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TC74VHC123,221AF/AFN/AFT/AFK
TOSHIBA CMOS Digital Integrated Circuit Silicon Monolithic
TC74VHC123AF,TC74VHC123AFN,TC74VHC123AFT,TC74VHC123AFK TC74VHC221AF,TC74VHC221AFN,TC74VHC221AFT,TC74VHC221AFK
Dual Monostable Multivibrator TC74VHC123AF/AFN/AFT/AFK Retriggerble TC74VHC221AF/AFN/AFT/AFK Non-Retriggerble
Note: xxxFN (JEDEC SOP) is not available in Japan.
TC74VHC123AF, TC74VHC221AF
The TC74VHC123A/221A are high speed CMOS MONOSTABLE MULTIVIBRATOR fabricated with silicon gate C2MOS technology.
There are two trigger inputs, A input (negative edge), and B input (positive edge). These inputs are valid for a slow rise/fall time signal (tr = tf = 1 s) as they are schmitt trigger inputs. This device may also be triggered by using CLR input (positive edge).
After triggering, the output stays in a MONOSTABLE state for a time period determined by the external resistor and capacitor (RX, CX). A low level at the CLR input breaks this state.
Limits for CX and RX are: External capacitor, CX: No limit External resistor, RX: VCC = 2.0 V more than 5 kΩ VCC ≥ 3.0 V more than 1 kΩ
An input protection circuit ensures that 0 to 5.5 V can be applied to the input pins without regard to the supply voltage. This device can be used to interface 5 V to 3 V systems and two supply systems such as battery back up. This circuit prevents device destruction due to mismatched supply and input voltages.
Features
• High speed: tpd = 8.1 ns (typ.) at VCC = 5 V • Low power dissipation
Standby state: 4 μA (max) at Ta = 25°C
Active state: 600 μA (max) at Ta = 25°C
• High noise immunity: VNIH = VNIL = 28% VCC (min) • Power down protection is equipped with all inputs.
• Balanced propagation delays: tpLH ∼− tpHL • Wide operating voltage range: VCC (opr) = 2 to 5.5 V • Pin and function compatible with 74HC123A/221A
TC74VHC123AFN, TC74VHC221AFN
TC74VHC123AFT, TC74VHC221AFT
TC74VHC123AFK, TC74VHC221AFK
Weight SOP16-P-300-1.27A SOL16-P-150-1.27 TSSOP16-P-0044-0.65A VSSOP16-P-0030-0.50
: 0.18 g (typ.) : 0.13 g (typ.) : 0.06 g (typ.) : 0.02 g (typ.)
1 2007-10-19
Pin Assignment
1A 1 1B 2 1CLR 3 1Q 4 2Q 5 2CX 6 2RX/CX 7 GND 8
(top view)
IEC Logic Symbol
16 VCC 15 1RX/CX 14 1CX 13 1Q 12 2Q 11 2CLR 10 2B 9 2A
1A (1) 1B (2)
1CLR 1CX
1RX/CX
2A 2B
(3) (14) (15)
(9) (10)
2CLR
2CX 2RX/CX
(11) (6) (7)
TC74VHC123A &
R CX RX/CX
&
R CX RX/CX
(13) 1Q (4) 1Q
(5) 2Q (12) 2Q
Truth Table
Inputs A B CLR
HH XLH HXH LH LH XXL
X: Don’t care
Outputs QQ
LH LH
LH
Function
Output Enable Inhibit Inhibit Output Enable Output Enable Reset
TC74VHC123,221AF/AFN/AFT/AFK
1A (1) 1B (2)
1CLR 1CX
1RX/CX
2A 2B
(3) (14) (15)
(9) (10)
2CLR
2CX 2RX/CX
(11) (6) (7)
TC74VHC221A &1
R CX RX/CX
&
1
R
CX RX/CX
(13) 1Q (4) 1Q
(5) 2Q (12) 2Q
2 2007-10-19
Block Diagram (Note 1) (Note 2)
TC74VHC123,221AF/AFN/AFT/AFK
A B
1 2
DX
CX 14 15
RX
VCC
CX RX/CX 13 Q
3 CLR
4Q
A B
9 10
DX
CX 67
RX
VCC
CX RX/CX 5 Q
11 CLR
12 Q
Note 1: CX, RX, DX are external
Capacitor, resistor, and diode, respectiv.