Standard ICs
8-bit static shift register
BU4021B / BU4021BF
The BU4021B and BU4021BF are 8-bit static shift registers c...
Standard ICs
8-bit static shift register
BU4021B / BU4021BF
The BU4021B and BU4021BF are 8-bit static shift registers consisting of 8 register cells, each of which has parallel input. Control of the parallel / serial control input (P / S) enables serial input / serial output with clock synchronization, as well as parallel input / serial output conversions.
Absolute maximum ratings (V
Parameter Power supply
voltage Power dissipation Operating temperature Storage temperature Input
voltage
SS
= 0V, Ta = 25°C)
Symbol VDD Pd Topr Tstg VIN Limits – 0.3 ~ + 18 1000 (DIP), 500 (SOP) – 40 ~ + 85 – 55 ~ + 150 – 0.3 ~ VDD + 0.3 Unit V mW °C °C V
Logic circuit diagram
P/S (9) Ds (11) CLOCK (10) P1 (7) P2 (6) P3 (5) P4 (4) P5 (13) P6 (14) P7 (15) P8 (1)
Block diagram
P8 1 P8 Q6 2 Q6 Q8 3 Q8 P4 4 P4 P3 5 P3 P2 (2) Q6 (12) Q7 (3) Q8 P1 6 P2 DS CLOCK 11 Q7 12 Q7 DS P5 13 P5 P7 P6 14 P6 16 VDD 15 P7
D Q C
D Q C
D Q C
D Q C
D Q C
D Q Q C
D Q Q C
D Q C
7
P1
P/S
10
CLOCK P/S
VSS
8
9
Truth table Serial operation
t n n+1 n+2 n+3 CLOCK DS L H L H X P/S L L L L L Q6 Q7 Q8 (t = n + 6) (t = n + 7) (t = n + 8) 0 1 0 1 Q6 ? 0 1 0 Q7 ? ? 0 1 Q8
Parallel operation
CLOCK DS P / S Dm X X
X: Irrelevant
Qm∗ L H
H H
L H
∗: Q6, Q7, and Q8 are external
1
Standard ICs
Electrical characteristics DC characteristics (unless otherwise noted, Ta = 25°C, V
Parameter Symbol Min. 3.5 Input high level
voltage VIH 7.0 11.0 — Input low level
voltage VIL — — Input high level current Input...