SN74AS169A
- Fully Synchronous Operation for Counting and Programming
- Internal Carry Look-Ahead Circuitry for Fast Counting
- Carry Output for n-Bit Cascading
- Fully Independent Clock Circuit
- Package Options Include Plastic Small-Outline (D) Packages, Ceramic Chip Carriers (FK), and Standard Plastic (N) and Ceramic (J) 300-mil DIPs
These synchronous 4-bit up/down binary presettable counters feature an internal carry look-ahead circuitry for cascading in high-speed counting applications. Synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincident with each other when so instructed by the count-enable (, ) inputs and internal gating. This mode of operation eliminates the output counting spikes normally associated with asynchronous (ripple-clock) counters. A buffered clock (CLK) input triggers the four flip-flops on the rising (positive-going) edge of the clock waveform.
These counters are fully programmable; that is, they may be preset to either level. The load-input circuitry allows loading with the carry-enable output of cascaded counters. Because loading is synchronous, setting up a low level at the load (LOAD\) input disables the counter and causes the outputs to agree with the data inputs after the next clock pulse.
The internal carry look-ahead circuitry provides for cascading counters for n-bit synchronous application without additional gating. and inputs and a ripple-carry output () are instrumental in accomplishing this function. Both and must be low to count. The direction of the count is determined by the level of the up/down (U/D\) input. When U/D\ is high, the counter counts up; when low, it counts down. is fed forward to enable . , thus enabled, produces a low-level pulse while the count is zero (all inputs low) counting down or maximum (15) counting up. This low-level overflow ripple-carry pulse can be used to enable successive cascaded stages. Transitions at or are allowed regardless of the level of the clock input. All inputs are diode clamped to minimize transmission-line effects, thereby simplifying system design.
These counters feature a fully independent clock circuit. Changes at control inputs (, , , or U/D\) that modify the operating mode have no effect on the contents of the counter until clocking occurs. The function of the counter (whether enabled, disabled, loading, or counting) is dictated solely by the conditions meeting the stable setup and hold times.
The SN54ALS169B and SN54AS169A are characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ALS169B and SN74AS169A are characterized for operation from 0°C to 70°C.
관심 가지실만한 유사 제품
비교 대상 장치와 동일한 기능을 지원하는 핀 대 핀
비교 대상 장치와 유사한 기능
기술 자료
유형 | 직함 | 날짜 | ||
---|---|---|---|---|
* | Data sheet | Synchronous 4-Bit Up/Down Binary Counters datasheet (Rev. B) | 1994/12/01 | |
Selection guide | Logic Guide (Rev. AB) | 2017/06/12 | ||
Application note | Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) | 2015/12/02 | ||
User guide | LOGIC Pocket Data Book (Rev. B) | 2007/01/16 | ||
Application note | Semiconductor Packing Material Electrostatic Discharge (ESD) Protection | 2004/07/08 | ||
Application note | TI IBIS File Creation, Validation, and Distribution Processes | 2002/08/29 | ||
Application note | Designing With Logic (Rev. C) | 1997/06/01 | ||
Application note | Advanced Schottky Load Management | 1997/02/01 | ||
Application note | Input and Output Characteristics of Digital Integrated Circuits | 1996/10/01 | ||
Application note | Live Insertion | 1996/10/01 | ||
Application note | Advanced Schottky (ALS and AS) Logic Families | 1995/08/01 |
설계 및 개발
추가 조건 또는 필수 리소스는 사용 가능한 경우 아래 제목을 클릭하여 세부 정보 페이지를 확인하세요.
14-24-LOGIC-EVM — 14핀~24핀 D, DB, DGV, DW, DYY, NS 및 PW 패키지용 로직 제품 일반 평가 모듈
14-24-LOGIC-EVM 평가 모듈(EVM)은 14핀~24핀 D, DW, DB, NS, PW, DYY 또는 DGV 패키지에 있는 모든 로직 장치를 지원하도록 설계되었습니다.
패키지 | 핀 | CAD 기호, 풋프린트 및 3D 모델 |
---|---|---|
PDIP (N) | 16 | Ultra Librarian |
주문 및 품질
- RoHS
- REACH
- 디바이스 마킹
- 납 마감/볼 재질
- MSL 등급/피크 리플로우
- MTBF/FIT 예측
- 물질 성분
- 인증 요약
- 지속적인 신뢰성 모니터링
- 팹 위치
- 조립 위치