and ACLR\, SCLR\, and are high. The up/down (U/D\) input controls the direction of the count. These counters count up when U/D\ is high and count down when U/D\ is low.

A high level at the output-enable () input forces the Q outputs into the high-impedance state, and a low level enables those outputs. Counting is independent of . ENT\ is fed forward to enable the ripple-carry output (RCO\) to produce a low-level pulse while the count is zero (all Q outputs low) when counting down or maximum (9 or 15) when counting up. The clocked carry output (CCO\) produces a low-level pulse for a duration equal to that of the low level of the clock when is low and the counter is enabled (both ENP\ and ENT\ are low); otherwise, CCO\ is high. CCO\ does not have the glitches commonly associated with a ripple-carry output. Cascading is normally accomplished by connecting or CCO\ of the first counter to ENT\ of the next counter. However, for very high-speed counting, should be used for cascading since CCO\ does not become active until the clock returns to the low level.

The SN54ALS569A is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ALS568A and SN74ALS569A are characterized for operation from 0°C to 70°C.

• 3-State Q Outputs Drive Bus Lines Directly
• Counter Operation Independent of 3-State Output
• Fully Synchronous Clear, Count, and Load
• Asynchronous Clear Is Also Provided
• Fully Cascadable
• Package Options Include Plastic Small-Outline (DW) Packages, Ceramic Chip Carriers (FK), and Standard Plastic (N) and Ceramic (J) 300-mil DIPs

• TLC59482 - 具有 6 位全局亮度控制的 16 通道、16 位 PWM LED 驱动器
• DS25CP102Q-Q1 - 具有 Tx 预强调和 Rx 均衡功能的自动 3.125 Gbps 2X2 LVDS 交叉点交换器
• OMAP3503 - 应用处理器
• CD4510B - CMOS 可预设置的 BCD 加/减计数器
• SN55454B - 双路非常高速大电流外设驱动器
• DRV2605L - 用于具有内置库和智能环路架构的 ERM 和 LRA 触觉驱动器
• DRV8821 - 具有 1/8 微步进分度器的 1.5A 双路双极步进电机驱动器（Step/Dir 控制器）
• DP83843 - PHYTER
• CD74HC03 - 具有漏极开路的高速 CMOS 逻辑四路 2 输入与非门
• UC2906 - 铅酸线性充电管理 IC