Document
FAST CMOS OCTAL TRANSCEIVER/ REGISTERS (3-STATE)
Integrated Device Technology, Inc.
IDT54/74FCT646T/AT/CT/DT - 2646T/AT/CT IDT54/74FCT648T/AT/CT IDT54/74FCT652T/AT/CT/DT - 2652T/AT/CT
FEATURES:
• Common features: – Low input and output leakage ≤1µA (max.) – Extended commercial range of –40°C to +85°C – CMOS power levels – True TTL input and output compatibility – VOH = 3.3V (typ.) – VOL = 0.3V (typ.) – Meets or exceeds JEDEC standard 18 specifications – Product available in Radiation Tolerant and Radiation Enhanced versions – Military product compliant to MIL-STD-883, Class B and DESC listed (dual marked) – Available in DIP, SOIC, SSOP, QSOP, TSSOP, CERPACK and LCC packages • Features for FCT646T/648T/652T: – Std., A, C and D speed grades – High drive outputs (-15mA IOH, 64mA IOL) – Power off disable outputs permit “live insertion” • Features for FCT2646T/2652T: – Std., A, and C speed grades – Resistor outputs (-15mA IOH, 12mA IOL Com.) (-12mA IOH, 12mA IOL Mil.) – Reduced system switching noise
DESCRIPTION:
The FCT646T/FCT2646T/FCT648T/FCT652T/2652T consist of a bus transceiver with 3-state D-type flip-flops and control circuitry arranged for multiplexed transmission of data directly from the data bus or from the internal storage registers. The FCT652T/FCT2652T utilize GAB and GBA signals to control the transceiver functions. The FCT646T/FCT2646T/ FCT648T utilize the enable control (G) and direction (DIR) pins to control the transceiver functions. SAB and SBA control pins are provided to select either realtime or stored data transfer. The circuitry used for select control will eliminate the typical decoding glitch that occurs in a multiplexer during the transition between stored and realtime data. A LOW input level selects real-time data and a HIGH selects stored data. Data on the A or B data bus, or both, can be stored in the internal D flip-flops by LOW-to-HIGH transitions at the appropriate clock pins (CPAB or CPBA), regardless of the select or enable control pins. The FCT26xxT have balanced drive outputs with current limiting resistors. This offers low ground bounce, minimal undershoot and controlled output fall times-reducing the need for external series terminating resistors. FCT2xxxT parts are plug-in replacements for FCTxxxT parts.
IDT54/74FCT652/2652 ONLY GBA GAB
FUNCTIONAL BLOCK DIAGRAM
IDT54/74FCT646/2646/648 ONLY G DIR CPBA SBA CPAB SAB
B REG 1 OF 8 CHANNELS 1D C1 646/2646/652/2652 ONLY
A1
A REG 1D C1
B1
646/2646/652/2652 ONLY
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
2634 drw 01
TO 7 OTHER CHANNELS
MILITARY AND COMMERCIAL TEMPERATURE RANGES
©1996 Integrated Device Technology, Inc.
SEPTEMBER 1996
DSC-2634/9
6.20
1
IDT54/74FCT646/2646/652/2652T/AT/CT/DT, 648T/AT/CT FAST CMOS OCTAL TRANSCEIVER/REGISTER
MILITARY AND COMMERCIAL TEMPERATURE RANGES
CPAB NC VCC
GND NC B8
A7
A8
B7
B6
CPAB SAB DIR A1 A2 A3 A4 A5 A6 A7 A8 GND
1 2 3 4 5 6 7 8 9 10 11 12
P24-1 D24-1 SO24-2 SO24-7* SO24-8 SO24-9* & E24-1
24 23 22 21 20 19 18 17 16 15 14 13
VCC CPBA SBA
DIR
G
FCT646/FCT2646T FCT648
A1 A2 A3 NC A4 A5 A6
5 6 7 8 9
4
SAB
INDEX
3 2 1 28 27 26 25 24 23 L28-1 22 21
CPBA SBA
PIN CONFIGURATIONS
G
B1 B2 NC B3 B4 B5
B1 B2 B3 B4 B5 B6 B7 B8
2634 drw 02
10 20 1112 13 14 15 16 17 1819
2634 drw 03
DIP/SOIC/SSOP/ QSOP/TSSOP/CERPACK TOP VIEW
* FCT646/2646T/AT/CT/DT only
LCC TOP VIEW
GAB
CPAB SAB GAB A1 A2 A3 A4 A5 A6 A7 A8 GND
1 2 3 4 5 6 7 8 9 10 11 12
P24-1 D24-1 SO24-2 SO24-7* SO24-8 & E24-1
24 23 22 21 20 19 18 17 16 15 14 13
VCC CPBA SBA
FCT652/FCT2652T
A1 A2 A3 NC A4 A5 A6 5 6 7 8
GBA
4
SAB
INDEX
B1 B2 B3 B4 B5 B6 B7 B8
2634 drw 04
3 2 1 28 27 26 25 24 23 L28-1
CPAB NC VCC
CPBA SBA
GBA
B1 B2 NC B3 B4 B5
2634 drw 05
22 21 9 10 20 19 11 12 13 14 15 16 17 18
GND NC A7 A8 B8 B7 B6
DIP/SOIC/SSOP/ QSOP/CERPACK TOP VIEW
* FCT652/2652T/AT/CT/DT only
LCC TOP VIEW
PIN DESCRIPTION
Pin Names A1 - A 8 B1 - B 8 CPAB, CPBA SAB, SBA GAB, GBA DIR, G Description Data Register A Inputs Data Register B Outputs Data Register B Inputs Data Register A Outputs Clock Pulse Inputs Output Data Source Select Inputs Output Enable Inputs (646/648) Output Enable Inputs (652)
2634 tbl 01
6.20
2
IDT54/74FCT646/2646/652/2652T/AT/CT/DT, 648T/AT/CT FAST CMOS OCTAL TRANSCEIVER/REGISTER
MILITARY AND COMMERCIAL TEMPERATURE RANGES
FUNCTION TABLE (646/648)
Inputs Data I/O(1) SAB X X X X L H SBA X X L H X X A1 - A8 Input Output Input B1 - B8 Input Input Output Operation or Function FCT646T/FCT2646T Isolation Store A and B Data Real-Time B Data to A Bus Stored B Data to A Bus Real-Time A Data to B Bus Stored A Data to B Bus FCT648T Isolation Store A and B Data Real-Time B Data to A Bus Stored B Data to A Bus Real-Time A Data to B Bus Stored A Data to B Bus
2634 tbl 02
G
H H L L L L
DIR X X L L H H
CPAB H or L ↑ X X X H or L
CPBA H or L ↑ X H or L X X
FUNCTION TABLE (652)
Inputs GAB L L X H L L L L H H H Data I/O SAB X X X X(2) X X X X L H H SBA X X X X.