Document
D Function, Pinout, and Drive Compatible
With FCT, F Logic, and AM29821
D Reduced VOH (Typically = 3.3 V) Version of
Equivalent FCT Functions
D Edge-Rate Control Circuitry for
Significantly Improved Noise
Characteristics
D Ioff Supports Partial-Power-Down Mode
Operation
D Matched Rise and Fall Times D Fully Compatible With TTL Input and
Output Logic Levels
D ESD Protection Exceeds JESD 22
– 2000-V Human-Body Model (A114-A)
– 200-V Machine Model (A115-A)
– 1000-V Charged-Device Model (C101)
D 64-mA Output Sink Current
32-mA Output Source Current
D High-Speed Parallel Register With
Positive-Edge-Triggered D-Type Flip-Flops
D 3-State Outputs
CY74FCT821T 10-BIT BUS-INTERFACE REGISTER
WITH 3-STATE OUTPUTS
SCCS033B– MAY 1994 – REVISED NOVEMBER 2001
P, Q, OR SO PACKAGE (TOP VIEW)
OE
D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 GND
1 2 3 4 5 6 7 8 9 10 11 12
24 VCC 23 Y0 22 Y1 21 Y2 20 Y3 19 Y4 18 Y5 17 Y6 16 Y7 15 Y8 14 Y9 13 CP
description
This bus-interface register is designed to eliminate the extra packages required to buffer existing registers and provide extra data width for wider address/data paths or buses carrying parity. The CY74FCT821T is a 10-bit-wide buffered version of the popular CY74FCT374 function. This device is ideal for use as an output port requiring high IOL/IOH.
This device is designed for high-capacitance load drive capability, while providing low-capacitance bus loading at both inputs and outputs. Outputs are designed for low-capacitance bus loading in the high-impedance state.
This device is fully specified for partial-power-down applications using Ioff. The Ioff circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down.
PIN DESCRIPTION
NAME I/O
DESCRIPTION
D I D flip-flop data inputs
CP O Clock pulse for the register. Enters data into the register on the low-to-high clock transition.
Y O Register 3-state outputs
OE
I
Output control. When OE is high, the Y outputs are in the high-impedance state. When OE is low, true register data is present at the Y outputs.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.
•POST OFFICE BOX 655303 DALLAS, TEXAS 75265
Copyright 2001, Texas Instruments Incorporated 1
CY74FCT821T
10-BIT BUS-INTERFACE REGISTER
WITH 3-STATE OUTPUTS
SCCS033B– MAY 1994 – REVISED NOVEMBER 2001
ORDERING INFORMATION
TA
PACKAGE†
SPEED (ns)
ORDERABLE PART NUMBER
TOP-SIDE MARKING
QSOP – Q Tape and reel
6
CY74FCT821CTQCT
FCT821C
Tube
6 CY74FCT821CTSOC
SOIC – SO
FCT821C
Tape and reel 6 CY74FCT821CTSOCT
DIP – P
Tube
7.5 CY74FCT821BTPC
CY74FCT821BTPC
–40°C to 85°C
Tube
7.5 CY74FCT821BTSOC
SOIC – SO
FCT821B
Tape and reel 7.5 CY74FCT821BTSOCT
QSOP – Q Tape and reel
10 CY74FCT821ATQCT
FCT821A
Tube
10 CY74FCT821ATSOC
SOIC – SO
FCT821A
Tape and reel 10 CY74FCT821ATSOCT
† Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are available at www.ti.com/sc/package.
FUNCTION TABLE
INPUTS OE D CP
INTERNAL OUTPUTS
QY
FUNCTION
HX↑ L Z
Z
HL↑LZ
HH ↑ H Z LL↑LL
Load
L H ↑ HH
H = High logic level, L = Low logic level, X = Don’t care, ↑ = Low-to-high transition, Z = High-impedance state
logic diagram (positive logic)
1 OE
CP 13 D0 2
C0 Q
D0
23 Y0
To Nine Other Channels
•2 POST OFFICE BOX 655303 DALLAS, TEXAS 75265
CY74FCT821T 10-BIT BUS-INTERFACE REGISTER
WITH 3-STATE OUTPUTS
SCCS033B– MAY 1994 – REVISED NOVEMBER 2001
absolute maximum rating over operating free-air temperature range (unless otherwise noted)†
Supply voltage range to ground potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 7 V DC input voltage range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 7 V DC output voltage range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 7 V DC output current (maximum sink current/pin) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 mA Package thermal impedance, qJA (see Note 1): P package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67°C/W
(see Note 2): Q package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61°C/W (see Note 2): SO package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46°C/W Ambient temperature range with power applied, TA . . .